The Precipitates in Packaged Beer Caused by β-Glucanase

Abstract

When acid protease preparation was added to packaged beer to prevent the papain-involved gushing, the white flake-like precipitates were formed after several days at room temperature. The precipitates were mainly consisted of β-glucan (β-(1→3):(1→4)=1:4.0) and pentosan (Arabinose: Xylose=1:2.7). In order to clarify the cause of the precipitation, its precursor and the factor which took part in these precipitate-formation were studied. The precursors of precipitates were β-glucan (β-(1→3):(1→4)=1:2.3) and arabinoxylan (Arabinose:Xylose=1:1.4-1.7) in beer, and these origins were considered to be β-glucan from barley endosperm cell wall and arabionoxylan from husk, respectively. The precipitate-forming factors which were isolated from the enzyme preparation, were found to be mainly β-glucanase and arabinofuranosidase.