A Review on Vegetable Oil Refining: Process, Advances and Value Addition to Refining by-Products

Nowadays, consumer food choices are driven by health awareness and sustainability concerns. As vegetable oil is an important component of the human diet, the source and the processing play an important role in consumer acceptability. To remove impurities that affect the color, palatability, stability, and safety of oil, crude vegetable oil must be refined. This review highlights the processes and steps used in vegetable oil refining. Depending upon the oil source type, either chemical or physical refining is employed to get the desired oil specifications. Oil refining steps are sequential, with each step removing one or more specific impurities. Refining advances aim towards minimizing chemical usage, nutrient losses, oil losses, and avoiding the formation of trans-fatty acids. The review also discusses the prospect of using the refining by-product stream for obtaining high-value products like phosphatidylcholine, tocopherols, and tocotrienols. The edible oil industry can be made more economical and sustainable through the valorization and integration of waste product streams obtained at different refining steps.