摘要
[目的]研究不同培养基、培养温度和培养时间对原料牛乳中嗜冷菌水平的影响,旨在提高原料牛乳中嗜冷菌检测的准确性和一致性。[方法]本试验采用《SN/T 2552.4—2010乳及乳制品卫生微生物学检验方法嗜冷微生物菌落计数》第一法中6.5℃菌落计数法(简称“PCMA法”)及第二法21℃菌落计数法(简称“PCMA快速法”)、《ISO 6730:2005乳嗜冷微生物菌落计数6.5℃菌落计数技术》(简称“PCA法”)和《ISO 8552:2004乳嗜冷微生物的评估21℃菌落计数技术(快速法)》(简称“PCA快速法”)中的平板计数法对2017年华南地区8个牧场的2个奶类,共计66份原料牛乳样品在不同培养条件下的嗜冷菌水平进行检测。[结果]PCA法与PCA快速法在检测同类型原料牛乳时数据一致性较差;PCMA法与PCMA快速法在检测原料牛乳时亦表现出数据一致性不佳的问题。尽管PCA法与PCMA法在检测同类型原料牛乳时数量上一致,但PCMA法的培养基较为浑浊,菌落形态较小,容易导致误判。[结论]不同培养基、培养温度和培养时间对原料牛乳中嗜冷菌检测结果存在影响。采用PCMA快速法可对原料牛乳中嗜冷菌水平进行初步判断,然而更加准确的菌落技术结果,仍建议以PCA法作为最终判定依据。
[Objective]To study the effects of different culture media,culture temperatures and culture times on the levels of psychrotrophiles microorganisms in raw cow's milk,aiming to improve the accuracy and consistency of the detection of psychrophiles detection in raw cow's milk.[Method]This experiment adopted the 6.5℃colony counting method(referred to as“PCMA method”)in the first method and the 21℃colony counting method(referred to as“PCMA rapid method”)in the second method of“SN/T 2552.4-2010 Microbiological Testing methods for Milk and Dairy Products”and“ISO 6730:2005 Milk—Enumeration of colony forming units of psychrotrophic microorganisms—Colony-count technique at 6.5℃”(referred to as“PCA Method”)and“ISO 8552:2004 Milk—Estimation of psychrotrophic microorganisms—Colony-count technique at 21℃(Rapid Method)”(referred to as“PCA Rapid Method”)was used to detect the levels of psychrophiles in a total of 66 raw cow's milk samples from 2 dairy products of 8 dairy farms in South China in 2017 under different culture conditions.[Result]The data consistency of the PCA method and the PCA rapid method was poor when detecting the same type of raw cow's milk.The PCMA method and the PCMA rapid method also showed the problem of poor data consistency when detecting raw cow's milk.Although the PCA method and the PCMA method were consistent in quantity when detecting the same type of raw material milk,the culture medium of the PCMA method was relatively turbid,and the colony morphology was small,which was prone to misjudgment.[Conclusion]Different culture media,culture temperatures and culture times have an impact on the detection results of psychrophilic bacteria in raw cow's milk.The PCMA rapid method can be used to make a preliminary judgment on the level of psychrophiles in raw cow's milk.However,for more accurate colony technology results,it is still recommended to use the PCA method as the final determination basis.
作者
吴思敏
谢翠连
林秋莹
傅金凤
WU Simin;XIE Cuilian;LIN Qiuying;FU Jinfeng(Guangzhou Fengxing Dairy Co.,Ltd.,Guangzhou Guangdong 510510)
出处
《中国乳业》
2025年第12期52-58,共7页
China Dairy
关键词
嗜冷菌
检测
培养基
培养温度
培养时间
psychrophiles
detection
culture medium
culture temperature
culture time
