Figure 3: Decrease in polyphenol percentage recovery after reusing Amberlite XAD-2 resin for three consecutive extractions. Gallic acid (GAL), benzoic acid (BNZ), dihydroxybenzoic acid (DHB), naringenin (NGE), naringin (NGI), rutin (RTN), quercetin (QCT), trans-cinnamic acid (TCM), and vanillic acid (VNL).