Assessment of maximum cooking temperatures in previously heat treated beef. Part 1: Near infrared spectroscopy

Near infrared diffuse reflectance (NIR) and transmittance (NIT) spectroscopy were studied as potential methods for determination of the previous heat treatment of beef. Ninety-four samples of M longissimus dorsi from 33 bulls were heat treated at nine different temperatures between 50 and 85°C, and analysed by NIR and NIT spectroscopy. The samples were analysed by NIR and NIT in both ‘wet’ and freeze dried states. The NIR and NIT methods were able to determine the maximum temperature of previously heat treated beef with a prediction error of 2.0-2.1°C in the temperature range 50–85°C. Freeze drying of the samples prior to analysis reduced the prediction error to 1.4°C for the NIR method. NIR and NIT should be useful as fast screening methods to determine whether beef has been adequately heat treated.