Extraction of anthocyanins from grape skins assisted by high hydrostatic pressure Review Article

The effect of different parameters such as high hydrostatic pressure (HHP) (200, 400, 600 MPa), ethanol concentration (20–100%), time (30–90 min) and temperature (20–70 °C) was studied for the optimal anthocyanin extraction from red grape skins. Extracts obtained at an ethanol concentration of 50%, at 70 °C and 600 MPa possessed the highest antioxidant capacity image and the extraction yields were three-fold greater than control extractions. The antioxidant capacity of the extracts was not directly correlated to the highest amount of anthocyanins, which were optimal extracted with the set of conditions – 100% ethanol, 50 °C and 600 MPa – achieving extraction yields about 23% higher than under control conditions. Anthocyanin recovery under HHP was selective and increased according to the glucoside moiety linked to the flavylium nucleus; p-coumaroylglucoside anthocyanins were more favourably extracted than mono- and acetylglucosides. Therefore, a higher extraction rate was related to the higher number of methoxyl and hydroxyl groups linked to the C3 and C5 of the flavylium nucleus, hence extraction of malvidin > peonidin > petunidin > delphinidin > cyanidin.