Improvement of DNA damage protection and antioxidant activity of biotransformed pearl millet (Pennisetum glaucum) cultivar PUSA-415 using Aspergillus oryzae MTCC 3107

Solid-state fermentation of pearl millet cultivar PUSA-415 was carried out up to 10 days by employing Aspergillus oryzae MTCC 3107 as starter culture. Aspergillus fermented millet (AFM) and unfermented millet (UFM) grains were extracted with aqueous ethanol (50%) (1:20 w/v), at 44.5 °C for 45 min. Extracts of AFM and UFM were assessed for DNA damage protection activities employing Fenton's reagent and for the presence of bioactive compounds with antioxidant potential using TPC, DPPH, ABTS, FRAP, HFRSA, CUPRAC, TAC and RPA assays. Fermentation significantly modulated the bioactive compounds, antioxidant potential and DNA damage protection activity of PUSA-415. Maximum amount of extractable TPC (18.73 mg GAE/g dwb) found in 10th day AFM sample as compared to UFM (6.11 mg GAE/g dwb). Condensed tannin contents were enhanced from 54.67 in UFM to 127.33 mg CE/100 g dwb in AFM. HPLC results further confirmed modulation of phenolic compounds viz., catechol, benzoic acid, p-coumaric acid, cinnamic acid, gallic acid and ascorbic acid resulting in enhanced antioxidant activity of AFM. Ascorbic acid was additionally modulated in AFM. This study may be helpful in designing a suitable protocol for the development of fermentation based functional food products from pearl millet that could be promising in management of chronic diseases, oxidative stress and age related ailments.