DETERMINATION OF THE FAT, PROTEIN AND LACTOSE CONTENT OF MILK USING FOURIER-TRANSFORM INFRARED SPECTROMETRY

In this paper the quantitative in-line determination of the composition of milk using Fourier transform infrared spectrometry is described. The fat, protein and lactose content are predicted of which the former two are compared with Rose-Gottlieb and Kjeldahl reference values respectively. Fat, protein and lactose are also determined using a MultiSpec infrared filter instrument. Calibration techniques such as classical and inverse least squares regression, principal component regression and partial least squares regression are applied and the results are compared. All methods appear to perform comparably with respect to prediction error and are equivalent to the conventional filter based method.