Dietary Supplement Oil Classification and Detection of Adulteration Using Fourier Transform Infrared Spectroscopy

• Published in: Journal of agricultural and food chemistry 2003-09, Vol.51 (20), p.5871-5876
• Main Authors: Ozen, Banu F, Weiss, Ilan, Mauer, Lisa J
• Format: Article
• Language: English
• Subjects: Dietary Fats, Unsaturated - analysis; Dietary Fats, Unsaturated - classification; Dietary Supplements; Food Contamination - analysis; Plant Oils - analysis; Plant Oils - classification; Spectroscopy, Fourier Transform Infrared
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf034245h

Fourier transform infrared spectroscopy (FT-IR) methods and common chemometric techniques [including discriminant analysis (DA), Mahalanobis distances, and Cooman plots] were used to classify various types of dietary supplement oils (DSO) and less expensive, common food oils. Rapid FT-IR methods were then developed to detect adulteration of DSO with select common food oils. Spectra of 14 types of DSO and 5 types of common food oils were collected with an FT-IR equipped with a ZnSe attenuated total reflectance cell and a mercury cadmium telluride A detector. Classification of DSO and some common food oils was achieved successfully using FT-IR and chemometrics. Select DSO were adulterated (2−20% v/v) with the common food oils that had the closest Mahalanobis distance to them in a Cooman plot based on the DA analysis, and data were also analyzed using a partial least-squares (PLS) method. The detection limit for the adulteration of DSO was 2% v/v. Standard curves to determine the adulterant concentration in DSO were also obtained using PLS with correlation coefficients of >0.9. The approach of using FT-IR in combination with chemometric analyses was successful in classifying oils and detecting adulteration of DSO. Keywords: Dietary supplement oils; Fourier transform infrared spectroscopy; FT-IR; adulteration