Integrated utilization of grape skins from white grape pomaces

An approach for the integrated utilization of grape skins from white grape pomaces has been proposed. This consists of consecutive or simultaneous extraction of grape skins with neutral organic solvent and water under reflux. Organic extract is a valuable raw material for the isolation of oleanolic acid. The aqueous extract (ca 50%, w/w) is composed of essentially hexoses and suitable for the high yield (till 51%) bioethanol production at a maximum specific cell growth rate (μmax) of 0.29 h−1. The remained extracted grape skins are the complex of structural polysaccharides embedded into cutinous matrix. Extracted grape skins were shown to be a prospective raw material for the production of low-density boards (d ≤ 0.40) for insulation needs. The boards produced from grape skins and bind of 8% urea-formaldehyde resin revealed reasonable tensile strength (0.4 MPa) and a low thermal conductivity (0.09-0.12 W (m K)−1) over a wide range of temperatures (40-200 °C).