## 3 Results and Discussion
### Effect of Input Parameters on Total Gossypol Reduction (TGR)  
The combined effects of input parameters viz. acetone %, time of extraction, liquid-to-solid ratio (LSR), and no. of extraction cycles on TGR were analyzed using the response surface technique. Figure 8a shows the reduction in total gossypol percentage with time of extraction and acetone percentage. The combined effect of both parameters showed that TGR increased with an increase in acetone % and reduction in time. The ANOVA table indicates that the interaction of time and acetone % is not statistically significant. However, the maximum TGR percentage obtained at higher acetone percentage (90%) at the minimum time (30 min), while the minimum TGR was recorded at a lower level of acetone and a higher level of time (60 min). Figure 8b illustrated the combined effect of liquid-to-solid ratio (LSR) and acetone % on TGR percentage. The effect of interaction between LSR and acetone is also not statistically significant, and it is seen that the highest TGR percentage occurred at 85% acetone and a higher level of LSR (10), while the lower value of TGR obtained at the lower value of acetone % and lower value of LSR.  
Figure 7: (**a**) 3D surface plot between no. of extraction cycles and time of extraction (**b**) 3D surface plot between no. of extraction cycles and LSR.  
Figure 9a shows the 3D response graph for the reduction in total gossypol percentage due to the combined effect of two parameters, namely no. of extraction cycles and acetone %. The results indicated that the increase in acetone percentage and no. of extraction cycles resulted in an increased TGR percentage. The maximum gossypol reduction occurred at 85% acetone level and 4 no. of extraction cycles, whereas the lower value of TGR was obtained at 70% acetone with 2 number of extraction cycles. Similarly, the combined effect of two varying parameters viz. LSR and time of extraction on TGR percentage illustrated in Figure 9b keeping other input parameters (acetone% and no. of extraction cycles) at constant. It can be seen that TGR increases with an increase in LSR and reducing time of extraction. The maximum TGR was obtained at higher LSR (10) and lower value of time (30 min), whereas the lower value of TGR was obtained at the lower level of LSR and the higher level of time.  
Figure 9a shows the 3D response graph for TGR percentage by studying the interaction between two parameters, no. of extraction cycles, and time of extraction. The results showed that by increasing the no. of extraction cycles and reducing the time, the TGR percentage increases. The highest TGR percentage obtained at a higher level of no. of extraction cycle and lower value of time. Figure 10b illustrates the effect of input parameters, namely no. of extraction cycles and LSR, on TGR percentage. It can be seen in Figure 10b that increasing the no. of extraction cycles and LSR resulted in increased TGR percentage.  
Figure 8: (a) 3D surface plot between time of extraction and acetone % (b) 3D surface plot between LSR and acetone %.  
Figure 9: (a) 3D surface plot no. of extraction cycles and acetone % (b) 3D surface plot between LSR and time of extraction %.  
The higher value of TGR was obtained at a higher level of no. of extraction cycle and liquid-solid ratio.