On the possibility of using biologically active substances of aspen bark in brewing
Vestnik Voronežskogo Gosudarstvennogo Universiteta Inženernyh Tehnologij
The integrated use of aspen biomass can ensure the effective development of forestry and timber processing industries, reduce the share of waste. From the bark of aspen we obtained aqueous and water-alcohol extracts containing a complex of extractive substances possessing biological activity and representing practically all classes of organic compounds found in plants (vitamins, enzymes, proteins, fats, essential oils, etc.). As a raw material, a crushed aspen bark with a moisture content of 5%
... and an equivalent particle diameter of 2 mm was used. Extractants – water distilled and water-alcoholic solution 1:1. Extraction conditions: hydromodule– 10 g/g, temperature – 40°C, ultrasound frequency – 44 kHz. The effect of water-alcohol extracts on the fermentation of sucrose by beer yeast S-33 was studied. The expediency of using water-alcohol extract of aspen cortex at a dosage of 1% of the nutrient medium is shown. At the same time ferment activity of yeast increases, sugar consumption decreases by the side processes of fermentation, the economic coefficient showing the yield of ethanol from a unit of substrate is increased by 5,5% in comparison with the control. The kinetic characteristics of the fermentation process are calculated. The maximum specific growth rates of yeast and sugar consumption are observed when using water-alcohol extract of bark of aspen at a dosage of 1% and are 0,0052 h-1 and 0,049 g/(g-h), respectively. On the basis of the conducted studies, it can be concluded that the water-alcohol extract of the aspen bark should be used at a dosage of 1% of the nutrient medium. At the same time ferment activity of yeast increases, sugar consumption decreases by the side processes of fermentation, the economic coefficient showing the yield of ethanol from a unit of substrate is increased by 5,5% in comparison with the control. Industrial use of this extract in the production of beer will shorten the duration of the main fermentation for 1 day, increase the capacity of the fermentation unit and reduce the specific rates of energy consumption.