The development of a nonmicrobial off-condition in fresh meat.

It has long been accepted, prima facie, that bacteria are the sole cause of a "sour" condition which is occasionally but persistently found in some fresh beef rounds. Evidence is presented which indicates that this condition often bears no relation to the bacteriology of the muscle involved. It was observed that sour rounds contain elevated quantities of volatile fatty acids. On the basis of experiments in which this condition was artificially induced in vivo, it is suggested that a metabolic block of meat enzymes could account for this build-up of short chain acids.