养殖大黄鱼冷却链全程细菌定性和定量研究

对在闽东三都湾养殖密集海区所捕获的大黄鱼冷却链全过程的产品品质和细菌相变化进行了定性和定量研究。刚捕获的大黄鱼,其细菌总数受养殖水域卫生状况影响很大,为4.1×106cfu/g,菌群中嗜水气单胞菌(Aeromonas hydrophila)居优势,占25.2%,阴沟肠杆菌(Enterobacter cloacae)和弗氏柠檬酸杆菌(Cirtobacterfreundii)占较大比例。处理后的细菌总数和细菌相表明,加工处理过程没有明显的细菌污染。冰藏初期细菌总数明显下降,菌群中好冷的不动细菌(Acinetobactria)和摩氏杆菌(moxeralle)比例上升,其他菌群不同程度下降,出现了较多比例的假单胞菌(Pseudomonasspp.)和腐败希瓦氏菌(Shewanella putrefaciens),表明鱼体温度迅速下降对有些细菌产生了冷冲击致死作用。冷藏过程中,腐败希瓦氏菌增殖比其他细菌快,在货架期终点达到86.0%,是冷却链大黄鱼产品的优势腐败菌。货架期终点12 d时,细菌总数为6.7×107cfu/g。

Qualitative and Quantitative Characterization of the Bacteriology of Cultured Pseudosciacna crocea in a Chilled Chain

The quality and bacterial flora changes of cultured Pseudosciacna crocea from SanDu bay in Fujian province in a chilled chain were investigated.The total viable count that was influenced by sanitary condition of the cultured waters on newly caught Pseudosciacna crocea reached 4.1×10~6 cfu/g.Aeromonas hydrophila(25.5%) dominated in the microflora,and Enterobacter cloacae and Cirtobacter freundii were in smaller proportion.There was no significant pollution in the preservation on basis of the total viable count and the bacterial flora.During the initial period of chilled storage, the total viable count decreased dramatically,the proportion of Acinetobactria and moxeralle increased,the proportion of other bacteria decreased.The higher proportion of Pseudomonas spp.and Shewanella putrefaciens indicated the dramatically temperature decrease in fish body had a coldfatal effect on some bacteria.During a chilled storage,Shewanella putrefaciens that dominated in the bacterial flora of Pseudosciacna crocea in chilled chain grew faster than other bacteria,and its proportion reached 86.0% at the end of shelf life.The total viable count reached 6.7×10~6 cfu/g at the end of shelf life(12 d).