Improvement in the quality of used sunflower oil by organic and inorganic adsorbents

The objective of the present work was to improve the quality of used sunflower oil. Inorganic (normal and modified silica gel) and organic (normal and modified cellulose powder) adsorbents were used as regeneration agents. Sunflower oil was heated at 180 ± 5 °C, 4 h every day for five consecutive days. The adsorbent materials were individually added to use sunflower oil at 2% level (w/v). Some physico-chemical characteristics were measured to assess the quality of treated-used sunflower oil. The results indicated that all adsorbents under study were effective in improving the overall quality of used sunflower oil. Normal silica gel with small particle size permitted high adsorbing capacity and close to that induced with Magnesol XL which is used commercially in a large scale to improve oil quality. The polarity of the adsorbent substance had a remarkable effect on removing the secondary oxidation products of used sunflower oil. The mode of adsorbents action is discussed.