Volatiles retention during the drying of aqueous carbohydrate solutions

Measurements were made, at time intervals of Me2CO in an aq. droplet suspended from a wire in a current of air. As a model juice, an aq. soln. of malto-dextrin was used to form the drop, and Me2CO-14C was added to serve as a model aroma. A film formed on the surface of the drop during drying, film formation rate increasing with increase in initial carbohydrate concn. This film was permeable to water, but not to Me2CO, C6H6, EtOH, or AcOEt. It is suggested that formation of a membrane impermeable to aromas is responsible for aroma retention during the drying of droplets, and that adsorption is not involved.