Isomerization of hop extract α-acids

An isomerization process of the alpha-acids contained in hop extract (with magnesium oxide, potassium hydroxide and magnesium peroxide as catalysts at ambient temperature) was carried out. The influence of two factors (the amount of applied catalyst and the isomerization time) was studied. Ultra-high performance liquid chromatography was used for the evaluation of the isomerization process. The best results were obtained with magnesium oxide. In this case, the influence of the operating variables on the isomerization process and optimal process parameters were determined using statistical methods. The isomerization method described above could be carried out with high efficiency without heating and could be easily adopted and applied on an industrial scale. Copyright (C) 2016 The Institute of Brewing & Distilling.