## 3 Discussion
A protein efficiency factor of 2.99 and a chemical rating of 1.05 of the hydrolyzate were adequate enough to be recommended as a high protein fraction. Since alkalase is a proteolytic enzyme, like collagenase, our studies are in good agreement with the results of [39], in which neutrale is also inferior in proteolytic properties to alkalase (collagenase). Analysis of the obtained results showed that hydrolysis under the action of the studied enzyme products proceeded almost completely, and a significant amount of free amino acids was formed in the hydrolyzate, and a bound complex of glycosaminoglycans was released. The quantitative content of hexosamines, chondro sulfates, hyaluronic acid, and hexose in the samples of collagenase and Neutrase 1.5 MG hydrolysis products was practically identical (Table 3). It was found that samples of hydrolysis products obtained using Neutrase 1.5 MG contained fewer hexoses than samples obtained using collagenase. The mass fraction of hexoses in the samples of collagenase hydrolysis products was 1.17 times higher than in Neutrase 1.5 MG hydrolysis products. Both collagenase and Neutrase 1.5 MG hydrolysis samples contained about 2% hyaluronic acid. Its presence has increased the biological, therapeutic, and prophylactic value of hydrolyses as a possible basis for effective chondrocytes that contribute to OA prevention and treatment. There are studies proving the reparative capacities and the ability to curb the progression of osteoarthritis with drugs including hyaluronic acid, which are confirmed by MRI and histological examination of tissues [44; 45; 46]. The studies [47; 48] investigated the antioxidant and enzymatic (hydrolytic) activities of enzymes (neutralase, alkalase, papain, savinase, esperase, and collagenase). It was found that by antioxidant and enzymatic activity, enzymes can be arranged in the following order: collagenase > alkalase > savinase > papain > esperase > neutralization. When comparing the same amount of peptide, peptides from secondary collagen-containing raw materials hydrolyzed by collagenase were the most effective for use as chondoprotectors in drugs aimed at preventing and treating OA. Neutrase was the least effective protease [47]. The study [49] developed and approved a method for the quantitative determination of chondro sulfate in raw materials and food additives in the range from about 5% to 100%. Chondroitin sulfate was first selectively hydrolyzed with the enzyme chondro-nase to form non-, mono-, di-, and trisulfated unsaturated disaccharides. The resulting disaccharides were then quantitatively determined using ion-pair liquid chromatography with ultraviolet detection. The amounts of the individual disaccharides were added together to obtain the total amount of chondro sulfate in the material. The reproducibility accuracy for the total chondro sulfate content ranged from 1.60 to 4.00. The relative standard deviation was 72%, with HorRat values ranging from 0.79 to 2.25. The extraction of chondro sulfate from collagen-containing waste was 6.23%, which is consistent with our research data. The study [50] investigated the quantitative content of hexosamines, chondro sulfates, hyaluronic acid, and hexoses in samples of hydrolysis products of collagen-containing raw materials obtained by collagenase and neutrase enzymes. It was found that the amount of hexose, free hexosamine, and hyaluronic acid in the hydrolysis products obtained by collagenase exceeded the content of these chondrocytes obtained during hydrolysis by neutrase. The content of chondro sulfates was practically the same in all hydrolysis products, which is consistent with our studies. The study [51] showed that highly mineralized collagen-containing raw material is a source of valuable protein nutraceuticals. They consisted of high-molecular-weight proteins, oligopeptides, and amino acids, of which the anabolic and physiological potential was not used sufficiently.