ON THE ANALYSIS OF HOP BITTER ACID

Abstract

A High Performance Liquid Chromatography (HPLC) method for automated routine analysis of the hop bitter acids is described. It allows the simultaneous determination of α-acids, β-acids, cohumulone and colupulone. This analysis based on two chromatographic runs takes less than 1/2 h. With this new method as reference, the defects of existing conductometric titration techniques were studied and a new improved conductometric method based on toluene-buffer extraction was developed. The new methods are applicable to all forms of hop products containing α- and β-acids. Analysis for α-acids with ether-acid aqueous methanol extraction gives results which are too high because of several basic defects.