激光微孔保鲜袋包装对荔枝采后果皮褐变及活性氧代谢的影响

Research on the Relationship Between Laser Microporous Film Packaging Control Postharvest Pericarp Browning and Reactive Oxygen Metabolism in Litchi Fruit

【目的】荔枝果实采后极易发生果皮褐变,严重降低其商品价值。前期研究表明激光微孔保鲜袋(Laser Mmicroporous Film,LMF)包装可有效控制荔枝果实采后果皮褐变的发生,故进一步研究LMF包装对荔枝采后果皮活性氧代谢的影响,以期阐明LMF包装如何通过影响荔枝果实采后果皮活性氧代谢进而延缓果皮褐变,为将LMF包装应用于荔枝果实采后褐变控制提供理论依据。【方法】以‘岵山晚荔’荔枝果实为试材,分别用LMF和聚乙烯薄膜袋(对照)包装荔枝果实,置于25℃恒温箱中,在贮藏第0、2、4、6、8 d测定荔枝果皮的活性氧代谢相关指标。【结果】与聚乙烯袋包装相比,LMF包装能使荔枝果实保持较低的褐变指数,降低果皮超氧阴离子(O2-.)产生速率和减少果皮丙二醛(MDA)的积累,维持较高的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性,保持较高的抗坏血酸(AsA)和谷胱甘肽(GSH)含量,以及较高的果皮1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除能力和还原力。【结论】LMF包装能使采后荔枝果实保持较高的活性氧清除能力,从而减少活性氧的大量积累,降低果皮膜脂过氧化损伤,从而抑制荔枝果实褐变,延缓荔枝果实品质的下降。

【Objective】Litchi fruit is prone to browning after harvest,which seriously reduces its commercial value.Previous studies have shown that laser microporous film(LMF)packaging has effectively controlled the occurrence of postharvest pericarp browning of litchi fruit.Therefore,further studies have been conducted on the effects of LMF packaging on postharvest pericarp active oxygen metabolism of litchi fruit.In order to elucidate how LMF packaging can delay the browning of litchi fruit by affecting the active oxygen metabolism of litchi fruit,and provide a theoretical basis for the application of LMF packaging to control the browning of postharvest litchi fruit.【Method】In this study,the litchi fruits of‘Hushanwanli'were packaged with LMF and polyethylene bags(Control),respectively,and placed in an incubator at 25℃.Active oxygen metabolism related indexes of litchi pericarp were determined at 0,2,4,6 and 8 days of storage.【Result】Compared to polyethylene bag packaging,LMF packaging could effectively prevent pericarp browning of litchi fruit,reduce superoxide anion(O2-.)production,and decrease malondialdehyde(MDA)content in the pericarp.It also maintained the higher activities of superoxide dismutase(SOD),catalase(CAT),and ascorbate peroxidase(APX),as well as higher levels of ascorbic acid(AsA)and glutathione(GSH)in the pericarp of litchi fruit.Furthermore,LMF packaging preserved higher levels of 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical scavenging ability and reducing power in the litchi pericarp.【Conclusion】Packaging with LMF could maintain higher antioxidant capacity of postharvest litchi fruits,thereby reducing the accumulation of reactive oxygen species and decreasing lipid peroxidation damage in the fruit pericarp.This inhibited browning of litchi fruits and delayed the decline in fruit quality.