Refino de óleos vegetais via extração líquido-líquido em escala piloto com eliminação das etapas de clarificação e desodorização

Abstract

Considering the need to reduce chemical contaminants in vegetable oils during the extraction and refining process, the objective of this work was to apply on a pilot scale, the liquid-liquid extraction technique with hydrated ethanol, for refining canola and soybean mechanically extracted oils . Bench scale tests were carried out to define the conditions of the refining process, and then the technique was applied in a prototype for liquid-liquid extraction, operating in batch by stirring. The clarification and deodorization steps have been eliminated. The preliminary test with soy oil reached an average of 79.4% for deacidification, and 95.0% of mass yield. Samples of oil from the experimental apparatus reached 87.5% yield for deacidification of canola oil, 83.3% mass yield and an average of 4.4 contacts per test. Regarding the quality characteristics, some parameters did not comply with the legislation, with greater attention to the moisture content in both types of oil, and a high peroxide index for soybean oil. In general, the physical and chemical properties of oils refined by liquid-liquid extraction are comparable to those of oils refined by conventional processes, but further studies are needed with better quality crude oils. For oxidative stability, refined canola oil showed 0.28% free fatty acids in oleic acid and peroxide value of 12.65 meqO2 / kg after 24 hours at 65 ºC. This pilot study demonstrated the possibility of refining soy and canola oils without applying techniques that lead to the formation of chemical contaminants in vegetable oils. A liquid-liquid extractor was designed for industrial scale operations, and processing times were determined.