DETERMINATION OF ANTHOCYANOGENS: III. ANALYSIS OF BARLEY AND MALT

Abstract

The AT method previously described for the determination of anthocyanogens in beer has now been modified for the analysis of barley and malt. Studies on the extraction of anthocyanogens from the grain with alcohol have shown that maximum yield is obtained with 60% ethanol in about 5 hr. Longer extraction periods result in appreciable losses of anthocyanogens which can be prevented by adding ascorbic acid. 95% ethanol extracts only about 30% of the total anthocyanogens in malt, but also extracts the substances which produce a brown colour when heated with HCI. This extract has provided data which confirm the greater specificity of Agent AT and the MP reagent, as compared with Nylon and the butanol reagent, in the determination of anthocyanogens. The method has been applied in preliminary studies of varietal differences in the anthocyanogen content of barley and the changes during malting and mashing.