Raman Spectroscopy as a Rapid Tool for Quantitative Analysis of Butter Adulterated with Margarine

Abstract

Butter adulteration with margarine continues to be a threat for consumers; therefore, new rapid analytical tools are needed for quality control/quality assurance purposes. In this study, we used Raman spectroscopy coupled with partial least squares regression to quantify butter adulteration with margarine. The main difference between Raman spectra of butter and margarine comes from two bands associated to C=C double bond (1656 and 1268 cm(-1)) and the band associated to phospholipids' choline group (973 cm(-1)). The intensity of these peaks decreases with a decreasing margarine content. The coefficient of determination (R (2) = 0.994) and root-mean-square error of prediction (RMSEP = 2.754) display very good overall model performance. The sample preparation procedure that we employed was notably simplified compared to previous studies. This confirms that Raman spectroscopy can be effectively applied to quantify butter adulteration with margarine and further indicates that simplification of the analysis procedure is possible. These results could aid the efforts for implementation of this technique in routine rapid quality analysis of butter.