Meat Spoilage and Evaluation of the Potential Storage Life of Fresh Meat

Abstract

Microbiological processes by which meat develops qualities unacceptable to consumers vary with the composition of the meat and spoilage microflora. Composition of the spoilage microflora is affected by meat composition and storage conditions. Aerobic spoilage microfloras are usually dominated by pseudomonads. With this type of microflora, spoilage occurs when glucose in meat is no longer sufficient for the requirements of the spoilage microflora and the bacteria start to degrade amino acids. When meat is deficient in glucose, spoilage becomes evident while bacterial numbers are relatively small. Anaerobic microfloras are usually dominated by lactobacilli which produce spoilage by the slow accumulation of volatile organic acids. Meat of high utimate pH packaged anaerobically spoils rapidly because the high pH allows anaerobic growth of bacterial species of higher spoilage potential than the lactobacilli. Before overt spoilage develops, the spoilage status of meat can be accurately assessed from the bacterial numbers on meat only when there is assumption or knowledge of meat composition, storage conditions and the types of bacteria present. Methods for estimating spoilage which depend upon detection of products of amino acid degradation have little predictive value as such products will only be present after attack on amino acids has commenced and are irrelevant to spoilage under anaerobic conditions. Estimation of the concentrations of other spoilage products may be the only method applicable to assessment of incipient spoilage of meat stored anaerobically. It is, therefore, unlikely that any single test can give unequivocal information on meat quality under all circumstances, but rapid tests for meat quality could be of value for specific commercial purposes. provided such tests are appropriate to the circumstances and the inherent limitations of any test are recognized.