Through the derivation of Equation 4 , using the software Maple®, the higher yield for the second-order equation was found under conditions of 70% ultrasound power, 1.79 mass ratio buffer solution/oil, and 0.25 mass ratio of catalyst/substrate, in the fixed condition of 3 minutes at initial room temperature, with a yield of 87.98%. In the same conditions, one experiment was carried out yielding 85.0 ± 2.6%, which confirms that within the studied range, the model can predict the yield satisfactorily.
The response surface plot for the enzymatic hydrolysis yield of the Crambe oil with in natura seeds is presented in Figure 2 . Each of the variables can affect the hydrolysis reaction by giving more or less energy to the system, causing enzymatic denaturation, modifying the medium viscosity, and altering the availability of sites for lipase catalysis. The ultrasound power, however, does not have a significant effect on the response surfaces in the investigated range, unlike the B/O and C/S variables. Although the amount of buffer solution affects the yield of the enzymatic hydrolysis reaction, this effect will have less influence on the reaction yield above 1.0 (Figure 2-a ). A similar effect is observed in Figure 2-b , where for a ratio of catalyst/substrate above 0.15, the impact of the variable is less significant; conversely, an increase in the yield can still be observed when increasing the ultrasound power. Notably, a high amount of catalyst (in natura seeds) makes the reaction medium more viscous, demanding more ultrasound power to emulsify the medium, resulting in the correlation of the two variables. In Figure 2-c , the effect of the most significant variables is evaluated simultaneously, and a higher correlation between both variables can be observed, resulting in increased yield as both variables increase.