Extraction of bioactive polyphenols with high antioxidant activity from bilberry (Vaccinium myrtillus L.) processing waste

Bioactive polyphenols were extracted from the peel fraction of bilberry processing waste using aqueous ethanol as solvent. A response surface methodology was used to evaluate the effects of liquid-to-solid ratio (R), solvent composition (C), extraction time (E) and temperature (T) on the extraction yield. The following optimal conditions were determined: R = 30 mL/g, C = 57%, E = 160 min, T = 40 °C. Phenolic extracts with a polyphenol content of 83.75 ± 4.16 mg GAE/g and an antioxidant activity of 7.64 ± 0.43 mmol TE/g were also produced using a batch extractor operating under optimal process conditions.