鲜猪肉在保藏中的主要腐败菌分析

为确定市售鲜猪肉的货架期，通过分析肉品分别在4 ℃和25 ℃条件下保藏销售过程中的感官指标、挥发性盐基氮（total volatile base nitrogen，TVB-N）值、细菌总数和腐败菌的变化情况对其腐败临界点进行研究，并采用皮尔逊相关系数分析腐败菌与肉样腐败品质间的相关性。结果显示：鲜猪肉在4、25 ℃保藏条件下出现明显腐败品质特征的时间分别为96、24 h，其TVB-N值分别为（19.28±0.22） mg/100 g和（20.14±0.21）mg/100 g，细菌总数分别为（8.11±0.29）（lg（CFU/g））和（7.91±0.23）（lg（CFU/g））；4 ℃保藏条件下肉样的假单胞菌数与细菌总数和TVB-N值的相关性分别为0.955（P＜0.01）和0.901（P＜0.01），均高于肠杆菌的0.914（P＜0.01）和0.871（0.01＜P＜0.05），而25 ℃保藏条件下肉样的肠杆菌数与细菌总数和TVB-N值的相关性分别为0.989（P＜0.01）和0.963（P＜0.01）。结果表明，鲜猪肉在4 ℃和25 ℃保藏条件下的销售货架期分别为96 h和24 h，其TVB-N值、细菌总数在货架期终点均与其感官指标基本一致，且4 ℃保藏肉样的致腐菌以假单胞菌为主，其次为肠杆菌，而25 ℃保藏肉样的致腐菌以肠杆菌为主。

Analysis of Main Spoilage Bacteria in Fresh Pork during Storage

The sensory index, total volatile base nitrogen (TVB-N) value, total number of bacteria and spoilage bacterial
flora in fresh pork stored at 4 and 25 ℃ were investigated to discover the critical point of spoilage and to determine its shelf
life. The correlations between quality parameters related to spoilage and spoilage bacteria were analyzed and described by
Pearson correlation coefficient. The results showed that the fresh pork stored at 4 and 25 ℃ displayed significant changes in
sensory index after 96 and 24 h of storage, respectively. The TVB-N values were (19.28 ± 0.22) and (20.14 ± 0.21) mg/100 g,
and bacterial count were (8.11 ± 0.29) and (7.91 ± 0.23) (lg(CFU/g)), respectively. There were remarkable relationships
between Pseudomonas spp. and the total number of bacteria or TVB-N values, with Pearson correlation coefficient of 0.955
(P < 0.01) and 0.901 (P < 0.01) at 4 ℃, respectively. At 25 ℃, there were remarkable relationships between Enterobacteriaceae
and the total number of bacteria or TVB-N values, with Pearson correlation coefficient of 0.914 (P < 0.01) and 0.871 (0.01 <
P < 0.05), respectively. These results demonstrated that the shelf life of fresh pork stored at 4 and 25 ℃ were 96 and 24 h,
respectively. There was consistency between sensory index and TVB-N values or total number of bacteria at the end of shelf
life. The main spoilage bacteria in fresh pork stored at 4 ℃ were Pseudomonas spp. and Enterbacteriaceae at 25 ℃.