大豆蛋白基明胶复合膜性能稳定性分析

Performance and Stability Analysis of SPI-Based Gelatin Composite Film

以大豆蛋白和明胶为主要原料,采用戊二醛溶液交联方式和戊二醛饱和蒸汽交联制备大豆蛋白基明胶复合膜,通过对两种交联方式制备的复合膜机械性能稳定性和降解性测定,比较分析戊二醛不同交联方式对复合膜机械性能稳定性、降解性及微观结构影响。结果表明,在3个月贮藏期内,戊二醛溶液交联改性、蒸汽交联改性处理复合膜拉伸强度稳定性提高了20.58%、38.51%,延伸率稳定性提高了31.71%、54.49%,水蒸气透过系数稳定性提高了31.74%、52.19%,透氧率稳定性提高了0.24%、18.01%,降解实验中降解速率分别为未经改性处理大豆蛋白基明胶复合膜>溶液交联改性处理复合膜>蒸汽交联改性处理复合膜。同时,蒸汽交联复合膜表面及拉伸断面形成结构致密的三维立体网络结构。因此,戊二醛蒸汽交联制备的大豆蛋白基明胶复合膜机械稳定性能及微观结构均优于戊二醛溶液交联改性处理复合膜。

Composite films were prepared from soy protein isolate (SPI) and gelatin by cross-linking with aqueous glutaraldehyde and saturated glutaraldehyde vapor, respectively. This work comparatively analyzed the effect of different cross-linking methods on the microstructure, degradability and mechanical properties of films by evaluating the mechanical properties and degradability of the two composite films. The results showed that during a three-month period of storage, thetensile strength stability of the composite films processed with aqueous glutaraldehyde and saturated glutaraldehyde vaporwas increased by 20.58% and 38.51%, extensibility stability by 31.71% and 54.49%, water vapor permeability coefficientstability by 31.74% and 52.19%, and oxygen permeability stability by 0.24% and 18.01%, respectively. The degradationrates of three different SPI-based composite films were in the decreasing order of native SPI-based composite film > aqueousglutaraldehyde cross-linking modified SPI film > saturated glutaraldehyde vapor cross-linking modified SPI film. In addition,the surface and tensile fracture cross-section of the third film were dense and smooth, forming a dense three-dimensional network structure. Therefore, saturated glutaraldehyde vapor cross-linking was a better method to modify SPI-gelatin composite film than aqueous glutaraldehyde cross-linking in terms of mechanical property stability and microstructure.