The Effects of Refining Operations on Quality and Quantity of Sterols in Canola, Soyabean and Sunflower Seed Oils

Sterols due to their properties might be considered as valuable products to be employed in food, pharmaceutical and cosmetic industries. Vegetable oils, namely canola, soyabean and sunflower seed oils, contain considerable quantities of phytosterols, mainly β–sitosterol. The aim of this research is to determine the effect of refining operations, particularly deodorization on this valuable class of compounds. Three popular and common vegetable oils were sourced from local refineries and were subjected to neutralization, bleaching and deodorization procedures. The sterols were determined by saponification of the oils followed by extraction of the nonsaponifiable matter, and isolation of sterols by TLC and their final qualitative and quantitative determination by application to gas chromatography apparatus. The results indicated that sterols are lost in neutralization, bleaching and particularly deodorization stages to some extend and some might be collected in the distillate after deodorization. The distillate that is considered as a valuable source of sterols might be purified and used in various applications and industries.