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

Abstract

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 °C, respectively. All 3% wax‐fish oil oleogels shows slower oxidation than the bulk fish oil at 35 °C. Beeswax is not as effective as other waxes during storage at 50 °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. Practical Application: This study clearly shows that the oleogel technology can be used to prevent oil oxidation by immobilizing oil in food products. This technology can be used for commercial products such as fish oil supplements to prevent oil oxidation during production, transportation, and storage. The information presented in this study can also be used for new omega‐3 oil fortified food products such as margarine, spreads, shortening, cookies, and other related products. The oleogel technology can be easily applied as a drop‐in method. Natural waxes used as oleogelator are inexpensive and widely available, and most of them are already used in many food products. Peroxide value of 3% wax‐fish oil oleogels stored at 35 °C for 7 days.

Physicochemical Properties of Foam‐Templated Oleogel Based on Gelatin and Xanthan Gum

“…At the end of the period, the oleogel PV was unexpectedly lower than value of the oil, which could be associated to the presence of polymer structure in the oleogel that provides barrier network keeping oil far from oxygen. This finding was in agreement with data reported by Huwang et al who stated that natural waxes reduced PV of the oleogel than bulk fish oil at 35 °C due to limiting oil in the gel network during 21 days . Similarly, investigation of PV in CO and the related HPMC oleogel during 18 days at 60 °C demonstrated that polymeric oleogel had a tendency to extend oxidative stability due to the limitation in oil mobility…”

Sunflower wax recovered from oil tank settlings: Revaluation of a waste product from the oilseed industry

“…Instead, it is recovered from the filter cakes from the winterization process, and the oil‐tank settlings are used for animal feed with low commercial value. Several studies were developed using commercial waxes but studies of wax recovered from sunflower oil processing are scarce . Argentina produces 1.1 million metric tons of sunflower oil, and a large proportion of this oil is exported as crude oil (ranking third worldwide) .…”

Addition of Sesamol Increases the Oxidative Stability of Beeswax Organogels and Beef Tallow Matrix Under UV Light Irradiation and Thermal Oxidation

“…However, oxidative stability in wax‐based organogels were affected by the types of waxes. Beeswax had some prooxidative properties compared to candelilla wax to certain extent due to the lower melting point of beeswax (Hwang et al., ). The reported onset melting temperature of organogel made of 5% (w/w) beeswax, rice bran wax, and sunflower wax with rice bran oil were 53.99, 72.5, and 66.8 °C, respectively, whereas those of crystallization temperature were 46.97, 56.71, and 62.13 °C, respectively (Doan, Walle, Dewettinck, & Patel, ).…”

“…Thermal characteristics including melting and crystallization points were analyzed by a differential scanning calorimeter (DSC) according to the previous method (Hwang, Fhaner, Winkler‐Moser, & Liu, ), and performed on a Perkin‐Elmer DSC 4000 (Perkin‐Elmer Corp., Norwalk, CT, USA). Samples of 7 to 8 mg were weighed in aluminum pans and sealed with covers.…”