Oxidative stability of encapsulated sunflower oil: effect of protein-polysaccharide mixtures and long-term storage
Résumé
In this study, sunflower oil was encapsulated using pea protein isolate (PP) in combination with different polysaccharides (sodium alginate, inulin, maltodextrin or pectin) using the spray-drying technique. The addition of polysaccharides resulted in increase of viscosity and average droplet size of emulsion, water activity, moisture content and mean size of microparticles. Oxidative stability of powders during long-terms storage (25 °C for up to 300 days) was investigated using Rancimat accelerated oxidation test. Microparticles prepared with addition of inulin, maltodextrin and pectin showed the higher gain in oxidative stability (∆IP) compared to those obtained with PP alone, which confirmed the formation of glassy coating and decrease of oxygen diffusion in wall material. For example, at t = 100 days, ∆IP of microparticles prepared with PP alone and in combination with pectin was 3.5 and 11.2 h respectively. Microparticles, formed by employing proposed experimental conditions could be potentially used for the development of functional foods.