Optimization of chlorogenic acid extraction from Elm tree, Ulmus minor Mill., fruits, using response surface methodology

Abstract

Elm tree, Ulmus minor Mill. belongs to the Ulmaceae family. Some main compounds in this plant are including mucilage, tannins, caffeic acid derivatives, especially chlorogenic acid (CGA) and sterols. Among them, caffeic acid derivatives, especially chlorogenic acid (CGA) with widespread usage in food, cosmetic and pharmaceutical industries, caught our attention and we decided to detect, quantify and finally optimize its extraction from Elm tree, (Ulmus minor Mill.) fruits. Herein, the extraction process was optimized by means of response surface methodology (RSM). Various factors such as temperature, solvent percentage, solid to solvent ratio and extraction time can be effective in an extraction. Screening and selection of important factors was accomplished by 2- level full factorial design and the result of normal probability plot. Based on the results the effect of time was not important and in the next stage of the study using RSM was omitted. In this step, 3-level full factorial central composite rotatable design (CCRD) was used for optimization, in which the temperature, ethanol percent, and solvent ratio were relevant independent variables. Based on the practical results by HPLC and statistical analysis, the optimum conditions for maximum yield was when temperature, solvent to solid ratio and solvent percent were equal to 54.98 °C, 40 (mL/g) and 70% (v/v), respectively, and its desirability function was 0.94.