Extraction and concentration of phenolic compounds from terminalia chebula friuts

Abstract

This study aimed to extract phenolic compounds from T.chebula fruits and concentrate the extract using sugaring out concentration process. The water-ethanol (EtOH) and water- propylene glycol (PG) solvent systems were used in extraction process and the design of experiment (DOE) was employed to determine the optimal extraction conditions (temperature, concentration of EtOH and PG and extraction time). The results showed the optimal condition for water-EtOH was obtained at the temperature of 76C and concentration of EtOH 76.4 %v/v and 82 min. For water-PG system, the optimal extraction condition was at temperature of 57C, PG concentration of 36%v/v and extraction time of 23 min. In sugaring out concentration of the extracts, glucose was added to the extracts that contained highest phenolic compounds in both solvent systems from the extraction experiment. The concentration of glucose that gave the desired phase separation ratio as well as the distribution coefficients of gallic acid (GA) and ellagic acid (EA), two major phenolic compounds in T. chbula, was determined 200 g/L for both water-EtOH and water-PG systems. The phase ratios for water-EtOH and water-PG were 1.94 and 1.85, respectively. The distribution coefficients of total phenolic for both solvent systems were the same, which was 1.98. Those of GA and EA were 4.89 and 3.52 for water-EtOH, and 4.34 and 3.22 for water-PG system, indicating that sugaring out concentration is a potentially effective method for pheonic compound concentration. Finally, the concentrated extracts show higher antioxidant activities than the nonconcentrated extracts and that antioxidant activity of extract in water-PG was higher than those of the water or water-EtOH extracts.