THE TWIN-SCREW EXTRUSION TECHNOLOGY, AN ORIGINAL AND POWERFUL SOLUTION FOR THE BIOREFINERY OF SUNFLOWER WHOLE PLANT

摘要

The objective of this study was to evaluate the feasibility of an aqueous process for the biorefinery ofrnsunflower whole plant using a twin-screw extruder. Aqueous extraction of oil was chosen as an environment-friendlyrnalternative to the solvent extraction. The extruder was used to carry out three essential unit operations: grinding,rnliquid/solid extraction, and liquid/solid separation. Wringing out the mixing was effective. However, drying of therncake meal was not optimal. Lixiviation of cotyledon cells was also incomplete. Extraction efficiency depended onrnoperating conditions: screw rotation speed, and input flow rates of whole plant and water. In the best conditions, oilrnyield was 57%. Residual oil content in the cake meal was 14%. These conditions leaded to the co-extraction ofrnproteins, pectins, and hemicelluloses. The corresponding protein yield was 44%. Oil was extracted in the form of twornoil-in-water emulsions. These hydrophobic phases were stabilized by phospholipids and proteins at interface. Anrnaqueous extract containing part of the water-soluble constituents, mainly proteins and pectins, was also generated. Asrna mixture of fibers and proteins, the cake meal was molded by thermo-pressing. Panels produced had interestingrnmechanical properties in bending. The obtained fractions may have applications as bases for industrial products.