The use of enzymatic modification in recycling of meat and bone collagen-containing byproducts
The objective of this research was to study the process of extraction of valuable protein water-soluble substances from highly mineralized meat and bone raw materials during hydrolysis by proteolytic enzymes. The experiments were carried out on beef tubular and costal bones using enzymes Alcalase 2.5 L, Protamex, Protosubtilin G3x. The efficiency of protein hydrolysis was evaluated by the accumulation of non-protein amino nitrogen in the aqueous protein extract, the amount of which was determined by formol titration. The chemical composition of raw materials and hydrolysis products was evaluated by standard physicochemical methods. The drying of hydrolyzed protein fractions was carried out on a lyophilic freeze dryer at a condenser temperature of -55 ° C. Drying of the sedimentary protein-mineral fraction was carried out by convection method at 60 <sup>about</sup>C. The general chemical composition of raw materials and protein hydrolysates is established. It was shown that fermentolysis in an aqueous medium with preliminary separation of fat and subsequent separation of fractions makes it possible to obtain low molecular weight water-soluble peptides and protein-mineral insoluble compositions, as well as fat products in the amount of 13.3-14.4 % of raw materials by weight. The yield of proteins by the content of solid products in water-soluble freeze-dried products was 6.1-7.9 %, depending on the type of enzyme and hydrolysis conditions. The bulk of the raw material's protein mass is precipitated together with mineral substances during fermentolysis. The solids content in dense sediments was 66.5-73.8 %. It is recommended to use the fermentolysis of meat and bone raw materials for pre-treatment in subsequent high-temperature hydrolysis. Protein products obtained by enzymatic modification of meat and bone raw materials are recommended for use as part of feed supplements, microbiological media and fertilizers, as well as feed for aquaculture. To accomplish that, it is necessary to study their amino acid composition and conduct biological tests. The extracted fat may also serve as a raw material for a number of fat products (margarine, spreads, soap).