Valorization of Euterpe edulis Mart. agroindustrial residues (pomace and seeds) as sources of unconventional starch and bioactive compounds

Abstract

Juçara fruit pomace is one of the most abundant byproducts of the pulp-making process, generally discarded despite their attractive nutritional content. In this sense, this study aimed to investigate the potential of juçara fruit pomace as an alternative source of starch and natural dyes. Starch extracted from juçara seed (JS) was characterized in approximate composition, crystallinity, thermal profile, morphology, and equilibrium moisture data. Total phenolic content, anthocyanins content, and in vitro antioxidant capacity were assessed for the juçara seedless pomace (JSP). JSP is rich in monomeric anthocyanins (7.19 to 7.23 mg cyanidin 3-O-glycoside/g dry matter [dm]), presents high antioxidant potential, elevated dietary fibers (72.7% dm), considerable amount of lipids (12.8% dm), low protein content, and ash traces. JS is a rich carbon source (76.91% fibers [dm]; 12.21% amylaceous reserve). Being high in carbohydrates, mainly starch, it can be classified as high starch content flour (juçara seed starch-flour [JSS-F]). JSS-F presented B-type crystallinity and conventional starch-like thermal stability. JSS-F exhibited type III sorption isotherm behavior and the Gugghenheim-Anderson-DeBoer model adequately represented the moisture equilibrium data. As a nutritive source of bioactive compounds and starch, juçara pomace should be regarded as a coproduct to be explored as an alternative natural ingredient to food, pharmaceutical, and chemical industries. PRACTICAL APPLICATION: Juçara agroindustrial residues (pomace and seeds) are a promising source of antioxidants and unconventional starch, which are usually discarded after depulping, representing approximately 74% of the fruits. Juçara pomace can be used to produce flour with marketing potential due to their functional properties and nutritional value. This flour can be incorporated directly into formulations or be used in extraction processes to obtain components of interest, for example, anthocyanins, to be used as a natural food dye. Starch can be extracted from juçara seeds, presenting adequate technological properties for partial replacement of conventional starches.

Keywords: amylaceous source; anthocyanins; antioxidant capacity; juçara; sorption isotherm.