The effect of temperature on colorimetric values of electrically stimulated beef

Abstract

The effect of electrically stimulating bovine carcass on the relation between temperature and the colorimetric variables L*, a*, b*, C* and H* was determined using a sample of 260 carcasses processed in a federal inspection type slaughter plant (TIF) located in Mexicali, Mexico. Two types of linear regression models that included a dummy variable were used, which assumed a value of 1 when the carcass was stimulated and 0 when not, the first model determined the change in intercept resulting from electrical stimulation and the second model measured the change in the slope. In the first model, the differential effect of the stimulation was estimated for L*, a*, b*, C*and H* while in the second model the change in the dependent variable as a result of a unit change of temperature was measured. It was found that the electrical stimulation of the carcasses increased the values of a*, b*, C*and H* 24 hours after slaughter and that the stimulated carcasses showed a higher value for the same variables as a result of temperature reduction when compared with non-stimulated carcasses. No statistical relation was found in the case of L*. Considering that electrical stimulation is a qualitative variable, regression models with dummy variables may be considered useful tools to measure its effects.