Department Agricultural Food Environmental and Animal Science, University of Udine, Via Sondrio 2/a, 33100, Udine, Italy.
Department Agricultural Food Environmental and Animal Science, University of Udine, Via Sondrio 2/a, 33100, Udine, Italy.
Food Microbiol. 2021 Apr;94:103654. doi: 10.1016/j.fm.2020.103654. Epub 2020 Oct 7.
Three hundred Clostridium strains were isolated from spoiled wurstels and were identified by traditional and molecular methods as Clostridium perfringens. The phenotypic characteristics of the strains were studied. All the strains produced acetic and butyric acids and enterotoxin. C. perfringens grew in the spoiled wurstels because it was present in raw meat (Lot 150) at a level of 3.2 log CFU/g due to an unchecked cooling phase that took 28 h to decrease the temperature of the wurstels from 60 to 9-10 °C, which is the lower limit for C. perfringens growth. During the 28 h of cooling, the concentration of C. perfringens increased to 6.5 CFU/g. It was concluded that its presence and the long cooling time were the main factors responsible for the spoilage. Wurstels intentionally made with contaminated meat (3 log CFU/g) but cooled after cooking for 17 h to 9 °C did not support C. perfringens growth; consequently, these wurstels remained unspoiled. The packages of the spoiled wurstels were blown, and the products were soft (soggy), textureless and had the odour of acetic acid, ethanol and sulfur.
从变质的香肠中分离出 300 株梭菌，并通过传统和分子方法鉴定为产气荚膜梭菌。研究了菌株的表型特征。所有菌株均产生乙酸和丁酸以及肠毒素。由于冷却阶段失控，导致香肠温度从 60 降至 9-10°C，这是产气荚膜梭菌生长的下限，需要 28 小时，因此产气荚膜梭菌存在于生肉（Lot 150）中，水平为 3.2 log CFU/g，从而使变质的香肠中存在产气荚膜梭菌。在 28 小时的冷却过程中，产气荚膜梭菌的浓度增加到 6.5 CFU/g。结论是其存在和长时间冷却是导致变质的主要因素。故意用污染肉（3 log CFU/g）制作但在烹饪 17 小时后冷却至 9°C 的香肠不支持产气荚膜梭菌的生长；因此，这些香肠仍然没有变质。变质香肠的包装被吹胀，产品变软（潮湿）、无质地，并带有乙酸、乙醇和硫的气味。
