PHENOLIC COMPOUNDS AND PHYSICAL–CHEMICAL PROPERTIES OF TROPICAL FRUIT WASTES

Waste resulting from the processing of tropical fruits such as umbu (Spondias tuberosa), siriguela (Spondias purpurea) and juçara (Euterpe edulis) can be used as a source of bioactive compounds and nutrients. Fruits acquired in a local market in Rio de Janeiro were depulped and their wastes were dried and crushed to obtain flours from siriguela seed (FSS), siriguela peel (FSP), umbu seed (FUS), umbu peel (FUP), umbu pulp refine cake (FUC) and juçara pulp refine cake (FJC). They were evaluated for total phenolic content (TPC); antioxidant capacity using the ABTS˙⁺, DPPH˙ and FRAP methods; physical–chemical properties; and mineral composition. The results were expressed in dry basis. For the TPC content, FSS, FSP, FUS, FUP, FUC and FJC presented values ​​of 249, 1492, 369, 1850, 1058 and 774 mg GAE/100 g, respectively. The antioxidant capacity by ABTS^•+, DPPH^• and FRAP showed that FUP had the highest antioxidant potential and FSS had the lowest. The lipid content for FSP, FUS, FUP and FUC was approximately 1%, while for FJC it was 10% and for FSS it was negligible. Ash content varied from 1 to 4% with emphasis on FSP​​. Finally, the FSS presented the highest values for Ca (239.7 mg/100 g), Cu (27.1 mg/100 g) and Mg (183.3 mg/100 g) while for K, the FSP sample showed the highest value (1403.9 mg/100 g). The values for Mn ranged from 0.3 to 13.7 mg/100 g. Therefore, the flours obtained from processing the waste of tropical fruits can be used as a source of bioactive compounds and nutrients in developing new products or as total or partial replacements for conventional flours in bakery products.