Effect of oil-water surface area on the aroma release behavior of mono-dispersed oil-in-water emulsions

The size of emulsion droplets can influence the taste and texture of food. Therefore, we investigated the effect of droplet diameter of oil-in-water (O/W) emulsions on the aroma release rate from emulsions. O/W emulsions were prepared to droplet sizes of 0.4, 2.0 and 20 µm. The release rates for seven aroma compounds, viz., limonene, ethyl hexanoate, 2-methylpyrazine, benzaldehyde, ethyl benzoate, α-terpineol, and benzyl alcohol, from the O/W emulsions were measured under non-equilibrium. The aroma release rate of 0.4-µm droplets was higher than that of 2.0- and 20-µm emulsion droplets irrespective of their partition coefficients. Aroma compounds in small oil droplets can rapidly diffuse in the water and air phases because a small droplet has a large oil-water surface area. Overall, our findings suggest that small droplet emulsions can be used to release more aroma compounds than large droplet emulsions without changing the emulsion components.