Kotula A W, Pierson M D, Emswiler B S, Guilfoyle J R
Appl Environ Microbiol. 1979 Nov;38(5):789-94. doi: 10.1128/aem.38.5.789-794.1979.
The effects of two transport systems and cryoprotective agents on the survival of bacteria in ground beef samples were evaluated. Survival of Clostridium perfringens in ground beef samples after simulated transport (72 h) was higher (about 99%) in Dry Ice than in Trans Temp shipping units (-3 degrees C). There were no significant differences between the two transport systems in survival of coliforms, Escherichia coli, Staphylococcus aureus, or aerobic bacteria. Mixing ground beef samples at a ratio of 1:1 (wt/vol) with 10, 20, or 30% buffered solutions of dimethyl sulfoxide or glycerol before freezing improved the survival of C. perfringens and coliforms in both transport systems. Recovery of E. coli was significantly higher with the addition of 10% dimethyl sulfoxide before Dry Ice transport. Addition of 10% dimethyl sulfoxide resulted in a 100% recovery of both S. aureus and aerobic bacteria from ground beef after simulated transport in Trans Temp shipping units. The use of cryoprotective agents can improve the survival of bacteria during transport of ground beef samples.
评估了两种运输系统和冷冻保护剂对绞碎牛肉样本中细菌存活率的影响。产气荚膜梭菌在模拟运输（72小时）后的绞碎牛肉样本中的存活率，在干冰运输时（约99%）高于在Trans Temp运输装置（-3℃）中的存活率。两种运输系统在大肠菌群、大肠杆菌、金黄色葡萄球菌或需氧菌的存活率方面没有显著差异。在冷冻前，将绞碎牛肉样本按1:1（重量/体积）的比例与10%、20%或30%的二甲基亚砜或甘油缓冲溶液混合，可提高产气荚膜梭菌和大肠菌群在两种运输系统中的存活率。在干冰运输前添加10%的二甲基亚砜，大肠杆菌的回收率显著提高。在Trans Temp运输装置中模拟运输后，添加10%的二甲基亚砜可使金黄色葡萄球菌和需氧菌从绞碎牛肉中的回收率达到100%。使用冷冻保护剂可提高绞碎牛肉样本运输过程中细菌的存活率。
