OIL AND FAT CLASSIFICATION BY FT-RAMAN SPECTROSCOPY

One hundred and thirty-eight edible oil and fat samples from 21 differ ent sources, either vegetable (Brazil nut, coconut, corn, high oleic s unflower, alive oil, peanut, palm, palm kernel, rapeseed, soybean, sun flower, etc.) or animal (butter, hydrogenated fish, and tallow) have b een analyzed. The spectral features of the most noteworthy bands are s tudied, and their correlations with the amount of fatty acids quantifi ed by gas chromatography are presented. Principal component analysis i s applied to classify the set of samples by their level of unsaturatio n [saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA)]. The most remarkable MUFA and PUFA oil sources are indep endently classified by applying stepwise linear discriminant analysis to the Raman shifts selected by their correlation with fatty acids or structural assignments. The results show that FT-Raman spectra not onl y have information of the degree of unsaturation but also of the balan ce among the amounts of SFA, MUFA, and PUFA. The scattering intensitie s near different Raman shies (3013, 1663, and 1264 cm(-1)) show high c orrelations with the fatty acid profile determined by gas chromatograp hy.