Developing a rapid and sensitive method for determination of trans-fatty acids in edible oils using middle-infrared spectroscopy

Several countries have adopted labelling policy concerning the declaration of trans fatty acids (TFAs) content in the nutritional facts panel of processed food. Consequently, the food industry requires rapid methods to measure low levels of TFAs. This paper reports the development of a rapid method to determine TFAs <1% in edible oils (palm, peanut, soybean and sunflower) and oils/fat samples extracted from finished products using attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). Traditional linear regression and Partial Least Squares (PLS) statistical tools were applied to model the spectroscopic data. The calibration models of edible oils/fat samples showed a coefficient-of-correlation ⩾0.982 and standard error of prediction (SEP) between 0.03% and 0.06%. The ATR-FTIR results of extracted oils/fat are in good agreement with the capillary gas chromatography with flame ionisation detector (GC/FID). This study has demonstrated that ATR-FTIR technique can be used to rapidly determine trans fatty acids <1% in oils/fat.