Feijoa (Acca sellowiana) peel flours: A source of dietary fibers and bioactive compounds

Feijoa (Acca sellowiana) is an important native fruit from Southern Brazil with potential beneficial health effects, whose peels are usually discarded. The main objectives of the study were to obtain and characterize both macro and microelements to explore the technological properties of feijoa peel flours (FPF) as an alternative source of bioactive ingredients. Feijoa fruits' peel were processed for the elaboration of two formulations of FPF, using two different sets of raw materials: only the mesocarp (FPF1) or with both the epicarp and mesocarp (FPF2). Both FPF were compared for their physicochemical content, monosaccharide composition, technological properties, bioactive compounds and in vitro antioxidant activity. Both FPF did not differ significantly in their ash, insoluble dietary fiber and phosphorus contents. Both FPF were rich in potassium and calcium. FPF2 showed higher values of acidity and pH, as well as of crude protein, total lipid, soluble dietary fiber and total dietary fiber contents than FPF1. Nevertheless, both FPF were classified as high in dietary fibers (45-48%). Predominant monosaccharides included glucose (34-43%) and xylose (33-37%), followed by uronic acid (9-12%). FPF1 showed higher water holding capacity than FPF2, however, they did not differ in their oil-holding capacity. Moreover, FPF were rich in total phenolics, total flavonoids and carotenoids, which showed comparable antioxidant capacity in vitro. Thus, this study confirmed the feasibility of using feijoa peel by-products as flours with potential application in sustainable and functional food products.