Serine peptidase inhibitors, the best predictor of beef ageing amongst a large set of quantitative variables

Stepwise linear regression was used to determine the best equation (p < 0.05) for predicting toughness at 6 days post-mortem. A 6-variables predictive equation including serine peptidase inhibitors (partial R2 = 0.4), the rate (partial R2 = 0.25), and the extent of pH decline (partial R2 = 0.03), the at death LDH activity (partial R2 = 0.24), the extent of increase in osmotic pressure (partial R2 = 0.13), and the rate of μ-calpain activity loss (partial R2 = 0.09), explained 70% of the variability in meat toughness at 6 days post-mortem. This equation was developed from 20 animals and the other 3 animals, chosen randomly, were used to validate it. The absolute need for a predictive model of meat toughness and the nature of the serine peptidase inhibitors together with their potential target enzymes are discussed.