Detection of palmolein oil adulteration in milk fat using ATR-FTIR Spectroscopy and Chemometrics

Abstract

Clarified milk fat (ghee), a household staple in domestic India faces the threat of adulteration due to its economic value.  Examination of the purity of milk fat by chemical analysis is complex and time-consuming. The presence of palmolein oil in clarified milk fat was investigated using ATR-FTIR spectroscopy in combination with chemometric techniques. Spectral data within the wavenumber range of 4000-500 cm⁻¹ were obtained for pure ghee, palmolein oil, and spiked ghee samples at various palmolein oil concentrations (1, 3, 5, 10, 15, and 20%). PCA identified distinct spectral clustering patterns at specific wavenumbers (1167-1137 cm^-1) at a 5% significance level, effectively separating pure ghee from adulterated samples. The SIMCA method yielded a remarkable 100% classification efficiency for both pure ghee and palmolein oil samples. Additionally, developed PLS and PCR models exhibited strong predictive accuracy, with high R² values (0.96), enabling the detection of palmolein oil adulteration in ghee, even at concentrations as low as 1%. This research showcases the potential of ATR-FTIR with chemometrics analysis in ghee adulteration, offering a faster and more accurate routine analysis method.