蛋壳膜酶解肽对大豆蛋白包装膜抑菌、抗氧化性能的影响

Effect of Eggshell Membrane Enzymatic Hydrolysate on Antibacterial and Antioxidant Properties of Soybean Protein Packaging Film

蛋白膜具有良好的机械性能,是一种环境友好的可食性包装材料,但其抑菌、抗氧化性能等包装活性较差,限制其在某些易腐食品包装领域的广泛应用。本研究以大豆分离蛋白(soy protein isolate,SPI)为成膜基质,加入不同添加量的蛋壳膜(eggshell membrane,ESM)酶解肽制备复合膜,以机械性能、阻隔性能、光学性能、接触角、自由基清除率及抑菌圈直径为指标,考察复合膜的物理和功能特性,并结合傅里叶变换红外光谱、X射线衍射分析和扫描电子显微镜等手段对其进行结构表征,探究ESM酶解肽添加量对复合膜性能与结构的影响及作用机理。结果表明,与纯SPI膜相比,添加4 g/100 g ESM酶解肽复合膜的厚度、拉伸强度、断裂伸长率和接触角分别增加了115.38%、100.78%、57.87%和110.42%,水蒸气透过率和氧气透过率分别降低了63.54%和84.07%,且抗氧化与抑菌性随ESM酶解肽添加量增加而大幅提升,通过结构表征分析结果可知,复合膜表面结构因分子间生成氢键而形成致密的网络结构,且SPI与ESM酶解肽相容性良好。结果可为易腐食品的活性包装、蛋品副产物综合利用方面提供理论基础和技术支持。

Soybean protein film has good mechanical properties and is an environment-friendly edible packaging material.However, its antibacterial and antioxidant properties are poor, which limits its application to perishable food packaging.In this study, composite films were prepared from soy protein isolate(SPI) as the film-forming substrate with different amounts of an enzymatic hydrolysate of eggshell membrane(ESM) added, and their physical and functional properties were investigated such as mechanical, barrier and optical properties, contact angle, free radical scavenging capacity and antibacterial zone diameter. Fourier transform infrared(FTIR) spectroscopy, X-ray diffraction(XRD) and scanning electron microscopy(SEM) were used to characterize their structures. Finally, we discussed the effect and mechanism of ESM hydrolysate concentration on the structure and properties of composite films. The results showed that the thickness, tensile strength, elongation at break and contact angle of the composite film with 4 g/100 g enzymatic hydrolysate increased by 115.38%, 100.78%, 57.87% and 110.42% respectively compared with pure SPI film, and the water vapor permeability(WVP)and oxygen permeability(OP) decreased by 63.54% and 84.07%, respectively. The antioxidant and antibacterial properties of composite films increased with increasing hydrolysate concentration, and the surface exhibited a dense network structure,due to the formation of intermolecular hydrogen bonds, and good compatibility between SPI and ESM hydrolysate. The results of this study will provide a theoretical basis and technical support for designing active packaging for perishable foods and comprehensive utilization of egg by-products.