微波蒸馏-固相微萃取-气相色谱-质谱-嗅觉检测器联用分析鳙鱼鱼肉中的挥发性成分

用微波蒸馏(MD)-固相微萃取装置(SPME)提取鳙鱼鱼肉中的挥发性成分,利用气相色谱-质谱联用仪(GC-MS)对气味化合物成分进行了定性分析,同时利用嗅觉检测器鉴别了部分挥发性物质的气味特征。实验中优化了MD的操作条件(加热功率、加热时间及载气流速等)、SPME参数(萃取头种类、萃取温度、萃取时间、无机盐离子浓度及搅拌速率等)。通过NIST 02质谱数据库检索共定性确定出鳙鱼鱼肉挥发性成分中的53种化合物,其中主要为 C6~C9 的羰基化合物和挥发性醇类。经过嗅觉检测器分析,这些成分分别具有青草味、鱼腥味、泥土味等气味特征,其协同作用构成了鳙鱼鱼肉特殊的鱼腥味、泥腥味。该方法可用于水产品中挥发性成分的分析,并可为不良风味化合物的定量研究提供参考。

Analysis of Volatile Compounds in Bighead Carp by Microwave Distillation and Solid Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry and Olfactometry

A technique for the analysis of flavour compounds from fish muscle employing microwave distillation(MD),solid phase microextraction(SPME) coupled with gas chromatography-mass spectrometry(GC-MS) and olfactometry is described,and 53 compounds responsible for the aroma of bighead carp were identified from NIST 02 MS data base.The extraction of microwave distillation was developed by optimizing the flow rate of carrier gas,heating time and power.Solid phase microextraction procedure was optimized by using different kinds of fiber for the qualitative determination of the volatile compounds observed in the headspace of microwave distillation,including extraction time,temperature,magnetic stirring speed and desorption time in GC-MS equipment.Furthermore,a simple data acquisition and processing system was developed by using human nose as a sensitive detector for the identification of flavour and off-flavour key compounds in fish tissue. The result showed that the components associated with fish flavour were mostly 6-9 carbon aldehydes,ketones and alcohols.According to the olfactory analysis, these compounds were characterized by grassy,fishy,earthy or muddy odors separately,and their synergistic actions were forming the distinct fishy and earthy odors of bighead carp.The rapid method developed by this study may be applied to quantitative analysis of the off-flavour compounds in fresh-water fish.