Effect of duration of solid state fermentation by Aspergillus awamorinakazawa on antioxidant properties of wheat cultivars

Wheat grains from different cultivars (belonging to Triticum aestivum and Triticum durum spp.) were fermented with a fungal strain Aspergillus awamorinakazawa using solid state fermentation technique and studied for bioactive properties. The bioactive properties studied were total phenolic content (TPC), antioxidant activity (AOA), ABTS scavenging capacity, total flavonoids content (TFC), and metal chelating activity. It was found that TPC, AOA, ABTS, TFC and metal chelating were significantly (p < 0.05) increased after fermentation. TPC and metal chelating activities of flours from fermented wheat cultivars increased to maximum till 4th day of fermentation whereas AOA, ABTS radical scavenging activity and TFC showed the maximum values on 5th day of fermentation. Paired t-test values were calculated to study the effect of duration in terms of the number of days of fermentation (0 day compared with 2-6 days). Comparison revealed significant differences (p < 0.05 and 0.01) in t-values for various bioactive properties studied. TPC and DPPH radical scavenging activity of wheat cultivars were highly positively correlated (r = 0.984, p < 0.05). A positive correlation was also observed between TPC and ABTS radical scavenging activity (r = 0.808, p < 0.05). Type of wheat species did not result in variation in antioxidant properties. (C) 2016 Elsevier Ltd. All rights reserved.