2,6-dichlorophenol-indophenol is more stable in 75% ethanol than in aqueous solution and ascorbic acid reacts considerably faster in this media than glutathione. The activity determination of glutathione: dehydroascorbic acid oxidoreductase was based on these observations by a photometric measurement of the ascorbic acid resulting from the catalysis. Extracts from various types of wheat were tested and relatively high enzyme activities were found.