Modeling and optimization of the spray drying parameters for soapwort (Gypsophila Sp.) extract

In this study, the effects of spray drying parameters as feed soluble solid content, inlet air temperature and outlet air temperature on spray drying of soapwort (Gypsophila arrostii) extract have been examined. Central composite design was used with 15-30 °Bx, 110-160 °C and 50-80 °C for feed soluble solid content, inlet air temperature and outlet air temperature, respectively. Moisture content, water activity, tapped density, total saponin content and foam volume of the obtained powders were measured as responses of the experimental plan. The spray drying parameters were optimized by considering saponin content and foam volume by response surface methodology. According to the numerical optimization, optimum feed soluble solid content, inlet and outlet air temperatures were 15 °Bx, 160 °C and 67 °C respectively with a desirability factor of 0.822. After verification at optimum conditions, the error percentages were found to be 5.96% and 2.15% for saponin content and foam volume respectively.