Vitamin E Content of Margarine and Reduced Fat Products Using a Simplified Extraction Procedure and HPLC Determination

Abstract

A liquid chromatographic method is described for the analysis of vitamin E in margarine and vegetable oil products (spreads). The tocopherol homologs (α, γ, δ-tocopherol) are extracted in hexane with anhydrous MgSO₄ added to remove water. Complete resolution of the homologs is achieved on a normal phase column and a mobile phase of 0.9% isopropanol in hexane with fluorescence detection. Based on five repetitive assays the mean recoveries were 99.0±1.4, 97.4±2.2%, and 99.5±2.6% for α-, γ-, and δ-tocopherol, respectively. The method is rapid, specific, and accurate for the measurement of vitamin E in margarine and vegetable oil spreads. Further, the method avoids: (1) saponification techniques (2) emulsion forming organic solvent extractions and (3) the use of chlorinated solvents. The limit of detection for α-, γ-, and δ- tocopherol were 23.2, 2.96, and 1.98 μg/100g, respectively. The limit of quantitation for α-, γ, and δ- tocopherol were 39.8, 5.00, and 3.02 μg/100g, respectively. The vitamin E content of the margarine and spreads ranged from 5.58 to 24.2 α-TE/100g.