## 3 Results and Discussion
### Lipid Hydrolysis
#### 3.3.2 Influence of Lipase/Lipidic Substrate Ratio (\(Eo^{\prime}\)/\(So^{\prime}\))  
The experiments were conducted at various ratios, ranging from 0.28 and 1.19 kLU/g (0.5-2.1% g of Resinase/g lipids in meat waste), to examine the effect of the \(Eo^{\prime}\)/\(So^{\prime}\) ratio on product recovery. This range is consistent with the tests by [PERSON] et al. [68], which required 1.0 to 1.5% g of lipase per gram of lipids to hydrolyze lard, and the experiments by [PERSON] et al. [71], which used 2.0% g of lipase per gram of lipids to hydrolyze cod liver oil and obtain fatty acids. The pH (8.0) and the temperature (50 \({}^{\circ}\)C) were fixed according to our results from the previous section. The findings demonstrate how hydrolysis is favored by the high lipase/lipidic substrate ratios, producing a higher percentage of recovered lipids (Table 11). The results suggest a value around 0.83 kLU/g as the most suitable \(Eo^{\prime}\)/\(So^{\prime}\) ratio for lipolytic hydrolysis of meat waste because the ratios under 0.55 kLU/g show a significant decrease in the percentage of lipids hydrolyzed and, for the ratios above 1.11 kLU/g, similar percentages (very close to each other) are obtained. Similarly to what happened in protein hydrolysis, the rise in the relative amount of enzyme in relation to that of the lipidic substrate (higher \(Eo^{\prime}\)/\(So^{\prime}\)) generates a greater number of bonds between the Resinase and the lipid fraction of meat waste, promoting a high number of broken lipidic bonds, favoring the hydrolysis, and generating an increase in the amount of hydrolysate produced. There are no previous studies in the literature on \begin{table}
\begin{tabular}{c c} \hline \hline \(Eo^{\prime}\)/\(So^{\prime}\) (kLU/g) & **Recovered Lipids (\%)** \\ \hline
0.28 & 65.00 \(\pm\) 0.75 \\
0.55 & 79.05 \(\pm\) 0.48 \\
0.83 & 95.40 \(\pm\) 0.33 \\
1.11 & 97.07 \(\pm\) 0.76 \\
1.19 & 97.45 \(\pm\) 0.01 \\ \hline \hline \end{tabular}
\end{table} 
Table 11: Recovery of lipids at different lipase/lipidic substrate ratios (\(Eo^{\prime}\)/\(So^{\prime}\)). Figure 2: Influence of temperature on total free fatty acids (_TFA_) obtained from lipolytic hydrolysis. the influence of the _Eo'/So'_ ratio on lipid hydrolysis; however, from the research carried out, this influence is evident. This effect was also noted in the amounts of fatty acids obtained. Table 12 shows the quantities of fatty acids released at the different _Eo'/So'_ ratios tested. It can be seen that the amount of individual fatty acids increases with the enzyme/substrate ratio. [PERSON] [72] observed the same phenomenon in hydrolysis of soybean oil with different lipases, including Resinase HT. Figures 3 and 4 show the average amounts obtained of the individual fatty acids for the different _Eo'/So'_ ratios tested. From these figures, there is a linear dependence between the amount of individual fatty acids (_IFA_) released and the _Eo'/So'_ ratio expressed as:  
\[IFA=a\cdot Eo^{\prime}/So^{\prime}+b \tag{4}\]  
The values of the coefficients \(a\) and \(b\) were obtained, as well as the corresponding determination coefficient (R\({}^{2}\)), and they appear in Table 13.  
Figure 5 shows the fatty acids released categorized according to the number of double bonds they have in their carbon chain: saturated (no double bonds), monounsaturated (one double bond), and polyunsaturated (several double bonds). In this figure, the three types of fatty acids have a linear dependence with the lipase/lipidic substrate ratio. Saturated fatty acids turned out to be the majority of the recovered acids when compared with monounsaturated and polyunsaturated acids separately but, if the comparison is made between saturated and unsaturated fatty acids (including monounsaturated and polyunsaturated acids), unsaturated fatty acids are predominant.