解冻猪肉中优势腐败菌致腐能力研究

Spoilage Capability of Dominant Spoilage Bacteria in Thawed Pork

将解冻猪肉中的优势腐败菌(假单胞菌属、热死环丝菌和肠杆菌科)接种到灭菌肉上研究其在不同温度贮藏过程中腐败的特点。在贮藏期间每天进行感官评价,测定各腐败菌的菌落数(CFU)、挥发性盐基氮(TVB-N)、脂肪氧化值,并以产生腐臭味时的TVB-N产量因子Y(TVB-N/CFU)作为各优势腐败菌腐败能力的定量指标。研究结果表明:至贮藏期第5天时解冻猪肉已产生强烈的腐臭味,热死环丝菌菌数在4、0℃和-5℃贮藏时分别达11.28lg(CFU/g)、9.63lg(CFU/g)和6.62lg(CFU/g),而相应的TVB-N值分别达14.92、14.50mg/100g和9.10mg/100g;与之类似,假单胞菌属菌数4、0℃和-5℃贮藏时分别达9.46lg(CFU/g)、8.87lg(CFU/g)和5.37lg(CFU/g),TVB-N值分别达21.59、14.49mg/100g和8.97mg/100g。研究表明热死环丝菌和假单胞菌属导致解冻猪肉腐败能力较强。

In order to explore the spoilage characteristics of dominant spoilage bacteria,Pseudomonas spp.,Brochothrix thermosphacta and Enterbacteriaceae were inoculated into sterilized pork at different storage temperatures of 4,0 ℃ and-5 ℃.Sensory evaluation score,aerobic bacteria count,total volatile basic nitrogen（TVB-N） value and thio-barbituric acid（TBA） value were determined on each storage day.Bacterial poilage capability was evaluated based on TVB-N production factor Y（TVB-N/CFU）,which was calculated from TVB-N value divided by colony forming unit（CFU）.The results indicated that strong spoilage odor occurred on the 5th storage day.The counts of B.thermosphacta in thawed pork were 11.28 lg（CFU/g）,9.36 lg（CFU/g） and 6.62 lg（CFU/g） at storage temperatures of 4,0 ℃ and-5 ℃,respectively;while TVB-N values were 14.92,14.50 mg/100g and 9.10 mg/100g,according to relative storage conditions.Similarly,the counts of Pseudomonas spp.were 9.46 lg（CFU/g）,8.87 lg（CFU/g） and 5.37 lg（CFU/g） under the storage temperature of 4,0 ℃ and-5 ℃,respectively;while TVB-N values were 21.59,14.49 mg/100g and 8.97 mg/100 g,respectively.This study showed that B.thermosphacta and Pseudomonas spp.were dominant in thawed pork,with significantly stronger spoilage capability than others dominant bacteria.