玉米冻藏过程中挥发性成分变化及主成分分析

Changes and principal component analysis of volatile compounds in corn ears during frozen storage

为研究冻藏温度和时间对玉米挥发性风味的影响,采用顶空-固相微萃取(HS-SPME)结合气相色谱-质谱联用技术(GC-MS),分别对在-4、-18、-40℃条件下冻藏1、2、3个月的玉米样品进行分析,为玉米贮藏保鲜提供理论指导。研究表明:随着贮藏时间的增加,当贮藏温度为-4℃和-18℃时,烃类物质相对含量先增加后减少,醇类物质种类数量及相对含量均不断增加,酮类物质种类数量不断减少;当贮藏温度为-18℃与-40℃时,醛、酸、酯类物质相对含量先减少后增加。此外,当贮藏时间为1个月时,贮藏温度越低,烃类、酮类物质种类数量越多,相对含量越小;当贮藏时间为3个月时,贮藏温度越低,烃、酮、酯类物质相对含量越大,醛类物质种类数量和相对含量越小。随后,选取63种主要挥发性成分进行主成分分析,挥发性成分主要指向醛、酮、酯类物质,棕榈酸乙酯、癸醛、2,3-辛二酮、4-甲基二苯甲酮、辛醛、植烷、癸二酸二壬酯、棕榈酸异丙酯、邻苯二甲酸二异丁酯、十四酸异丙酯是玉米挥发性成分的主要特征化合物。

In order to study the effects of storage temperature and duration on the volatility of corn,HS-SPME and GC-MS were used to detect the volatile flavor in corns stored at -4℃,-18℃,and -40℃ for 1,2,3 months.This provides a theoretical guidance for storing and preserving corn ears.This research showed that with prolonged storage time,the relative contents of hydrocarbons increased first and then decreased at -4℃ and -18℃.The quantities and relative contents of alcohols increased continuously,while the amounts of ketones decreased continuously.When the storage temperature was -18℃ and -40℃,the relative contents of aldehydes,acids,and esters decreased first and then increased.In addition,when the storage pericd was 1 month,the lower the storage temperature,the greater the quantities of hydrocarbons and ketones,but their relative contents were smaller.When the storage period was 3 months,the lower the storage temperature,the greater the relative contents of hydrocarbons,ketones,and esters,and the amounts and relative contents of aldehydes were smaller.Then,63 major volatile compounds were selected for principal component analysis.The volatile compounds were mainly aldehydes,ketones,esters.Ethyl palmitate,decanal,2,3-octanedione,4-methylbenzophenone,octanal,phytan,dinonyl sebacate,isopropyl palmitate,diisobutyl phthalate,isopropyl myristate were the main volatile compounds of corn ears.