Thermal deterioration of the trans-/Cis-ratio of bittering agents of commercial beers

Carlos A. Blanco, Isabel Caballero, Martín Buffa

    Research output: Contribution to journalArticleResearchpeer-review

    2 Citations (Scopus)


    The use of reduced isomerised hop extracts to achieve both bitterness and light stability became very popular during the last decade. Changes during storage in four hop extracts and seven commercial lager beers are studied using HPLC and spectrophotometric techniques. The degradation of the iso - acids and tetrahydro iso - acids as a function of time is represented by the ratio, in percentage, of the sum of trans-isomer concentration to the sum of the cis-isomer concentration (T/C). The results provided conclusive evidence that the gradual decreased of bitterness intensity in beer was due to the degradation of iso - acids, notably to the instability of the trans-iso - acids. When the beers were stored for 14 days at 45C the decrease of the T/C average varied from 8.6 to 14.0%, except in lemon beer, in which case, T/C decreased 36.9%. The results allowed us to infer that in open storage and/or warm conditions the deterioration of beer was critical above 35C. On the other hand, the results showed that tetrahydro iso - acids remained unaltered. Copyright © Central Institute of Postharvest Engineering & Technology.
    Original languageEnglish
    Pages (from-to)1277-1285
    JournalInternational Journal of Food Properties
    Publication statusPublished - 1 Nov 2011


    • Bitterness
    • Brewing
    • Commercial beers
    • Hop
    • Iso - acids
    • Storage
    • Tetrahydro iso - acids


    Dive into the research topics of 'Thermal deterioration of the trans-/Cis-ratio of bittering agents of commercial beers'. Together they form a unique fingerprint.

    Cite this