Extraction of anthocyanins and polyphenolics from blueberry-processing waste

The effectiveness of temperature, SO,, citric acid, and industrial juice-processing enzymes (n = 9) for producing extracts of blueberries (Vaccinium corymbosum, cv. Rubel) and blueberry skins that are rich in anthocyanins and polyphenolics were evaluated individually and/or in combination. Enzyme treatment had little effect on total monomeric anthocyanins and on total phenolics recovery. Various combinations of heat, SO2, and citric acid yielded extracts with higher concentrations of ACY and TP than the control. The distribution of anthocyanins and polyphenolics in 'Rubel' was also investigated. Anthocyanins existed almost exclusively in the skins, and polyphenolics were mostly in the skins with lesser amounts in flesh and seeds. Skins were also highest in antioxidant activity. All portions contained the same individual anthocyanins but in varying amounts. Cinnamic acid derivatives and flavonol-glycosides were found in the skins and seeds, whereas the flesh contained only cinnamic acids.