The filter aids were added individually to the used frying oil at levels 1, 2 and 3 % (w / v), then mechanically stirred for 60 min at 105 °C. The results indicate that all the filter aids under study were characterized by high levels of Si and variable levels of other minerals. The highest level of Si was recorded for sugar cane bagasse ash (SCBA) was 76.79 wt. %. Frying process caused significant (P ≤ 0.05) increases in physico-chemical properties of sunflower oil.