Kvasny Prum. 1990; 36(5): 129-132 | DOI: 10.18832/kp1990016

Significance of polyphenolic compounds for protein precipitation during wort boiling.Peer-reviewed article

J. ŠKACH, A. MIKYŠKA

Effects of heat denaturation and "tannin power" of polyphenols on the protein precipitation during wort boiling were studied. The results show that even a relatively high dose of hop polyphenols has no higher effect on the protein precipitation. The same results were obtained with malts without anthocyanogenes, i. e. proteins that are probably high sensitive to the "tannin power" of hop polyphenols. From these results it can be concluded that the protein precipitation during wort boiling occurs mainly due to heat denaturation. Therefore, polyphenols from wort and hop have significantly lower effect on this process. The analysis of compounds that are precipitated from wort with changing pH showed that extract compounds of hopped wort having a low solubility at a usual pH of beer have come above all from malt and correlated well with the level of malt polyphenols. Using malts from barleys without anthocyanogenes lower precipitates from hopped wort were achieved at pH between 4 and 5.
(In Czech, English summary only)

Keywords: mashed wort, wort boiling, polyphenolic substances, proteins, hops

Published: May 1, 1990