试验以大豆分离蛋白为主要原料,对其与甘油制膜的成膜工艺进行研究。通过单因素试验考察大豆分离蛋白与甘油的比例、成膜pH值及其成膜温度对保鲜膜的各项性能-透水率、透光率、断裂应力、延伸率,及水溶性的影响。试验结果表明:随蛋白与甘油比例增大膜性能先达到最大然后下降。成膜温度与膜性能正相关。pH值必须远离6,但pH值高于9时膜性能没有显著提高颜色却显著变黄。综合分析得出最佳成膜大豆分离蛋白与甘油的比例为2.5∶1,pH值为8,温度为95℃。
In this study,the filming technology with raw material of soy protein isolated and glycerol was researched.By using single factor experiment,the effect of the ratio soybean protein isolated(SPI)to glycerol,film temperature and pH to the film properties were studied,including permeable rate,light transmittance,fracture stress,elongation and water-soluble of the film.The results showed that the film performance rose to its maximum and then declined with the increasing of the ratio SPI to glycerol and higher temperature contributed to the better performance of the film.Meanwhile,pH must stay away from6,but film properties non-significant increased when pH exceed9with the color of the film turning yellow greatly.The conclusion was that optimal conditions were SPI to glycerol for2.5:1,pH of8,95℃.