Abstract:

The inhibition effect of antioxidants on whey protein isolate (WPI) oxidation caused by reactive oxygen species was investigated. Experiments were divided into three groups designated as control group without antioxidants, α-tocopherol group with and BHA group. Protein oxidation was evaluated by the change of carbonyl group, total sulfydryl group, bityrosine, hydrophobicity and SDS-PAGE after oxidation for 1, 5 or 12 h. Results indicated that protein oxidation significantly increased the content of carbonyl group, dityrosine and hydrophobicity of WPI (P ＜ 0.05). However, compared with control group, WPI with α-tocopherol or BHA after 5 h oxidation exhibited 35.11% and 50.15% decrease in carbonyl group and 27.73% and 38.82% increase in sulfydryl group, respectively. Therefore, the addition of antioxidants can result in the decrease in polymerization of proteins to inhibit the oxidation of WPI.

Key words: antioxidation, whey proteins isolate (WPI), protein oxidation, hydroxyl free radical