Barley and yeast β-glucans as new emulsifier agents for the development of aqueous natural antifungal formulations

Barley and yeast β-glucans were selected, together with lecithin, to encapsulate resveratrol by emulsification-evaporation method to develop new and safer antifungal formulations. Different emulsification techniques were used: high-shear, high pressure and high pressure and temperature emulsification. Morphology, crystallinity, encapsulation efficiency and in vitro antifungal activity against Botrytis cinerea of the different formulations were evaluated. No significant differences between each emulsification procedure in particle size (below 90 nm) and in encapsulation efficiency (70–100%) were observed; only barley β-glucan emulsions showed lower efficiency due to the formation of a gel that retained most of the active compound. A great influence of the emulsification method and the encapsulating material on the crystallinity of the particles was observed. The highest antifungal activity (up to 53% growth inhibition) was obtained by the formulations with yeast β-glucans, indicating an enhanced absorption of encapsulated resveratrol through the cell wall of the fungus at the presence of (1–3, 1–6)-β-glucans.