CHANGES IN THE CONTENT OF β -GLUCANS DURING THE MALTING PROCESS

Abstract

β-glucans are non-starch polysaccharides found in the cell walls of endosperm. A high content of these polysaccharides in barley grain causes inadequate grain modification during the malting process, due to the fact that β-glucans inhibit enzymes to enter the cell walls of the endosperm. During malting process, barley germinates and produces hydrolytic enzymes that de-structure the endosperm, making the grains soft and friable. During mashing process, β-glucans lower the brewing yield and moreover they cause turbidity of brewed beer. The goal of this work was to analyse the degradation process of β-glucan content during the malting process. Two methods such as the enzymatic method and the flow injection analysis method were used to analyse the content of β-glucan in barley grain, in germinated grain as well as in the malt and in wort. Results showed the decrease of β-glucan content from barley to wort, β-glucans were degraded by 97 %. All evaluated varieties fulfilled requirements for β-glucan content in wort, values were lower than 250 mg.dm-3. Moreover, a positive significant correlation among the content of β-glucan in malt and the viscosity of worth was found but on the other hand significant correlation among the β-glucan content in wort and the viscosity was not proven. Statistical significant correlation was proven among the starch content in barley grain and friability of malted grain.