Obtaining of Peptide and Amino Acid Ingredients by Enzymatic Treatment of Aspergillus oryzae Biomass

Abstract

Currently, special attention is being paid to research on the use of residual biomass of Aspergillus fungi as a substrate for the production of food and feed ingredients. The most promising method is biocatalytic conversion of mycelial biomass polymers, which increases the availability of biologically valuable cell components. The objective of the present study to develop conditions for the enzymatic destruction of cell wall polysaccharides and protein substances of fungal biomass and secondary raw materials of enzyme production, to obtain peptide-amino acid ingredients. It has been established that the use of the enzymatic system, including intracellular proteinases and peptidases and a complex of exogenous β-glucanases, as well as regulation of the duration of their exposure, provide for the production of fermentolysates with a given structural fractional composition. Molecular mass (MM) distribution studies of peptide fractions in the fungal biomass of fermentolysates showed that over 6 h of hydrolysis, the proportion of peptides with MM over 29.0 kDa decreased by 2.8 times, and over 12 h, by 4.7 times. The content of low molecular weight peptides with MM less than 1.6 kDa increased 1.4 times, which accounted for 47.9% of the total. Comparative analysis of the spectra of peptides with MM less than 1000 Da in enzyme isolates of fungal biomass after 6 and 12 h of hydrolysis showed significant differences in their compositions. The contents of peptides with MM less than 500 Da and of free amino acids increase with an increase in hydrolysis duration by 1.6 times. The results confirm the promise of creating functional ingredients and dietary supplements enriched in a peptide–amino acid component with a predominant content of free amino acids and short bioactive peptides resulting from enzymatic treatment of fungal biomass.