基于主成分分析和聚类分析评价中华绒螯蟹蟹肉香气品质的研究

Evaluation on aroma-quality of meat of Chinese mitten handed crab(Eriocheir sinensis) by principal component analysis and cluster analysis

运用顶空固相微萃取-气-质联用技术,对采自阳澄湖的特级、1级、2级的雌性中华绒螯蟹体肉、钳肉和足肉中的香气成分进行了鉴定并以内标法对其定量。通过主成分分析法(PCA)和聚类分析法(CA)对不同蟹肉样品的香气品质进行评价。主成分分析结果显示:不同等级中华绒螯蟹钳肉和足肉的综合得分均大于零(2级-钳肉除外),香气品质较好,醇类、酮类、呋喃类、含氮类和芳香类五类成分对其贡献显著,是表征"高品质风味"的特征性香气成分;将部位因素统一考虑后,大闸蟹等级越高,蟹肉香气品质越好;将等级因素统一考虑后,大闸蟹足肉香气品质最佳,钳肉次之,体肉最差。经聚类分析发现:不同等级大闸蟹体肉及足肉样品香气轮廓可各自聚为一类。醇类、呋喃类、酮类、含氮类和芳香类5类香气成分可聚为一类。主成分分析和聚类分析结果存在一致性且可以相互补充,今后可利用两种方法建立不同大闸蟹蟹肉香气品质的评价模型。

HS-SPME-GC-MS（Headspace solid phase micro-extraction coupled with gas chromatography and mass spectrometry） technology was applied to detect the aroma compounds from various edible parts （abdomen,claw and leg） of female Yangcheng-Lake-crabs in different grades（special,first and second）. An internal standard （TMP） was introduced to quantitate the concentrations of aroma compounds and the concentration data were analyzed by principal component analysis（PCA） and cluster analysis（CA） methods. PCA results showed that,claw and leg meat from three grades,all acquired positive S-scores（except claw meat from second grade） and could be assumed to have the better aroma-quality. Meanwhile,alcohols, ketones,furans,N-containings and aromatics had been found out to be the five characteristic aroma species which related and contributed a lot to ＂better quality of aroma＂. With a unified consideration of edible part factor,it was found that higher grades of crabs resulted in better quality of aroma. However,claw meat acquired higher S-scores than abdomen meat and lower S-scores than leg meat. CA results showed that, aroma profile of abdomen and leg meat from three grades could be classified as one cluster. Similarly, alcohols,furans,ketones,N-containings and aromatics were in one cluster due to their high similarities. As a conclusion,consistency existed between PCA and CA results,indicating these two methods might mutual supply each other and could be used to establish a model for evaluating aroma-quality of crabmeat.