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STUDIES ON HAZE PRECURSORS IN BEERS AND WORTS
Author(s) -
Woof J. B.,
Pierce J. S.
Publication year - 1968
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.2050-0416.1968.tb03125.x
Subject(s) - chemistry , sephadex , elution , fractionation , adsorption , polyphenol , chromatography , tannin , flavonoid , hydrogen bond , alkali metal , organic chemistry , molecule , food science , antioxidant , enzyme
Detailed studies have been carried out on the fractionation of worts and beers on Sephadex and Bio‐gel columns with high degrees of cross‐linking. On G.25 Sephadex , the excluded fraction contains much of the total protein in the form of complexes with polyphenols bound in such a way that they do not interact with the column material. Continued elution with aqueous solvents gives many low molecular weight wort components and in addition some protein‐polyphenol complexes which are retarded by relatively weak adsorption on the column. These compounds have been further studied by rechromatography in urea to dissociate the complexes and after reaction with excess flavonoid. Since the adsorbed compounds interact with the column through hydrogen bonding of active phenolic bonds, it may be that these are also the compounds which cross‐link with other protein complexes in the beer to build up haze particles. Molybdate and alkali can be used subsequently to elute the free tannin and flavonoid molecules which are strongly absorbed.