本研究以聚乳酸（PLA）和乙基纤维素（EC）为壁材，茶多酚（TP）、ε-聚赖氨酸盐酸盐（ε-PL）和TP/ε-PL混合物为芯材使用喷雾干燥法制备了具有缓释性能的微胶囊。以美国红鱼鱼片为保鲜对象，研究了保鲜剂及其微胶囊的保鲜性能。结果显示，经保鲜剂及其微胶囊处理后，鱼片中微生物的生长受到抑制，pH的变化速度减缓，脂肪的氧化和蛋白质的分解速度降低，鱼片感官评分和质构指标下降速度减慢。至第11 d起，经包埋保鲜剂的微胶囊处理后，鱼片的菌落总数低于同期未包埋保鲜剂处理样品0.20~0.37 lg(cfu/g)。TP/ε-PL复合保鲜剂及其微胶囊处理鱼片的菌落总数低于同期单一保鲜剂及其微胶囊处理样品0.17~1.09 lg(cfu/g)。因此，保鲜剂微胶囊化具有长效抑菌性，TP和ε-PL复合具有协同增效作用，保鲜性能更优，可延长鱼片的货架期3~5 d。

In this study, microcapsules with sustained release properties were prepared by spray drying using polylactic acid (PLA) and ethyl cellulose (EC) as the wall materials, and tea polyphenols (TP), ε-polylysine hydrochloride (ε-PL) or TP/ε-PL mixture as the core substance(s). Using Sciaennops ocellatus fillets as the preservation objects, the preservation performance of the preservatives and their derived microcapsules were studied. The results showed that after the treatment with the preservatives and microcapsules, the growth of microorganisms in the fish fillets was inhibited, with the changing rate of pH being slowed down, the rates of fat oxidation and protein decomposition decreasing, and the decreasing rates of sensory score and texture index ranking for the fish fillets being reduced. From the 11th day, the total number of colonies of the fish fillets treated with microencapsulated preservatives was lower than that for those treated with unencapsulated preservatives in the same period (by 0.20 to 0.37 lg(cfu/g). The treatment with the TP/ε-PL composite preservative and its derived microcapsules led to a decrease of 0.17~1.09 lg(cfu/g) in the total number of colonies of the fish fillets, compared with the treatment with a single preservative and its derived microcapsules in the same period. Therefore, the microencapsulation of preservatives had a long-lasting antibacterial activity, and the combination of TP and ε-PL exhibited a synergistic effect and led to a greater preservative effect (which extended the shelf life of fish fillets by 3~5 days).

国家重点研发计划项目（2016YFD0400805）；国家自然科学基金资助项目（31371858）