APPLICATION OF BACTERIAL SOURDOUGH AND ENZYMES IN THE PRODUCTION OF BREAD FROM A MIXTURE OF RYE AND WHEAT FLOUR

Interest in sourdough rye-wheat bread with addition of enzymes is actively demonstrated by various manufacturers. Enzymes associated with the metabolic activity of sourdough microorganisms and exogenous enzymes deliberately added to the dough recipe are used in the production of these bakery products. Such combinations contribute to the improvement of both dough structure and the final product. The research investigated the influence of the combined application of the IPROVIT sourdough and enzymes α-amylase, glucoamylase and protease on the structural-mechanical properties of the dough and the quality of the resulting rye-wheat bread. Optimal concentrations of individual enzymes and their combinations were established: α-amylase – 0.35 mL, protease - 0.05 mL, glucoamylase - 3 mL, α-amylase+glucoamylase and α-amylase+protease in a 1:1 ratio. Adding enzymes at rational concentrations positively affected on the physical properties of the dough, making it elastic, shaping well into a ball and preventing spreading. Increased enzyme concentrations led to stickiness and eventual spreading of the dough. It was observed that the combined application of Lactobacillus plantarum, L. brevis, Lactobacillus paracasei ssp. paracasei bacteria and enzymatic preparations (α-amylase, protease, glucoamylase) of different actions positively affected the physical properties of the dough. The dough mixed well, did not stick to hands, maintained its shape, faster increased of volume and had moisture levels within the control range of 41–43%. The acidity of the resulting bread met the requirements of DSTU 4583:2005 and amounted to 8.9–10 degrees for all tested samples. Reduced acidity in the sample with the enzyme complex α-amylase+protease is explained by the fact that the amino acids formed as a result of the protease action were used by lactic acid bacteria as a source of nutrients. The combined application of lactic acid bacteria and enzymes positively contributed to intensifying fermentation processes, indicated by higher dough rising indicators, which were 3–9 min higher than the control. Through the use of enzymes with different actions, it was proven that the organoleptic characteristics of the bread improved, acquiring an attractive color, distinct taste and pleasant specific aroma with hints of nutmeg. The porosity of the experimental bread samples with the enzyme mixture was at the control level. Thus, the use of rye-wheat flour, sourdough and enzymes has a positive effect on the quality of bread and contributes to increasing its nutritional and biological value.