Changes in the physicochemical and microbiological properties of pork and chicken meats at ambient storage condition
Pork and chicken meat samples were collected from pre-selected slaughterhouses to characterize the pH, titratable acidity (%TA) and aerobic plate count (APC) from slaughter until end of shelf-life at ambient temperature (30±2ºC). Results showed that the population of microorganisms on meat samples increased over the storage time. On the other hand, pH and % TA were variable, showing no statistically significant changes throughout the storage period. Based on microbiological analysis, the shelf-life of pork and chicken meats ranged from 8 to 12 h and 3 to 6 h, respectively. Pearson correlation revealed there was no significant relationship between APC and pH of pork (r=-0.10, n=278, p>0.05) or between APC and %TA of pork (r=0.053, n=278, p>0.05). On the other hand, there was a weak negative relationship between APC and pH in chicken (r=-0.165, n=267, p<0.005) and a positive relationship between APC and %TA (r=0.401, n=266, p<0.005). This showed that pH cannot be used as a good indicator of meat spoilage. Furthermore, the differences between fresh and obviously spoiled meat samples, for both pH and %TA, were not great enough for practical use.