Fourier Transform Infrared Spectrometric Method for the Rapid Determination of Casein in Raw Milk

Abstract

A Fourier transform infrared (FTIR) spectrometric method was developed for the rapid, direct measurement of casein in raw milk. Data acquisition parameters such as resolution and the types of background spectra were studied in detail to achieve optimum conditions. Two chemometric approaches, partial least-squares (PLS) analysis and principal components regression (PCR), were used in data processing. The method was validated against the International Dairy Federation reference method and the results were satisfactory; the mean difference from the reference method was 0.041% casein. Regression analysis against the reference data gave a slope of 1.00 (± 0.052) and a correlation coefficient of 0.976.