Recovery of antioxidant compounds from aronia filter tea factory by –product: novel versus conventional extraction approaches

Black chokeberry ( Aronia melanocarpa L.) by-product from filter tea factory underwent subcritical water extraction (SWE) in order to recover polyphenolics and determine its antioxidant potential. In the current study Box-Behnken design was applied for optimization. Independent variables used in experimental design were temperature (T, 120–200 °C), extraction time (t, 15–35 min) and hydrochloride concentration (c, 0–1.5 %). Experimental results were fitted to a second-order polynomial model where multiple regression analysis and analysis of variance were used to determine fitness of the model and optimal conditions. The optimized SWE conditions for maximum responses of total phenols (TP), total flavonoids (TF) and monomeric anthocyanins (MA) contents, and minimum response of IC 50 were temperature of 120.4 °C, extraction time of 15.2 min and absence of acidifier. The predicted values of TP, TF, MA and IC 50 at these conditions were: 32.8863 mg GAE/g, 23.5164 mg CE/g, 0.5124 mg C3G/g and 0.0055 mg/mL, respectively.