Antioxidant activity of whey in a salmon oil emulsion

The antioxidant capabilities of whey in a Tween 20(TM)-stabilized salmon emulsion were investigated. Whey fractions inhibited formation of thiobarbituric acid reactive substances (TBARS) and lipid peroxides in a 10 % salmon oil emulsion ill the order of whey > high-molecular-weight (HMW) fraction > low-molecular-weight fraction, Heating the HMW fraction exposed sulfhydryls, with optimum exposure at 80 degreesC. Heating the HMW fraction above 80 degreesC increased antioxidant activity. The HMW fraction of whey (80 degreesC) alone, alpha -tocopherol (40 ppm) alone, and their combination inhibited TEARS 59, 19 and 86%, respectively, at 21 d of storage. Sulfhydryls oxidized before alpha -tocopherol, suggesting that sulfhydryls are the primary antioxidant, Results indicate that whey proteins could be useful antioxidants in food emulsions.