基于Nisin对琼脂/卡拉胶基复合膜的改性及应用评价

Modification and Application of Agar/Carrageenan Composite Film Based on Nisin

摘要:

为了防止微生物对蓝莓的侵害，改善传统石油基包装材料对环境造成的污染。研究采用琼脂、卡拉胶作为成膜基材，甘油作为增塑剂，以不同浓度的乳酸链球菌素（Nisin）作为抗菌剂来制备复合抗菌膜，对其理化指标及对蓝莓的保鲜效果进行综合评价。通过对抗菌膜的抑菌性、水溶性、光学性能、阻隔性能及机械性能进行全面分析得出以下结论，当复合抗菌膜中Nisin的质量分数为0.28%时，复合抗菌膜对金黄色葡萄球菌和李斯特菌的抑菌宽度为3.326 mm、1.812 mm，水溶性为45.01%，透光率为79.78%，抗拉强度为16.09 MPa，具有较好的应用特性。将含有0.28% Nisin的复合抗菌膜应用于蓝莓的保鲜研究中发现，在4 ℃和20 ℃的条件下，储藏期满时复合膜组的菌落数为4.20 lg cfu/g和2.46 lg cfu/g明显低于其他对照组，并且对减缓营养成分的流失有一定的作用。因此，试验制备的复合膜能有利于延长蓝莓的货架期。

Abstract:

A composite antibacterial film was prepared using agar and carrageenan as film-forming substrates, glycerol as the plasticizer, and different concentrations of the antibacterial agent nisin, and its physical and chemical indexes were comprehensively evaluated. This study was aimed at preventing microbial growth on blueberries and ameliorating the environmental pollution caused by traditional petroleum-based packaging materials. When the concentration of nisin in the compound antibacterial film was 0.28%, the antibacterial widths of Staphylococcus aureus and Listeria sp. were 3.326 and 1.812 mm, respectively; the water solubility, light transmittance, and tensile strength of the film were 45.01%, 79.78%, and 16.09 MPa, respectively. Therefore, the antibacterial film exhibited good water solubility and antibacterial, optical, barrier, and mechanical properties. Blueberries packaged with this antibacterial film at 4 and 20 ℃ had 4.20 and 2.46 lg cfu/g, respectively, of microbial content at the end of storage, and exhibited lower nutrient loss. Therefore, the composite film prepared for this test can help prolong the shelf life of blueberries.