将冷却猪肉用托盘、真空、气调的方式包装放置5℃条件下贮藏,通过主成分分析和聚类分析,研究不同包装冷却猪肉贮藏过程中腐败特性。结果表明:通过主成分分析品质指标变化发现,微生物和尸胺、腐胺、电导率、TVBN、pH都可以作为腐败指标反映冷却猪肉的腐败进程,影响其货架期的长短。主成分分析中的旋转因子空间成分图可以直观地确定一部分指标的相关关系,除去不相关的指标,进而进行聚类分析,树图把指标分为4大类,细菌总数与TVBN、热杀索丝菌、假单胞菌的距离分别为0.255、0.320和0.340;假单胞菌、电导率与TVBN的距离分别为0.282和0.305;腐胺与尸胺的距离为0.356,但与其他指标距离较远;pH与其他指标的距离均较远。因此,对于不同包装的冷却猪肉,细菌总数、TVBN、假单胞菌和电导率可以作为判断其腐败品质变化的重要指标,其含量变化可客观反映冷却猪肉的腐败变质进程。

In this paper,the chilled pork were packaged by pallet,vacuum and modified atmosphere under the conditions of storage at 5 ℃,and the principal component analysis and cluster analysis were carried out to study the correlation between the spoilage quality indicators and the different packaged chilled pork. The results from principal component analysis of the changes in quality indicators showed that microbiological cadaverine,putrescine,conductivity,TVBN and pH could be used as spoilage quality indicators to reflect the shelf life of chilled pork. Component plot in rotated space of the principal component analysis could visually determine the relationship of the partial indicators and delete the irrelevant indicators. Then the dendrogram of cluster analysis divided indicators into four categories as follows. The distance between the total viable counts and TVBN,Brochothrix thermosphacta,Pseudomonas spp. were 0. 255,0. 320 and 0. 340,respectively. The distance between TVBN and Pseudomonas spp. and Electrical conductivity were 0. 282 and 0. 305,respectively. The distance between putrescine and cadaverine was 0. 356,which was far compared with other indicators. The distance between pH and other indicators were farther. Therefore,the total viable counts,TVBN,Pseudomonas spp. and electrical conductivity could be used as spoilage indexes of chilled pork,and the contents reflected of the spoilage degree.