Rapid Determination of Free Fatty Acid in Animal and Vegetable Oil and Fat by Near-Infrared Spectrometry

Near-infrared spectrometry was applied to the rapid determination of free fatty acid in animal and vegetable oil and fat. The basic reference values were obtained by chemical method. Combining the results obtained by near-infrared spectrometry with partial least squares regression method, the calibration models of tallow, palm kernel oil and castor oil were established with coefficients of determination of 0.997 9, 0.997 4 and 0.976 7, and mean square deviations of calibration of 0.190%, 0.083 4% and 0.059 2% respectively. The proposed method was applied to the analysis of samples of animal and vegetable oil and fat, giving results in consistency with the values obtained by chemical method with RSD′s (n=10) less than 6%.