As shown in previous studies, not only the concentration of the dissolved beer ingredients but also their molecular size could influence their filterability. Therefore, polysaccharides of malt, especially P-glucan, are reported to have the greatest impact on filtration behavior. In the present study, the effects of barley (1,3; 1,4)- and yeast (1,3; 1,6)-beta-glucan combined with aroma-relevant substances of beer were studied in Kieselguhr and membrane filtration (polyethersulfone, 0.45 mu m) using ethanolic (4% w/w) model solutions. An increasing P-glucan concentration was found to have a negative impact on both applied filter types. The concentration increase of barley beta-glucan to 300 mg/L decreased the filtrate flux more than 40% during membrane filtration. In contrast, pure medium-chain fatty acid (MCFA) ethyl esters had no effect on filterability. Mixed with (1,3; 1,4)-beta-glucan, the filtrate flux decreased from 400 kg/(h x m(2)) to less than 250 kg/(h x m2). A decrease of MCFA ethyl ester up to 90% was measured in the filtrate. Compared with barley beta-glucan, an equivalent concentration of yeast beta-glucan caused a flux decrease of more than 95% during membrane filtration. In summary, synergistic effects on filterability with polysaccharides and fermentation byproducts could be shown.     «

As shown in previous studies, not only the concentration of the dissolved beer ingredients but also their molecular size could influence their filterability. Therefore, polysaccharides of malt, especially P-glucan, are reported to have the greatest impact on filtration behavior. In the present study, the effects of barley (1,3; 1,4)- and yeast (1,3; 1,6)-beta-glucan combined with aroma-relevant substances of beer were studied in Kieselguhr and membrane filtration (polyethersulfone, 0.45 mu m) us...     »