Effect of heat processing on the antioxidant properties of pearl millet (Pennisetum glaucum L.) cultivars

The effect of toasting (mild heat treatment) and cooking (severe heat treatment) on color and antioxidant properties of flours from pearl millet cultivars grown in India were investigated. The antioxidant properties studied were total phenolic content (TPC), total flavonoids content (TFC), antioxidant activity (AOA), metal chelating activity (MCA), and ABTS+ scavenging activity. Toasting resulted in increase in antioxidant properties (TPC, TFC, AOA, MCA, and ABTS+) as well as hunter a* and b* values. The hunter L* value was, however, decreased. Except for increase in hunter L* value and MCA all other antioxidant properties of flours studied showed a decrease after cooking as compared to flours from their native counterparts. Comparison of both the processing methods revealed that except for MCA, all other antioxidant properties of flours after toasting had significantly (p < 0.05) higher values than after cooking.