Western Illinois University, Chemistry, Macomb, IL 61455
Encapsulation of bioactive compounds in biopolymer-based carrier matrices has emerged as an innovative and effective technique in the food, pharmaceutical and cosmetic industries. In the present study, soybean oil containing ω-3 and ω-6 fatty acids (α-linolenic acid and linoleic acid respectively), and eicosa pentaenoic acid (EPA) were used to develop model systems including sucralose or trehalose and the stability of the systems were studied. The effects of changes in some thermodynamic variables are investigated. Soybean oil microdroplets were prepared by ultrasonication using successively, a mixture of whey protein, a solution of λ-carrageenan and either a solution of sucralose or trehalose. The emulsions were then stored at 4ºC for phase separation studies. Microdroplets of soybean oil emulsions show stability at low relative humidity and delayed phase separation at higher relative humidities (RH). In sucralose-coated soybean microdroplets, phase separation occurs at lower RH (33.3% RH). Furthermore, in trehalose-coated system, EPA microdroplets were stable even at higher RH. Changes in peroxide value were used to assess the antioxidant activity of sucralose and trehalose in the systems. After two weeks of storage, the amount of peroxide value in the trehalose-containing system was 42.36 (mM/kg oil) and that of the sucralose system was 86.42 (mM/kg oil). Determination of particle size distribution, glass transition temperatures (Tg), Zeta potential and HPLC analysis of oxidation products in EPA nanoparticles at various RH are under way.