Simultaneous determination of iodine value and trans content of fats and oils by single-bounce horizontal attenuated total reflectance Fourier transform infrared spectroscopy

A method for the simultaneous determination of iodine value (IV) and trans content from the Fourier transform infrared (FTIR) spectra of neat fats and oils recorded with the use of a heated single-bounce horizontal attenuated total reflectance (SB-HATR) sampling accessory was developed. Partial leas t squares (PLS) regression was employed for the development of the calibrat ion models, and a set of nine pure triacylglycerols served as the calibrati on standards. Regression of the FTIR/PLS-predicted IV and trans contents fo r ten partially hydragenated oil samples against reference values obtained by gas chromatography yielded slopes close to unity and SD of <1. Good agre ement (SD <0.35) also was obtained between the trans predictions from the P LS calibration model and trans determinations performed by the recently ado pted AOCS FTIR/SB-HATR method for the determination of isolated trans isome rs in fats and ails.