低溫保存 sausage로부터 微生物叢의 分離와 그들의 蛋白分解能

Isolation of microflora from sausages stored at low temperature and their proteolytic activities

The pork and Korean native goat sausages were stored at 5℃ for 50 days. The psychrotrophic bacterial counts in the materials during storage were made at 10-day intervals and the methods adapted for the enumeration of psychrotrophic organisms were those widely used by the dairy microbiologists. The microflora in the materials were cultivated on various selective media and the proteolytic activities of the isolates were determined by using casein agar. The results obtained were summarized as follows; 1. No differences were found either between different temperatures or between different media in the psychrotrophic bacterial counts. 2. The psychrotrophic bacterial count was less than 1,000 per gram of material at day 10 of storage; it increased up to 10⁶ per gram of material at day 50 of storage. 3. At day 10 of storage, viable bacterial count was most numerous: the rest were in the decreasing order Gram-positive cocci, Gram-negative bacilli, psychrotrophic bacteria, acid-producing bacteria and yeasts. 4. The number of Gram-positive cocci decreased to less than 50 per gram at day 50 of storage, while the number of acid-producing bacteria increased up to 1 per gram at the same interval. 5. About 41% of the psychrotrophic bacteria manifested proteolytic activities. 48.9% of Gram-negative bacilli, 34.3% of Gram-positive bacilli and 30.4% of Gram-positive cocci, respectively, showed proteolytic activities. In the present experiments, it was noted that the method of choice for psychrotrophic bacterial count could be the bacterial culture on plate count agar or CVT media for 3 days at 25℃. It was also found that the microflora in the sausages could be rapidly enumerated by using selective media.