Kvasny Prum. 1999; 45(3): 66-70 | DOI: 10.18832/kp1999005

Role of amino acids and higher alcohols in nonenzymatic oxidation of beer.Peer-reviewed article

J. ŠAVEL, D. ZDVIHALOVÁ

The oxidation of aromatic and heterocyclic higher alcohols furfurylalcohol, phenylethanol, benzylalcohol and amino acid phenylalanine with potassium peroxodisulfate has proved their sensitivity to oxidation reactions. By oxidation of phenylalanine and phenylalcohol was formed phenylacataldehyd, with subsequent development of haze forming substances. The degradation of furfurylalcohol and furfural is possible to monitored spectrometrically after steam distillation, which can be used from monitoring of antioxidative effect of different substances. Antioxidative effect is also possible to determine according to changes of natural chemiluminescence of beer and its intermediates after addition of solution of potassium peroxodisulfate. An aqueous extract of hops exhibited antioxidative effects. After addition of potassium peroxodisulfate to the solution of melanoidic substances the intensity of chemiluminescence increased, which is possible to consider the evidence of their prooxidative activity. Melanoidins are able to oxidize the mixture of acids present in beer under development of volatile substances, which can be determined by UV spectrometry. The mechanism of ageing of beer is based on prooxidative action of melanoidic substances under simultaneous gradual consumption of antioxidative compounds of beer.The oxidation of aromatic and heterocyclic higher alcohols furfurylalcohol, phenylethanol, benzylalcohol and amino acid phenylalanine with potassium peroxodisulfate has proved their sensitivity to oxidation reactions. By oxidation of phenylalanine and phenylalcohol was formed phenylacataldehyd, with subsequent development of haze forming substances. The degradation of furfurylalcohol and furfural is possible to monitored spectrometrically after steam distillation, which can be used from monitoring of antioxidative effect of different substances. Antioxidative effect is also possible to determine according to changes of natural chemiluminescence of beer and its intermediates after addition of solution of potassium peroxodisulfate. An aqueous extract of hops exhibited antioxidative effects. After addition of potassium peroxodisulfate to the solution of melanoidic substances the intensity of chemiluminescence increased, which is possible to consider the evidence of their prooxidative activity. Melanoidins are able to oxidize the mixture of acids present in beer under development of volatile substances, which can be determined by UV spectrometry. The mechanism of ageing of beer is based on prooxidative action of melanoidic substances under simultaneous gradual consumption of antioxidative compounds of beer.

Keywords: beer, oxidation aminoacids, higher alcohols, radical ractions, haze, chemiluminiscence

Published: March 1, 1999