Microflora of cold and frozen-stored meat

Abstract

Summary The bacteriological analysis of three different muscles, L. dorsi, P. major and P. minor, and Extensor and Flexor, taken from buffalo, beef, and mutton was carried out. Five, groups of bacteria, namely: mesophilic, psychrophilic, lipolytic, proteolytic, and coliform were studied. The presence and counting of these groups were examined in the samples immediately after slaughtering and then during storage at 4°C and -10°C for different periods up to 6 months. The results revealed that the total number of bacteria slightly and gradually decreased during the refrigerated storage of meat. No differences could be detected according to either the type of muscles or the kind of animal investigated. Inconsiderable increase in the numbers of lipolytic, proteolytic, and psychrophilic bacteria was detected. Coliform bacteria were present in all fresh samples of meat. However, the numbers of this group could be detected by the end of the fourth week of refrigerated storage, with the exception of L. dorsi, P. major and P. minor muscles of buffalo meat, in which coliform bacteria disappeared by the third week of storage. On the other hand, the microflora of the above mentioned muscles of different types of the investigated meat was markedly influenced by storage at -10°C. The number of bacteria which survived 6 months of storage under the experimental conditions ranged between 11–26%, as compared with the initial numbers in fresh meat. Meanwhile, the coliform bacteria could not be detected in the samples, even after one month of storage at -10°C.