Freezing rate effects on the drip loss of frozen beef.

One of the quality parameters of frozen meat is the amount of exudate which arises during thawing. The amount of drip obtained by centrifugation under standard conditions, and the protein composition of the exudate, has been correlated for different thermal histories. The results obtained show that the amount of exudate varies in relation to the time that the sample needs to pass from -1°C to -7°C (characteristic freezing time). On the other hand, pH and concentration of proteins do not show significant differences between frozen and unfrozen samples. Similarly, neither one nor the other varies with the rate of freezing. The proteins were also analysed by electrophoresis in polyacrylamide gel. In this case, no differences were observed either between frozen samples and unfrozen ones or between samples which had been frozen at different rates. Hypotheses on the origin of cellular damage and alternatives which lead to the establishment of a standard of quality for quick frozen meat are presented in relation to the results obtained.