Aroma Release at the Nano- and Microscale: Molecules to Droplets

Aroma release is governed by physico-chemical factors like partition coefficents which regulate the relative amounts of an aroma in the gas and food phases. While this relationship holds good for many liquid and semi-solid foods, it only applies to systems where aroma is homogenously distributed and where aroma is present in solution. The effect of length scale on aroma release in vivo and in vitro has been studied to better understand release from encapsulated systems. When aroma was incorporated into foods in alternate aromatized and un-aromatized layers, overall release was not affected due to mixing by mastication, which negated the aroma separation. In the presence of co-solutes (propylene glycol, triacetin, ethanol) aroma release from high solids gel systems was affected. The physical state of the aroma (solubilized or microdroplet) also has significant effects and may explain the aroma burst observed from encapsulated flavors.