Effects of a complex phytase-containing enzyme preparation on the rye wort fermentation process

A complex of amylases, proteases, and hemicellulases is known to enhance deep conversion of polysaccharides and proteins, especially in the processing of difficult-to-ferment raw materials, such as rye, providing grain wort with soluble carbohydrates, amino acids, and peptides. Grain is also a source of phosphorus, whose bioavailability can be increased by hydrolysing the grain with phytase-containing enzyme preparations. However, their catalytic action during the preparation of grain wort for alcohol production has hardly been studied. This study aimed to investigate the effect of a new complex phytasecontaining enzyme preparation on yeast metabolism and the efficiency of rye wort fermentation. The work was carried out in the Russian Research Institute of Food Biotechnology. The Glucavamorin complex enzyme preparations derived from recombinant strains were the object of our research. The preparations differed in the activity level of the main enzyme, lucoamylase, and minor hemicellulase enzymes, as well as in the presence of phytase. The results confirmed their biocatalytic ability to efficiently hydrolyse polymers of rye grain. An increased content of hemicellulases in Glucavamorin-Xyl improved the rheological properties of rye wort. The greatest effect was achieved with the phytase-containing Glucavamorin-Ply. This preparation improved the phosphorus nutrition of yeast, which increased its biomass by 30% and decreased the level of fermentation by-products by 18–20%. Alcohol yield tended to increase and its strength reached 10.5–10.9% vol. When using a phytase-containing enzyme complex, it was possible to reduce the amount of the main enzyme, glucoamylase, without causing the key fermentation indicators to degrade.