The present proposal of this doctorate thesis has as main purpose the study of the technical feasibility of the solvent replacement commonly used on the process of vegetable oils extraction, known as hexane, by short-chains alcohols, with or without hydration. The proposed solvents in this research, ethanol and isopropanol, are generally recognized as safe (GRAS). Such characteristic is a striking advantage compared to the high toxicity and flammability related to hexane. Furthermore, these solvents, if replaced, can be easily recovered after the process of extraction due to their partial miscibility to the oil at room temperature. Even though some advantages of the hexane replacement by alcoholic solvents are evident, there are some gaps that must be filled through a systematic study of the solid-liquid extraction process. On recent finalized research projects (FAPESP 2009/17855-3, 2010/03058-1 e 2010/13285-5), made by a research group led by the doctoral advisor of this proposal, it was studied appropriate conditions to provide the usage of alcoholic solvents to extract the vegetable oils from solid matrixes. On these projects, the matrixes used were expanded soybean and rice bran in pellets, as an evaluation object, the influence of the variables of the process on the composition of the extract and the quality of the protein fraction indices present in the defatted bran.In this doctorate thesis project is suggested a refinement of the study of indices of the quality from the protein fraction present in the defatted rice bran, after the process of rice bran oil extraction by using alcoholic solvents. These indices will be evaluated based on analyses that describe more deeply the protein fraction and indicate how the operating conditions can influence the functional properties of the protein present in the rice bran protein concentrated that will be produced. On a parallel research will be monitored the physical-chemical features of the oil and the behavior of the protein fraction on the study of the solid-liquid extraction on the sesame seed cake oil, searching for the increase of the extraction income and the appreciation of the defatted material, using the proposed alternative solvents.Moreover, on the next level to the extraction process, it is proposed the study of the liquid-liquid equilibrium as function of temperature to systems composed by sesame oil and solvent. This stage of the project aims the evaluation of the operation of the partial recovery of the alcoholic solvent contained in the extract and the study of the partitioning of minor compounds of nutritional interest contained in the sesame oil, such as sesamin.
News published in Agência FAPESP Newsletter about the scholarship: