Comparison of ergocalciferol nanodispersions prepared using modified lecithin and sodium caseinate: insights of formulation, stability and bioaccessibility

In this work, we compared the formulation, stability and bioaccessibility of ergocalciferol nanodispersions using modified lecithin (ML) and sodium caseinate (SC) as natural emulsifiers. The mean particle size of nanodispersions stabilized by ML (56 nm) was much smaller than those stabilized by SC (112 nm). The ML-stabilized nanodispersions were stable over a wide range of pH, NaCl concentrations and heating, but became unstable with slight increase in particle size when exposed to CaCl 2 solution. In comparison, SC-stabilized nanodispersions were relatively unstable to particles aggregation at pH 4 and 5, CaCl 2 addition and heating. Long-term stability for ergocalciferol were observed in both ML- and SC-stabilized nanodispersions. In the absence of milk, the ergocalciferol bioaccessibility was strongly dependent on the emulsifier type, with ML providing much higher bioaccessibility than SC. During in vitro gastrointestinal digestion, the incorporation of milk into nanodispersions could increase the bioaccessibility and stability for ergocalciferol.