Oxidation of Fish Oil Oleogels Formed by Natural Waxes in Comparison With Bulk Oil

The aim of this study is to evaluate the oleogel (or organogel) technology as a new method to prevent oxidation of fish oil by immobilizing oil and to provide useful information on oxidation of oleogels for their application in actual food products. Four different natural waxes, rice bran wax, sunflower wax, candelilla wax, and beeswax are used to prepare fish oil oleogels. Peroxide value, conjugated diene value, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are measured after storing oleogels at 35 and 50 degrees C, respectively. All 3% wax-fish oil oleogels shows slower oxidation than the bulk fish oil at 35 degrees C. Beeswax is not as effective as other waxes during storage at 50 degrees C due to its lower melting point. The color penetration measurement method is developed as a convenient method to predict the oxidation rate of oleogel. Cooling oleogel at a faster rate can significantly reduce the oxidation rate of the oleogel. A larger amount of wax is not recommended to increase the protective effect, which can give a negative effect due to the prooxidant activity of wax. The oleogel technology may be applied to reduce oxidation of food products and nutritional supplements containing omega-3 oil.