ホップβ酸変換物

Thermal treatment of the hop β-acid colupulone under wort boiling conditions yielded cohulupone, hulupinic acid, nortricyclocolupone and several tricyclocolupone epimer pairs as major bitter-tasting products. Depending on structure these showed recognition thresholds from 7.9 to 90.3 µmol/L. The lowest were 7.9 µmol/L for cohulupone, described as imparting a short-lasting, iso-α-acid-like bitter impression, and 14.7 µmol/L for hydroxytricyclocolupone, described as a long-lasting, lingering and harsh bitterness perceived on the posterior tongue and throat. Concentrations differed remarkably between beer types.