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GENERAL COMPOSITION OF NON‐BIOLOGICAL HAZES OF BEERS AND SOME FACTORS IN THEIR FORMATION: II. CHROMATOGRAPHIC SEPARATION OF HOP AND MALT TANNINS
Author(s) -
Harris G.
Publication year - 1956
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1956.tb02879.x
Subject(s) - hop (telecommunications) , chemistry , chromatography , composition (language) , chromatographic separation , tannin , food science , high performance liquid chromatography , computer science , computer network , philosophy , linguistics
The polyphenolic constituents of hops and of malt have been examined by means of paper chromatography. The mixtures from the two sources were very complex but quite different in composition. This is in agreement with the results recorded earlier, which had revealed very considerable differences between the phenolic acids derived from barley tannins and from hop tannins by treatment with alkali. While none of the typical malt tannins has as yet been characterized, several individual hop tannins have been identified by means of their chromatographic behaviour and ultraviolet absorption spectra. In addition to the leucoanthocyanins previously recorded, several flavonol glycosides—including iso quercitrin, quercitrin and rutin—have been detected, as well as chlorogenic acid, neochlorogenic acid and allied compounds; gallic acid, protocatechuic acid and caffeic acid have also been observed. Among the phenolic acids formed by degradation of the parent tannins with alkali, caffeic acid, ferulic acid and syringic acid have been identified in addition to protocatechuic acid and vanillic acid.