Solubility of Muscle Proteins as a Result of Autolysis and Microbiological Growth

Bovine Longissimus dorsi samples, collected aseptically 3 hr postmortem, were used to determine natural muscle enzyme activity. Samples of this tissue were inoculated with Pseudomonas putrefaciens or Lactobacillus casei and incubated 0, 1, 7, 14, and 21 days at 2°C and 0, 1, and 3 days at 25 and 37°C. Protein solubility, pH and microbial counts were determined after appropriate periods of storage. Only small differences were noted in the solubility of muscle proteins between the muscle treatments after 21 days of storage at 2°C compared to much larger differences noted after only 3 days of storage at higher incubation temperatures (25 and 37°C).