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Fruit, Nutrition, and Evolution.
HEALTH,
NUTRITION; THEORY > THE
EVOLUTIONARILY APPROPRIATE DIET > FRUIT
> COMMONLY AVAILABLE FRUIT
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Apple Apricot
Asian Pear Avocado Banana
Blackberry Blueberry
Carambola Cherimoya
Cherry Feijoa Fig
Grape Grapefruit
Guava,tropical Kiwifruit
Lemon Lime Lychee
Mango Melon Cantaloupe
Orange Papaya
Passion fruit, Purple Peach
Pear
Persimmon, Oriental
Pineapple Plum
Raspberry Strawberry
Tamarillo Tangerine/Mandarin
Watermelon
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Fruit Western People Commonly or
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These notes are a look at the fruits that are commercially
available
that we Westerners eat, but from a hunter-gatherer evolutionary
perspective.
It is a 'guided tour', not of the diversity of fruits in the natural
environment
we evolved in, but rather the fruits that are now
commercially
available to eat, and how it is we came to be eating only these fruits.
Evolution has forced us to become vitamin C junkies - unlike most
animals, we can't synthesize it ourselves, we have to obtain it from
the
food we eat. Fruit and vegetables, and to a lesser extent, organ meats,
are the prime source.
Only some of the wild fruits that were all around our ancestors
have
been domesticated. So the number of species available to us now is less
- at first glance. But because commerce provides us with fruit from all
the continents of the world, our actual daily possible selection range
is probably as good as was available to our ancestors. And the fruits
we
now have available have much fewer unpleasant tannins and glycosides
than
some of the wild fruits. The fleshy part is larger, and the seediness
in
some cases reduced or eliminated.
Most people in the West today do not eat enough fruit and
vegetables
for good health. Those who eat a natural diet, particularly if they
have
additional supplies from their home orchard, get more than enough, and
may need to limit their fruit consumption. But today, such
circumstances
apply to only the tiniest minority .
The sweet calories of fruit compete with the sweet calories of
all
manner of 'junk food'. The difference is that fruit has the soluble
fiber,
the minerals, the vitamins, the antioxidant chemicals, where 'junk
food'
has few of these - yet demands vitamins and minerals stored from other
foods to allow the body to enzymatically process them.
Fruit growers tread a fine line between oversupply of fruit, low
prices and resultant penury, and short supply, high prices, and
consumer
resistance. In the same way, supermarkets value fruit sales as one of
the
most important 'profit centers', and must also tread the line between
'profit
maximization' and consumer resistance. The commercial availability of a
wide variety of fruit at a price affordable to all depends on these
tensions
not becoming excessive in any one party's favor.
The urban hunter-gatherer can only look for 'loss leaders' at the
supermarkets, and seek out subsidized, and therefore cheaper, lines as
they become available. In general, canned fruit are nearly as
nutritionally
valuable as fresh fruit, so they become part of the urban
hunter-gatherer's
fruit collection strategy.
NOTE: THIS WEB
'PAGE'
PRINTS OUT AS ABOUT 24 PAPER PAGES
Apple Malus pumila
(M. domestica)
"In the foothills of the mountain areas of...Turkestan,
there are also forests of fruit trees. In some regions walnuts (Juglansregia),
as well as apples, form the entire woods...The area of wild apples is
extensive.
In the Caucasus the fruits of the wild apple are fairly small, but
those
in Turkestan are comparatively large. Individual trees there bear fruit
which is not inferior in quality to that of cultivated forms. Some are
of astonishingly large size, and the trees are exceptionally
productive.
The whole spectrum of transition from the typically small, sour apple
to
the cultivated, perfectly edible type is found. Among wild apples, Malus
pumila with purple-red coloring of the flesh occurs. Here, the
whole
process of development from wild apples to [human] acceptable
forms,
by hybridization between the species accompanied by mutation, took
place
without the intervention of man." - F. Roach, 'Cultivated Fruits of
Britain'
The origin of the cultivated apple is not definitely known, but the
center
of origin is probably in the area containing the Caucasus, Central Asia
and the Himalayas. The modern cultivated varieties probably derive from
the central Asian Malus pumila, perhaps with incursions of
genes
from other species present in the area of origin, such as Malus
sieversii.
Other
species of wild apple evolved both in the west (Europe) and east
(Western
China) of the original range, and genes from Western species, such M.
florentina have probably also been added in to M. pumila's
makeup.
Thus, the modern apple, M. pumila, resulted from natural
hybridization
between these wild species. Some of these wild species, such as M.
sylvestris
are astringent, intensely sour, and small. Others, such as Malus
sieversii
are pleasant, relatively sweet, almost like a miniature
version
of a modern apple.
As our African ancestors radiated out of Africa through the middle
East
and up through modern day Turkey and South
West Asia they, like the bears, will have eaten wild apples of all
kinds - some of the 30 or so species being more palatable than others.
Our ancestors radiated straight into woodlands of apple, pear, grape,
berry
and nut tree (and bears!). Even today, the people of the Northern
Caucasus
go into the woods to gather wild apples to eat, in spite of the ready
availability
of commercial apples.
Charred apple remains of have been found inside the
prehistoric
lake dwellings of Switzerland. It is quite likely that fruit collected
from the best trees would have a better chance of survival - spread by
humans in their faeces, and if the core was thrown aside near the camp
better forms would spring up near habitation. These would in turn be
more
likely to be eaten, being close at hand, and be further spread to other
camps. Until the technique of grafting was invented-very recently,
relatively
speaking-the best types could only ever be spread by sowing seed. But
the
process of selecting bigger, sweeter, less acid and astringent apples
was
probably accelerated even further when the fruit forests of the
Caucasus
and Turkestan were cleared for growing grains as man became an
agriculturist.
The local tribespeople left the very best fruiting trees in place -
naturally
- and any further natural seed distribution by humans would again have
been weighted in favor of these better forms. By 4000 BC these
tribespeople
of the Caucasus had invaded present day Iraq to the east, and southern
Europe to the West. No doubt they took supplies of dried fruit, perhaps
including shriveled apples, with them. Both bears and man have been
responsible
for dispersing apple seeds into within South West Asia and Europe, but
man has tended to spread improved kinds. Apples were well established
in
Greece by at least 800 BC, and in Italy presumably as well. Apple trees
were introduced to Britain in Roman times and from there to North
America
by settlers about 1630.
Today, apples are of course grown throughout the temperate, warm
temperate,
and to small degree, subtropical world.
Apples are an unique fruit in that they have a variety of flavors,
degrees of sugar and acid, different flesh textures, and differing
juiciness.
The number of varieties is legion, but only a very few are produced
commercially.
Some of the less commercially acceptable varieties are smaller, less
juicy,
more acid, have very 'hard' dense flesh, and probably have a great deal
more fiber than more 'melting' fine fleshed commercial cultivars. They
may perhaps be more like the wild apples our ancestors ate. These
connoisseur
varieties can be found sold 'at the gate' at specialist
orchards. Unfortunately, there is a trend to produce and market
fruit
which are too large, especially for children. And some fruit is picked
not fully tree ripened, which can be disappointing. New varieties may
alleviate
these problems.
Apples vary from a 'fairly good' to a 'very good' source of vitamin
C, as there are significant differences
between the varieties. 'Crab apples', possibly Malus sylvestris,
are listed as having very little vitamin C content (compared weight for
weight to modern apples). Given the great number of selections of
ornamental
crab apples, this measurement may not necessarily apply to wild crab
apples,
or all species of wild crab apples, at least. Apples are a good source
of the B vitamin 'biotin'. Apples are also a good source of a variety
of
minerals-magnesium, iron, chromium, and manganese. Apples ( as distinct
from the expressed juice) are a good source of soluble fiber, which has
been shown to slow the release of sugars in the blood and also slightly
drop blood cholesterol levels.
Apples have from about 27mg to 300mg per 100 grams fresh weight of
of
'polyphenols' -substances in plants hypothesised to confer
reduced
cancer risk benefits ( tests with apple skin extract have been shown to
inhibit various cancer cell lines in laboratory bench top tests.
Whether
ther is a significant effect in humans has not been shown, but it is at
least suggestive. For perspective, of the data I have seen, one variety
of plum analysed at 4mg/100grams fresh weight at the low end, and a
particular
variety of grape analysed at nearly 500mg per 100 grams fresh weight at
the high end. Further investigations of the total anti-oxidant capacity
( a sum of it's vitamin C content and other phytochemicals, such as
phenols-that
turn the flesh brown when left in air- and flavenoids) Eating 100 grams
of fresh red delicious apple with the skin on provides the total
anti-oxidant
activity equal to 1,500 milligrams of vitamin C. The phenolic component
of the protective phytochemicals varies from season to season, and it
would
be reasonable to suppose it varies between different varieties.
Apricot Prunus
armeniaca
The apricot is native to Central Asia, with it's place of first origin
thought to be in the hills of Western China. The wild population in the
hills of South West Asia, (including Armenia, for which Western
botanists
named the species) is regarded as a secondary center of diversity.
Whatever,
the apricot's wild range is all of Central
Asia and parts of South
West
Asia. The apricot is found semi-wild and wild in the northern hills
of China, and in a broad belt across the hills, mountains, and plateaus
of Central Asia as far as the Caucasus mountains, between the Caspian
and
Black seas. Wild apricots are very similar to cultivated varieties,
except
that the fruit are smaller, as are the stones, with the amount of flesh
relative to the stone also being less favorable. Most, but not all,
have
bitter kernels within the stone. Many parts of the range of the apricot
are very dry, and dried apricots may have been a part of the human diet
for almost as long as we have been in these regions. The first record
of
the domestication of apricots is an account of it's cultivation in
China,
attributed to Emperor Yu, about 4,000 years ago. We can guess that the
tribespeople of Central Asia would have developed 'traditional rights'
to harvest 'their' parts of the apricot forests for millennia before
this
time. In China, selection by humans was for fruit with non-bitter
stones,
as well as good fruit. In some of the isolated valleys of the Central
Asian
Pamir mountains, apricot oil has been the primary oil for cooking, and
in China the 'sweet' kernels are a valued food item, as well, of
course,
as the fruit.
Apricots were late coming to the West. It was supposed to have been
brought to Greece following Alexander the Great's invasion of Central
Asia.
From Greece, the apricot went to Italy, where Pliny referred to it as
'the
Armenian plum', and eventually arrived in English 'noblemen's' gardens
around 1540. From England, the tree was exported with the colonists to
the 'new colonies' of the British Empire - America, Australia, South
Africa
and New Zealand.
Modern production has given us larger, brighter fruit, probably with
higher vitamin A content. The need to pick and ship firm fruit has also
given us fruit that very often have less sweetness, and much firmer
flesh
than a home tree matured fruit. Curiously, no effort has been made to
select
for 'sweet' kernels in the West, so 'waste' stones from canning and
drying
fruit are presumably used for oil extraction, at best. New techniques
in
plant breeding are starting to produce some very
interesting hybrids between apricots and plums. Some of these are
very
good eating, but whether their nutritional value - primarily vitamin A
content - matches apricots, I don't know.
Apricot flowers are easily damaged by frost, and the plant really
needs
a hot, relatively dry growing season. This limits the areas in which
apricots
can be grown, and in addition, unlike apples, they can't be stored for
months and months and months. This means that apricot production will
always
be limited.
Dried and canned fruit from areas near their natural range are good
value, and their nutritional worth is still very high.
Apricots can't be regarded as a significant source of vitamin C, but
are a good source of vitamin A (as carotene)- one 35 gram apricot has
914
International Units of vitamin A, making them the third richest source
of vitamin A of all the common commercial fruit listed on this page.
Canned
apricots are also good source of Vitamin A, with one canned
apricot
having very approximately half the content of a fresh fruit.
Apricots are also high in potassium.
Nutritional
analysis
of a commercial apricot cultivar can be found at the Cape fruits
website.
Asian Pear Pyrus
pyrifolia
( syn. serotina)
Pears originated in the mountains, foothills, and plateau of
Central and South West Asia, in the company of apples, apricots, grapes
(in some parts), and various minor fruit not commercially available
today.
The Asian pear probably originated in the hills of Western China. While
this fruit has been familiar to the larger part of humanity for
millennia,
it has only recently arrived in the west.
Pyrus pyrifolia is thought to be a major contributor to the
make-up
of the 'European' (actually, Central Asian) pear. So, genetically, we
are
well familiar with this fruit. Pear species in general abounded in the
woods and forests of South West Asia as we came out of the Levantine
coastal
corridor into the wide, wide world of South West Asia and beyond. The
pear
species seem able to cross with each other without too much difficulty,
and some Asian pears are actually complex hybrids between P.
pyrifolia, P. ussuriensis, and P. bretschneideri.
'Asian Pears' are still something of a novel fruit in the west, and
most introductions are from East
Asia
, and quite recent. Europeans, at least, having been aculturated to
'European
pears', find Asian Pears don't have the same depth of flavor. Some
varieties
of Asian Pear have an extraordinary sweet caramel flavor when fully
tree
ripened, but these are too ripe to be successfully commercially
marketed.
In an attempt to 'popularise' Asian pears, they have been crossed
with
'European' pears to try to create a finer textured flesh, more depth of
flavor, and an attractive skin color. Only time will tell whether or
not
these efforts will bring us a new fruit.
Asian pears can't be regarded as a significant source of vitamin C,
but, as with all fruit, are important for soluble dietary fiber.
Avocado Persea
americana
The Avocado is probably descended from a very primitive wild form now
limited to a small lowland area of Honduras and a small part of Costa
Rica.
There are three distinct 'races' of avocado (previously regarded as
three
closely related species) that arose from selection by the early
colonizers
of South America of better forms from the local wild populations.
Primitive
wild forms of the Mexican race have been found (guess where?) in
Southern
Mexico, primitive wild forms of the 'Guatemalan' race (the commercially
important knobbly skinned 'Hass' variety is derived from this race)
have
been found in isolated parts of Mexico, Guatemala, and Honduras.
Similarly,
primitive wild forms of the 'West Indian' race (the typical
thin-skinned
tropical avocados are very often derived from this race) have been
found
in Colombia. The wild avocado in it's natural range has small fruit, a
large stone, and little flesh. Hunter gatherers appreciated this most
nutritious
of fruits from earliest times- the earliest evidence of human's
association
with avocados is from cave deposits in the Tehuacan Valley, near
Puebla,
Mexico. These deposits have been dated to more than 12,000 years ago.
There
is some suggestion from archaeological sites that avocados may have
been
selected for larger fruit size as long ago as 6,000 years ago.
Selection
by the native inhabitants continued up until their decimation by
Spanish
and Portuguese tribepeople. In fact, today's varieties are little
improved
over the varieties that were being grown by Native South Americans at
the
time of the European invasion of South America. Avocado fruits are a
dream
fruit for the human animal - heavy bearing, easily digestible, fruiting
all year round (in tropical areas), no toxicity, they store 'on the
tree'
for months, nearly twice the amount of protein as rice, for example,
and
with a similar calorific value to sustain daily activity.
Native South Americans had introduced the fruit as far south as
Peru,
and the Spanish continued it's spread into their colonies in Chile, the
West Indies, and their Island colonies off West Africa - Madeira and
the
Canaries. From there it spread to all the regions where the climate and
soil suited it. In recent times, avocado varieties spread mainly from
Western
USA (California) to former British colonies such as Australia, New
Zealand,
and South Africa.
It is now grown in virtually all tropical, subtropical, and warm
temperate
areas with well drained soils and relative frost freedom. In most parts
of Europe it is still something of a luxury, whereas in the local areas
of production it has become an everyday commodity. In parts of rural
South
America, and in many poor Pacific Islands, it is an extremely important
food.
The more subtropical rather than tropical varieties of avocado have
a higher oil content (largely monounsaturated), with a valuable 124
calories
per 100 grams. In addition, avocados have up to 4% protein.
Avocados have the highest potassium content of any common domestic
fruit
(at about 600mg/100gms). While most meats are as high in potassium as
fruit,
they are accompanied by more sodium (and we add far more in cooking).
In
hunter gatherer (=natural) times, potassium to sodium ratios were
skewed
very much more toward high potassium and low sodium than our standard
Western
urban 'diet'. High potassium fruits help partially restore the
evolutionary
balance, and avocados are top performers in the potassium stakes.
While avocados are only a fairly good source of vitamin C, they are
rich in many vitamins; avocados have appreciable levels of the B
vitamin
thiamin (about the same as lamb muscle meat, and better than beef
muscle
meat.); they also have useful levels of riboflavin (B2), with half an
avocado
providing about 6% of an s recommended minimum daily intake. Half
an avocado also supplies about 10% of an s recommended minimum
intake
of Niacin (B3), and about 15% of an s daily Pantothenic acid (B5)
and pyridoxine (B6) needs. The recommended daily intake of folate is
200mcg
( pregnant women may need more), and half an avocado will fill about a
quarter of this required minimum daily quota. Your half an avocado also
has around 600 International Units of vitamin A - quite a useful
amount.
All in all, avocados are an excellent food for the human animal.
Banana Musa x
paradisiaca
Of the 30 or so species of 'banana' only two may be regarded as edible,
and neither are in our African homeland. There is a wild banana that
grows
just above the Tropic of Capricorn in sub-equatorial Africa, in
rainforests
from the west coast across to the East. This species, Ensete
ventricosum
(previously Musa ventricosum), produces bunches of dry seedy
fruit
with a small amount of dry and insipid flesh that is eaten only in
times
of famine.
Wild banana fruits of the two edible species are full of hard,
small-pea-sized
black seeds embedded in the starchy, sweet/acidulous pulp. The size of
the fruit varies according to how many seeds (i.e. how well pollinated
the flower was) are present. The more seeds, the larger the fruit.
Unpollinated
flowers remain as small, empty shells. Within some parts of the
wild populations of one of the parents of the modern banana (Musa
acuminata),
there are genes that result in the plant being able to form fruit
(seedless)
from an unpollinated flower. Only those flowers in the bunch that are
pollinated form seedy fruit, the rest being seedless. A few individuals
within the small population of plants that were able to make edible but
seedless fruit from the unpollinated flowers in the bunch developed yet
another mutation; the female part of all the flowers in the
bunch
became sterile. Thus no flower forms seeds, and all flowers formed fat,
edible, totally seedless fruit. And when our ancestors migrated out of
Africa, down thru' Myanma (Burma), Vietnam and Malaysia, this is the
kind
of variation they found in the wild banana plants of the forest. Almost
all seedy, the occasional one with seedy and seedless fruit in the same
bunch, and the odd rare individual with totally seedless fruit. The
bananas
found in the northern part of the wild range also included
natural
hybrids between M. acuminata and the more drought and cool
tolerant
Musa
balbisiana. These hybrids had natural 'hybrid vigor', growing
faster,
and having larger bananas, but are usually sterile.
Our ancestors were onto a good thing with bananas. Bananas are easy
to propagate, and as our numbers increased we doubtless deliberately
increased
those clumps that gave some or all seedless fruit. As we moved camp
within
our territory it would have been easy to carry a small side-shoot plant
of our favorite clump with us for re-planting in the new location.
Bananas
come into bearing in 15 months or so, so it wouldn't take a lot of
fore-thought.
With the coming of slash and burn agriculture, then rice based
culture,
selection of best types had high pay-off.
So the predominant type became the faster growing M.
acuminata
x M. balbisiana hybrids, now collectively known as 'Musa
Xparadisiaca'.
And these are the bananas of commerce.
The other species of edible banana arose in New Guinea and nearby
Pacific
Islands. This 'Fe'i' group was probably derived from the New Guinean Musa
maclayi, but they are now rare. Introduced acuminata/balbisiana
varieties
have displaced them.
Bananas were introduced to Africa, probably by Indonesian settlers
of
Madagascar, before 2,500 years ago, and were carried into the Pacific
about
a thousand years ago.
The banana was taken from the European colonists' African
'territories',
to their tropical South American colonies early on. However, mainly the
best varieties were taken, which were seed free, sterile varieties. As
a consequence, much of the world's banana biodiversity was left in
Asia,
and the commercial crops were established on a very, very, narrow
genetic
base. The precariousness of this has come home in the last 50 years or
so as diseases take a toll on the commercial varieties, with no
variation
in the plants to select disease resistance from. And of course, the
wild,
seeded types have been dramatically reduced in number due to
de-forestation
of the land, and in remote village areas, by replacement with better
fruiting
but seedless varieties.
The huge banana trade in USA and other Western countries developed
when
a Cape Cod sea captain, Capt. Lorenzo Baker, brought several bunches to
Boston, where he found they made good money sold as individual fruit.
The
bunches had been given him as a gift from a Jamaican plantation owner.
What started as an almost accidental item of cargo soon became a
regular
part of his normal trade with the Caribbean. After fifteen years he
founded
a company to import bananas on a large scale. He merged his company
with
a Costa Rican company that had also involved itself in the same trade,
and established the United Fruit Company in the late 1890's.
Refrigeration was developed about this time, and this proved the key
to expansion - by the mid 20's bananas were distributed by refrigerated
ship and refrigerated rail cars right throughout the United States, and
then beyond.
Today, the major commercial export production plantations are
American
owned plantations in South America, and to a lesser degree, the
Philippines.
Half of the world's banana crop is (still) grown in Africa, where it is
eaten locally, both cooked green bananas as a starchy food, and as a
ripe
fruit full of fruit sugars. Most tropical countries of Asia and South
East
Asia and the Pacific produce bananas, but, like Africa, almost all of
it
is consumed domestically.
Bananas are a good source of vitamin C, altho' an would need
to
eat 6 in a day to get even the rather conservative 'Recommended Daily
Allowance'
of 60mg ( not that anyone relies on a single type of food for their
daily
vitamin C needs).
Bananas have the second highest potassium content of any common Western
domestic market fruit.
They also have useful levels of riboflavin (B2), with one small banana
providing about a sixteenth of an s recommended minimum daily
intake.
A medium sized banana supplies about a third of an s recommended
daily
intake of pyridoxine (B6).
Bananas are probably the most easily digestible fruit there is; while
allergies to some fruits are not unknown, it is extremely rare for
someone
to be allergic to bananas.
Blackberry Rubus
species and complex hybrids
The species of blackberry our distant ancestors would have been
familiar
with is Rubus pinnatus. It produces it's small, shiny black
fruit
at forest margins and in tall grass in tropical East Africa down the
East
coast to the cooler Cape. Various blackberry species (Rubus
laciniatus,
R.
rusticanus, R. nitoides, R. thrysiger, R. coryfolius
and others) are native to an area that stretches right across Europe
and
Asia (some species are regional within this area). Virtually wherever
we
radiated to, we found blackberries. And when some of our ancestors
reached
the North American continent, they found various species of blackberry
there, too (Rubus allegheniensis, R. argutus, R.
setosus,
R.
cuneifolius, R. trivialis, R. ursinus, and
complex
natural hybrids between these species). Blackberries would have formed
a useful seasonal adjunct to our diet. The plants are usually
associated
with forest margins and river flats, and were probably not as
widespread
as after the coming of agriculture, with it's destruction of forests
and
new clearings.
Blackberries have only been domesticated very, very, recently - wild
berries were always available in hedgerows and woodland margins, and
some
species were aggressive weeds of pastures and fields, so the idea of
deliberately
planting them was regarded as madness. But with increasing
urbanization,
access to wild berries was much reduced, and in from the late 1860's
onward
there was an effort to find bigger and better wild berry plants to
bring
into the garden, especially in America. It is from natural hybrids in
America,
and selections and hybridization between wild species in Europe, that
most
of our commercial blackberries come. It would be fair to say that
modern
blackberries are not much different from wild berries except in size.
Blackberries have a very short shelf life, they are liable to damage
in transport and handling, and the plant can be subject to quite a few
diseases. When conditions are good, they are very productive, and well
suited to 'commoditization' as a frozen or pulp product for use in
other
manufactured 'foods'. Fresh market berries are consequently relatively
expensive, and have a short season. Frozen berries may give best value
for money.
At 21 mg of vitamin C per 100 grams, fresh blackberries are a very
good
source of vitamin C. So about a quarter of a supermarket 250 gram
punnet
delivers an about a fifth (20%) of their daily minimal needs; at
the same time it delivers nearly 10% of an s daily folate (B
complex,
folic acid) needs.
Blackberries were ranked fourth in tests to identify the most
antioxidant
rich fruits and vegetables. The natural antioxidant 'phenols' in
blackberries
have been found to have antioxidant properties comparable to fresh
grapes
and red wines. Interestingly, further studies have shown that
blackberries,
while having the fourth highest anti-oxidant concentration, are SECOND
in actual chemical effectiveness in preventing oxidation in cells. Most
of this anti-oxidant activity is in the juicy portion
Laboratory tests also suggest some berries may reduce the buildup of
LDL (low-density lipoprotein) cholesterol, a contributor to heart
disease,
stroke and atherosclerosis. And blackberries were tested as having the
highest LDL inhibitory effect. Whether frozen berries have the same
protective
effect has not been studied - but it would be reasonable to suppose
they
do. The question of whether frozen berries would give the same effect
is
as yet unanswered. The phenolic composition of the same berries before
and after freezing would have to be tested, as well as testing for the
antioxidant activities of frozen berries. But if the antioxidants are
still
active, it would mean the outstanding power of blackberries'
antioxidants
are available year round, not just in it's normal brief summer season
of
fresh fruit.
Blueberry Vacciniumangustifolium,
V. corymbosum, V. asheii
There is a blueberry native to Africa - Vaccinium exul - but
it is limited to the mountains of the eastern part of the Tranvaal
province
of South Africa, so unless it was more widely distributed in ancestral
times, it would not have been a common food item. The 90 or so species
of Vaccinium are distributed widely across from Northern
Mediterranean,
Southern Europe, Central Europe, Northern Europe, North Asia, South
Asia,
Central Asia, and East Asia. And this includes the 50 or so species
native
to North America (three of which species have become the
blueberries
of commerce) and also several South American species.. In other words,
wherever we radiated, the bogs, the damp forests, whether temperate or
subtropical, broadleaf or conifer, there were blueberries of varying
degrees
of edibility, productivity and density of population. This is a species
with a very long association with the part of the human race that
radiated
out of Africa.
In the forest-tundra belt of north Europe and North Asia berries of
Vaccinium
vitis-idaea, and V. uliginosum are still gathered from the
wild;
in a similar way wild 'huckleberries' as well as wild blueberries are
gathered
by bears and humans alike in North America. Lingonberries (Vaccinium
vitis-idaea) are found in the temperate boreal forests from
Europe's
North Atlantic shoreline to Eastern Siberia; and down as far as
Southern
Europe, Albania, and some of the Dalmatian (former Yugoslavia)
countries.
It too, has been regarded as an important food item, especially in the
North, and the bright red berries are still gathered in the wild. One
of
the advantages of blueberries in general is that they can be dried for
use in Autumn and Winter. The indigenous tribes of North America
certainly
capitalized on this resource in this way, and no doubt other tribal
peoples
did the same
American species have been cultivated since around 1840, as have
some
of the European Vacciniums. But it is the North American
species
that have been perhaps most actively selected and improved, and
blueberry
culture has not only become relatively extensive in USA, but the North
American species have also been imported into other temperate countries
of the world to start local industries. In Europe, the lingon berry is
commercially produced, and bigger and better varieties are coming on
stream.
Blueberries require very particular kinds of soil and moisture
conditions,
the fruit don't have a very long shelf life, and are easy to damage in
transit. Therefore, the fresh berries will always be relatively
expensive.
Blueberry plants are very productive, and the fruit are well suited for
freezing for use as an ingredient in industrial food. The best value,
therefore,
is in buying frozen blueberries.
At about 14 mg vitamin C per 100 grams, fresh blueberries can at
best
be described as a fairly good source for this essential vitamin.
Blueberries were ranked third overall in tests to identify the most
antioxidant rich fruits and vegetables. Interestingly, further studies
have shown that blueberries, while having the third highest
anti-oxidant
concentration, are FIRST in actual chemical effectiveness in preventing
oxidation in cells. Most of this anti-oxidant activity is in the juicy
portion
Laboratory tests suggest some berries may reduce the buildup of LDL
(low-density lipoprotein) cholesterol, a contributor to heart disease,
stroke and artherosclerosis. In this study, blueberries were tested as
having the fourth highest LDL inhibitory effect of all the berries
investigated.
Whether the powerful antioxidant effect is present in frozen
blueberries
hasn't been studied. Commonsense tells us that it is likely that there
will be similar levels in frozen fruit as are in fresh fruit.
Recent studies on rats have shown that blueberry extract have actually
reversed some of the effects of aging - particularly, loss of balance
and
co-ordination, a 'normal' feature of advancing age. Strawberries and
spinach,
both with a high antioxidant capacity, improved short term memory-as
did
blueberry extract; but only blueberry extract reversed
the
normal decline in motor skills. Whether blueberries will show the same
effect in humans has not yet been tested.
While there are specific compounds and combinations of compounds in
fruit and vegetable which have either specific or general health
benefits,
one measurable attribute is the 'oxygen radical absorbance capacity' of
a fruit or vegetable. This measures the protective effect against
oxidative
processes suspected to be responsible in part for heart disease and
cancers,
and particularly responsible for aging - without trying to figure out
which
natural plant chemical or combination is actually responsible for the
protective
effect. The 'ORAC' for blueberries is not just high, it is astoundingly
high,
with a quarter of a cup having 800 'ORAC units'.(To put it in context,
'about' five servings of fruit and vegetables a day yeild a total of
1,600
units.) Blueberries have, on average, 20 'ORAC units' per gram.
The average size individual blueberry fruit has 30 ORACs, and
large
fruited varieties have 40 ORACs per fruit; if all varieties were
counted
as having the same ORAC levels. But in fact, there are differences
between
varieties - with the poorest variety and stage of ripeness measuring 15
ORACs/gram, and the best a whopping 40 ORAC units per gram. But, on
average,
4 blueberry fruits yeild a massive 100 ORACs!
Generalizing, the highbush types (V. corymbosum) -
specifically
the commercial varieties 'Bladen' (42 ORACs/gram), 'Rubel' (37
ORACs/gram),
and 'Rancocas' (32 ORACs/gram) - and some late harvested rabbiteye
types
(V. asheii) -specifically the varieties 'Tifblue' (38
ORACs/gram)
and 'Brightwell' (34 ORACs/gram) - have the highest ORAC scores. Wild
lowbush
(Vaccinium angustifolium) blueberries varied in ORAC by
local
population - one major area had a mean score of 42 ORACs/gram, another
area had a mean of 28 ORAC's/gram. (Note: all fractions of an ORAC
rounded
to the nearest whole number).
Ripest berries have the highest ORAC score. Mature berries from
'Brightwell'
and 'Tifblue' had from one and a half to two times higher ORAC score
than
those picked seven weeks earlier from the same bush. Berries are picked
early to secure a better price, or to avoid bruising in transit.
Overall,
the highest ORAC score comes with the highest anthocyanin content,
which
comes with the longest time left on the bush to ripe. Pick your own, or
grow
your own, is generally best.
Blueberries have from about 135mg to 280mg per 100 grams fresh
weight
of of 'polyphenols' -flavenoid substances in plants hypothesised
to confer reduced cancer risk benefits. For perspective, of the data I
have seen, one variety of plum analysed at 4mg/100grams fresh weight at
the low end, and a particular variety of grape analysed at nearly 500mg
per 100 grams fresh weight at the high end. This makes them the
(commonly
available) fresh fruit with the highest polyphenol content.
Vaccinium
Antioxidant
and Nutraceutical News - JJJ
A
page at the North American Blueberry Council site which reports and
references
the studies into the antioxidant effect of blueberries, as well as
specific
activities against Urinary tract infections, and assistance with
eyesight.
http://www.blueberry.org/nutraceu.htm
Blueberries
for health JJ A nice, short, easy
read
page summing up the health benefits of eating blueberries. At Norris
Blueberry
Farm site.
http://www.norrisfarms.com/health.htm
Carambola Averrhoa
carambola
The carambola originated in Sri Lanka (Ceylon) and the Maluku islands
(Moluccas) of the Indonesian archipelago of South East Asia. Human
populations
radiating into South East Asia would have been familiar with this
fruit.
Wild plants tend to have fairly acidulous, if refreshing fruits.
Carambola
is in the family Oxalidaceae, and contains some oxalic acid, which is
said
to be injurious in large amounts. Judging by it's use by present day
tribal
people, our African ancestors almost certainly ate the bulbs and
occasionally
the leaves of the Oxalis herb that grows wild in parts of Sub
Saharan
Africa. Our human physiology has been exposed to small amounts of
oxalic
acid for countless millennia, so on this basis the relatively low
amounts
in carambola are unlikely to do harm.
It has been carried to China, India, the Philippines, Africa, and
virtually
all other tropical countries. It was introduced to Florida, USA around
1887. The USDA's Subtropical Horticultural Research Unit and some
Research
stations in South East Asia have developed larger and sweeter
varieties.
Most Carambola are consumed in the country of origin, and the fruit
are something of a luxury item in the supermarkets as a result. Most
varieties
in Western Supermarkets are low oxalic acid 'sweet' types.
One fruit has about a third of the recommended daily requirement of
vitamin C, with about 20 mg, so are rated as a good source of Vitamin
C;
carambolas are also a good source of potassium, and a relatively
good source of Vitamin A.
Cherimoya Annona
cherimola&
Atemoya Annona cherimola x A. squamosa
The Cherimoya and Atemoya of Western commerce have an African relative
- the 'wild custard apple', Annona senegalensis. This fruit
grows
throughout tropical Africa, and also the eastern part of Southern
Africa.
Like a miniature, deep orange skinned, sugar apple (A. squamosa)
in appearance, it is said to have a pineapple fragrance and apricot
flavored
flesh. Unsurprisingly, it is "considered to be one of the best of
tropical
African fruits". Another species, A. stenophylla, grows in
central
Southern Africa, in Botswana and Zimbabwe. This dwarf species has
"large,
very pleasant tasting fruits". So Annonaceous fruits are part of the
human
animals environmental background.
Wild African Annonas have never become an article of commerce. But
the
two South American species, Annona squamosa (a tropical Annona)
and Annona cherimola ( a subtropical to warm temperate
species),
did. The tropical 'sugar apple' is almost impossible to market because
it becomes soft to the point of falling apart when very ripe. The
'cherimoya'
is much larger and has a much better shelf life. Accordingly, the two
were
deliberately crossed to produce the 'Atemoya', a large 'cherimoya-like'
fruit that grows well in the tropics and subtropics and has a
reasonable
shelf life.
'Reasonable' in the case of cherimoyas and atemoyas is still quite
short.
The trees require fairly specific soil and climate conditions, which
limits
their possible range. And so the fruit can only be a luxury item. Given
the superb sweetness and flavor characteristics of most of these
seasonal
fruits, they are a treat worth paying for.
Cherimoyas are a fairly good source
of vitamin C . They have useful levels of riboflavin (B2), with a
serving
sized slice providing about a sixteenth of an s recommended
minimum
daily intake, as well as about 5% of an s minimum daily Niacin
(B3)
needs.
Wild
Annona species- from the Center for New Crops
& Plant
Products, at Purdue University Site, an extract from Julia Morton's
Book
'Fruits of warm climates'. Discusses and describes Annona
senegalensis,
with a little on Annona montana. Also covers origin and
distribution,
uses. Concise, informative. 1 good photos of A. montana fruit
http://www.hort.purdue.edu/newcrop/morton/wild_custard_apple_ars.html
Cherry Prunus avium
The first ancestral Prunus species probably arose in Central
Asia, and gave rise to plums, apricots, peaches, almonds, and
cherries.
The Center of origin of cherries is probably the western part of
Central
Asia, and a secondary center of origin is Europe. Sour cherries (often
called 'morello', or 'pie' cherries), Prunus cerasus, evolved
from
the sweet cherry, perhaps with infusion of genes from another Central
Asian
Prunus
species. There are around a hundred odd of species wild cherry in
the temperate zone of Europe and Asia, with most in Asia. Most are
bitter,
or have very little flesh, although some, such as the Nanking Cherry (Prunus
tomentosa), are not bad. The certain fact is, once we radiated out
of Africa into Eurasia, our distant ancestors were in cherry territory,
and, if we could beat the birds to them (Prunus avium means
'bird'
prunus), we certainly would have eaten them.
Cherries were probably domesticated around 2,500 years ago in
Southern
Turkey or Greece. The Romans knew and valued numerous types of better
quality
cherry, and they spread these forms throughout their empire. With the
decline
and fall of the Roman Empire, cherries faded from attention, and by the
thirteenth century only the general types 'sweet' and 'sour' were
recognized
by the writers of the day. However, interest revived, and by the the
sixteenth
century, they were extensively planted in Europe. European settlers
took
them to North America, where sweet cherries were favored in the Pacific
west coast, and sour types for pies were favored in the east.
Cultivated cherries have a fairly narrow genetic base, especially
the
sour cherries, and the varieties within a particular group are all
fairly
similar to each other. In the sweet cherry, there are various 'Heart'
types
and 'Bigarreau' types, hearts being softer and juicier than the firmer
Biggarreaus. Sour cherries are not so much sour as acid. 'Morellos'
have
colored juice, 'Amarelles' have colorless juice. The 'Duke' types are
crosses
between sweet and sour cherries.
Cherries have a relatively short season, a short shelf life, are
liable
to split in rain, can be wiped out by hail at the wrong time, are
liable
to be damaged by birds, bruise easily, and can be expensive to pick. No
wonder fresh cherries tend to be expensive! But nothing else tastes
like
a cherry! Fresh cherries are a delightful treat in season, but best
value
may come from buying frozen or canned dark cherries for addition to
fruit
salads and meat
patties.
At 10 mg per 100 grams of flesh, both fresh sweet cherries and
fresh sour cherries rank as a good source of vitamin C. But even frozen
sour cherries have useful amounts-5mg/100gram. When it comes to vitamin
A, sour cherries are a standout - they have almost ten times (1,000
International
Units per 100 grams) more vitamin A than sweet cherries (110 I.U. per
100
grams). There will almost certainly be differences between varieties -
light colored varieties probably have less vitamin A and anthocyanins
than
dark skinned and fleshed varieties. 20 sour cherries contain 12-25
milligrams
of active compounds called anthocyanins, which at that concentration
were
found to prevent oxidative damage about as well as the commercial
antioxidants
added to many foodstuffs to prevent rancidity. Curiously, the same
dosage
was also observed to have an anti-inflammatory effect. Interestingly,
recent
tests on the anti-oxidant effectiveness of various commercial fruit put
fresh cherries at number seven in anti-oxidant effectiveness
against
damaging oxidative processes in cells. The research didn't reveal if
they
were dark or light cherries.
Laboratory tests suggest some fruit may reduce the buildup of
LDL (low-density lipoprotein) cholesterol, a contributor to heart
disease,
stroke and atherosclerosis. Sweet cherries were tested as having the third
highest LDL inhibitory effect, of those species and varieties of
fruits
tested (it is likely dark cherries and sour cherries would test even
higher).
Cherries have from about 60mg to 90mg per 100 grams fresh weight of
of 'polyphenols' -substances in plants hypothesised to confer
reduced
cancer risk benefits. For perspective, of the data I have seen, one
variety
of plum analysed at 4mg/100grams fresh weight at the low end, and a
particular
variety of grape analysed at nearly 500mg per 100 grams fresh weight at
the high end.
Feijoa Feijoa
sellowiana
The Feijoas is native to Southern Brazil, Paraguay, and Uruguay.
It is a member of the Myrtaceae family, and the related Syzigium
genus is present in Africa; the Syzigium berries of one
species,
at least, are still collected for food. Wild feijoa fruits are quite
variable
in sugar content, acidity and size, but all are pulpy, and edible.
Feijoas
are a forest margin plant, and the fruits are most acceptable. Apart
from
being highly favored by fruit fly maggots in their native range (which
cause them to drop prematurely and destroy the pulp) where edible fruit
could be found, they would have been a favored food of the humans
expanding
down into South America in ancient times.
Feijoas are a good source of vitamin C. Six average sized
fruits
fill an s daily vitamin C needs. They are also a good source of
folate
(B complex, folic acid), with one fruit delivering about 10% of an
s
minimum daily needs.
Feijoa flesh (not pulp) tends to 'go brown' fairly quickly after
being
cut (the degree varying with the variety). Altho' it has never been
investigated,
this may be an indication that the fruit is particularly high in
phenols.
Fig Ficus carica
The fig is native to Southern Arabia. If our distant ancestors used
a route across the mouth of the Red Sea (at the present Straits of Bab
el Mandeb) they would have come upon trees of the wild fig. They would
have recognized it immediately, for there are quite a few Ficus
species in Africa that are edible. F. vogelii is a species of
tropical
Africa as well as eastern Southern Africa. It produces it's small,
yellow
fruit in coastal forests, on dune lands, as well as swampy sites. There
are the insipid yellowish green fruits of F. soldanella of
Southern
Africa, the small, reddish and "remarkably appetizing for a wild fig"
fruits
of F. stuhlmannii in Central and East Africa, the edible "when
not
insect infested" F. salicifolia, and many others.
Another species of fig, the 'sycamore fig', F. sycomorus, is
grown in Egypt and the countries of the East Mediterranean. The
pear-shaped
fruit are sweet and slightly aromatic, but they are inferior to the
common
fig.
Domestication dates aren't known; fig seeds have been found in
bronze
age settlements in the Mediterranean, but it's impossible to say
whether
they were from wild or domestic trees.
Figs are very soft when they are ripe, so they are particularly
difficult
to market as a fresh fruit. Most of the fruit is dried.
Extracts from the fruits of F. sycomorus and another wild
fig
with even poorer fruit, F. benjamina, have shown both
"significant
antibacterial activity" as well as "possible antitumor activity".
The common fig has relatively high levels (.5% of dry weight) of
a phytochemical class called 'coumarins'. These compounds have been
used
in the treatment of prostate cancer, and one form of this phytochemical
is being investigated for its activity against skin cancer. The other
possibly
anti-tumour compound is benzaldehyde, which has shown significant
activity
against cancers in at least one test tube study. These results may
indicate
a possible preventative effect at the level found naturally in
the
fruit.
Commercially dried figs (treated with sulfur dioxide and
potassium
sorbate) have one of the highest contents of 'polyphenols'
-substances
in plants hypothesised to confer reduced cancer risk benefits - of
commonly
consumed foods, at around 1,000mg per 100grams of dried fig. Only some
seeds have similarly high amounts.
While it doesn't rate as a source of vitamin C, figs have one of the
highest amount of calcium of any common fruit (35 mg per 100 grams),
and
dried figs have genuinely useful amounts - 146 mg/100grams. (the RDA
for
calcium for an is 800 grams).
Grape Vitis vinifera,
V.
species
While I have been able to find no species of Vitis recorded
in
our ancestral African homeland, there are several species of the genus
Rhoicissus
in Africa which bears a strong resemblance to the grape, and are in the
same family (Vitaceae). The fruit are deep purple, same size as grapes,
and grow in forested lands. They are very acid, but native people eat
them
- although one account associated them with a case of "severe colic and
diarrhea" in three children, with one subsequently dying.
The grape is native to mountainous Central
Asia, the natural home of so many important fruits. So our
ancestors
would have run more or less straight into them as they radiated out of
Africa. Wild grapes are generally good to eat, occurring as both black
and white forms, with the black tending toward high acidity and low
sugar,
and the white the reverse. No doubt our ancestors made good use of the
autumn harvest of these vines - especially as they may well have been
climbing
wild plum or wild pear trees. As the deciduous forests in the region
were
chopped down to make way for agriculture, the best vines - and the
trees
they grew on - were kept. The grape extends as far west as hills
bordering
the southern shores of the Black and Caspian seas; and it is probably
from
here that they spread west as humans became village people and started
protecting and cultivating nice fruits. The grape had been domesticated
in the western part of South
West
Asia for about 6,000 years before present. Cultivation
reached
Greece maybe around 3,000 years ago, and then was spread throughout the
Mediterranean along the Phoenician sea routes. Vine culture went with
the
Romans throughout Europe, and monasteries in Europe become one of the
repositories
of knowledge of culture and varieties. The Spanish and Portuguese took
the vine with them in all their colonization's of North, Central, and
South
America.
North America is rich with Vitis species, and when the Asian
grape was introduced in the seventeenth Century to the Atlantic
seaboard,
it set the scene for hybridization with native species, especially as
the
introduced species was subject to many diseases in it's new country.
Seedlings
of these spontaneous hybridisations were appreciated as important
having
the disease resistance of the native 'fox', 'muscadine', and
'riverbank'
grapes, and the superior sweetness and size of the Asian/European
grape.
The well known 'Concord' variety of grape is one example.
The Asian/European grape is now commercially grown throughout the
world,
with western Europe, the Balkans, California, Australia, South Africa,
and Chile being major producers.
Grapes are pretty easy to eat, and by the time you have snacked on
100
grams (around a dozen grapes, depending on size), and will have
satisfied
about 18% of their recommended daily requirement of vitamin C. Grapes
have
long been known as a 'health' food, and it is thought they may contain
useful amounts of antioxidant, protective, natural plant chemicals. It
is likely that the most darkly colored (black) grapes will have the
most
protectant phytochemicals in them, although this has not been
investigated
(except for American 'scuppernog' muscadine grape species, where bronze
and dark skinned varieties have been shown to be high in resveratrol).
Resveratrol, a phenolic compound, is the best known protective compound
in grapes, and it is particularly prevalent in darker skinned grape
varieties.
It is present in red wine, and some suggest that moderate red wine
consumption
is associated with a decrease in risk of coronary heart disease. Dark
grape
juice contains the same protective compounds. As do raisins. Recently,
the molecular basis of how resveratrol has been worked out. It
interferes
with an unhelpful bodily process that prevents cancer cells being
recognised
and destroyed by the bodies natural defends.
"A couple of years ago, a group at the University of Illinois
found
that Resveratrol has both anti-inflammatory and anti-cancer
properties...this
is very exciting work because we believe it explains how diet modulates
changes at the molecular level; it provides a molecular rationale for
the
broad chemo-preventive properties of trans-Resveratrol and by
extention,
grapes and grape products."
- Dr. Minnie Holmes-McNary, UNC-CH School of Medicine's Lineberger
Comprehensive Cancer Center
Dried grapes ('raisins') were ranked second in scientific tests
to identify the most antioxidant rich fruits and vegetables. On
this basis, raisins have to be an excellent
'protective-value-for-money'
choice.
Interestingly, recent tests on the anti-oxidant effectiveness of
various
commercial fruit put fresh red grapes at number six in
anti-oxidant
effectiveness
against damaging oxidative processes in cells.
Nutritional
analysis JJJ of
commercial
white and black grapes can be found at the Cape fruit website
Grapefruit Citrus
paradisica
Citrus as a genus are not represented in Africa - although there is
one obscure, very Citrus like member of the citrus family
present,
and that is Citropsis daweana. The Mozambique 'Cherry Orange'
is
a small tree of riverine valleys with citrus smelling leaves, and
small,
probably edible fruit. So when we radiated to South East Asia, the
possible
real origin of the grapefruit, we would have been meeting wild citrus
not
too different from Citropsis, except larger and more edible.
Edibility
is fairly widespread in the citrus as a group, with quite a few of the
35 or so species being a potential food item.
The commercial grapefruit arose in the eighteenth century in the
West
Indies. There is still some uncertainty whether it is a true species,
or
a hybrid of unknown origin, but probably of the South East Asian
Pummelo,
C.
maxima, which it closely resembles.
The main grapefruit producing areas are southern and western United
States.
Grapefruit are an excellent source of vitamin C, with an
average
serving dealing to two thirds of an s daily minimum requirement.
Grapefruit juice contains citrus flavonoid compounds not in other
citrus
juices. The most prevalent flavonoid is naringin,
responsible for the characteristic bitter taste of grapefruit juice.
Flavonoids in general have shown protective biochemical effects.
Grapefruit have natural plant chemicals ('phytochemicals') called
'monoterpenes'
in their skin that both protect against cells becoming cancerous, and
help fight existing cancers. At least, as studied in laboratory mice -
but there is no reason to think these chemicals wouldn't be active in
humans.
Unless they are certified as 'organically grown', commercial citrus may
have been dipped/sprayed with anti fungal chemicals to prevent storage
rots (they may also be dyed to heighten the color, and waxed
with
a vegetable derived wax to heighten the appearance). Therefore it is
advisable
to select only organic fruit to chew on the peel. It is unknown if the
tumor fighting chemicals survive heat and processing when marmalade is
made.
Guava, tropical Psidium
guajava
Native to tropical America, from Mexico to Peru. Remains of guava have
been identified in 2,800 year old human settlements in Peru, but
whether
domesticated or wild harvested is impossible to tell. There are said to
be about 150 species of the genus Psidium, but only the
'tropical'
guava has become a commercial crop - presumably because it is larger,
and
much firmer than most other species.
Spanish and Portuguese colonizers took the guava back to Europe with
them, and then on to their colonies in Africa and South East Asia.
Tropical guavas are very subject to fruit fly infestation, which
limits
their production in some areas. Most fruit are consumed locally, as the
fruit doesn't have a long shelf life. Guavas are very variable in size,
sweetness, skin and flesh color - in some respects it is suprising that
they have not been selectively bred for better market characteristics.
After all, from the nutritional point of view, they are a quite
exceptional
fruit.
The tropical guava is the most outstanding fruit for vitamin C
content
of any commercial fruit listed here. It has an exceptional 165mg
of vitamin C per fruit - twice the amount of the second place
holder,
the kiwifruit - an exceptionally good source itself. Cooked guava
products,
in the form of 'guava sauce' (presumably cooked pulp), is also an
exceptional
vitamin C source, at 143mg/100 grams. According to the South African
canning
industry, some pink guava varieties have an astonishing 400 to 450
mg/100
gms of vitamin C!
One guava (90 gram size) supplies about 5% of an s minimum daily
Niacin (B3) needs. A guava of this size also has nearly 800
International
Units of vitamin A, a very useful contribution to the daily
requirement,
and making it the sixth highest source amongst the fruits on this page.
Tropical guavas are also high in Potassium, and an excellent source of
dietary fiber.
There is one report that of guava fruit consumption results in
reduced triglyceride levels in the blood (a risk indicator for heart
disease)
and reduced hypertension, while increasing the level of high density
lipoprotein
('good') cholesterol.
Kiwifruit Actinidia
deliciosa, A. chinensis, A. arguta
The kiwi is native to East Asia, where there are about 40
species of kiwifruit, some bland, some sweet, some 'peppery', some
cherry sized, some the size of a smaller grade commercial fruit. These
vigorous climbers fruit heavily, and we can be sure humans have used
the
fruit (that the birds, bears, and monkeys leave) for food from the time
ancestral humans first moved into the kiwifruits' range. People have
always
harvested these fruit, and in parts of Russia, at least, a cold hardy
kiwi,
Actinidia kolomikta, is still harvested from the coniferous
forests.The
amount of vitamin C varies between species, and also between individual
plants in a species. Some of the most common wild kiwifruit,
particularly
Actinidia
kolomikta, A. arguta, and A. chinensis, have
spectacular
amounts of
vitamin
C.
The commercialization of the green fleshed kiwifruit (A. deliciosa)
was slow, in spite of it's excellent keeping qualities and bruise
resistance.
British missionaries sent seed to a New Zealand nurseryman, who first
fruited
the plant in 1910. A selection said to be from this seedling population
gave rise to the kiwifruit industry in New Zealand in the 1970's and
80's,
and it's success saw the commercial form spread to USA, Chile, South
Africa,
and parts of Europe.
New hybrids between the various species have been developed in
France,
Canada, USA, and New Zealand. As these become available, expect to see
grape sized kiwifruit, red kiwifruit, yellow fleshed kiwifruit, and
perhaps
a kiwifruit with a vitamin C content even more magnificent than the
present
green 'Hayward' variety. This is because one wild species, A.
eriantha,
is said to have 1,000 milligrams of vitamin C per 100 grams of flesh.
Unfortunately,
A.
eriantha is also not very palatable. A new yellow fleshed kiwifruit
will be launched worlwide in the year 2000, and this
fruit has around 100 mg vitamin C per fruit, which is quite
exceptional.
Kiwifruit are one of the most 'nutritionally dense' foods - there is
a higher concentration of vitamins and minerals per calorie than most
other
fruits. Most important of all, perhaps, one kiwifruit provides about
115
% of the USRDA for Vitamin C! Kiwifruit are an exceptional source
of this vitamin. Vitamin C can greatly improve our bodies ability to
absorb
and use iron, and one kiwifruit has about 2% of the USRDA for iron.
One fruit also delivers around around 14% of an s daily folate
(B complex, folic acid) requirement. Given that the best sources of
folate-
green leafy vegetables - typically lose 50% of their folate in cooking,
the folate of kiwifruit (usually eaten without cooking) is more
valuable
than it would first appear.
The potassium content is fourth highest of any domestic fruit (332mg
per100grams). The calcium content of a kiwifruit, at 2.25% US
Recommended
Daily Allowance, is not particularly high, but it is higher than all
but
a few other fruits. The amount of the micronutrient chromium needed in
human nutrition hasn't been established (chromium has a role in
heartbeat
and carbohydrate use in the body. It may be one factor in
avoiding
diabetes and heart disease). Current tentative indications are that
between
0.05 mg and 0.2 mg daily is required. One kiwifruit has, on average,
0.17
mg of chromium. This represents 35% of the daily need if it is set at
0.05mg,
and 10% of the daily need if it is set at 0.2mg.. While kiwifruit are
sometimes
touted as having useful amounts of vitamin E, this is in the tiny
seeds,
which pass through the body undigested.
Interestingly, recent tests on the anti-oxidant effectiveness of
various
commercial fruit put fresh kiwifruit at number eight in anti-oxidant effectiveness
against damaging oxidative processes in cells.
A kiwifruit has around 1.5 grams of 'crude fiber', and "several times"
that amount of dietary fiber (gums, pectins etc.), which makes it an
exceptionally
good fiber source - fiber being important in bowel health, and in
removing
toxins in the intestines.
Lemon Citrus limon
The lemon developed from ancestral plants probably in South east Asia.
The cultivated lemon is possibly a natural hybrid of two wild
species,
most likely lime, C. aurantifolia, and citron, C. medica.
Some believe it arose solely from ancestral versions of C. medica.
The first written mention of the lemon was in an Sanskrit writing in
India
from 2,800 years ago. It's spread with agriculture and settlement was
to
the East, into south Asia, southwest Asia, and then to the eastern
Mediterranean.
Lemons went from the Middle East along the shipping routes to Spain and
northern Africa in the Middle Ages. The Spanish and Portuguese soon
introduced
it to their colonies in South America and the Caribbean.
Lemons have natural plant chemicals ('phytochemicals') called
'monoterpenes'
in their skin that both protect against cells becoming cancerous, and
help fight existing cancers. At least, as studied in laboratory mice -
but there is no reason to think these chemicals wouldn't be active in
humans.
Unless they are certified as 'organically grown', commercial citrus may
have been dipped/sprayed with anti fungal chemicals to prevent storage
rots (they may also be dyed to heighten the color, and waxed
with
a vegetable derived wax to heighten the appearance). Therefore it is
advisable
to select only organic fruit to chew on the peel. It is unknown if the
tumor fighting chemicals survive heat and processing when marmalade is
made
Lime Citrus
aurantifolia
The Limes developed from ancestral plants probably in Eastern India.
It's spread via human culture pretty much mirrors the lemon, except
that
it requires a marginally warmer climate. Limes and lemons are obviously
not a fruit you would eat like an apple, but it says a great deal about
flavoring food that we have valued this fruit for so long.
Limes have natural plant chemicals ('phytochemicals') called
'monoterpenes'
in their skin that both protect against cells becoming cancerous, and
help fight existing cancers. At least, as studied in laboratory mice -
but there is no reason to think these chemicals wouldn't be active in
humans.
Unless they are certified as 'organically grown', commercial citrus may
have been dipped/sprayed with anti fungal chemicals to prevent storage
rots (they may also be waxed with a vegetable derived wax to
heighten
the appearance). Therefore it is advisable to select only organic fruit
to chew on the peel. It is unknown if the tumor fighting chemicals
survive
heat and processing when marmalade is made
Lychee Litchi
chinensis
The Lychee is native to the warmer forests of Southern China and
probably
Vietnam. It has been cultivated in China for well over a thousand
years,
and would no doubt have been a keenly sought after forest fruit in
subtropical
Sino-Vietnamese Asia. However, the human stem population that remained
in Africa had fruit in the same family (Sapindaceae) that were quite
similar.
Fruit of Zanha africana from central Africa has velvety
yellowish
small fruit with orange colored pleasant pulp. Zanha golungensis,
also from central Africa, has edible, bright orange, smooth oval
fruit borne in heavy profusion.
Lychees are so delightful it is hardly suprising they have been
brought
into cultivation. Unfortunately, they don't have a startlingly long
shelf
life, and are relatively easily damaged in transport and handling. The
trees themselves bear heavily when the conditions suit them, but they
are
notoriously demanding in climatic conditions. So they will always be a
luxury fruit, except as a canned fruit. Lychees can be dried
within
their skin/shell. Sun or fire dried lychees are known as lychee-nuts
and
taste a bit like a raisin.
At 72mg of vitamin C per 100 grams of flesh, lychees are a very good
source for this essential vitamin. Three lychee fruits would meet a
third
of an s daily vitamin C requirement.
Mango Mangifera indica
The mango belongs to a group of species of large forest tree
native to an area that stretches from northern eastern India down thru'
South East Asia to New Guinea. Several of the 40 or so species have
fruits
that are wild harvested (M. caesia, M. quadifera and M.
pajang, in Borneo, for example) but only 'the' mango, M.
indica,
has become a domesticated plant.
Mango germplasm in the wild seriously endangered - a
short
article
http://www.siu.edu/~ebl/leaflets/mango.htm
Wild mangos have fruit that are very fibrous, with high
concentrations
of 'turpentiney' resin. Some, such as M. quadifera have strong
unidentified
'pungent' chemicals in the flesh. Some wild species are large, others
small,
with varying shaped fruit. The low fiber, relatively small stoned and
resin
free fruit we have today is the result of millennia of human selection.
Mango seedlings are highly variable, so there was good opportunity for
better sorts to arise as agricultural settlement commenced.
Mangoes need a dry period during fruit set; they also need
subtropical
to tropical conditions without frost. Spread was therefore mainly to
the
east, into Myanmar (Burma), Vietnam, and south. It is suspected that
Portuguese
merchants or travelers took the mango from India to east Africa, West
Africa,
and then to their colonies in the Americas, probably in the sixteenth
century.
Mangoes were grown in the West Indies in the eighteen century, and
Florida
in the nineteenth.
Mangoes have a relatively short shelf life, but the advent of air
freight
has meant mangoes can be exported from tropical South East Asia,
Mexico,
India and Africa and arrive in Europe and North America in excellent
condition.
However, given the cost of air freight, and the lack of extended shelf
life, mangoes will always tend toward the luxury end of the market
(except
in countries where they can be grown locally). Which is a pity, because
they are a particularly useful human food.
Not only are mangoes an excellent source of vitamin C (one
fruit
pretty much fills an s daily vitamin C requirement), they also
have
the highest concentration of vitamin A of any commercial fruit listed
here
(an excellent 3,894 International Units per 100 grams of flesh).
Melon, Cantaloupe Cucumis
melo
The melon is, like ourselves, an African. There are quite a few species
of the genus Cucumis in Africa, and the wild melon that humans
eventually
domesticated is a native of sub Saharan eastern tropical Africa. It is
believed to have been domesticated fairly late, relative to other
crops,
but once domesticated many and variable forms arose. It succeeded best
in the drier, longer season parts of India and South West Asia; in fact
it naturalized in India, and India is regarded as a secondary center
of
wild germplasm. From South West Asia it spread to Greece and
Italy,
and all parts of the historic Mediterranean world. It captured the
imagination
of France not long after it reached there about the fifteenth century,
where one intellectual produced a treatise enumerating fifty different
ways of eating melons, including in soup, fritters, and served with
salt
and pepper! The English 'aristocracy' prided themselves on the perfect
melons their gardeners produced in their glasshouses. From England and
the content, the melon went to America and all the colonies of the 'new
world'.
Melons are reasonably priced and seasonably available in countries
that
span several climatic zones, such as Australia and the USA. While they
don't have a very long shelf life, varieties have been bred with
reasonably
robust rinds to handle long distant transit. The variety and complexity
of flavors, sizes, flesh colors and textures makes the melon one of the
most exciting and interesting fruits there is. It is also an important
source of some nutrients.
High in Potassium, rock melons/canteloupes are an excellent
source
of vitamin A - they are the second best source (after mangoes) of all
the
fruit mentioned on this page, with a very respectable 3,224
International
Units per 100 grams. In addition, normal serving meets about half an
s
daily vitamin C requirements, making them a very good vitamin C source.
Orange Citrus
sinensis
Citrus as a genus are not represented in Africa - although there is
one obscure, very Citrus like member of the citrus family
present,
and that is Citropsis daweana. The Mozambique 'Cherry Orange'
is
a small tree of riverine valleys with citrus smelling leaves, and
small,
probably edible fruit. So when we radiated to South East Asia, thru
Myanmar
(Burma) and into Eastern India (the possible place of origin of the
sweet
orange), we would have been meeting wild citrus not too different from
Citropsis, except larger and more edible. The wild ancestral form
of
the sweet orange hasn't been found. Edibility is fairly widespread in
the
citrus as a group, with quite a few of the 35 or so species being a
potential
food item. But the sweet orange is one of the best. The first
historical
record of the orange is in Chinese writings from 4,400 years ago.
As with most citrus and other good things, the rise of agricultural
settlement and both land and sea trading between Europe, the greater
Mediterranean
through South West and South Asia to China, resulted in the spread of
the
orange into all these areas. Small citrus groves and protected
'orangeries'
of the 'noble' courts were well established in suitable European
climates
from at least 2,000 years ago. Spanish and Portuguese explorers carried
the orange to the 'new world' colonies in the Caribbean Islands and
South
America in the fifteenth and sixteenth centuries. Late in the
eighteenth
century citrus culture was already established in Florida, and just
introduced
into California. The orange was introduced to Australia by the British
colonizers in the nineteenth century, and from Australia to New Zealand
shortly after.
Today, of course, orange growing is big business, and carried out on
a vast scale. This means reasonably priced fruit for the consumer.
Oranges
travel well, can be cool stored to extend their availability, and some
varieties store 'on the tree' in the orchard for quite a while, further
extending the season. Most oranges are actually used to make orange
juice
and other products, with only about 20% of the USA crop, at least,
going
on the fresh market.
Research into orange growing continues, and one of the more
interesting
developments, from the nutritional point of view, is the increasing
number
of 'blood' oranges being grown. These have anthocyanins in the juice,
giving
a red look to the flesh. Although noone appears to have investigated
the
matter, it would be reasonable to suspect that they would have
increased
antioxidant value.
One orange will meet about 20% of an s daily folate needs, as
well
as being an excellent source of vitamin C - one orange supplying just
over
the entire US recommended daily intake (60mg for an ).
Oranges have natural plant chemicals ('phytochemicals') called
'monoterpenes'
in their skin that both protect against cells becoming cancerous, and
help fight existing cancers. At least, as studied in laboratory mice -
but there is no reason to think these chemicals wouldn't be active in
humans.
One monoterpene, d-limonene, comprises more than 90% of the oil in
orange
peel. Unless they are certified as 'organically grown', commercial
citrus
may
have been dipped/sprayed with anti fungal chemicals to prevent storage
rots (they may also be dyed to heighten the color, and waxed
with
a vegetable derived wax to heighten the appearance). Therefore it is
advisable
to select only organic fruit to chew on the peel. It is unknown if the
tumor fighting chemicals survive heat and processing when marmalade is
made
Recent tests on the anti-oxidant effectiveness of various commercial
fruit put oranges at number five in effectiveness against damaging
oxidative
processes in cells.
Scientists have recently identified several bioflavonoids from
citrus
that inhibit certain cytochrome P450 enzymes. One cytochrome enzyme,
P450
1B1, can activate cigarette smoke, pesticides and other substances (
'procarcinogens')
in the body to become carcinogens. Hesperetin, the most abundant
bioflavonoid
in the juice of oranges, has been found to inhibit P450 1B1 from
metabolizing
procarcinogens, significantly reducing the opportunity for them to be
converted
into carcinogens.
Papaya Carica papaya
While no members of the genus Carica are present in Africa,
there are two species of the closely related genus Cylicomorpha,
from central Africa. There is no information on whether or not it has
edible
fruit.
But Caricas definitely do. There are twenty two species of Papaya,
of varying plant and fruit size and edibility. Several more cold hardy
species, C. pubescens, C. stipulata and natural hybrids
between
the two, are used as food in South America. C. stipulata
tends
to be high in the protein digesting enzyme papain, which can cause
irritation
to the lips; C. pubescens has tough flesh that only
yields
to cooking (although the seeds are embedded in a soft sweet pulp). Most
are canned in syrup these days. Other species are too small, too dry,
too
flavorless, have odd tastes, and so on. Only Carica papaya
seems
to have had the sweetness, flavor, and flesh tenderness to be avidly
sought
after by the indigenous peoples of South and Central Americas.
The 'tropical papaya' (called by the English and their
colonial
descendants 'pawpaw') was probably native to the tropical lowlands of
eastern
Central America. Botanists believe the ancestral fruits were small,
probably
only 50 or 100 grams or so, and that the present forms are due to
millennia
of human selection. It spread widely through tropical middle
America,
from Mexico to Panama. Being easily grown from seed, and having
excellent
eating qualities, it quickly spread with the Spanish and Portuguese
colonizers
to the Caribbean, Africa, India, and all places where the climate and
soil
would allow it to grow.
Papaya are liable to damage in handling, and have only a moderate
shelf
life. They are reasonably priced in local markets in the tropics, as
they
grow quickly and easily and produce heavily. Apart from countries with
multiple climatic zones, they are otherwise something of a luxury
fruit.
As a human food, they are of excellent flavor and sweetness, and mix
and
match with tangy lime juice in a classic combination . And their
nutrition
value is high.
One serving of papaya will meet about 20% of an s daily folate
needs, and provides about 75% of an s daily vitamin C needs, an excellent
percentage for any food.
Passionfruit,
PurplePassiflora
edulis
The purple passionfruit is native to an area going from Southern Brazil
to Northern Argentina. There are no Passiflora species indigenous to
Africa.
There are, however, in Asia. I have no information on the edibility or
otherwise of the Asian species, but many of the 120 or so species
of Passifloras are edible. Some have tiny fruit, some have quite soft
leathery
skin, one has a rind that can only be opened with a hammer, many are
rather
small, one, the size of a football, is too big. Even so, there are very
nice flavored passionfruit with good handling characteristics, such as
P.
ligularis, that are never available commercially.
Although passionfruit are - or used to be - prolific fruiting common
dooryard fruits in the countries whose climate allows them to grow and
fruit, they are quite demanding as to climate and soil conditions.
Consequently,
the fruit appear on the market more or less as a luxury item.
Purple passionfruits have the third highest potassium level of any
domestic
fruit on these pages, at 348mg per100 grams.
They have useful amounts of vitamin A, at 700 International Units per
100 grams.
Peach Prunus persica
The ancestral Prunus species which gave rise to both the almond
and the peach (they are closely related) was probably native to Central
Asia. The peach evolved toward the east of central Asia, toward Western
China. The wild peaches of China show enormous variability, with flat
fruit,
beaked fruit, round fruit, red skin, whites skin, and yellow or white
flesh.
Our ancestors radiating out of Africa into Central and Western Asia
would
probably found a much smaller fruit than the one we know today, but it
would still be welcome as a summer treat in the hot, dry woodlands of
the
West Asian interior. Two other species, P. ferganensis of
Central
Asia and P. mira of West Asia also have edible fruit,
but
they are inferior to the peach (altho' P. ferganensis has been
domesticated
in the former USSR).
With agriculture came domestication, and peaches have been
cultivated
in China for millennia. Almost all peach seedlings produce worthwhile
fruit,
and they don't take long to come into bearing, so villagers selecting
larger
or better tasting fruit would soon have improved the fruit. Traders on
the silk road took the peach from China to Kashmir and over the central
Asian mountains to Iraq (known as Persia in early historic times). When
it arrived in Persia and adjacent countries isn't known, but it soon
became
naturalized there. It is mentioned in Egyptian records about 3,400
years
ago, however, so it must have arrived some long time before then. The
spread
to Europe via South West Asia and the middle East was inevitable. The
peach
may have been introduced to Greece by Alexander the Great, after his
epic
wars in Central Asia. The Europeans thought the peach came from Persia,
so named this fruit from China 'persica', which means 'Persia'. From
Europe,
the peach. went to the new world with Spanish and Portuguese explorers
and colonizers of the 16th to17th centuries. Interestingly, the Spanish
introduced the peach to the Northern Florida/Georgia coast of the USA.
Peaches are a fairly ephemeral fruit of the summer season. They
don't
keep well, have to be picked at exactly the right stage if they are to
ripen 'off the tree' but not bruise in store, and so are worth the
price
being asked. Firmer fleshed, deep yellow varieties are grown for
canning,
and these represent excellent value.
One peach ( of around 100 gram size) supplies about 5% of an s
minimum daily Niacin (B3) needs. Fresh and canned peaches have about
the
same amount of vitamin A, with one medium sized peach having about 530
International Units.
Pear Pyrus communis
Pear species in general abounded in the woods and forests of Central
and South West Asia as we came out of the Levantine coastal corridor
into
the wide, wide world of South West Asia and beyond, so genetically, we
are well familiar with this fruit and it's relatives. The
ancestral
pear, Pyrus communis, grows wild in the forests of parts of
Central
and South West Asia. The 'European' pears' origin was therefore
certainly
in this general region, more or less, but it is not an unaltered
descendant
of P. communis. In the wild P. communis fruits, like
most
wild pear species, are barely edible - they are small, gritty, hard,
astringent
and sour. Other species, P. nivalis, the 'snow pear', and P.
serotina, the 'Asian pear' are thought to have naturally crossed
with
P.
communis to produce the early forms of the pear we know today.
Other
species may also have been involved, particularly P. ussuriensis.
It was likely these natural hybrids that our ancestors and bears alike
preferred. Of the 22 odd species of Pyrus, only the
'European'
(actually 'Central Asian'), the 'Asian' pear and the 'Ussuri' pear (P.
ussuriensis) have been domesticated.
The pattern of selection and improvement is linked to sparing
preferred
trees as the forests were cut to make way for agriculture and herding;
spreading of seed of selected trees in human manure; and, very
recently,
learning how to propagate individual plants by grafting twigs to
seedlings
grown for the purpose.
Pears from South West Asia spread with settlement and trade into
Europe,
probably fairly late, as they are not mentioned in the bible. They were
highly regarded, both for wine making and as a fresh fruit - altho'
even
as late as the seventeenth century some writers were claiming raw pears
were poisonous! From Europe they went to England, then in the boats of
the colonizers to the American eastern seaboard and Australasia.
Today, the people of the North Caucasus mountains still collect wild
Pyrus
fruit, in spite of having ready access to a range of domestic fruit.
And,
in an echo from our ancient past, no doubt fathers still show
their
children where 'the best pear trees are'.
Pears, like their relative the apple, have a good storage life.
Unlike
an apple, you can't pick up a fully colored, ripe, crisp pear and eat
it.
Pears have to ripen and soften - not too much, or they are floury.
This,
and the trees susceptibility to a particular bacterial disease, are the
limiting factors in consumer acceptance and grower expansion.
Few fruit can match a perfumed, sweet, juicy and fine fleshed,
almost
buttery, pear. But this marriage of superior variety and exact point of
ripeness is not always easy to find. New pears are being bred, using
the
'Asian pear' as a parent. Hopefully, this will produce a fine fleshed,
slightly crisp, perfumed and aromatic fruit that will be edible from
the
moment we select it from the supermarket display. We shall see.
Persimmon, OrientalDiospyros
kaki
The genus Diospyros includes quite a few African plants,
and a suprising number have reasonably edible fruit. D. lycoides
is a small shrub of Central and Southern Africa with small reddish
fruit
and translucent flesh. The pulp is "faintly sweet and insipid". Unlike
D.
mespiliformis, whose pulp is very sweet. It's small purple
or
yellowy fruits are sometimes dried and stored by African tribespeople.
D.
mespiliformis is common in the gallery forests alongside rivers in
Southern Africa. There is increasing evidence that the fruit, fish, and
animal resources of such gallery forests constituted one of the major
habitats
that humans evolved in. D. mespiliformis may, therefore, have
been
one of our most longstanding dietary items. I have not seen any
analysis
of this fruit, but another wild Southern African Diospyros. D.
dichrophylla,
has about 40 mg/100grams of flesh (compare with domestic persimmon
fruit,
below) Not all
wild African
Diospyros are small - D. batocana is small apple
sized,
yellowy orange, with a very acid pulp. The fruit of D. chamaethamnus
have already been mentioned.
The tropical African D. kirkii has small, sweet mealy fleshed
fruit
in spring, and is considered by one writer as perhaps being worth
domesticating.
Even when a portion of the human species started radiating out of
our
African homeland, we did not leave 'persimmons' behind. There are wild
species from central to East Asia, and also down into South East Asia.
One of these, D. roxburghii from the northern part of South
East
Asia and the southernmost part of Central Asia, was possibly the
progenitor
of D. kaki.
D. kaki has tannins in the flesh which are responsible for
the
'astringency' ( an unpleasant 'furry' feeling in the mouth) of the
unripe
fruit. Most fruit have a lot of tannins, which do not reduce until the
fruit is soft ripe - at which point it absolutely cannot be handled
without
damage. It is probably for this reason that the fruit was so long to
come
to the west, apart from it's need for particular climatic conditions
and
slowness to fruit from seed. And it is also for this reason that people
have seized upon any chance seedlings with less tannin in the flesh.
Some plants, such as peaches, are easy to grow from seed, almost
always
give a good fruit, and take only three or four years to come into
bearing.
These kind of fruits soon become widespread along the trade routes.
Persimmons
are the antithesis, which explains, in part, why reduced tannin fruit
have
been so slow to 'arise'.
It wasn't really until the American and British contact with Japan
in
the nineteenth century that nurseries in America and Australasia
started
to obtain varieties of persimmon. They are hard to propagate, the fruit
are unfamiliar and difficult to handle, so they had a fairly sparse
distribution
even then. It is only with the twentieth century identification of
types
with tannin levels so low they can be eaten when ripe but still firm
that
the persimmon became a commercial proposition.
And that is where they are today. Persimmons are still climatically
demanding, and even in the low tannin fruits, there needs to be a
further
reduction.
This ancient fruit, whose territory we shared in all the stages of
our
evolution and radiation, could undoubtedly be improved. Perhaps species
from Africa may impart wider adaptation and even lower tannin levels.
We
will never know; as with all fruits of low commercial 'penetration',
there
is little effort to radically improve the fruit.
Persimmons are an excellent
source of vitamin C, with from 25 to 52mg per 100 grams of flesh,
depending
on the variety. The most common commercial low tannin variety, 'Fuyu',
has 52mg/100 grams. Interestingly, and similar to apples, persimmons
have
very high concentrations of ascorbic acid in the skin. 'Fuyu' peel, for
example, has more than four times the already excellent amount in the
flesh.
Lycopene, a carotenoid protective against prostate cancer, is present
in some varieties in quite high concentrations, as it is primarily
responsible
for the bright red color of the skin. How much, if any, is in the
flesh,
is uncertain. Other varieties have no lycopene at all (the lycopene
component
of the caretonoids in persimmon fruits varies, depending on the
variety,
from 0 to 30%). While some very thin skinned home garden varieties can
be eaten skin and all, most are peeled before eating. The redder the
skin,
the higher the lycopene. Commercially, it would be prudent to select
'no
spray' or 'organic' fruit if you wanted to eat the skin as well.
Pineapple Ananus
communis
"On the margins of the Campo wild pine-apples also grew in great
quantity. The fruit was of the same shape as our cultivated kind, but
much
small, the size being that of a moderately large apple. We gathered
several
quite ripe; they were pleasant to the taste, of the true pine-apple
flavour,
but had an abundance of fully developed seeds, and only a small
quantity
of eatable pulp"
- Henry Bates, 'The Naturalist on the Amazons', 1879.
The pineapple is thought thought by some to be derived from Ananus
species native to the tropical Parana-Paraguay basin. The possible wild
progenitors, A. bracteatus, A. paraguazensis, and Pseudananas
sp. of the tropical Amazon all have edible, but seedy fruit;
the more probable wild ancestor, a wild form of A. communis
itself, probably indigenous to much drier lowland South Americas
forests,
has not been found. And because most lowland South Americas forests
have
been destroyed, it will probably be extinct by now. The native people
of
the American tropics have grown pineapples by planting offshoots and
crowns
for a very long time. Propagules of this 'fruit of kings' were spread
west
and north from the tropical Amazon, if that is it's area of origin.
Regardless,
related species are seedy, and the odd 'mutant' self fertile pineapple
will have as many as 3,000 hard seeds. People aren't stupid -
they
infinitely preferred the seedless form, and spread it preferentially.
In
fact, the indigenous peoples of South Americas had selected varieties
with
different flesh color, different acidity levels, and different flavors.
Maritime trading Indian tribes traded and raided South Americas west
coast and river systems. The Carib Indians introduced the pineapple to
their Islands in the sea now named after them. The first westerner to
see
the pineapple was Christopher Columbus, in 1493, at Guadeloupe, one of
the Caribbean Islands. His expedition records that the Carib Indians
had
clearly hastily deserted their village in fear of these strange men,
because,
apart from vessels of human body parts, they had left behind the
dessert
of freshly gathered fruit - including the pineapple.
This strange and wondrous fruit was taken back to Spain, from whence
it was re-distributed to all suitable Spanish colonies, chiefly in the
Pacific.
The world's first commercial plantation was set up in Oahu, Hawaii
in
1885. Hawaii remained the world's main producer of
pineapples until the 1960's, when production relocated and
expanded
in the Philippines. Pineapples are produced in all climatically
suitable
countries, and South East Asia is the dominant producer.
Pineapples keep fairly well, and, because of mass production
methods,
are relatively cheap.
Most varieties are a good source of vitamin C with a typical serving
having around 13mg (about 20% of the recommended daily intake for an
).
Canned pineapple loses about a third of it's vitamin C content in
processing,
but still contains a useful amount. There is some varietal differences
in vitamin C content - 'Queen Victoria' pineapple has about 24mg/100
grams,
and the variety 'Del Monte Gold™' has about 53mg/100 grams, making this
particular variety an excellent source of vitamin C.
Pineapples contain the enzyme 'bromelain'. Bromelain tablets
(extracted
from the pineapple plant stems) are sold in health stores with claims
they
help combat heart disease, arthritis, and various other illnesses .
Scientists
testing the tablets on the incidence of mammary gland infection in cows
(mastitis) found that on average, they reduced the number of white
blood
cells (a normal immune system response to chronic infection) by a
third.
How bromelain does it isn't certain, but scientists suspect the enzyme
interferes with the synthesis of inflammatory substances in the body,
such
as prostaglandins.
Plum Prunus sp.
There are two main kinds of plum - the European plum, Prunus
domestica,
generally
oval, mellow and often intriguingly flavored fruit (it also
includes
the prune plums) and the Japanese plums, P. salicina,
the main fresh
plums of commerce. There is a third type, P. institia, a native
of Western Asia, which includes the small, acid, purple damsons and the
small yellow mirabelle plums. Neither of these are of any commercial
importance.
The plums our ancestors most likely encountered as some left Africa
for Central and then South West Asia was a small plum called the cherry
plum or bullace, P. cerasifera, a reasonably edible
fruit.
Other wild plums in the region included P. spinosa, the sloe
plum.
This plum is pretty much inedible, being very astringent indeed. Our
expansion
into China found us amongst the wild P. salicina, the
'Japanese'
plum (correctly, obviously, the 'Chinese' plum - it wasn't introduced
to
Japan until around 400 years ago).
The advances in fruit quality went hand in hand with the rise of
agriculture,
as it has (but not always) with most fruit. the 'Japanese' plum has
probably
had the longest human attention; the 'European' plum, P. domestica,
is a natural hybrid between the edible P. cerasifera
and the largely inedible P. spinosa, and it is suspected to
have
only occurred in the last 2,000 years or so, probably (but perhaps not
only) in the Caucasus Mountain region of South West Asia.
From the South of South West Asia it is a short hop to Mediterranean
Europe. Accordingly, Spanish missionaries introduced the European plum
to west coast North America, and British colonizers took it to the east
coast. Similarly, the European plum was taken to temperate and warm
temperate
climate colonies within the British Empire.
The 'Japanese' plum was much slower to reach the west, somewhat
curiously
- although it does need warmer climatic conditions than the European
plum.
As the name suggests, it wasn't until American and British contact with
the previously closed society of Japan in the late nineteenth and early
twentieth century that nurserymen in the west acquired plants of this
'novel'
fruit.
The Japanese plums and their hybrids are somewhat susceptible to
bacterial
disease in humid climates, and this has limited their extensive culture
to dry climate areas. Plums, along with peaches, are the archetypal
'summer
fruit', and the firmer fleshed modern varieties have a good shelf life,
store for a while, and handle quite well. Their season is all too
short.
Plums are good 'fruit of the season', and fresh or dried, a valuable
contributor
to the human animals diet.
Plums have useful levels of riboflavin (B2), with two (66 gram
sized)
plums providing about a sixteenth of an s recommended minimum
daily
intake, and fairly good amounts of vitamin C.
Dried prune plums ('prunes') were ranked an outstanding first in tests
to identify the most antioxidant rich fruits and vegetables. Studies
have
shown that fresh plums have the fourth highest chemical effectiveness
in
preventing oxidation in cells of any other commercial fruit. Most of
this
anti-oxidant activity is in the juicy portion.
Dried plums (prunes), like dried figs, contribute a useful amount of
of calcium toward meeting the recommended daily requirement of 800 mgs.
Raspberry Rubus
idaeus
There are several species of wild raspberry in our African evolutionary
homeland. Rubus ludwigii, from Southern Africa, has small,
white
pleasant fruit, and R. rigidus, with it's glossy purple-black
berries,
is common from central Africa to the Cape.
As we radiated out into the fruit and nut filled woodlands of South
West Asia, we would have come upon the wild form of the red raspberry,
R.
idaeus (named after Mt.Ida in the Caucasus Mountains), as well as
related
wild fruits such as Rubus chamaemorus, R. arcticus,
R.
saxatilis of the forest tundra belt of North Asia. Raspberries are
easy to propagate, as plants or seed. They would have been taken to
Europe
by traders and soldiers, and the Romans, in particular, played their
part
in spreading them far afield. The British improved the fruit in the
middle
ages, and like most fruits, plants were sent to it's colonies,
including
America (in the late eighteenth century). The red raspberry was already
present in America however. A variety of the Southwest Asian raspberry,
Rubus
idaeus variety strigosus is indigenous to eastern
North
America. The black raspberry Rubus occidentalis, is found
only
in North America, and it wasn't domesticated until the 1800's.
Raspberries have a very short shelf life, they are liable to damage
in transport and handling, and the plant can be subject to quite a few
diseases. When conditions are good, they are very productive, and well
suited to 'commoditization' as a frozen or pulp product for use in
other
manufactured 'foods'. Fresh market berries are consequently relatively
expensive, and have a short season. Frozen berries may give best value
for money.
Laboratory tests suggest some berries may reduce the buildup
of
LDL (low-density lipoprotein) cholesterol, a contributor to heart
disease,
stroke and atherosclerosis. Raspberries were tested as having the
second
highest LDL inhibitory effect. Interestingly, the anthocyanin content
(believed
to be a protective antioxidant) of raspberries increases in
storage,
thus increasing their antioxidant value over time.
Strawberry Fragaria
ananassa
The forty or so species of strawberry are all more or less
edible,
and one of the most widespread, F. vesca, the wood strawberry,
is
found in North Africa. Wherever we roamed in the temperate zone, there
were woodland and meadow strawberries to be found. The best of these
were
F.
vesca, F. viridis, and F. moschata (hautbois or
musk
strawberry). No great improvement seems to have occurred in these
species
subsequent to the commencement of farming, and while all three species
were domesticated to a greater or lesser degree, the strawberry that we
know today did not exist.
It wasn't until seeds of a North American species, F. virgininiana
(long used by indigenous Indians) were sent to Europe in the sixteenth
century that the stage was set for production of the modern strawberry.
The 'meadow strawberry', as it was called, was no bigger than the
existing
cultivated forms of the European woodland strawberry, but had a
different
flavor and were a different color. Quite a few varieties were selected
from this introduction, and they became quite well spread amongst
gardens
of the day. The Indians of Chile had domesticated another American
species,
F.
chiloensis, and the Spanish, impressed with it's size and eating
quality,
spread it to other parts of South America, and mentioned it in
documents
of the day. A Frenchman was stirred to introduce plants to France in
1714.
These proved to be fruitless unless cross pollenized by either
F. moschata
or
F. virgininiana. The natural cross pollenizing eventually
resulted
in a chance seedling hybrid between chiloensis and virginiana.
This new 'Pine Strawberry' ('pine' as in 'pineapple') was first
described
in 1759, and was the first ever modern strawberry. And from this
beginning
breeders have developed the large, firm, red varieties we buy in the
shops.
Fruit in general are not good sources of the B vitamin pantothenic
acid,
with the conspicuous exception of avocados, but strawberries have
useful
amounts. Half a dozen strawberries will provide almost a third of an
s
minimum daily requirement.
Strawberries have very good quantities of vitamin C; five strawberries
provide better than half the daily requirement for an .
As with tomato consumption, regular strawberry consumption has been
significantly associated in one study, at least, with reduced risk of
prostate
cancer. Strawberries do not contain lycopene (the active carotenoid in
tomatoes), so an as yet unidentified natural plant chemical unique to
strawberries
is responsible for the protective effect.
Strawberries were ranked sixth overall in tests to identify the most
antioxidant rich fruits and vegetables. Laboratory tests in another
study
re-inforce this, suggesting some berries may reduce the buildup of LDL
(low-density lipoprotein) cholesterol, a contributor to heart disease,
stroke and atherosclerosis. In this last mentioned study, strawberries
were tested as having the fifth highest LDL inhibitory effect of all
the
berries investigated. Interestingly, further studies have shown that
strawberries,
while having the sixth highest anti-oxidant concentration, are THIRD in
actual chemical effectiveness in preventing oxidation in cells. Most of
this anti-oxidant activity is in the juicy portion. As with
raspberries,
the anthocyanin content (believed to be a protective antioxidant) of
strawberries
increases
over time in storage, thus increasing their antioxidant value while
on the shelf.
Tamarillo Cyphomandra
betaceae
The tamarillo is a short lived small tree grown all along the Andes
at 1000 to 3000 Meters altitude. It has been grown for so long by the
native
peoples that it's natural range and actual place of origin is now
unknown.
C.
betaceae does require relatively frost free, mild conditions, which
has limited it's spread. The approximately egg shaped fruit are usually
yellow or orange, although the commercially available varieties are
usually
a red skinned form selected in New Zealand. There are several
very
closely related species found in the wild, and one, from Bolivia
(although
present in USDA and New Zealand) Cyphomandra
maternum, is suspected to be the distant ancestor of this
species.
Both the tree and the fruit of C. maternum are almost identical
to the tamarillo, except that the ripe fruit from the only C.
maternum,
population that has been examined so far are so laden with 'hot'
chemicals
that humans can't eat them. Pigs, interestingly, eat them with aplomb.
However, Cyphomandras are distant relatives of tomatoes, and they are
quite
variable. The tamarillo may once have been as inedible as C.
maternum
- in fact, some varieties have a very slight hint of the chemicals in C.
maternum. Humans have a highly discriminating palate, and have
always
selected sweeter, more pleasant fruit, and millennia of human
preference
may well have been responsible for the palatable fruit we have today.
In fact, the first commercial tamarillo varieties lacked sweetness,
had a tendency to acidity, and had dark orange flesh and darkest purple
seeds pulp. Today, most commercial varieties have red or pinkish red
skin,
but orange or yellow flesh, orange or yellow seed pulp, and are
(usually)
sweeter.
Today, tamarillos are produced commercially for export by only a few
countries - chiefly New Zealand. There is a small domestic market in
New
Zealand, Australia, India, and some South American countries. However,
no country is actively developing new varieties (unusually for a crop
plant,
there is also no germplasm collection - anywhere in the world), and it
is likely to remain a minor fruit in the supermarket, in
spite
of it's potential. It is not helped by having relatively poor storage
characteristics.
Altho' I have seen no data, it would be reasonable to assume that
tamarillos
would have a good vitamin A content, and may have the same kind of
health
beneficial red and yellow plant pigments that tomatoes have. Some
writers
describe tamarillos as having a 'very good' vitamin C content, which is
very likely; however, I have seen no figures. While it is likely to be
high in antioxidants - especially the more acid red seeded kinds - it
appears
not to have been investigated for antioxidant content.
Tangerine/MandarinCitrus
reticulata
Citrus as a genus are not represented in Africa - although there is
one obscure, very Citrus like member of the citrus family
present,
and that is Citropsis daweana. The Mozambique 'Cherry Orange'
is
a small tree with citrus smelling leaves, and small, probably edible
fruit
that grows in riverine valleys in Mozambique and Zimbabwe. So when we
radiated
to Myanmar (Burma), South East Asia, and southern China, the possible
origin
of the mandarin, we would have been meeting wild citrus not too
different
from Citropsis, except a bit larger and more edible. The wild
ancestral
form of the mandarin hasn't been found; either that or the mandarin is
ancestral to both the orange and mandarins.
Edibility is fairly widespread in the citrus as a group, with quite
a few of the 35 or so species being a potential food item. But the
mandarin
is one of the best. As with most citrus and other good things, the rise
of agricultural settlement and both land and sea trading between
Europe,
the
greater Mediterranean through South West and South Asia to China,
resulted
in the spread of the mandarin into all these areas. In time, the
mandarin
was spread to Spanish, Portuguese, and- eventually - British colonies.
The tangerine was introduced to Australia by the British colonizers in
the nineteenth century, and from Australia to New Zealand shortly
after.
Mandarins don't travel quite as well as oranges, but they can be
cool
stored to extend their availability, and the complex hybrids now being
produced have better storage and handling characteristics. Hybrids
include
tangelos (tangerine x grapefruit), tangors (tangerine x orange), and
tangtangelos
(tangerine x tangelo). Mandarin hybrids, in particular, look set to
become
a standard market fruit, and excellent nutritional value.
Tangerines are a good source of vitamin A - in fact, they rank
number
5 in the list of top sources from commercial fruit, with 920
International
Units per 100 grams. They are a very good source of vitamin C - one
fruit
provides almost half an s daily requirement.
Tangerines have natural plant chemicals ('phytochemicals') called
'monoterpenes'
in their skin that both protect against cells becoming cancerous, and
help fight existing cancers. At least, as studied in laboratory mice -
but there is no reason to think these chemicals wouldn't be active in
humans.
Unless they are certified as 'organically grown', commercial citrus may
have been dipped/sprayed with anti fungal chemicals to prevent storage
rots (they may also be dyed to heighten the color, and waxed
with
a vegetable derived wax to heighten the appearance). Therefore it is
advisable
to select only organic fruit to chew on the peel. It is unknown if the
tumor fighting chemicals survive heat and processing when marmalade is
made.
Watermelon Citrullus
lanatus
The watermelon is native to the Kalahari desert of Southern Africa.
One form of the fruit is bitter, due to the presence of a glucoside
called
'cucurbbitacin'. The other form lacks this bitter chemical, and is the
progenitor of all domesticated watermelons. Kalahari tribesmen grind
the
seed for bread, they dry the flesh, and eat the young fruit as a
vegetable.
The wild form is quite large, | |
