## 3 Discussion  
Hydrolysis forms a complex mixture of decomposition products of protein molecules with different molecular weights. The quantitative and qualitative composition of the decomposition products of protein molecules of collagen-containing raw materials depends on the technological parameters of the hydrolysis (biodegradation) process and the properties of the applied enzyme preparation [34]. It is generally accepted that the efficiency of enzymatic biodegradation of collagen-containing raw materials by enzyme preparations depends on the quantitative ratio of enzyme:substrate [35]. In our study (Figure 1a), up to 300 min of enzymatic hydrolysis by collagenase at concentrations of 250 and 300 U/g showed almost the same dynamics. Starting from 300 min, no difference (\(p>0.05\)) in the hydrolysis degree of the samples depending on the preparation concentration was found. An increase in the concentration of collagenase above the U/g of the substrate increases the hydrolysis degree, but it should be noted that the increase in concentration is unreasonable and is associated with additional time and costs [36]. Throughout hydrolysis with Neurase 1.5 MG (Figure 1b), the samples obtained at a concentration of 150 U/g significantly differed (\(p<0.05\)) in the hydrolysis degree from samples obtained with a higher enzyme preparation concentration. In the interval from 180 to 420 min, the hydrolysis degree of the samples obtained with the addition of Neutrase 1.5 MG 300 U/g was significantly higher than in other samples. After 420 min of hydrolysis, the samples obtained with the addition of Neutrase (200-300 U/g) did not differ significantly from each other. Throughout the entire hydrolysis process by collagenase, the best indicators for the hydrolysis degree were achieved at pH = 7.0. The samples obtained at pH = 6.0 and 8.0 had no statistically significant differences. The samples obtained by hydrolysis with neutrale at pH = 6.0 significantly exceeded the rest of the samples. It was found that the use of collagenase with a substrate concentration of 250 U/g led to an increase in the hydrolysis degree in a neutral medium, while the maximum activity of Neutrase 1.5 MG was manifested in an acidic medium. When the duration of hydrolysis by collagenase was more than 360 min, the change in temperature did not significantly affect the hydrolysis degree. At 30 and 35 \({}^{\circ}\)C, no significant differences were observed throughout the hydrolysis by Neutrase 1.5 MG. The advantage of collagenase is confirmed by the potential of using it for enzymatic hydrolysis of collagen-containing raw materials without the additional use of inorganic acids that accelerate the hydrolysis process. The highest degree of biodegradation of collagen-containing raw materials in the samples was achieved using collagenase with a substrate concentration of 250 U/g at 40 \({}^{\circ}\)C and a process duration of 6 h, while Neurase 1.5 MG maximally hydrolyzed the collagen-containing raw materials at a higher temperature. It was found that the hydrolytic activity of Neutrase 1.5 MG is lower than \begin{table}
\begin{tabular}{l c c} \hline \hline  & \multicolumn{2}{c}{**The Proportion of Carbohydrate Components in the**} \\
**Indicator** & \multicolumn{2}{c}{**Hydrolyzate, \%**} \\ \cline{2-3}  & **I** & **II** \\ \hline Hexose & 0.33 \(\pm\) 0.01 & 0.28 \(\pm\) 0.01 \\ Hexosamines & 2.14 \(\pm\) 0.06 & 2.12 \(\pm\) 0.06 \\ Free hexosamines & 6.87 \(\pm\) 0.20 & 6.64 \(\pm\) 0.20 \\ Hylauronic acid & 1.61 \(\pm\) 0.04 & 1.58 \(\pm\) 0.04 \\ Chondrotin sulfates & 6.32 \(\pm\) 0.18 & 6.31 \(\pm\) 0.18 \\ \hline \hline \end{tabular}  
[FOOTNOTE:]Footnote : footnotetext: — collagen waste hydrolyzate obtained by collagenase; II—collagen-containing waste hydrolyzate obtained by Neutrase 1.5 MG.[ENDFOOTNOTE]  
\end{table} 
Table 3: Results of the carbohydrate composition analysis of collagen-containing waste hydrolysis products. that of collagenase. Our data are in good agreement with the results of the study [37].