乙烯利对1-MCP处理南果梨冷藏后香气及香气合成过程中关键酶活的影响  

Effect of Different Concentrations of Ethephon on Aroma and Key Enzymes Related to Aroma Formation in 1-MCP-Treated Nanguo Pear after Refrigerated Storage

作　　者：张丽萍[1] 纪淑娟[1] 

机构地区：[1]沈阳农业大学食品学院,辽宁沈阳110161

出　　处：《食品科学》2013年第10期294-298,共5页Food Science

基　　金："十二五"国家科技支撑计划项目(2012BAD38B07);国家农业科技成果转化资金项目(2012GB2B000085)

摘　　要：以南果梨为试材,研究冷藏(0±0.5)℃5个月后常温货架期间脂肪酸代谢途径关键酶脂氧合酶(LOX)、氢过氧化物裂解酶(HPL)、醇脱氢酶(ADH)、醇酰基转移酶(AAT)活性的变化,探讨外源乙烯对南果梨香气代谢的作用机理,为1-MCP和外源乙烯应用于南果梨贮藏保鲜提供理论依据。南果梨采收当天用0.75μL/L的1-MCP保鲜剂处理24h,在常温条件下放置7d后冷藏5个月,出库后分别用2、4、6、8mmol/L乙烯利处理2min。结果表明:除2mmol/L外源乙烯处理的乙酸庚酯和庚酸乙酯的相对含量低于对照组外,2mmol/L外源乙烯处理的乙酸乙酯、丁酸乙酯、己酸乙酯、乙酸己酯和苯乙酸乙酯的相对含量均明显高于对照和其他几种处理。2mmol/L外源乙烯处理的LOX、HPL和AAT活性始终高于对照和其他几种外源乙烯的处理;不同浓度的外源乙烯对ADH酶活性的影响作用不明显,对照和不同浓度乙烯利处理的ADH酶活性值相差不多。由此可知,2mmol/L外源乙烯处理效果最好,可以提高LOX、HPL和AAT的酶活性,从而更有利于提高南果梨果实冷藏后货架期间的香气品质。After post-harvest 1-MCP treatment and subsequent storage at（0 ± 0.5） ℃ for 5 months,Nanguo pear fruits were immersed in ethephon solutions of different concentrations and then exposed to normal temperature conditions in order to investigate changes in the activities of key enzymes of fatty acid metabolism pathways,lipoxygenase（LOX）,hydrogen peroxide repressible enzyme（HPL）,alcohol dehydrogenase（ADH） and alcohol acyltransferaseand（AAT）,and explore the mechanism of action of exogenous ethylene on the metabolism of aroma compounds in Nanguo pear to provide a theoretical guideline to apply 1-MCP and exogenous ethylene for Nanguo pear storage and preservation.Post-harvest treatment of Nanguo pears with 0.75 μ/L 1-MCP for 24 h started on the same day after harvesting,followed by 7 d of storage at normal temperature.After subsequent cold storage for 5 months,the Nanguo pears were treated with ethephon solutions of different concentrations（2,4,6 mmol/L and 8 mmol/L） for 2 min.The results showed that 2 mmol/L exogenous ethylene treatment exhibited lower relative contents of acetic acid heptyl ester and heptanoic acid ethyl ester but remarkably higher relative contents of ethyl acetate,butanoic acid ethyl ester,hexanoic acid ethyl ester,acetic acid hexyl ester and benzeneacetic acid ethyl ester than control group.During a shelf life of 28 d after 1-MCP treatment,the activities of LOX,HPL and AAT in 2 mmol/L 1-MCP group were always higher than in three other concentration groups and control group.Almost no differences in ADH activity were observed among control group and 1-MCP treatments at different concentrations.From these findings we conclude that treatment with 2 mmol/L exogenous ethylene can increase the activities of LOX,HPL and AAT and accordingly improve the aroma quality of Nanguo pear during shelf life after cold storage.

关 键 词：南果梨 外源乙烯 脂氧合酶 氢过氧化物裂解酶 醇脱氢酶 醇酰基转移酶 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]