Through the use of the software Maple®, the derivative of the above
equation was found with the conditions of 67.8% ultrasound power, 1.67
mass ratio buffer solution/oil, and 0.06 mass ratio of
catalyst/substrate, yielding 69.50%. The experimental yield result
found under the above conditions was 71.50 ± 2.5%, confirming that
within the investigated conditions, the model can satisfactorily
describe the yield of the hydrolysis reaction.
In Figure 5 are presented the response surface plots for
enzymatic hydrolysis yield of the Crambe oil with oil-free seeds as a
catalyst. In Figure 5-a , it is observed that the highest yield
region is in the highest ultrasound power and buffer solution/oil mass
ratio region. When the power effect is evaluated together with the
amount of catalyst (Figure 5-b ), the result is different from
the seeds in natura. When a higher power was needed for higher values of
catalyst ratio, the two variables had little correlation, and a
parabolic effect was observed for the catalyst/substrate ratio effect,
with the yield reaching a maximum value at a ratio of approximately
0.05. After that, a small drop occurred, indicating that in this range,
the substrate is already saturated with the enzyme, and the increase
only hinders the reaction by increasing the viscosity of the medium. InFigure 5-c, an interesting effect is observed. The higher the
amount of buffer solution added to the reaction, the lower the amount of
catalyst required for a good yield. The opposite was also observed, the
higher the amount of catalyst, the less amount of solution was
necessary. With these results, it is possible to perform a cost analysis
to determine the best conditions under particular situations.