The analysis of alpha tocopherol and other E-group vitamers in cereal grain foods

Abstract

Recent studies of cereal foods have been focused upon water soluble vitamins and many of these are relatively unstable during processing. Among the conditions that are important determinants of retention are processing steps of heating as well as pH. However, it has also been shown that procedures for extraction and analysis of the vitamin require careful adaptation for particular foods as well as evaluation and validation. The purpose of the current study has been to investigate methods for measurement of vitamin E in cereal foods. The challenge is to measure up to eight vitamer forms including both tocopherol and tocotrienols and a number of HPLC methods have been compared. As alternatives to the normal phase approaches commonly used, reversed-phase systems have been trialled as a means of reducing cost and environmental issues associated with the solvents required. None of the alternative approaches have been effective and so normal phase options have been compared. Newly reported approaches for extracting vitamin E using accelerated solvent extraction (ASE) have been compared with traditional saponification. Suitable options have been evaluated for separation and quantitation of the vitamers from cereal grains and the procedures have been applied to investigations of wholemeal flours and the retention of vitamin E during the bread-making process.