Adsorbent Purification of Frying Oils

Brian S. Cooke, Dallas Group of America 
Jeffersonville, USA

Regardless of origin, virgin frying oils are non-polar in nature.  However, polar compounds are formed as these oils degrade due to oxidation, hydrolysis, heat stress, etc.  It is generally accepted that polar compounds are a reliable measure of oil quality and correlate to the taste, appearance and nutritional properties of fried foods.  The concentration of polar materials increases until the oil becomes unfit for use.  Countries have established legal limits or guidelines for polar materials, polymers, and free fatty acids in the oil.  

Synthetic magnesium silicate has been shown to have a strong adsorptive affinity for polar materials.   The effects of daily treatment of frying oil with DALSORB®, a magnesium silicate-based adsorbent, were observed in a commercial frying operation. The use of DALSORB® allowed for continued frying operation with no oil discard by sharply reducing levels of free fatty acid (91%), alkaline materials (86%), colors (70%), total polar compounds (47%), polymers (20%) and anisidine value (20%).