Development of a Rapid Method for Enumeration of Bacteria in Pork Mince

A rapid method for counting bacteria on pork mince was developed, based on membrane filtration of the meat homogenate and fluorescent staining of bacteria. A number of methods of pretreating the pork mince sample were investigated, including filtration through a 5.0 (jm filter, flocculation and the use of proteolytic enzymes. The most successful technique involved the use of an enzyme, Alcalase 0.6 L, to degrade meat proteins. The resulting suspension was passed through a polycarbonate membrane and the bacteria retained were stained using acridine orange. A correlation coefficient of 0.97 was obtained between this method and the standard plate count Five samples could be analysed in 20 minutes.