Quantitative Determination of Trans Fatty Acids in Branded and Unbranded Vanaspati Ghee Using FTIR Spectroscopy and Chemometric Modeling

Hydrogenated vegetable fats contain trans fatty acids (TFA) which are recognized as primary dietary risk factors of cardiovascular and metabolic diseases. The primary source of industrially manufactured trans-fat in developing countries is vanaspati ghee, because of the partial hydrogenation of vegetable fats prior to production. In this study, we aimed to assess the level of trans fats in samples of branded (n = 8) and unbranded (n = 15) vanaspati ghee using Fourier Transform Infrared (FTIR) Spectroscopy and to develop a chemometric model for quantitative determination of trans fats in samples. FTIR spectra were collected from the mid-infrared region of the spectrum and specifically focused on the 966 cm─1 peak, which corresponds to the wavelength of the trans double bond. A Partial Least Squares (PLS) regression model was developed from the calibration data which showed excellent linearity and a high (R² = 0.99920) coefficient of determination together with a low root mean square error for calibration (RMSEC = 0.223) and prediction (RMSEP = 0.115), validating the method's precision and robustness. It was determined that most of the samples had low detectable levels of trans fats with the branded products showing relatively consistent amounts, however, the unbranded products had much greater variability. Conversely, the inconsistency found in unbranded samples may indicate unreliable processing conditions or possible substitution with saturated fats to achieve lower trans-fat levels. These findings demonstrate that FTIR spectroscopy, when used in conjunction with chemometric modeling, is a reliable and efficient non-destructive and cost- effective method for trans-fat analysis, which offers an excellent means for ongoing quality control and trans-fat monitoring of edible fats.