FURTHER STUDIES ON THE OXIDATION OF HOP RESINS

Abstract
The autoxidation of humulone, isohumulone, colupulone and cohulupone has been studied using chromatography on an ion-exchange resin. Humulone gave a mixture of products which were largely insoluble in light petroleum whereas most of the products obtained by autoxidation of colupulone were soluble in that solvent. Cohulupone was isolated for the first time from the autoxidation of colupulone. The brewing value of a water-soluble fraction of hops was also examined. The degree of resolution obtained from the ion-exchange chromatographic system enabled a detailed examination of the constituents of hop concentrates and extracts to be made.