Kvasny Prum. 1959; 5(7): 153-160 | DOI: 10.18832/kp1959018

Polyphenolic substances in malt steeping water.Peer-reviewed article

A. KOCKOVÁ-KRATOCHVÍLOVÁ, M. LUKÁŠOVÁ-NOVOTNÁ

Polyphenolic substances which are present in raw materials used by breweries find their way into final product and deteriorate its properties. In the first place tanning matter from barley should be mentioned. It is therefore desirable to leach the greatest possible part of such matters by steeping process in malt plants. The experiments with steeping barley in alcalic water indicate that the method is efficient and can remove a substantial proportion of polyphenolic substances. Chromatograms of extracts from alcalic water are distinguished by spots of more intensive and brighter fluorescence than chromatograms of conventional water. The results of research work aimed at isolation and identification of polyphenolic substances in the steeping water can be summed up as follows: 1.An efficient method has been worked out for extracting polyphenolic compounds and classifying them into groups. 2.After extraction individual fractions were divided by paper chromatography. 3.Various derivates were isolated by leaching the spots on chromatograms and repeated application of paper. 4.The secondary spots were supposed to be pure substances and were consequently identified by means of spectrophotometric methods. 5.Seven polyphenolic derivates were isolated from steeping water. The reaction of one of the compounds is identical with the chlorogen acid. The absorption spectrum of the second matter is very much the same as that of catechine. Another substance has its absorption maximum in the region of flavonoids. This substance was not identified more precisely. Yet another matter may be determined, using criteria recommended in various papers, as tannic acid. 6.Derivates differentiated by paper chromatography were studied from the point view of their influence upon germination process of barley. The substance with properties of chlorogen acid has an inhibiting effect. So does the substance identified as tannic acid. Less perceptible effect has the substance with the absorption curve similar to catechine and yet another substance present in each of the tested solutions characterized on chromatograms as orange fluorescent spot.
(In Czech, English summary only)

Keywords: maltery, polyphenols, steeping water

Published: July 1, 1959