Optimization of Process Parameters for Foaming of Bael (Aegle marmelos L.) Fruit Pulp

Foam expansion and foam stability of the bael (Aegle marmelos L.) fruit pulp foam was studied. Foams were prepared from various pulp concentrations (PC) by adding different concentration of glycerol monostearate (GMS) and methyl cellulose (MC) at different whipping time (WT). Response surface methodology was used to predict the foam stability and expansion. Thirty experiments were carried out using a central composite rotatable design with four independent variables (GMS, MC, PC, and WT). Second-order polynomial equations were developed after removing insignificant terms for predicting foam expansion (R ² = 0.85) and stability (R ² = 0.95). The optimum conditions achieved after the numerical and graphical optimization for maximum foam expansion and stability was: GMS (3.10 g/100 g pulp), MC (0.32 g/100 g pulp), PC (13.2°Bx), and WT (2 min). The desirability of 0.712 was achieved at this optimum point. The predicted values of foam density and foam drainage volume were 0.658 g cm⁻³ and 1.75 mL, respectively, at optimum parameters while the experimental values were 0.635 ± 0.02 g cm⁻³ and 1.75 ± 0.12 mL, respectively.