EVALUATION OF A MATHEMATICAL-MODEL FOR PREDICTION OF LIPID OXIDATION IN HEAT-TREATED BEEF DURING CHILL STORAGE

Ground beef was heated to temperatures ranging from 60 to 120 degrees C and was stored at 5 degrees C for 0-7 days. The oxidative status of the meat samples was quantified by sensory evaluation and by measurement of thiobarbituric-cid-reactive substances (TEARS). A model describing the effect of moderate heating temperatures (60-80 degrees C) and chill storage time on the development of TEARS has been developed previously, and experiments were conducted to evaluate and extend this model. It was demonstrated that the model could be used for prediction of the individual effects of heating time and heating temperature. The level of TEARS during chill storage almost doubled when the heating temperature increased from 60 degrees C to 70 degrees C, but it was unaffected by increasing heating temperatures from 70 degrees C to 100 degrees C. Higher heating temperatures caused a remarkable increase in the oxidative stability, TEARS hardly increased during storage after heating to 110 degrees C or 120 degrees C. A more elaborate model was developed to describe the effect of heating temperatures in the range of between 60 degrees C-120 degrees C on development of TEARS, but the predictive value turned out to be unsatisfactory. The sensory evaluations were highly correlated with TEARS, and the use of TEARS as a measure of warmed-over flavour was verified.