通过测定大菱鲆在4℃冷藏过程中的感官品质、菌落总数和TVB-N值等指标的变化,确定贮藏20d时已达腐败阶段。利用电子鼻检测新鲜及腐败鱼肉的气味差异,并对所获数据进行主成分分析,同时结合顶空固相微萃取(HS-SPME)和气质联用技术(GC-MS)对新鲜及腐败鱼肉的挥发性成分进行分析鉴定。结果表明:电子鼻对新鲜及腐败鱼肉整体风味的区分快速、灵敏,其分析结果与常规新鲜度评价指标的变化致;采用GC-MS法在新鲜及腐败鱼肉中分别检测出27及28种挥发性物质,主要为醛类、酮类、醇类、酯类、烃类和胺类化合物等,其中醛类、酮类和醇类物质在新鲜鱼肉中的含量较高,而胺类物质在腐败鱼肉中含量较高。

Turbots under a storage period of 20 days were selected as tainted samples by analyses of sensory evalutation,TVC,TVB-N and K value of turbot stored at 4 ℃.An electronic nose was used to detect the flavor difference between fresh and spoiled turbot samples,and the data obtained were analyzed by principal component analysis( PCA).Meanwhile,the volatiles in fresh and spoiled turbot samples were extracted by headspace solid phase microextraction( HS-SPME) and identified by gas chromatography-mass spectrometry( GC-MS).The results indicated that electronic nose was rapid and sensitive enough to distinguish the overall flavour of fresh and spoiled turbot samples, and were in agreement with the changes of conventional freshness evaluation indices.The GC-MS analysis showed that total of 27 and 28 volatile compounds were identified in fresh and spoiled turbot samples,respectively.Among the identified compounds,the predominant ones were aldehydes,ketones,alcohols,esters,hydrocarbon and amines and so on.The content of aldehydes,ketones and alcohols were high in fresh samples,whilst the amounts of amines were high in spoiled ones.