Kinetic study of controlled release of flavor compounds from spray-dried encapsulated yeast powder using dynamic vapor sorption-gas chromatography

The release profile of d-limonene and ethyl hexanoate was investigated using a dynamic vapor sorption (DVS) system coupled with gas chromatography. The flavors were encapsulated by spray drying using Saccharomyces cerevisiae cells from which beta-glucan had been partially extracted. Relative humidity (RH) was stepped from 20% to 50, 60, 70, and 80% at 30, 40, 50, and 60oC. The maximum release flux for d-limonene and ethyl hexanoate was around 12 and 28 mg/s.m(2.)g-powder at 80% RH and 60oC incubation. The Weibull distribution function was well fitted with the experimental data to analyze release kinetics. The release mechanism parameter was greater than 1.0, which indicates a controlled release with initial induction time. The activation energy for ethyl hexanoate (6 kJ/mol) was lower than d-limonene (41 kJ/mol) at 80% RH, which indicates higher affinition of ethyl hexanoate to migrate from the lipid bilayer membrane towards the water phase.