Fermented barley bran: An improvement in phenolic compounds and antioxidant properties

Abstract

Barley bran (BB), a by-product of the milling process, is rich source of bioactive compounds that have potential nutraceutical effect. Solid substrate fermentation (SSF) of BB was performed for 7 days Aspergillus oryzae (MTCC 3107). Soluble free phenolic compounds were extracted from nonfermented (NFBB) and fermented barley bran (FBB). SSF improved the bioactive compounds of BB as indicated by enhanced TPC (from 1.23 to 14.32 mg GAE/g). An increase in bioactive compounds significantly enhanced the antioxidant potential of BB. Further, more bioactive compounds in FBB than NFBB counterparts were confirmed using high-performance liquid chromatography (HPLC). NFBB showed ascorbic acid (20.44 µg/g), gallic acid (12.75 µg/g), and catechin (9.9 µg/g). FBB extract showed the presence of ascorbic acid (107.15 µg/g), gallic acid (405.5 µg/g), catechin (88.3 µg/g), vanillin (40.89 µg/g), and resorcinol (20.7 µg/g), respectively. The outcome of the present study may be helpful in designing BB-based functional food products with many health benefits. Practical applications Despite the beneficial advantages deriving from the consumption of BB, very little information in the literature deals with the fermentation of their by-products. Catechin and proanthocyanidins are among the polyphenol compounds contained in BB. The application of BB fermentation by Aspergillus oryzae could combine the nutrients and health benefits of both BB and A. oryzae. Therefore, FBB may be a useful procedure for enrichment of antioxidants in BB, considering the design of different functional foods and nutraceuticals.