Investigating the impact of solvent extraction parameters on oil yield and oil properties: a review
Abstract
Oilseeds are rich in fatty acids, proteins, fibers, minerals, and vitamins that are necessary for human health. It mainly comprises triglycerides and other minor components, including phytosterols, phenols, carotenoids, tocopherols, and phospholipids. Oils can be extracted using a variety of extraction methods including but not limited to the conventional mechanical and solvent method, and novel methods like supercritical fluid extraction. However, the quality and quantity of extracted oil depends on the process parameters. Among many process parameters temperature is the main parameter which controls the yield and its quality. Temperature range depends upon the nature and type of oilseed. High temperature leads to increased yield while relatively low temperature results in low oil yield and longer extraction time. Large particle size of the solid creates a temperature gradient between the inner and outer surface of the seeds which in turn lowers oil yield. Based on this review, an extraction temperature slightly below the boiling point of the solvent is recommended.