大豆分离蛋白-壳聚糖可食用性抗菌膜的制备与性能评价

Preparation and performance evaluation of soybean protein isolate-chitosan edible antibacterial film

以大豆分离蛋白(SPI)为载体,加入抗菌剂壳聚糖(CS),采用溶液浇铸法制备一种绿色环保可食抗菌SPI-CS复合膜,研究SPI与CS不同质量比对复合膜机械性能、阻隔性能、抑菌性能、抗氧化性能以及物质释放性能的影响。结果表明:随着复合膜中CS含量增加,SPI与CS分子间作用力逐渐增强,其透光率、拉伸强度、水蒸气透过率、水接触角、抗氧化性、抑菌性逐渐增大;由于亲水性基团的减少,断裂延伸率、水溶性和释放率逐渐减小。当SPI与CS质量比值为1∶2时,复合膜有较好的综合性能,其拉伸强度为32.55 MPa,断裂延伸率为31.38%,水蒸气透过率为2.43×10^(10)g·mm·m^(-2)·s^(-1)·pa^(-1),水溶性为30.8%,接触角为81.82°,DPPH·清除率为51.4%,CS释放率为16.19%。此外,SPI-CS复合膜对食物病原菌有良好的抑菌效果,对于细菌敏感性为鼠伤寒沙门氏菌>金黄色葡萄球菌>大肠埃希氏菌。

An environment-friendly and edible antimicrobial composite film based on soybean protein isolate(SPI)containing various mass fraction of chitosan(CS)was prepared by solution-casting method.The effects of different mass ratios of SPI and CS on the composite film’s mechanical properties,barrier properties,antibacterial properties,antioxidant properties and substance release properties were investigated.The results indicated that the intermolecular force between SPI and CS gradually increased with the addition of CS,along with their light transmission,tensile strength,water vapor transmission,water contact angle,antioxidant and antibacterial properties.As a consequence of decreasing hydrophilic groups,the elongation at break,water solubility and release rate decreased.The composite film exhibited good properties when the mass ratio of SPI to CS was 1∶2,including tensile strength of 32.55 MPa,elongation at break of 31.38%,water vapor permeability of 2.43×10^(10)g·mm·m^(-2)·s^(-1)·pa^(-1),water solubility of 30.8%,contact angle of 81.82°,DPPH·scavenging of 51.4%and CS release rate of 16.19%.Furthermore,the films exhibited significant antibacterial effects against both Gram-negative and Gram-positive bacteria.The sensitive level to bacteria was Salmonella typhimurium>Staphylococcus aureus>E.coli.