天然保鲜剂对枇杷采后膜脂过氧化保护酶活性的影响

Effect of Natural Preservatives on Membrane Lipid Peroxidation Related Enzymes Activities in Pulp During Storage of Loquat Fruit

以‘解放钟’枇杷为试材,研究天然保鲜剂处理贮藏过程中枇杷果实膜脂过氧化及其相关保护酶的活性变化动态。结果表明:天然保鲜剂不仅能明显抑制果实贮藏过程中MDA含量的上升,延缓CAT活性下降,在贮藏前期不同程度的提高了膜脂保护酶SOD和POD的活性,中后期延缓SOD酶活性下降。壳聚糖对膜脂过氧化保护酶活性的调节作用优于水杨酸,从而延缓MDA生成。

Experiment was conducted with fruit of Jiefangzhong loquat cultivar collected from Sichuan province for studying the effect of natural preservatives on membrane lipid peroxidation and its related enzymes activities in pulp, especially the changes in activities of SOD, POD and CAT in loquat fruit treated by natural preservatives during fruit storage process, in order to find out the senescence mechanism of storage fruit. The results showed that natural preservatives could not only restrain MDA content, but also influenced protective enzymes activities in pulp during storage of loquat fruit. In comparison with control, CAT activities were delayed decreasing, and the activities of SOD and POD in pulp increased in varying degrees in the earlier stage of storage, and then they decreased gradually. However, POD activities increased rapidly in the later stage of storage, which related possibly with POD participating in lignification metabolism. Thus, it was suggested that natural preservatives raised the storage level of loquat fruit though activities of protective enzymes which decreased membrane lipid peroxidation. Furthermore, compared with salicylic acid, chitosan regulated better the activities of lipid peroxidation related enzymes to restrain MDA content.