| Abstract: | A husk polysaccharide component from a malt causing premature yeast flocculation was isolated and characterized, and its effect on the fermentation pattern of Saccharomyces cerevisiae 2036 established. A particular malt husk extract, obtained using a mild aqueous extraction procedure, induced premature flocculation when added to fermentations in normal wort. In sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of the malt husk extract, 4 protein bands (42,600; 17,500; 15,100 and 13,100 daltons) and a high molecular weight polysaccharide were identified. These components were separated by gel chromatography and their effect on the fermentation pattern established. Only the polysaccharide fraction induced premature flocculation. Sugar analysis of this fraction indicated the presence of arabinose, galactose, glucose, mannose, xylose, rhamnose and an acidic sugar component. The polysaccharide fraction showed haemoagglutination activity, which was not inhibited by any of 11 simple sugars tested. |
