乳清蛋白成膜条件及其应用

以乳清蛋白(WPC)为基质,研究不同成膜方法对乳清蛋白膜性能的影响以及应用特性。结果表明,物理法的最佳成膜工艺条件为pH 8.0,超声功率240 W,90℃热处理;化学法的条件为添加增塑剂甘油4.0%、还原剂L-半胱氨酸0.10%和交联剂阿魏酸0.20%;酶法的条件为谷氨酰胺转胺酶(TG酶)加酶量20 U/g蛋白,50℃酶解90 min。在最佳成膜工艺条件下,乳清蛋白膜机械性能和阻隔性能均显著提高。综合评价圣女果失重率、抗坏血酸含量和感官评定等指标,乳清蛋白膜对圣女果的涂膜保藏效果依次为:酶法>化学法>物理法,且3种方法均优于不涂膜对照组。

Film Forming Conditions of Whey Protein and Its Application

The film based on whey protein(WPC),the effects of different film-forming methods on the properties and application characteristics of the film were studied.The results showed that the best process condition of film formation by physical method was pH 8.0,ultrasonic power 240 W,90℃heat treatment;the chemical method was to add 4.0%glycerine as plasticizer,0.10%L-cysteine as reducer and 0.20%ferulic acid as cross-linking agent;enzymatic method was that the amount of transglutaminase(TG)was 20 u/g protein,enzymatic hydrolysis at 50℃for 90 min.At the optimum reaction condition,the mechanical properties and barrier properties of whey protein films have been improved to a certain extent.By measuring the weight loss rate,ascorbic acid content and sensory evaluation of virgin fruit,the preservation effect of whey protein film on cherry tomatoes was:enzymatic method>chemical method>physical method,and the three methods were better than the control group without coating.