比较3批商品化复合型LG培养基（简称：复合型LG）与由3个饮料生产厂自行采购原料配制的LG培养基（简称：自配LG）的感官指标、pH及生物学指标，从而评价复合型LG与自配LG培养基的稳定性，以及对无菌冷灌装生产线验证效果的影响。结果表明：在感官方面，3批复合型LG一致，3个自配LG培养基感官参差不齐，有的存在沉淀或杂质现象，不符合LG培养基的外观标准。在pH方面，3批复合型LG培养基pH一致，均在标准要求范围（6.5±0.2）内，pH使用前无需调试可直接使用，优于三个自配LG的培养基。在生长速度方面，复合型LG 3批效果相当，均优于3个自配，第7 d时，8个测试菌在3批次复合型LG上生长均已达最大值，而自配G和自配H分别接种黑曲霉和洋葱假单胞菌的管未见生长。结论：复合型LG培养基总体性能佳，批间稳定性很好，非常适合无菌冷灌装生产线的无菌验证。自配LG培养基批间稳定性差，检测灵敏度较低，存在低浓度微生物漏检的风险。

The sensory and biological characteristics and pH properties of three batches of commercial composite LG media (referred to as the composite LG) and LG media prepared by three beverage companies using raw materials purchased by themselves (referred to as the self-made LG) were compared to evaluate the stability of the composite and self-made LG media and their performances in ensuring the sterility of cold aseptic filling production lines. Results reveal that the three batches of composite LG have similar sensory characteristics, whereas the three self-made LG have markedly different sensory characteristics. As precipitation or impurities are noted, the three media do not meet the appearance standards. Meanwhile, the pH values of the three batches of composite LG are all within the standard range (6.5±0.2), indicating that these media can be used directly without modifying their pH before use; in this regard, they outmatch the self-made LG media. Moreover, the composite LG media give similar culture rates, higher than those of the self-made LG. More specifically, the maximum growth of the eight examined bacteria was noted on the 7th day of culture for the three batches of composite LG, while Aspergillus Niger and Pseudomonas onioniae did not grow in two of the self-made LG media, namely media G and H. Therefore, the following conclusions are drawn: The overall performances of the composite LG are satisfactory, and adequate stability is noted for different batches. Hence, they are suitable for use in cold aseptic filling production lines because they can ensure the sterility of the latter. In contrast, the self-made LG media of different branches show poor stability. Moreover, as low detection sensitivity is observed for all self-made media, the risk of low counts of microorganisms remaining undetected exists when these media are used.

国家重点研发计划项目（2018YFC1604201）；肇庆市引进西江创新团队项目（肇人才领2018-8）