EFFECT OF DIFFERENT SOLVENTS ON THE EXTRACTION OF SOYA BEAN OIL

Abstract

Extraction of soya bean oil is often by mechanical and solvent expression with mechanical expression efficiencies seldomly exceeding 80%, compared to over 98% achieved by solvent extraction. Solvent extraction, however, acquires its efficiency from the solvent hexane, which the government of the United States of America Clean Air Act has banned based on health and safety reasons for working staff and its explosive nature. This research presents the findings of the use of alternate solvents (isopropyl alcohol and petroleum ether) as a replacement for hexane, conditions required to optimise maximum oil recoveries using parameters such as moisture content, duration, texture of samples and leaching rate per solid-liquid phase for each solvent and an assertion of the quality of soya oil extract through physicochemical analysis. The results indicated that petroleum ether had higher oil recovery (fine = 95.4% medium= 69.1 %, and coarse = 55.6) than isopropyl alcohol (fine = 33%, medium = 32% and coarse = 18.3%) with texture of sample as a determinant. The physicochemical analysis of the oil indicated its high quality.