Application of Response Surface Methodology for Optimization of Inulin Extraction from Salsify Plant

Inulin is widely used in functional foods throughout the world due to its useful nutritional and functional properties such as fat replacer, texture improvement and prebiotic effects. Salsify Plant is the one of valuable source of inulin, but few studies exist on its extraction. In this research, central composite design (CCD) was performed to investigate the effect of each variable, time (5-40 min), solvent: solid ratio (5-15 v/w) and temperature (40-90°C) on inulin extraction yield from salsify and optimization of conventional extraction of inulin. Response surface methodology (RSM) was also employed to optimize multiple variables to predict the best performance conditions with a minimum number of experiments. Chemical properties and mineral contents of salsify plant were also determined according to AOAC methods. The results of analysis of variance showed that effects of time and temperature on inulin extraction were significant (P < 0.05). The optimal conditions for maximizing inulin extraction yield (13.23%) were at 56.24°C, solvent: solid ratio of 8.97:1 (v/w) for 39 min.