Açaà Palm
) or
Euterpe is a genus of 25-30 species of
palms native to tropical
Central and
South America, from
Belize south to
Brazil and
Peru, growing mainly in floodplains and swamps. They are tall slender attractive palms growing to 15-30 m tall, with
pinnate leaves up to 3 m long. The
fruit, a small, round, black-purple
drupe similar in appearance and size to a
grape but with less pulp, is produced in branched panicles of 700 to 900 fruits. The fruit has a single large
seed about 7â€"10 mm in diameter.
The fruit is a globose
drupe, presenting flower residues, with a diameter varying between 1 and 2 cm and an average weight of 1.5 g. The
epicarp of the ripe fruits is a deep purple color, almost black, or green, depending on the kind of açaà and its maturity. The
mesocarp is pulpy and thin, with a consistent thickness of 1 mm or less. It surrounds the voluminous and hard
endocarp which contains a
seed with a diminutive
embryo and abundant
endosperm.
The genus is named after the
muse Euterpe of
Greek mythology. The vernacular name is also sometimes spelled
Assai Palm in English.
Harvesting and Uses
The extraction of the palm's heart (the soft inner growing tip) involves the inevitable death of the palm as its growing tip is removed, and it cannot recover. Some species are self suckering, not single stem, and produce multiple stems, sometimes up to 40 on one plant, so harvesting palm heart is not such an environmental problem as the original stock plant can live on. Given that harvesting is still a costly and labour intensive task, palm heart dishes are regarded as a delicacy more than a staple diet - palm's heart is sometimes called "Millionaire's Salad" due to the high price.
In northern Brazil, açaà is traditionally served in
cuias with
tapioca and sometimes
sugar. There, people drink it rather than eat it. Açaà has become a fad in southern Brazil, where it is consumed cold as
açaà na tigela ("açaà in the bowl") mixed with
guaraná syrup and served with slices of
banana and a small dish of
granola on the side to be added as desired. The juice and pulp of açaà fruits are frequently used in various beverages and smoothies, or marketed in North America blended with the more familiar flavor of grape juice.
Açaà fruits deteriorate rapidly after harvest, so outside its growing region it is generally only available as juice or frozen fruit pulp. The frozen fruit pulp is very deep purple and is reminiscent of a blueberry sorbet or ice cream with a hint of chocolate. It can also be eaten raw or used as a condiment, most commonly with shrimp or
manioc. It is considered one of the most nutritious fruits of the
Amazon, second perhaps to the
Brazil Nut. The leaves of the tree are often used in weaving and basket making.
Açaà is widely sold in
South America, where it can even be found in sodas. People often complain about finding it very difficult to find Açaà products. It is sold in juice form, as well as in various smoothies.
Nutritional Content
Açaà are used (particularly
Euterpe edulis) for their "
palm heart", which is eaten as a steamed dish, and (particularly
Euterpe oleracea) for their highly-prized fruits, which are rich in a diversity of macro- and micronutrients, as follows:
Macronutrients (gram amounts per 100 grams of fruit)
* calories, 247
* carbohydrates, 36
* proteins, 13
* fats, 48
* fibers, 34
* pH, 5.8
The above contents for fats and dietary fibers are exceptional among fruits, deserving further discussion.
Açaà pulp is particularly rich in
oleic acid (60% of total fats, an omega-9 fat),
palmitic acid (22%) and
linoleic acid (12%, an omega-6 fat), fat sources most commonly found in fruit seeds. β-sitosterol
beta-sitosterol, a
phytosterol that competes with
cholesterol for absorption, is also unusually rich (78% of total sterols).
Having nearly one-third of its mass as
dietary fiber, açaà is an exceptional source for this valuable macronutrient. A 100 gram serving of fruit pulp would provide all the recommended fiber needs for adults (30 grams per day). The fiber components are both insoluble (from skin) and soluble (pulp polysaccharides), although these have not been quantified to date.
MicronutrientsPreliminary analyses of açaà pulp show significant richness of vitamins and minerals. Vitamins B1, B2, B3, C and E are present.
Vitamin C content was measured at 17 mg per 100 grams (about the same as blueberries) and
vitamin E at 45 mg per 100 grams, is an extraordinary content for fruits.
Potassium content is high in açaà (932 mg per 100 grams). Other minerals isolated included sodium, calcium, magnesium, iron, copper, zinc, phosphorus and sulphur.
Sixteen
amino acids were found in açaà pulp, with especially high contents of
aspartic acid and
glutamic acid.
Antioxidant PhytochemicalsThe dense
pigmentation of açaà led to experimental studies of its
anthocyanins which had a total density of 44 mg per 100 grams of pulp.
Studies have been completed on the antioxidant strength of açaà expressed as the
oxygen radical absorbance capacity or
ORAC. Unfortunately, the sources of açaà and preparations for the ORAC determination (e.g., whole fruit, juice, extract or soluble powder) for reporting the results vary.
One ORAC study had açaà soluble powder from pulp at 5800 μmol TE per 100 grams whereas another analysis (by Brunswick Laboratories Inc., a third-party contract analysis firm) showed açaà ORAC at 53,600 μmol TE per 100 grams, the highest score yet reported for fruit. Further research and clarification of these antioxidant capacities are obviously needed.
Possible Health Benefits
Açaà has been called "the power berry" or "super berry" and even "the
Amazon's
Viagra" because of the numerous nutrients ascribed to it.
Açaà has even been used topically for its
astringent and antibacterial properties.
Due to its rich content of anthocyanin pigments (especially cyanidin-3-glucoside and cyanidin-3-rutinoside) that give it the characteristic deep purple color, açaà likely imparts important health benefits associated with consumption of antioxidant pigments, such as reduced risk or prevention of cancer, diabetes, chronic inflammation, heart and vascular disease, Alzheimer's disease and other types of neurodegeneration, high blood cholesterol, stroke, bacterial infections, urinary tract infections, age-related visual deterioration and premature aging.
Açaà itself does not contain
caffeine. However, in commercially available products the fruit is usually combined with
guaraná, which is a source of caffeine and/or structurally very similar
alkaloids.
Medical ResearchAs a relatively new discovery, açaà has appeared in the online database of the US National Library of Medicine â€"
PubMed -- only since 2004. Since then, just 6 reports are listed (August 2006).
Due to its deep pigmentation, orally-administered açaà has been tested as a contrast agent for magnetic resonance imaging of the gastrointestinal system.
Four studies analyzed the antioxidant properties of açaÃ, showing powerful effects from pulp and seeds against specific oxidizing agents like peroxyl radicals and
peroxynitrite. One finding of interest was that the total antioxidant capacity of açaà could be accounted in just 10% of the identified anthocyanins. This finding indicates that açaà is endowed with other, yet unidentified, antioxidant phytochemicals.
In 2006, a study performed at the University of Florida showed that açaà antioxidants could induce more rapid death (
apoptosis) of
leukemia cells in vitro.
This preliminary research indicates a possible anti-cancer effect of anthocyanins and other pigments, as shown for North American dark berries like the
blueberry and
black raspberry.
*
Pictures of Açaà palms trees and fruit from an article by
The Nature Conservancy.
*
University of Florida study confirms that açaà berries contain antioxidants that destroyed cultured human cancer cells*
English-language abstract of Brazilian study: "The descending order of antioxidant capacity was acerola> mango> strawberry> grapes> açaÃ> guava> mulberry> graviola> passion fruit> cupuaçu> pineapple."* [
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