Bioactive compounds and antioxidant capacity of grape pomace flours

Grape pomace is the main residue from juice and wine industries, and their derived products such as flours, can be a rich source of phenolic compounds and antioxidants. The overall objective of this study was to assess the phenolic compounds, antioxidant capacity, biogenic amines, and amino acids in flours obtained from grape pomace. Four cultivars ('Niagara Rosada', 'Bordo', 'BRS Violeta', and 'IAC 138-22 Máximo') were used, isolated or as blends, for juice production and from the resulting pomace, flours were produced. All flours assessed, independently of the cultivar or blend, showed valuable potential to addition in new products. The lowest levels of phenolic compounds and antioxidant capacity were observed in the flour produced entirely from cultivar 'Niagara Rosada'. However, when 'Niagara Rosada' was incorporated in blends with other cultivars, flours with increased levels of phenolic compounds and antioxidant capacity were obtained. The flour production gives a better destination for industrial waste, since these flours can be used for food, cosmetic, and pharmaceutical industries as additives or supplements to improve the antioxidant and bioactive content of their products. •Four grape cultivars were used to extract juice and produce grape pomace flours.•Grape blends resulted in flours with high amounts of bioactive compounds.•The main phenolics identified were anthocyanins, rutin, caffeic acid, and catechin.•Blends resulted in 'Niagara Rosada' flours with high bioactive compounds.•Production of grape pomace flours is a better destination for industrial waste.