Measuring changes in internal meat colour, colour lightness and colour opacity as predictors of cooking time

Consumers and cooks often assess the degree of doneness of roasted beef by the internal meat colour. Real-time colour measurement of the cooking process is therefore developed in order to determine the degree of doneness, and thus the end of the cooking process, by the internal meat colour. The colour values (X, Y, Z) provided by the true colour sensor show significant variation within initial values and end values. Change in colour lightness caused by the increase of meat colour opacity is dominant. Calculating the first deviation of the Y values (dY/dt) indicates that most rapid changes in lightness are within a temperature range of 42 °C and 56 °C. At this temperature, the degree of meat doneness is still assumed to be rare, but it is possible to predict the time needed from this point until the desired degree of doneness is reached.