Controlled formation and stabilization of nanosized colloidal suspensions by combination of soy protein and biosurfactant stevioside as stabilizers. (January 2016) - Wan, Zhi-Li
Abstract: In this work, we evaluated the potential of a novel combination of denatured soy protein (SPI) and biosurfactant stevioside (STE) as efficient and novel stabilizers for producing stable nanosuspensions using resveratrol (RES) as a model compound. The RES nanosuspensions (RESN) were prepared by the nanoprecipitation-ultrasonication method. Below the CMC of STE (0.25–0.5%), the RESN stabilized by the SPI-STE mixtures exhibited outstanding physicochemical characteristics, such as small particle size (below 200 nm) and high yield/entrapment efficiency (above 97%), which should be ascribed to the higher surface activity of mixtures due to SPI-STE complexation and hence faster adsorption on particle surfaces, thus contributing to the decrease in particle size. Meanwhile, the small molecule STE could function as a filler to fill the defects left by SPI, thus providing a more complete and compact coverage on particle surface. Accordingly, the RESN exhibited a remarkable storage stability and could maintain good redispersibility after direct freeze-drying even without any protectants. Nevertheless, at high STE concentrations (1–2%, above its CMC), the formation of RESN was hindered due to the decreased surface activity of mixtures and the presence of STE micelles, which could cause particle surfaces incompletely protected. As a result, the resultant RESN became very unstable and highly susceptible to particle aggregation during storage. Graphical abstract: Highlights: The denatured SPI-STE mixtures showed a good capacity to produce and stabilize RESN. The mixtures-stabilized RESN exhibited outstanding properties below the CMC of STE. The higher surface activity of mixtures could enhance nucleation rate of RES particle. The presence of STE led to a more complete and compact coverage on particle surface. The RESN showed a remarkable storage stability and good redispersibility.