INTEGRATED PROCESS EXTRACTION-ADSORPTION FOR SELECTIVE RECOVERY OF ANTIOXIDANT PHENOLICS FROM CHICORY BY-PRODUCTS: EXTRACTION YIELD, ANTIOXIDANT ACTIVITY AND ENERGY CONSUMPTION EVALUATION

Around 15,000 tons per year of chicory grounds, a by-product of chicory roots (Cichorium intybus L.), are generated in the north of France. Additionally, chicory grounds contains several compounds of interest, including antioxidant polyphenols. Selective recovery of antioxidant phenolics from chicory by-products was studied, using an integrated extraction-adsorption process, enabling the simultaneous extraction of phenolics and their purification in a single operation. In this way, products of high quality can be obtained in a simple eco-friendly process with reduced consumption of time and energy. The first part of this work aimed at studying adsorption and desorption steps in order to select the most efficient adsorbent among tested (amberlite XAD 16HP resin) and to define relevant experimental conditions for both steps regarding polyphenols recovery and antioxidant activity preservation. In a second part, the integrated extraction-adsorption process was studied, taking into account the influences of time (2, 4 or 6h), flow rate (1, 3 or 5L/h) and resin/chicory quantities ratio (1/3; 1/5 or 1/10 w/w) on kinetics of polyphenols extraction yield, antioxidant activity of the extract and energy consumption. These studies permitted multi-criteria optimization of the integrated extraction-adsorption process to obtain high quality products with low consumption of time and energy.