ANTIOXIDANT ACTIVITY OF DURUM-WHEAT BRAN

Freeze-dried extract from durum wheat bran exhibited stronger antioxidant activity than extracts from other milling fractions. At 9 h under active oxygen method (AOM) conditions, peroxide value (PV) determinations showed that oil with the bran extract had a PV of 38.0 Mequiv/kg while the control oil had a PV of 129.0 Mequiv/kg. Extracts from the bran fractions of six durum wheat varieties had similar antioxidant activities in soy oil (PV 37.6-42.0 Mequiv/kg). However,Tenox butylated hydroxyanisole-butylated hydroxytoluene (BHA-BHT) mixture and Rosemary-AR were significantly stronger antioxidants (P < 0.005) than the extract from durum wheat bran at all the levels studied. High-performance liquid chromatographic and thin-layer chromatographic analyses of the durum wheat bran extract revealed the presence of protocatechuic, p-hydroxybenzoic, gentisic, caffeic, vanillic, chlorogenic, syringic, p-coumaric, and ferulic acids. Among the identified free phenolics, ferulic, vanillic, and p-coumaric acids were present in the highest amounts. The phenolic acids also appear to be partially responsible for the antioxidant activity of the extract.