European Brewery Convention-Haze and Foam Group Amino Acid Composition of the Beer Haze Components Retained by Inorganic Adsorbents

The amino acid composition of the substances retained by bentonite, Stabifix and Stabiquick on addition to filtered Pilsner beers was determined by ion-exchange chromatography. The results indicate large differences between the 3 adsorbents. Stabifix is the most selective, for the amino acid composition of the adsorbed substances is very similar to that of the chill hazes of the E.B.C. The prolamin content is high. Bentonite adsorbs proportionally more salt-soluble proteins. Stabiquick, in agreement with its composition, is less selective than Stabifix, but adsorbs proportionally more prolamins than bentonite. The difference between the adsorbents was also confirmed by solubility measurements in the solvents most commonly used in this laboratory for the extraction of the prolamins. The desorption of the nitrogenous substances decreases from Stabifix to Stabiquick and from Stabiquick to bentonite. A comparison by Sephadex G-25 and G-50 chromatography of the beers before and after treatment indicated that in addition to the nitrogenous substances other components are retained by the adsorbents.