Effects of roasting temperature in sliced almonds and sesame seeds on the antioxidative activities

Abstract

Effects of roasting temperature on antioxidative activities in sliced almonds and sesame seeds were investigated. The antioxidative activities in the ethyl acetate-methanol (E-M, 7:3), methanol (M) soluble browning fractions extracted from roasted sliced almonds and sesame seeds were determined by using two radical scavenging methods, DPPH radical and superoxide radical (NBT), and two lipid peroxidation methods, peroxide (thiocyanate) and cytotoxic 4-hydroxy-2-nonenal (HNE) formation by a specific ELISA procedure. The browning levels (O.D. at 420 nm) in each fraction were increased with increasing roasting temperature. The highest level of DPPH radical and superoxide radical scavenging effects, and the strongest inhibition of peroxide and HNE formation from linoleic acid, were obtained at the highest roasting temperatures in the E-M fractions rather than in M fractions from sliced almonds and sesame seeds, especially sesame. These results indicated that the browning ethyl acetate-methanol soluble components formed during roasting seeds possessed antioxidative effects.