PCL/PVA/Nisin复合抑菌膜的制备和性能表征

目的 以可生物降解材料为成膜基材，添加天然抗菌物质，制备出复合抑菌薄膜，研究其各项性能，以期用于猪肉的保鲜。方法 以聚己内酯(PCL)、聚乙烯醇(PVA)为成膜基材，添加乳酸链球菌素(Nisin)，通过流延法制备出复合抑菌膜。通过改变Nisin的含量，研究其对复合薄膜光学性能、力学性能及抑菌性能的影响。结果 Nisin质量为0.7 g的复合薄膜其保鲜效果最佳，可以明显抑制金黄色葡萄球菌的生长，贮藏7 d后pH值为6.8，保鲜时间是空白组的2倍;该含量的薄膜透光率为86.13%，拉伸强度为23.30 MPa。结论 Nisin质量为0.7 g的复合抑菌薄膜的综合性能最佳，该膜有较好的抑菌性能、光学性能和力学性能，可以延长猪肉的保鲜时间，对功能性包装膜的研究有一定的指导意义。

Preparation and Characterization of PCL/PVA/Nisin Composite Antibacterial Films

The work aims to prepare composite antibacterial film with biodegradable material as film-forming substrate added with natural antibacterial substances to study its properties, so as to keep pork fresh. First of all, the composite antibacterial membrane was prepared by tape casting with polycaprolactone (PCL) and polyvinyl alcohol (PVA) which contained nisin. Then, its effects on the optical properties, mechanical properties and antibacterial properties of the composite films were studied by changing the content of nisin. The best preservation effect of composite film with nisin content of 0.7 g was obtained, which could significantly inhibit the growth of staphylococcus aureus. After 7 days of storage, the pH value was 6.8, and the preservation time was 2 times of the blank group. The transmittance of the film was 86.13 %, and the tensile strength was 23.30 MPa. Therefore, the composite antibacterial film with nisin content of 0.7 g has the best comprehensive performance. The film has good antibacterial, optical and mechanical properties, which can prolong the fresh-keeping time of pork, and has certain guiding significance for study of functional packaging film.