GC-MS结合电子鼻分析茶多酚对冷藏草鱼片挥发性成分的影响

采用5.0 g/L茶多酚溶液浸泡草鱼片，通过顶空固相微萃取-气相色谱-质谱（headspace solid phase microextraction-gas chromatography-mass spectrometry，HS-SPME-GC-MS）联用结合电子鼻技术检测冷藏草鱼片贮藏期内挥发性成分的变化。结果表明：HS-SPME-GC-MS法共检出挥发性成分161 种，主要为醛类及醇类物质；空白组检出的醛类及醇类物质相对含量随贮藏时间的延长呈持续增长趋势，烃类物相对含量先降低后升高，酯类物质相对含量先升高后降低，其他物质含量呈现上下波动趋势。茶多酚组检出的醛类物质显著低于空白组，醇类物质在贮藏后期少量存在，己醛、1-辛烯-3-醇等使鱼体呈腥味的物质大幅度降低，酸类物质相对含量增加。经电子鼻检测结果发现，茶多酚组在贮藏后期各传感器的响应值显著低于空白组。微生物检测结果表明，茶多酚处理能够有效抑制草鱼片在冷藏期内微生物包括产气细菌的生长。综上结果表明茶多酚可以显著降低冷藏草鱼片腥味物质的生成。

Effects of Tea Polyphenols on Volatile Compounds of Grass Carp Fillets during Refrigerated Storage as Analyzed by GC-MS and Electronic Nose

The effects of pretreatment by dipping in a solution of 5.0 g/L tea polyphenols (TPs) on the volatile compounds of grass carp fillets were examined over a storage period of 15 d. The changes in the composition of volatile compounds during the storage period were detected by head space solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and electronic nose. A total of 161 volatile components were identified by HS-SPME-GC-MS, mainly aldehydes and alcohols. The relative contents of aldehydes and alcohols in the control group were increased with storage time. The relative content of hydrocarbons was decreased firstly and then increased gradually; however, the opposite trend was observed for esters. The other volatiles showed irregular fluctuations. The aldehydes identified were significantly less abundant in the TPs group than in the control group. Only small amounts of alcohols appeared at the late period of storage. The contents of the fishy odorants hexanal and 1-octene 3 alcohol were reduced greatly and acids were increased. The results of electronic nose showed that the response value of the TPs-treated group at the end of storage was significantly lower than that of the control group. Microbial analysis showed that TPs treatment of grass carp fillets effectively inhibited the growth of microorganisms including gas-producing bacteria during the cold storage period. In conclusion, this study showed that TPs could significantly reduce the production of fishy volatiles during refrigerated storage.