Fermented pearl millet: a product with enhanced bioactive compounds and DNA damage protection activity

摘要

Pearl millet cultivar PUSA-415 was fermented for a period of 10 days using Rhizopus azygosporus as a starter culture. Aqueous ethanol (50%) was used as extraction phase to extract bioactive constituents from Rhizopus azygosporus fermented millet (RFPM) and unfermented millet (UFPM) flours at 44.5 °C for 23 min. Extracts were evaluated for the presence of bioactive compounds, antioxidant potential, enzymatic activities and DNA damage protection activity (DDPA). Solid state fermentation significantly(p<0.05) enhanced the bioactive constituents with the highest values being observed on 10th day of fermentation. The ranges for different bioactive properties [Total phenolic content (TPC), Condensed tannin content (CTC)] were, TPC [6.6–21.8 mg gallic acid equivalent/g dry weight basis (mg GAE/g dwb), CTC (101.3–176.7 mg catechin equivalent/100 g dwb)] and enzymatic activities [α-amylase (61–201 IU /gds), β-Glucosidase (4–86 IU /gds) and xylanase (7–77 IU /gds)]. Maximum DDPA was observed in RFPMextract (10th day). Thin layer chromatography confirmed the presence of catechin, catechol and ascorbic acid in both UFPM and RFPM. HPLC also confirmed the presence of specific bioactive compounds viz. p-Coumaric acid, catechol, ascorbic acid and gallic acid in extracts studied.