Effect of Phytase Addition to Buckwheat Wort on the Selected Fermentable Sugars, Polypeptide Profile and Nitrogen Content from Free Aminoacids

Abstract

Relatively high levels of phytates in buckwheat malt and the low activity of endogenous phytases that limit the effective use of substrates for fermentation and yeast metabolism (starch, proteins, minerals) are an argument for using phytases in beer production technology. Two mash-in programs were applied: (1) the Congress program, typical for basic raw materials, (2) a program with temperature optimized for phytase activity. Commercial preparations of 3-phytase (Finase P) and 6-phytase (Ronozyme) were used in the study. Monitored levels of selected fermentable sugars indicates a statistically significant effect of phytase addition on the glucose content in both mash-in programs used. The SEC-HPLC chromatography allowed to select a key polypeptide with an estimated molecular weight of 40 kDa, whose relative peak area decreases as a result of the applied mash-increase treatment with phosphorolytic enzymes, although this relation was not statistically confirmed in the analysis of free amino acids content. The analyses carried out also indicate that apart from the target molecules, namely phytate and inositol, the use of phytases in the process of buckwheat wort preparation slightly changes the profile of fermentable sugars and causes significant changes in the polypeptide profile of the final mash.