大豆分离蛋白基复合精油可食膜的制备及表征

Construction and Physicochemical Properties of Soy Protein Isolate-Composite Essential Oil Film

为提高大豆分离蛋白基可食膜的性能,本研究首先选用表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)对大豆分离蛋白(SPI)进行改性处理,然后将百里香-肉桂复合精油添加到可食膜中,研究了羧甲基壳聚糖(carboxymethyl chitosan,CMCS)的不同添加比例及不同pH对可食膜理化性质的影响,以期得到性能最优的蛋白膜。通过测定可食膜的结构及功能特性,探讨了EGCG改性、SPI与CMCS的复合比以及溶液体系pH影响膜性能的规律及其在鲜切苹果保鲜中的应用。结果表明,与单一蛋白膜相比,添加EGCG的薄膜抗氧化活性显著提高,添加CMCS后,可食膜的性能得到提升;用EGCG改性后的SPI与CMCS复合后在pH=7条件下制备的薄膜性能最优,该复合膜对鲜切苹果具有良好的保鲜效果。本研究为性能良好的抗氧化可食膜材料的开发提供了一定的参考。

In order to improve the properties of soy protein isolate-based edible films,epigallocatechin gallate(EGCG)was selected to modify SPI first,then the thyme-cinnamon composite essential oil was added to the edible film.Different pH conditions and different addition ratio of SPI and carboxymethyl chitosan(CMCS)were investigated to figure out the effect of CMCS on edible film’s physical and chemical properties to obtain the protein film with the best performance.By measuring the structural and functional characteristics of the edible film,the effects of modification of SPI,the composite ratio of SPI and CMCS and the pH of the solution system on the film performance and their applications in fresh-cut apple preservation were discussed.Results showed that the antioxidant activity of films supplemented with EGCG was significantly improved compared with protein films,and the performance of edible films was improved with the addition of CMCS.The optimal performance of the films was obtained at pH=7 after the addition of EGCG and CMCS,which significantly improved antioxidant activity and preservation of fresh-cut apple.This study provided a certain reference for the development of antioxidant edible film materials with good properties.