the effects of degumming and neutralization on the quality of crude sunflower and soyabean oils

abstract: degumming and neutralization processes are two essential stages carried out on crude edible oils in order to remove some unwanted impurities namely gums and free fatty acids. in this research study two popular less expensive commercial oils that are consumed to a great extent namely soyabean and sunflower seed oils are selected and subjected to both degumming and neutralization processes as recommended and described by the conventional methods. the effects of these two processes are investigated on both oils qualitatively and quantitatively. minor changes were detected in fatty acid composition meaning that slight oxidation reactions have taken place during the operations. the acid values representing the fatty acid concentrations were reduced as the result of neutralization with the lye solution. the peroxide value that indicates the primary oxidation products has been increased due to the oxidation chain reactions producing hydroperoxide. the phosphorus, iron and copper concentrations as well as the induction periods were reduced. the reduction in the induction period might be the result of phospholipid removals since they act as synergist with the tocopherols. the nonsaponifiable matter representing sterols, 4 methyl sterols, triterpene alcohols, tocopherols, hydrocarbons and some other components were reduced at the end of neutralization process along with the soap removal.