大豆分离蛋白可食膜的生产工艺及性能表征

选用大豆分离蛋白为原料，以卡拉胶添加量、甘油添加量、pH值和料液比为影响因素做正交试验，得到大豆分离蛋白膜的最佳配方。结果表明：以大豆分离蛋白为基数，卡拉胶添加量8%，甘油0.4mL/g，料液比1:15(g/mL)，调节pH值到7.0时大豆分离蛋白膜的性能最佳。最佳工艺条件下测得大豆分离蛋白膜的水溶性为32.7%，水蒸气透过系数为2.348g ·mm/(m2 ·h ·kPa)，抗拉强度为7.192MPa，断裂伸长率为128.1%。最佳膜的电镜分析结果：大豆分离蛋白分子在膜上的分布较均匀，一定程度上影响了膜的阻水性能，可以采用均质等方法加以改进，使大豆分离蛋白分子更好的分散在膜的表面，从而使膜具有更强的阻水性。

Preparation and Performance Characterization of Soy Protein Isolate Edible Film

Soy protein isolate(SPI) was used as the raw material and orthogonal tests were conducted to explore the optimal formula of SPI edible film through evaluating carrageenan addition amount,glycerol addition amount,pH and material-liquid ratio.The results showed that the optimal formula of SPI edible film was achieved under the conditions with carrageenan addition amount of 8%,glycerol addition amount of 0.4 mL/g on the basis of SPI,material-liquid ratio of 1:15(g/mL) and pH of 7.0.Under the optimal process conditions,the content of water-soluble SPI was 32.7%,water vapor permeability was 2.348 g·mm/(m2·h·kPa),tensile strength was 7.192 MPa,and breaking elongation rate was 128.1%.The electron microscopic results revealed the best film to have uniformed distribution of SPI in the film.The film had water-blocking capacity to some extents.Therefore,this method can improve the homogeneity to result in better dispersion of SPI in the film surface and enhancement of water-blocking capacity of the film.