Tong L M, Sasaki S, McClements D J, Decker E A
Chenoweth Laboratory, Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, USA.
J Agric Food Chem. 2000 May;48(5):1473-8. doi: 10.1021/jf991342v.
The antioxidant mechanisms of whey proteins in a Tween 20-stabilized salmon oil-in-water emulsion were investigated. The antioxidant activity of the high molecular weight (HMW) fraction of whey from pasteurized milk was found to increase with concentration, as determined by its ability to inhibit TBARS and lipid peroxide formation. The ability of sulfhydryl-blocked whey to inhibit TBARS formation was reduced 60% compared to the HMW fraction alone at 7 days of storage. HMW fraction was able to scavenge peroxyl radicals, with scavenging decreasing approximately 20% when sulfhydryls were blocked. HMW fraction was able to chelate iron away from the surface of negatively charged BSA-stabilized emulsion droplets, indicating that the whey proteins were able to chelate iron. A better understanding of the mechanisms by which whey proteins inhibit lipid oxidation could increase the use of whey proteins as food antioxidants.
研究了乳清蛋白在吐温20稳定的水包油型鲑鱼油乳液中的抗氧化机制。通过其抑制硫代巴比妥酸反应物（TBARS）和脂质过氧化物形成的能力测定，发现巴氏杀菌乳清中高分子量（HMW）部分的抗氧化活性随浓度增加而增强。在储存7天时，与单独的HMW部分相比，巯基封闭的乳清抑制TBARS形成的能力降低了60%。HMW部分能够清除过氧自由基，当巯基被封闭时，清除率降低约20%。HMW部分能够从带负电荷的牛血清白蛋白（BSA）稳定的乳液滴表面螯合铁，表明乳清蛋白能够螯合铁。更好地理解乳清蛋白抑制脂质氧化的机制可以增加乳清蛋白作为食品抗氧化剂的应用。
