Multivariate calibration of raw cow milk using NIR spectroscopy.
O. Kukačková, L. Čurda, J. JindřichCitation:Kukačková O., Čurda L., Jindřich J. (2000): Multivariate calibration of raw cow milk using NIR spectroscopy. Czech J. Food Sci., 18: 1-4.
At present, mid-IR spectroscopy is the preferred rapid method for milk analysis. NIR spectrometers have some advantages in comparison with mid-IR. The purpose of this study was to see a possibility of determining the total solids, fat and protein in milk. The total number of preserved raw cow milk samples was 65. NIR spectra were recorded in duplicate on the NIRS 6500 instrument (NIRSystems, Inc.) using a fiber optic probe. The reference method for milk samples used for calibration model was determined by oven drying to measure the total solids, by Gerber method to measure fat content, and by Kjeldahl method to measure protein content. A commercial spectral analysis NIRS 3 software was used to process and develop chemometric models. The calibration was calculated using the modified partial least squares (MPLS) regression. The following statistical values (correlation coefficient R and standard error of prediction SEP) were obtained: R = 0.975 and SEP = 0.160% for milk total solids, R = 0.967 and SEP = 0.179% for milk fat content, R = 0.965 and SEP = 0.049 % for protein content. Using the NIR instrument the multivariate models suitable for rapid fundamental analysis of milk were developed.Keywords:near infrared spectroscopy; raw cow milk; total solids; fat, protein