BEHAVIOR OF PSEUDOMONAS AERUGINOSA DURING MANUFACTURE AND STORAGE OF DAMIETTA CHEESE AND MINCED MEAT

SAAD, NAGAH M.; FATHI, SH.M.

doi:10.21608/avmj.1992.186647

BEHAVIOR OF PSEUDOMONAS AERUGINOSA DURING MANUFACTURE AND STORAGE OF DAMIETTA CHEESE AND MINCED MEAT

Document Type : Research article

Authors

10.21608/avmj.1992.186647

Abstract

Two portions of laboratory p < /strong>asteurized milk artifically contaminated with ap < /strong>prox. 10° pseudomonas aerugionsa/ml were used to manufacure Damietta cheese after addition of 5% and 10% sodium chloride and rennet. Cheese samples were stored in their whey at room temperature (30 + 1C) and examined periodically for Ps. aerugionsa count, pH value, moisture and salt contents. Pseudomonas aerugionsa increased in numbers during the initial stage of manufacture of both typ < /strong>es of cheeses. However, the organism was not detected after 3 and 6 weeks in these cheeses, respectively. Progressive reduction in Ps. aerugionsa count in cheeses was associated with a significant drop in pH and moisture content, while salt content increased during storage period. Also three samples of prepared minced meat were inoculated with ap < /strong>prox. 10° Ps. aerugionsa/g. Two samples, one with added 5% onion and the other one without onion were stored at chilling temperature (4+ 1 C), while the third one without onion was stored at deep freezing temperature (24 + 1 C), and tested periodically for Ps. aerugionsa count and pH value. The organism decreased gradually in numbers but can not be eleminated from minced meat. However the organism was detected after 9 and 12 days in minced meat without and with 5% onion at chilling temperature, respectively untill decomposition occur, and after 47 days in minced meat stored at deep freeezing temperture. There was a gradual decrease in pH value followed by gradual increase in three types of minced meat. The public health significance of these findings are discussed.