Optimization of encapsulation efficiency and average particle size of Hohenbuehelia serotina polysaccharides nanoemulsions using response surface methodology.

The aim of this research was to develop novel W1/O/W2 nanoemulsions for encapsulating Hohenbuehelia serotina polysaccharides to resolve the low soluble and unstable problems. The prepared parameters (PVA content, polysaccharides concentration, stirring speed and stirring time) of H. serotina polysaccharides nanoemulsions were optimized based on the response surface methodology. Through systematic analysis of the model, the optimal conditions were chosen as PVA content of 0.60%, polysaccharides concentration of 9.7μg/mL, stirring speed of 11,000rpm, and stirring time of 2.4min. Under the optimal prepared conditions, the encapsulation efficiency and particle size were respectively 75.42±0.69% and 410.1±2.3nm, which were well consistent with the predicted values. The optimized nanoemulsions possessed the spherical multilayer structure with the zeta potential value of -52.34±5.62mV, and they could be stably stored at 25°C for 6days. Moreover, the nanoemulsions had the excellent sustained-release characteristics in the simulated gastric fluid. This study may provide a valuable contribution for the application of nanoemulsions in the functional food field.