Evaluation of antioxidant properties of sodium-selenite microencapsulated in antioxidant-free soybean oil refined

Much research has been done approaching replacing synthetic antioxidants with adverse nutritional effects. In this study, the antioxidant effect of microencapsulated sodium selenite in delaying oxidation of soybean oil was investigated. Microencapsulation of sodium-selenite was carried out, comprising the following combination: Arabic gum (25, 26, 27, 28, and 29%) and a corresponding amount of Farsi gum (corresponding to Arabic gum, respectively 1, 2, 3, 4, and 5%) using the solvent (ethanol with purity 96% ) evaporation method. The ratio of ethanol to the mix solution [combination gum + sodium selenite] was (4, 6, 8, 10, and 12). Finally,  optimal formula1 (EE 94%, particle-size 64.9µm, Arabic gum 29%, Farsi gum 1%, and the ratio of ethanol to the mix solution 12 ) and the optimal formula2 (EE 84.4%, particle-size 74µm, Arabic gum 27%, Farsi gum 3%, and the ratio of ethanol to the mix solution 10) were selected. Consequently, the two selected optimal formulas (180.6PPM), the BHA(200PPM), and the un-microencapsulated sodium-selenite (8.6PPM) were added to antioxidant-free soybean oil and then were placed at the 55℃ for (0, 23, 46 days) equal to 20℃ (0, 180, 360 days) by shelf-life accelerator program. The oxidation indices were compared with soybean oil that did not contain any anti-oxidant. EE increased and particle size decreased with increasing Arabic gum levels and the ethanol to mix solution ratio. Encapsulated selenium, such as BHA, increased antioxidant activity and decreased soybean-oil oxidation indices. The effective and propositional treatments are presented in the following order respectively: blank (antioxidant-free) < un-microencapsulated sodium-selenite < BHA = Opt2 < Opt1.