ELECTROFOCUSING STUDIES ON THE FORMATION OF BEER HAZE

Abstract

The composition of protein fractions obtained from beers stored under differing conditions has been studied using a modified system for isoelectric focusing in thin layers of polyacrylamide gel which permitted the numerical evaluation of the focused bands by a scanning densitometer. The incorporation of concentrated urea in the gel enabled beer hazes to be assessed in this manner. The ageing of an unstabilized all-malt beer resulted in an increase in the proportion of acidic material (pl <5.0) although no new protein bands were formed. The derived hazes were enriched with acidic components but contained all except the most basic fractions present in the beer.