Prediction of the ageing of commercial lager beer during storage based on the degradation of iso‐α‐acids. (2nd January 2014)

• Record Type: Journal Article
• Authors: Blanco, Carlos A; Nimubona, Dieudonné; Caballero, Isabel
• Is Part Of: Journal of the science of food and agriculture. Volume 94:Number 10(2014:Aug. 15)
• Page Start: 1988
• Page End: 1993
• Publication Date: 2014-01-02
• Subjects: Food -- Periodicals; Agriculture -- Periodicals; 664
• DOI: 10.1002/jsfa.6513
• Languages: English
• ISSNs: 0022-5142

Abstract

<abstract abstract-type="main" id="jsfa6513-abs-0001"> <title>Abstract</title> <sec id="jsfa6513-sec-0001" sec-type="section"> <title>BACKGROUND</title> <p id="jsfa6513-para-0001"> <bold>Iso‐<italic>α</italic>‐acids and their chemically modified variants are responsible for the bitterness of beer and play a disproportionately large role in the final quality of beer. The current study was undertaken to predict the degradation of commercial lager beers related to changes in the concentration of <italic>trans</italic>‐iso‐<italic>α</italic>‐acids during storage by using high‐pressure liquid chromatography</bold>.</p> </sec> <sec id="jsfa6513-sec-0002" sec-type="section"> <title>RESULTS</title> <p id="jsfa6513-para-0002"> <bold>In the analysed beers the concentration of isohumulone (average concentration 28 mg L<sup>−1</sup>) was greater than that of isocohumulone (20 mg L<sup>−1</sup>) and isoadhumulone (10 mg L<sup>−1</sup>). The kinetic parameters, activation energy and rate constant, of the <italic>trans</italic>‐iso‐<italic>α</italic>‐acids were calculated. In the case of dark beers, the activation energy for the degradation of <italic>trans</italic>‐isocohumulones was found to be higher than for <italic>trans</italic>‐isohumulones and <italic>trans</italic>‐isoadhumulones, whereas in pale and alcohol‐free beers activation energies for the degradation of the three <italic>trans</italic> isomers were similar</bold>.</p> </sec> <sec id="jsfa6513-sec-0003" sec-type="section"> <title>CONCLUSION</title> <p id="jsfa6513-para-0003"> <bold>The loss of iso‐<italic>α</italic>‐acids can be calculated using the activation energy of the degradation of <italic>trans</italic>‐iso‐<italic>α</italic>‐acids and the temperature profile of the accelerated ageing. The results obtained in the investigation can be used in the beer industry to predict the alteration of the bitterness of beer during storage. © 2013 Society of Chemical Industry</bold> </p> </sec> </abstract>