In a separate study, Schauss et al. analyzed OptiAcai and identified anthocyanins (chiefly cyanidin 3-glucoside and cyanidin 3-rutinoside), proanthocyanidins (mainly polymers), and other flavonoids (i.e., homoorientin, orientin, isovitexin, scoparin, and taxifolin deoxyhexose, along with several unknown ones) as the primary phytochemical constituents. They also found oleic and palmitic acids to be the prevailing fatty acid components. Resveratrol was identified at trace levels, and 19 amino acids were found, comprising 7.59% of the total weight (J. Agric. Food Chem. 2006;54:8,598-603).
Nutritional Components
In a far-ranging study of açaí pulp culled in the Venezuelan Amazon from two harvests of the year 2005, investigators used spectrophotometric methods to determine the content of polyphenols, tannins, and anthocynanins. The study sought to characterize the polyphenolic content and antioxidant capacity of the fruit, along with other qualities, such as fatty acid content. Antioxidant capacity was analyzed through the 2,2-diphenyl-1-picrylhydrazyl method.
The researchers found that açaí has a high content of lipids, particularly oleic acid, as well as large amounts of protein, ash, and total dietary fiber. The antioxidant capacity was 88%. The investigators concluded that açaí confers significant nutritional value and contains antioxidant constituents such as polyphenols, tannins, and anthocyanins that may render the fruit ripe for industrialization (Arch. Latinoam. Nutr. 2007;57:94-8).
Researchers studying the antioxidant capacities of 11 commercial and noncommercial varieties of açaí fruit pulp against three reactive oxygen species found that all purple açaí samples were potent scavengers of peroxyl radicals, good against peroxynitrite, and poor against hydroxyl radicals, compared with recently studied common European fruit and vegetable juices. One white açaí species displayed low antioxidant capacity against all three reactive oxygen species. Anthocyanins were found to account for only about 10% of the overall antioxidant capacities of the fruit. The investigators concluded that as-yet unidentified constituents of the açaí fruit pulp appeared to be responsible for most of its antioxidant activity (Int. J. Food Sci. Nutr. 2005;56:53-64).
Seed Extracts
The same researchers, along with others, later assessed the antioxidant capacity of methanol and ethanol seed extracts from açaí against peroxyl radicals, peroxynitrite, and hydroxyl radicals. They found that the antioxidant activity of the seed extracts was similar to that of the pulp against peroxyl radicals, and was greater against peroxynitrite and hydroxyl radicals. They also determined that procyanidins contribute significantly to the overall antioxidant capacity of açaí, but as-yet unidentified compounds account for the majority of such activity (J. Agric. Food Chem. 2006;54:4,162-7).
In a recent study, Pacheco-Palencia et al. examined the absorption and antiproliferative effects of açaí pulp extracts and a polyphenolic-enriched oil derived from the fruit pulp of the açaí berry. Investigators ascertained the chemical composition, antioxidant activity, and polyphenolic absorption of phytochemical fractions in a Caco-2 monolayer, in addition to their cytotoxicity in a human colon cancer cell line (HT-29 adenocarcinoma cells).
In general, the study added to the relatively slim body of literature on the bioactive properties, chemical composition, and cellular absorption of açaí polyphenolics. The investigators found that polyphenolic mixtures from the açaí pulp and oil significantly inhibited cell proliferation, and that standardized extracts featured a preponderance of hydroxybenzoic acids, monomeric flavan-3-ols, and procyanidin dimers and trimers (J. Agric. Food Chem. 2008;56:3,593-600).
Phenolic Constituents
Later in 2008, Pacheco-Palencia and two of the same researchers identified for the first time the phenolic constituents in crude oil extracts of the açaí berry. Like the berry, the oil was found to contain high concentrations of phenolic acids (i.e., vanillic acid, syringic acid, p-hydroxybenzoic acid, protocatechuic acid, and ferulic acid), (+)-catechin, and several procyanidin oligomers. The researchers evaluated the thermal stability of the oil during short- and long-term storage for lipid oxidation and phenolic retention, in terms of the effects on antioxidant activity. They found that phenolic acids underwent a 16% loss at 20° or 30° C after 10 weeks of storage, and a 33% loss at 40° C. Procyanidin oligomers showed greater degradation: 23% at 20° C, 39% at 30° C, and 74% at 40° C, in both high- and low-phenolic açaí oils. Phenolic and antioxidant capacity decreased less than 10% during short-term (20 minutes) heating at 150° C and 170° C. The investigators concluded that the high phenolic composition of açaí oil renders it a potentially beneficial food and supplement option, as well as a promising cosmetic agent (J. Agric. Food Chem. 2008;56:4,631-6).
Conclusions
Açaí berry is a popular ingredient in beverages in Central and South America, and its popularity is steadily increasing in North America. It is highly touted for its antioxidant potency. The berry is available in oral supplement form and is advertised as a miraculous weight-loss elixir. It is not often found in topical preparations because of its blue color.