壳聚糖/木质素/ε-聚赖氨酸复合膜的制备及其保鲜效果研究

Preparation of chitosan/lignin/ε-polylysine composite film and its preservation effects

中文关键词:  保鲜  ε-聚赖氨酸  木质素  壳聚糖  沙糖桔  蓝莓

英文关键词:preservation  ε-polylysin  lignin  chitosan  Citrus reticulate ‘Shiyue Ju’  Vaccinium spp

中文摘要:

      目的 制备一种多功能壳聚糖基复合膜, 提高复合膜在水果保鲜中的应用价值。方法 本研究通过流延法制备了壳聚糖/木质素/ε-聚赖氨酸复合膜, 并探究其对沙糖橘和蓝莓采后保鲜效果的影响。结果 木质素的添加虽然使膜呈现棕黄色, 但其仍具有良好透明性、且赋予膜优异的耐水性和抗氧化性; 抑菌实验结果表明, 负载0.2% ε-聚赖氨酸的复合膜对金黄色葡萄球菌(Staphylococcus aureus, S. aureus)和大肠杆菌(Escherichia coli, E. coil)的抑菌率为100%。对沙糖橘和蓝莓的保鲜实验表明, 在优化复合膜组成的条件下(2.0%壳聚糖、0.023%木质素、0.2% ε-聚赖氨酸), 复合膜可有效延缓沙糖橘和蓝莓果实贮藏过程中的物理化学性质变化速率, 在常温贮藏12 d后, 相比于空白组(未经任何处理的果实), 复合膜处理的沙糖橘和蓝莓的腐烂率分别降低了22.22%和62.50%, 失重率减少了3.22%和3.67%, 而硬度提高了35.59%和2.02%。同时, 复合膜可有效维持沙糖橘和蓝莓中可溶性固形物、维生素C (vitamin C, VC)、可滴定酸等营养物质含量。结论 本研究所制备的壳聚糖/木质素/ε-聚赖氨酸复合膜有望替代化学保鲜剂应用在沙糖橘和蓝莓的保鲜中, 为新型绿色保鲜材料的开发提供参考。

英文摘要:

      Objective To prepare a multifunctional chitosan-based composite film and improve its application in fruit preservation. Methods A kind of chitosan/lignin/ε-polylysine composite film was fabricated, and its effects on the postharvest preservation of Citrus reticulate ‘Shiyue Ju’ and Vaccinium spp. were also investigated. Results The results showed that although the addition of lignin made the film brown, the good transparency, excellent water resistance and antioxidant property were also observed in the obtained film. Moreover, the results showed that the composite film loaded with 0.2% ε-polylysine exhibited 100% inhibition rate against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coil). The preservation experiment results indicated that, under the optimized film composition conditions (2.0% chitosan, 0.023% lignin, 0.2% ε-polylysine), the chitosan/lignin/ε-polylysine composite film could effectively delay the changes of physical and chemical properties during the fruits storage. After 12 days of storage at room temperature, compared with the blank groups (untreated Citrus reticulate ‘Shiyue Ju’ and Vaccinium spp.), the composite film-treated Citrus reticulate ‘Shiyue Ju’ and Vaccinium spp.’s rot rate decreased by 22.22% and 62.50%, the weight loss rate decreased by 3.22% and 3.67%, as well as the hardness of Citrus reticulate ‘Shiyue Ju’ increased by 35.59% and the hardness of Vaccinium spp. increased by 2.02%, respectively. At the same time, the composite film effectively maintained the content of soluble solids, vitamin C (VC), titratable acid and other nutrients in Citrus reticulate ‘Shiyue Ju’ and Vaccinium spp.. Conclusion The prepared chitosan/lignin/ε-polylysine composite film is expected to replace chemical preservatives in the preservation of oranges and blueberries, providing a reference for the development of novel green preservation materials.