29B-12 |
Classification and detection of adulteration for dietary supplement oils using Fourier-Transform infrared spectroscopy |
B. F. Ozen, I. WEISS, and L. J. Mauer. Dept. of Food Science, Purdue Univ., 745 Agriculture Mall Dr., West Lafayette, IN 47907-2009 Dietary supplement oils (DSO) are a significant part of the growing dietary supplement industry. Several health claims (anti-inflammatory properties, prevention of the formation of blood clots, and prevention of coronary heart disease, autoimmune disorders, cancers of breast, colon and prostate) are made for DSO (grape seed, flax seed, borage seed, and evening primrose oils). Authenticity is a quality criterion for food ingredients that is attracting increased attention as consumers agree to pay higher prices for products with perceived health benefits. DSO could be likely targets of adulteration with cheaper oils, and adulteration detection methods could be useful. The objectives of this study were to use FT-IR spectroscopy and multivariate statistical procedures to: 1) classify different types of DSO and cheaper oils, and 2) develop a rapid method for detection of adulteration of DSO with cheaper oils using FT-IR. Spectra of 15 types of DSO and 5 types of adulterant oils were collected with a FT-IR equipped with a ZnSe-ATR cell and MCTA detector. Discriminant analysis (DA) was used to classify all oils. Select DSO were adulterated with the adulterant oils (2-20%) that had the closest distance to them in DA, and data was analyzed by partial least square analysis (PLS). Classification of DSO and different types of vegetable oils was achieved successfully with FT-IR. The detection limit for the adulteration of DSO was 2%. Standard curves to determine the adulterant concentration in DSO were also obtained using PLS with correlation coefficients of >0.9 FT-IR is a powerful tool to detect the adulteration of DSO with cheaper oils. Adulteration as low as 2% could be detected accurately and rapidly using FT-IR in combination with multivariate statistics.
Session 29B, Food Chemistry: Lipids, antioxidants and emulsifiers
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