Enzymatic-Assisted Recovery of Antioxidants from Chicory and Fennel by-Products

Abstract The work was aimed to evaluate the antioxidant extraction efficiency of enzymatic-assisted extractions, alone or combined with sonication, applied to chicory and fennel by-products. Three enzymatic preparations were tested: enzyme mix 1, made of pectinlyase, polygalacturonase, pectinesterase, and arabinase; enzyme mix 2, composed of pectinlyase, cellulase, and acid proteas; xylanase. They were applied alone or coupled with a successive sonication performed according to the following conditions: 100 g/L; 45 °C; 40 min; 72 W. The results were compared with those of a solid-liquid extraction performed with a 70% ethanolic solution whose conditions were previously optimized to maximize the extraction of antioxidants from the specific matrix (chicory: 60–180 min, antioxidant content 6.15 ± 0.20 mg/g dm; fennel: 60–90 min, antioxidant content 7.60 ± 0.70 mg/g dm). Concerning chicory by-products, the three enzymatic treatments coupled with ultrasounds allowed the obtainment of extracts having approximately the same amounts of antioxidants than the conventional extraction (6.10–6.22 mg/g dm). Regarding fennel, all the enzymatic-assisted extractions (coupled or not with ultrasounds) gave lower antioxidant concentrations than the hydroalcoholic extraction. Enzymatic extraction and sonication significantly influenced type and quantity of phenolics in the extracts, highlighted that compounds other than phenolics contributed to their antioxidant properties.