Raman spectroscopy based characterization of desi ghee obtained from buffalo and cow milk

Raman spectroscopy bands (1006,1156 and 1520 cm(-1)) representing beta-carotenoids differentiated cow ghee from buffalo ghee. The band at 1080 cm(-1) represented free cholesterol, the concentration of which was higher in cow ghee than in buffalo ghee. Vitamin D and conjugated linoleic acid (CLA) in both cow ghee and buffalo ghee was identified through their Raman bands; the former contained more CLA isomers. A partial least squares regression model was developed to predict cow ghee adulteration of buffalo ghee and unknown samples. Coefficient of determination, standard error of prediction and standard error of calibration values of 0.96, 0.101 and 0.105, respectively, confirmed the authenticity of the model. Unknown samples loaded into the model yielded values of 0 or 1, indicating pure buffalo ghee or cow ghee adulteration, respectively. Nine unknown samples were tested blind; the root mean square error in prediction was 0.02, confirming the accuracy of the model. (C) 2018 Elsevier Ltd. All rights reserved.