Effect of Industrial Refining Process on Fatty Acid, Sterol, Volatile Compound Profile and 3-MCPD Ester Content of Canola and Corn Oils

Abstract

The study reports the changes in fatty acid and sterol composition; as well as volatile and 3-monochloropropane-1,2-diol (3-MCPD) ester content of two commercial vegetable oils at different steps of refining process. Canola and corn oils were collected from neutralization, bleaching, winterization and deodorization stages of a chemical refining plant and oil samples were evaluated for fatty acid, sterol, volatile compounds and 3-MCPD ester contents. Fatty acid and sterol profiles were determined using IUPAC and AOCS Official Methods respectively and 3-MCPD ester content was determined using DGF C VI 18 (10) Official Method. Results have shown that total sterol contents decreased throughout the process by 15.22% and 42.57% for canola and corn oils, respectively. Total volatiles of canola oil decreased gradually during refining, however corn oil had significant increases at bleaching step. 3-MCPD ester contents were between 0.19-0.26 mg kg -1 for corn and 0.20-0.48 mg kg -1 for canola oils. Deodorization was found to be the most influential refining stage for formation of 3-MCPD esters.