Figure 3.5. 2D Contour plot of the interaction of reaction time (hr) & lipase weight (%w/w)
The response surface model with the incorporation of the second order effects of non-linear relationships was the technique used to determine the best possible combinations of variables to predict the yield of tocopherols in this study. The grided surface plots shown in Figures 3.6 to 3.8 are the representations of the surface plot in 3-D space. According to Soumya (2017), the plots determining the optimum operating conditions reaching maximum from the best-fitted model with a map of contour lines, follow a direction of movement along the path of maximum response. Hence, for the response surface plots, responses are derived from the peak of the contour surfaces with respect to two underlying variables at a particular instaance as shown in Fig. 3.6, 3.7 and 3.8 respectively.