ANALYSIS OF ADULTERATION OF VIRGIN COCONUT OIL BY PALM KERNEL OLEIN USING FOURIER TRANSFORM INFRARED SPECTROSCOPY

Abstract

Virgin coconut oil, a relative newcomer in the fats and oil market, is fast becoming a valuable oil next to virgin olive oil. Therefore, it is important to establish reliable purity criteria to assure its premium quality. A study was carried out to assess the effectiveness of Fourier transform infrared (FTIR) spectroscopy in detecting adulteration of virgin coconut oil with palm kernel olein as a potential adulterant. Multibounce attenuated total reflectance measurements were made on pure and adulterated samples of virgin coconut oil. Detection of adulteration up to 1% was possible. Discriminant analysis using 10 principal components was able to classify pure and adulterated samples on the basis of their spectra. A partial least square calibration demonstrated good linear regression of actual value against that predicted by FTIR with coefficient of determination (R²) of 0.9875 and root mean square error of cross validation of 1.70. Discriminant analysis was also equally effective in designing virgin coconut oil samples as distinct from other vegetable oils.