Interaction of proteins and amino acids with iso-?-acids during wort preparation in the brewhouse

Abstract This paper investigates the binding behavior of iso-?-acids from hops on free wort amino acids and proteins concerning production process in breweries. The studies were carried out with different acids, bovine serum albumin wort. To identify nature reaction between these substances, analyses nitrogen, HPLC isothermal titration calorimetry performed. According to results, do not form covalent bonds However, iso-?-acids, especially isohumulone isoadhumulone, ionic proteins. A distinction must be made that are present hot trub, those still dissolved Proteins already coagulated precipitated no longer react iso-?-acids. Future experiments will investigate whether established preparation maintained during fermentation until finished beer or foam. If this is case, which induced by experiments, there a measurable loss wort, but at same time, gain for later foam retention, as stabilize it.