研究了高压脉冲电场(PEF)处理和热处理对牛乳总抗氧化能力和过氧化值的影响。采用牛乳对DPPH自由基的清除率来评价其抗氧化能力,用改进的IDF分光光度法测定了牛乳的过氧化值。结果表明:新鲜牛乳对DPPH自由基的清除率为49.65%,无论是低温长时(60℃、30min),高温短时(75℃、15s)巴氏杀菌,还是PEF(30kV/cm、400μs)处理,牛乳清除DPPH自由基的能力都略有下降,而过氧化值都有所升高。

In this study,the antioxidant capacity and lipid peroxidation of bovine milk subjected to thermal and PEF processing were investigated. "Diphenyl Picryl Hydrazyl" (DPPH) assay was used to evaluate the radical-scavenging capacity of the milk,the peroxide value (POV) method was determined by the modified International Dairy Federation (IDF) Fe-oxidation-based spectrophotometric method. The results showed that the radical-scavenging capacity of fresh milk was 49.65%,and no matter whether the milk processed by PEF(30 kV/cm,400 μs) or thermal processing (60 ℃ for 30 min or 75 ℃ for 15 s),the antioxidant capacity was decreased and the primary oxidation value were increased.