基于顶空-气相色谱-离子迁移谱分析蒸制过程中草鱼肉挥发性成分的变化

Identification of changes in volatile compounds in grass carp during steaming by headspace-gas chromatography-ion mobility spectrometry

为提高蒸制草鱼的风味品质,通过顶空-气相色谱-离子迁移谱(headspace-gas chromatography-ion mobility spectroscopy,HS-GC-IMS)结合主成分分析(principal component analysis,PCA)及感官评定研究了草鱼白肉和红肉在蒸制过程中挥发性成分的变化。在鱼肉中共鉴定出40种化合物,其中白肉(34种)和红肉(37种)共有的挥发性化合物有30种,主要是醛类、醇类、酮类和酯类。蒸制处理会促进鱼肉中挥发性化合物(异丁醛、戊醛、己醛、庚醛、2-乙基己醇和2-戊酮)的形成;蒸制后,红肉中挥发性成分的数量和相对含量都高于白肉。PCA结果表明,在蒸制过程中,红肉的风味变化较白肉更为丰富。在蒸制时间到达9 min时,鱼肉整体的风味趋于稳定,鱼肉中的挥发性成分可以代表熟草鱼肉的风味。感官评定的结果也显示,蒸制9 min的草鱼肉具有较好的风味和整体可接受度。综上,HS-GC-IMS和PCA的组合可以较好地描述不同蒸制时间的草鱼白肉和红肉挥发性化合物的变化,并为确定草鱼适宜的蒸制时间提供依据。

To improve the flavor quality of steamed grass carp,changes of volatile components in white meat and red meat of grass carp during steaming were investigated by headspace-gas chromatography-ion mobility spectrometry(HS-GC-IMS)combined with principal component analysis(PCA)and sensory evaluation.A total of 40 compounds were identified,including 34 compounds in white meat and 37 compounds in red meat,and 30 volatile components were identified in white meat and red meat,mainly aldehydes,alcohols,ketones,and esters.Steaming treatment promoted the formation of volatile compounds(2-methylpropanal,pentanal,hexanal,heptanal,2-ethyl-1-hexanol,and 2-pentanone)in grass carp.The amount and relative content of volatile components were higher in red meat than in white meat after steaming.The PCA results showed that the flavor changes were richer in red meat than in white meat.The overall flavor of grass carp stabilized and the volatile components in the fish could represent the flavor of cooked fish meat when the steaming time reached 9 min.The results of the sensory evaluation also showed that the grass carp meat steamed for 9 min had better flavor and overall acceptability.It was concluded that the combination of HS-GC-IMS and PCA could better describe the changes of volatile compounds in white meat and red meat of grass carp at different steaming times,and provided a basis for determining the appropriate steaming time for grass carp.