Experimental design data were analy

Experimental design data were analyzed using multiple regressions
through the least square method. The significance of the
regression coefficients was also tested by F-test and the F-test
was used to verify the statistical significance of models at p
≤
0.05
using the statistical software Design Expert 8.0.7.1 (Stat-Ease Inc.,
Minneapolis, USA). The results were analyzed using the Pareto
analysis of variance (ANOVA) and ANOVA tables were generated.
The quality of fit of the polynomial equation was expressed with
the coefficient of determination (R2). The effect and regression
coefficients of linear, quadratic, and interaction terms were determined.
Models and response surfaces were generated for each
response.