市售鲜湿米粉菌落总数及大肠菌群数繁殖动态的考察

Investigation on the total number of bacterial colonies and the breeding dynamics of coliform bacteria in fresh wet rice noodles sold in the market

中文关键词:  鲜湿米粉  食品的微生物检验  菌落总数  大肠菌群

英文关键词:fresh wet rice noodles  microbiological examination of food  aerobic plate count  coliforms

中文摘要:

      目的 考察南宁市售不同厂家的鲜湿类米粉的菌落总数、大肠菌群污染状况及后续繁殖动态。方法 按照GB 4789.1-2016《食品安全国家标准 食品微生物学检验 总则》抽样方法, 从餐饮店抽取6批不同厂家的未开封的鲜湿米粉。按照GB 4789.2-2016《食品安全国家标准 食品微生物学检验 菌落总数测定》、GB 4789.3-2016《食品安全国家标准 食品微生物学检验 大肠菌群计数》的检测方法, 分别在0、2、4、8、12、16、24 h对样品的菌落总数及大肠菌群项目进行检测, 在24 h同时取部分样品在沸水中焯1 min后平行检测, 对计数结果进行分析。结果 0 h时, 各样品的菌落总数在3.1×103~6.9×107 CFU/g, 大肠菌群在0~8.5×105 CFU/g。在22 ℃条件放置下, 随着时间推移, 各样品的菌落总数和大肠菌群数仍不断增殖。16 h(即保质期过后), 菌落总数达到7.2×107~1.9×109 CFU/g左右, 繁殖基本趋缓。24 h时, 在沸水中焯1 min后, 所有样品的菌落总数小于1.3×103 CFU/g, 大肠菌群均小于10 CFU/g, 远低于标准规定。结论 22 ℃储藏条件下并不能遏制鲜湿米粉的菌落总数及大肠菌群增殖, 沸水焯1 min可有效降至安全水平。

英文摘要:

      Objective To investigate the total number of colonies, coliform contamination and subsequent reproductive dynamics of fresh wet rice noodles sold by different manufacturers in Nanning. Methods According to GB 4789.1-2016 National food safety standard-Microbiology inspection-General principles sampling method, 6 batches of unopened fresh wet rice noodles from different manufacturers were taken from the restaurant. According to GB 4789.2-2016 National food safety standard-Food microbiology test-Detection of aerobic bacterial count, and GB 4789.3-2016 National food safety standard-Food microbiology test-Enumeration of coliforms, the total number of colonies and coliforms of the samples were detected at 0, 2, 4, 8, 12, 16 and 24 h, respectively. At 24 h, some samples were simultaneously blanched in boiling water for 1 min and then tested in parallel to analyze the counting results. Results At 0 h, the total numbers of colonies of sample were 3.1×103 to 6.9×107 CFU/g, and the coliform groups were 0 to 8.5×105 CFU/g. Under the conditions of 22 °C, the total number of colonies and the number of coliforms of each sample continued to proliferate over time. After 16 h (that was, after the shelf life), the total numbers of colonies reached 7.2×107~1.9×109 CFU/g, and the reproduction basically slowed down. At 24 h, after 1 min in boiling water, the total numbers of colonies of all samples were less than 1.3×103 CFU/g, and the coliform groups were less than 10 CFU/g, which was far below the standard. Conclusion Under the storage condition of 22 °C, the total number of colonies of fresh wet rice noodles and the proliferation of coliform bacteria can not be suppressed. It can be effectively reduced to a safe level after boiling in boiling water for 1 min.