菠萝原汁真空微波浓缩前后挥发性成分变化研究

菠萝浓缩汁是菠萝最主要的加工产品,在常规的加热浓缩过程中通常伴随着易挥发的香气成分损失.为了探明最容易挥发损失的香气成分,同时建立一种鉴别菠萝汁饮料是由鲜榨菠萝汁还是由菠萝浓缩还原汁生产的方法,进行了菠萝原汁的真空微波快速浓缩前后挥发性成分的变化规律研究.采用顶空固相微萃取-气质联用方法对菠萝原汁和菠萝真空微波浓缩还原汁的挥发性成分进行分析检测对比.结果显示菠萝经真空微波浓缩后消失的成分为己酸甲酯、2-甲基丁酸乙酯和罗勒烯,损失较大的几种成分分别是D-柠檬烯,十五烷以及古巴烯等.浓缩后增加的成分主要有香叶基丙酮.结果说明己酸甲酯、2-甲基丁酸乙酯、罗勒烯等成分可能是热浓缩过程中最容易挥发损失的成分,同时这些成分可作为鉴别鲜榨菠萝汁和浓缩菠萝汁还原果汁的特征性成分.

Changes of Aroma Compounds in Pineapple Before and After Vacuum-Microwave Concentration

Pineapple juice concentrate is the most popular product of pineapple.The aroma compounds reduced during concentration.To reveal the reduced and disappeared compounds,HS-SPME-GC/MS was used to detected the aroma compounds before and after vacuum-microwave concentration.There were six compounds disappeared or reduced after vacuum-microwave concentration.The disappeared compounds were methyl caproate,methyl ester of 2-methyl-butanoic acid,and cis-ocimene,and the highly reduced compounds were D-limonene,pentadecane,and copaene.But geranyl acetone increased after concentration.Therefore,the content of methyl caproate,methyl ester of 2-methyl-butanoic acid,and cis-ocimene could be used to distinguish the fresh pineapple juice and pineapple juice from concentrate.