Effect of alkylresorcinols derivatives on the activity of enzyme preparations

Abstract

Target setting. Rye is known to be a stubborn raw material for the industrial production of alcohol because of alkylresorcinols contained in grain of the said crop these effecting the enzymes of amylase complex in the negative way. Thus it is important to find and scientifically substantiate proper deactivating substances for batches preparation stabilizing enzyme activity without increase of normative consumption rates of enzyme preparations.

Actual scientific research and issues analysis. Outer cuticle shell of rye grain contains alkylresorcinols – compounds of resorcine and alkyls of different chain length and odd number of carbon atoms. The presence of alkylresorcinols containing carbon atoms is characteristic for rye only. While grinding grain, the most part of alkylresorcinols remains in bran. When effected by high temperatures alkylresorcinols partly disintegrate, and in alcohol production alkylresorcinols retain their native form and effect the activity of enzyme preparations in negative way.

Defining of uninvestigated parts of general matter. Objects of research were: rye, fractions obtained while grinding; batches and wort made of rye mill under the conditions of low temperature digestion with the use of enzyme preparations of alpha- and glucoamylase action and auxiliary cytolytic enzyme preparations, mature mash. To fulfill the research, media were prepared of rye mill and water, rye bran was added as a source of alkylresorcinols; fermentative hydrolysis of starch was fulfilled with the use of «Novozymes» enzyme preparations.

The research objective. The aim of the research was to determine the effect of alkylresorcinols derivatives upon the saccharifying ability of wort and to choose substances to neutralize alkylresorcinols.

The statement of basic materials. The efficiency of catalytic activity of enzyme preparation during wort fermentation is effected by a number of factors, the index of saccharifying ability of wort being an index of activity of enzyme preparations. The research of deactivating alkylresorcinols derivatives with different substances was fulfilled to confirm or to reject the said assumption. For the research, food grade sodium bicarbonate, ammonia water and sodium hydroxide solution were used as deactivators.

Conclusions and proposals. The alkylresorcinols contained in rye effect enzyme preparations of alpha amylitic action in the negative way. The neutralization of alkylresorcinol derivatives promotes retention of enzyme preparations activity along the entire fermentation period of the media. The use of ammonia water and lactic acid at the stage of batches preparation positively influences the fermentation activity of yeast owing to the media enrichment with a source of nitrogen and increases alcohol content in mature mash.