The antioxidant capacities of 11 commercial and non-commercial samples of Euterpe oleracea Mart. (açaí) fruit pulp were studied with the total oxidant scavenging capacity assay in a modified and automated version against three reactive oxygen species. The antioxidant capacities of all purple açaí samples were found to be excellent against peroxyl radicals, good against peroxynitrite and poor against hydroxyl radicals compared with common European fruit and vegetable juices recently analysed. In all cases the correlation between sample concentration and antioxidant capacities was non-linear. The antioxidant capacities against all three reactive oxygen species of the fruit pulp from one white açaí variety were very low. The phenolic compounds in purple açaí fruit pulp were identified by high-performance liquid chromatography-mass spectrometry, and the two major anthocyanins, cyanidin-3-glucoside and cyanidin-3-rutinoside, were quantified by high-performance liquid chromatography-visible spectrometry. The contributions of the anthocyanins to the overall antioxidant capacities of the fruit were estimated to be only approximately 10%. Obviously, compounds not yet identified are responsible for the major part of the antioxidant capacities of the açaí fruit pulp.

The Amazon region comprises a plethora of fruit-bearing species of which a large number are still agriculturally unimportant. Because fruit consumption has been attributed to an enhanced physical well-being, interest in the knowledge of the chemical composition of underexplored exotic fruits has increased during recent years. This paper provides a comprehensive identification of the polyphenolic constituents of four underutilized fruits from the Amazon region by HPLC/DAD-ESI-MS(n). Araçá ( Psidium guineense ), jambolão ( Syzygium cumini ), muruci ( Byrsonima crassifolia ), and cutite ( Pouteria macrophylla ) turned out to be primarily good sources of hydrolyzable tannins and/or flavonols. Additionally, different flavanonols and proanthocyanidins were identified in some fruits. The antioxidant capacity was determined by using the total oxidant scavenging capacity (TOSC) assay. Cutite showed the highest antioxidant capacity followed by jambolão, araçá, and muruci.

The antioxidant capacity of methanol and ethanol seed extracts from Euterpe oleracea Mart. (açaí) against the reactive oxygen species (ROS) peroxyl radicals, peroxynitrite, and hydroxyl radicals was studied with the total oxidant scavenging capacity (TOSC) assay in a modified and automated version. Cold methanol digestion was the most efficient extraction method with respect to the antioxidant capacity. The extracts exhibit good antioxidant capacity against peroxyl radicals, similar to the capacity of the pulp. The antioxidant capacity against peroxynitrite and hydroxyl radicals is even higher. The main antioxidants identified by HPLC-MS and HPLC-CEAD are five different procyanidins (di- through pentamers); furthermore, protocatechuic acid and epicatechin were identified as minor compounds. Determination of TOSC values of HPLC seed extract fractions indicates that the procyanidins contribute substantially to the overall antioxidant capacity. In addition, however, other compounds that have not yet been identified are responsible for a large part of the observed antioxidant capacity.

The aromatic flora of the Amazon has been inventoried for 30 years. In this sense, were made over 500 field trips to collect over 2500 plants and to obtain more than 2000 essential oils and aroma concentrates, all of them submitted to GC and GC-MS. This work led to the creation of a database for the aromatic plants of the Amazon, which catalogs general information about 1250 specimens. The database has allowed the publication of the chemical composition of the oils and aromas of more than 350 species, associated with a larger number of chemical types. The essential oils of many species offer optimum conditions for economic exploitation and use in national and international market of fragrances, cosmetics, agricultural and household pesticides

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