Kvasny Prum. 1996; 42(9): 275-277 | DOI: 10.18832/kp1996021

Colour constituents oxidation of unhopped and hopped wort.Peer-reviewed article

J. ŠAVEL, D. ZDVIHALOVÁ, M. PROKOPOVÁ

The absorbance variations of laboratory and plant unhopped wort were monitored during oxidation through ammonium and potassium peroxodisulfate under laboratory temperature by using differential spectrophotometry. During laboratory unhopped wort oxidation the absorbance was found to be regularly raising at all wavelenghts, most frequently at the low ones. At plant unhopped wort oxidation the absorbance was found initially decreasing, afterwards, raising, which was likely caused by melanoid substances oxidation. This tendency remained unchanged even at plant wort, which evidently is related to substances oxidation, having their origin during wort boiling, among them belonging melanoid substances from hop, possibly hop tannins. By adding ethanol during hopped wort oxidation it was partially possible to reduce turbidity formation measured at 20 C, nevertheless, it promoted turbidity precipitation at 0 °C.
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Keywords: wort, mashed wort, oxidation, colour constituents

Published: September 1, 1996