MICROBIOLOGY OF PALE, DARK AND NORMAL PORK

Abstract

ABSTRACT Pale, soft, exudative (PSE), dark cutting, and normal colored pork were compared to determine differences in susceptibility to microbial growth. Chops were packaged and stored under simulated retail conditions. Color, marbling, pH, numbers of total aerobic mesophiles, psychrotrophs, proteolytic and lipolytic bacteria and fluorescent Pseudomonas and incidence of Salmonella and coagulase positive Staphylococcus were recorded for pork chops as storage time progressed. Data were statistically analyzed. Differences in pH between PSE and normal chops, after aging, were significant, and dark chops had significantly higher pH values than normal chops. Development of microorganisms during storage was influenced by pH. Most rapid growth of organisms occurred on dark meat and slowest bacterial growth on PSE pork, although exudative conditions of the latter provided the highest expressible juice. pH of the meat also seemed to have a selective action on the microflora. Marbling of the meat did not influence growth of lipslytic bacteria. Relevance of various stages of processing as sources of contamination for the meat is discussed.