速冻水饺中背景菌对冷冻亚致死金黄色葡萄球菌修复及检测的影响

Effects of Native Microflora of Quick-frozen Dumplings on Recovery of Frozen-sublethal Staphylococcus Aureus

为了研究水饺中的背景菌对冷冻亚致死金黄色葡萄球菌修复的影响,首先将冷冻亚致死金黄色葡萄球菌在酵母含量为0.6%的胰蛋白胨大豆肉汤和10%氯化钠胰酪胨大豆肉汤中的生长情况作对比,然后将冷冻亚致死的金黄色葡萄球菌接种至含有不同浓度的速冻水饺背景菌的培养液中,24 h内每2 h测定其菌落总数和金黄色葡萄球菌的数量,用Gompertz模型计算其生长参数。结果表明:10%氯化钠胰酪胨大豆肉汤对冷冻亚致死金黄色葡萄球菌的修复有抑制作用;背景菌的存在对冷冻亚致死的金黄色葡萄球菌的生长速率和迟滞期有影响,背景菌的浓度越高,金黄色葡萄球菌的数量就越少。本研究结果对于速冻食品中金黄色葡萄球菌的定量检测技术及标准的建立具有一定的参考作用。

With the purpose of researching the effects of native microflora of frozen dumplings on recovery of sub-lethal Staphylococcus aureus acquired in Frozen Storage,primarily,the growth of frozen-sublethal Staphylococcus aureus in tryptise soy broth containing 0.6% yrast extract powder and 10% sodium chloride trypticase soy broth were compared.Moreover,different concentrations native microflora of frozen dumplings were added in tryptise soy broth containing 0.6% yrast extract powder.Both of the numbers of total microflora and Staphylococcus aureus were measured every tow hours within 24 hours.Finally,Gompertz model was used to calculate the growth characteristics of bacteria.The results showed that：10% sodium chloride trypticase soy broth suppressed the recovery of frozen-sublethal Staphylococcus aureus.The presence of native microflor had inflence on the growth rate and lag period of frozen-sublethal Staphylococcus aureus.In addition,the higher the concentration of background bacteria was,the fewer Staphylococcus aureus was.The results has certain instruction function to establish the quantitative detection technology and standard of Staphylococcus aureus in quick-frozen food.