Distributions of Microorganisms and Identification of Pathogenic Bacteria Isolated in Raw Beef of Jangzorim

Raw beefs used fer Jangzorim production were evaluated fur contamination of pathogenic bacteria and microorganisms related to spoilage and food safety. Eleven groups of mesophilic, psychrotrophic, and anaerobic microorganisms, and total coliforms were selected to evaluate degree of food contamination. Nine strains including Bacillus cereus, Clostridium botulinum, C. perfringens, and Listeria monocytogenes were selected to evaluate incidences of pathogenic bacteria. Raw beefs harbored large populations of microorganisms, which decreased greatly after heat treatment. Psychrotrophic microorganisms were found to be more abundant than other microorganisms. B. cereus, C. perfringens, and L. monocytogenes were isolated from raw beefs, whereas C. botulinum, Escherichia coli O157:H7, Salmonella spp., Shigella spp., Staphylococcus aureus, and Yersinia enterocolitica were not isolated. Isoiates from Cereus selective agar, clostridium Perfringens agar, and Oxford agar were in 99.8, 99.9 and 98.6% agreements with B. cereus, C. perfringens, and L. monocytogenes at species level, respectively. B. cereus produced enterotoxin with CRET-RPLA method, whereas C. perfringens did not produce enterotoxin with PET-RPLA method.

장조림 원료육의 미생물 분포 및 분리 병원성세균의 동정

장조림 원료 쇠고기 우둔살과 가열 처리한 쇠고기 우둔살에서 중온성균, 저온성균 등 11종의 미생물에 대한 분포도를 측정하였고, B. cereus, C. botulinum, C. perfringens, L. monocytogenes 등과 같은 9종류의 주요 병원성세균의 분리를 시도하였다. 원료육에서 미생물분포는 대부분 높은 분포를 보였으나 가열 처리육에서는 대부분 검출되지 않았다. 원료육에서 저온성균은 오염지표세균 중에서 가장 높은 분포를 나태낸 반면, 가열처리 후 급격하게 감소하였다. 식중독균인 B. cereus, C. perfringens 및 L. monocytogenes 등 3균주가 원료육에서 분리된 반면 C. botulinum, E. coli O157:H7, Salmonella spp., Shigella spp., S. aureus 및 Y. enterocolitica는 분리되지 않았다. 원료 쇠고기에서 분리된 B. cereus는 CERT-RPLA 방법에 의해 enterotoxin을 생성한 반면, C. perfringens는 PET-RPLA 방법에 의해 독소를 생성하지 않았다.