低密度聚乙烯内衬袋对‘富士’苹果贮藏品质及虎皮病的影响

Effect of Low Density Polyethylene Inner Liner Bags on Storage Quality and Superficial Scald of‘Fuji’Apple

为研究新型低密度聚乙烯(LDPE)内衬袋对‘富士’苹果贮藏品质和虎皮病发病情况的影响,以生产上常用的聚乙烯(PE)打孔内衬袋为对照,对比新型LDPE微孔内衬袋在(0±0.5)℃冷藏条件下对‘富士’苹果的影响。定期监测内衬袋微环境中的CO_(2)、O_(2)体积分数和乙烯含量,同时对果实品质指标及挥发性物质、酚类物质含量进行测定,并调查贮藏期间虎皮病发病情况。结果表明:与PE打孔内衬袋相比,LDPE内衬袋可以形成低氧高二氧化碳的微环境;苹果最早在冷藏150 d时出现虎皮病,LDPE组果实虎皮病发病指数低于PE组,货架7 d时LDPE组果实虎皮病发病率和发病指数均小于PE组;贮藏150 d时LDPE组果实失重率比PE组降低了0.48个百分点;LDPE内衬袋包装可提高果实的呼吸速率和乙烯释放速率,且对果实的质地、内在品质无不良影响;其还可促进苹果水杨酸、根皮苷等酚类物质积累;促进贮藏后期果皮挥发性物质中醇类含量的上升,延缓酯类尤其是丁酸戊酯、2-甲基丙酸丁酯和2-甲基乙酸丁酯含量的降低。综上,LDPE微孔内衬袋保鲜效果优于传统的PE打孔内衬袋,适合作为传统内衬袋的升级替换产品。研究结果可为企业规模化应用LDPE微孔内衬袋提供理论依据。

In order to study the effects of new type of low density polyethylene(LDPE)inner liner bags on the storage quality and the incidence of superficial scald of‘Fuji’apple,the effect of new type of LDPE micropore liner bag on‘Fuji’apple at(0±0.5)℃was compared to the commonly used perforated liner polyethylene(PE)bags in production.The concentrations of CO_(2),O_(2) and ethylene in the microenvironment of the liner bag were regularly monitored.At the same time,the fruit quality index,volatile substances and phenolic substances contents were detected,and the incidence of superficial scald during storage was investigated.The results showed that:compared with PE perforated liner bag,LDPE liner bag could create a microenvironment with low oxygen and high carbon dioxide.The earliest onset of superficial scald occurred on the 150th day during cold storage,and the incidence index of superficial scald in the LDPE group was lower than that in the PE group,and both the incidence rate and incidence index of superficial scald in the LDPE group were lower than that in the PE group on the 7th day of shelf life.After the 150 days of storage,the fruit weight loss rate of the LDPE group decreased by 0.48 percentage points compared with the PE group.The LDPE bag could improve the respiration rate and ethylene release rate of the fruit,and had no adverse effects on the texture and intrinsic quality of fruits,and could also promote the accumulation of the phenolic substances such as salicylic acid,phloridzin,benzoic acid,and promoted the increase of alcohol content in volatile substances in pericarp in the late storage period,and delayed the decrease of esters,especially amyl butyrate,butyl 2-methylpropionate and butyl 2-methylacetate contents.In conclusion,the LDPE microporous liner bag had better fresh-keeping effect than the traditional PE perforated liner bag,which was suitable as an upgrade substitute for traditional liner bag.The results can provide a theoretical basis for enterprise-scale application of the LDPE microporous liner bags.