The contribution of indigenous meat enzymes to spoilage is negligible compared to the action of microbial flora() Indeed the post-mortem glycolysis , caused by indigenous enzymes , ceases after the death of animal when ultimate pH reaches a value of 4.5 – 5.5 . On the other hand , the indigenous proteolytic and lipolytic enzymes are not enough to affect meat spoilage or conditioning (ageing). In the latter case, enzymes, or other chemicals, or mechanical means are applied to play an artificial role in meat tenderization