Kvasny Prum. 1961; 7(7): 145-152 | DOI: 10.18832/kp1961023

Direct quantitative determination of polypeptides in beer.Peer-reviewed article

J. HUMMEL

The article shows, that polarographic methods can be successfully applied for direct quatitative determination of polypeptides in beer to be delivered from breweries. The test is based upon the comparison of a standard sample with samples of beer of the same strength. The article deals further with the quatitative changes effecting polypeptides at processing beer with ammonium sulphate, with polyptides in samples taken during stabilization tests, with effect of the diatomite composition, of sorption earths and filtration upon polypeptides in 8 ˚ beer. Direct Brdička reaction can be used for determining the intensity of colloidal stabilization. The reduction of the catalytic wave height, expressed in mg % of cystine, as compared with the sample of nonstabilized beer of the same strength is taken as criterion. Two different stabilization methods have been compared. One consisted in introducing tannin and proteolyte, the other was a conventional one based on sorption substances. The durability of beer has been imporved there being no difference between the two methods, provided the polypeptides of Brdička reaction had been reduced by 25,5 % in the first case and by 28,7 % in the second. Low adsorption capacity of the Hyflo Super Cel diatomite is worth mentioning.
(In Czech, English summary only)

Keywords: beer, polypeptides, determination

Published: July 1, 1961