Biorefining of blackcurrant pomace into high value functional ingredients using supercritical CO2, pressurized liquid and enzyme assisted extractions

This study reports valorisation of blackcurrant pomace using multistep' processes for its biorefining into valuable food-grade ingredients. Firstly, supercritical carbon dioxide extraction (SFE-CO2) was optimized for effective isolation of lipophilic fraction using response surface methodology based on central composite design. Afterwards pressurized liquid (PLE) and enzyme assisted (EAE) extractions were applied for the isolation of higher polarity substances. The yield of SFE-CO2 at optimal parameters (60 degrees C, 45 MPa, 120 min) were up to 14.6%, while PLE and EAE with acetone, ethanol or water enabled additionally obtain 12.3-39.9% of extracts from SFE-CO2 residues. Lipophilic extracts were rich in polyunsaturated fatty acids (linoleic 46.89%, gamma-linolenic 14.02%) and tocopherols (in total 2468 mu g/g oil), while polar fractions demonstrated strong antioxidant capacity as it was evaluated by the total phenolic content, DPPH radical and ABTS cation radical scavenging, ferric reducing antioxidant power and oxygen radical scavenging capacity assays. (C) 2017 Elsevier B.V. All rights reserved.