不同厚度PE袋对冷链物流过程中荔枝褐变的影响

The Effect of Different Thickness Polyethylene Bags on Litchi Browning during Cold Chain Logistics

本研究采用厚度为10、20、30μm的聚乙烯袋包装‘鸡嘴荔’荔枝,结合冰袋模拟物流包装,研究在当前冷链物流体系不完善情况下对荔枝果皮褐变、细胞膜透性、花青素代谢的影响。结果表明:在贮藏过程中通过对果皮褐变、适销果比率及果实色差分量变化分析发现20μm聚乙烯袋包装效果较好,其次是10μm厚度,最差是30μm。并且20μm厚度聚乙烯袋显著抑制细胞膜透性上升,这体现为贮藏期间果实组织更低的相对电导率(P<0.05)。进一步研究结果表明:聚乙烯袋(20μm)能通过抑制花青素生物合成中的关键酶苯丙氨酸解氨酶活性延缓花青素分解,并结合抑制多酚氧化酶和过氧化物酶活性延缓荔枝果皮褐变。综上,20μm聚乙烯袋相对于其它厚度可明显抑制荔枝褐变,有效保持果实品质,延长货架期。

This study used polyethylene bags with thicknesses of 10,20,and 30μm to package"Jizuili"litchi,combined with ice bags to simulate logistics packaging,to study the effect on litchi peel browning,cell membrane permeability and anthocyanin metabolism under the current imperfect cold chain logistics system,in order to explore simple and efficient litchi fresh-keeping logistics technology for actual production.The results revealed that 20μm polyethylene bags had better packaging effects,followed by 10μm thickness,and the worst was 30μm,by analyzing of pericarp browning,commercially acceptable rate and fruit color difference components during storage.And the 20μm thickness polyethylene bags distinctly inhibited the increase in membrane permeability,which was reflected in the lower relative electrical conductivity of the fruit during storage(P<0.05).Further research results indicated that the 20μm polyethylene bag delayed the decomposition of anthocyanin via inhibiting the activity increase of phenylalanine ammonia lyase,the key enzyme of anthocyanin biosynthesis,combined with inhibiting the activities of polyphenol oxidase and peroxidase to delay the browning of the litchi.In summary,compared to other thicknesses,20μm polyethylene bags can significantly inhibit litchi browning,effectively maintain fruit quality and extend shelf life.