Ultrasound-assisted steam distillation (USD) increased the yield of cinnamon oils extracted from cinnamon leaves by fi tting

a mass transfer kinetic model during the distillation process. A response surface optimization experiment was conducted to

optimize the experimental conditions, which revealed that the order of factors was particle size, ultrasound power, ultrasound

time, and pulse ratio. The optimal conditions were determined to be a 40 mesh particle size, 286 W ultrasound power, 31

min ultrasound time, and 7:3 pulse ratio, resulting in a 2.36% yield of cinnamon oils. The yield of cinnamon oils was 0.57%

greater in USD than that of steam distillation (SD). The nonsteady-state diff usion model was the most suitable model for the

distillation process. The washing coeffi cient b value of USD was 0.0210, indicating that cinnamon oils were enriched on the

particle surface during the initial stages. The diff usion coeffi cient k of the USD was 0.1770, 40.36% higher than that of the

SD, indicating a higher mass transfer effi ciency. The main components in cinnamon oils were cinnamaldehyde, coumarin,

and 2-methoxycinnamaldehyde. Compared with those of SDs, USDs increased the diff usion coeffi cient k values of these

components increased by 48.51%, 77.67%, and 82.43%, respectively. Ultrasound cavitation improved the mass transfer

effi ciency of the distillation process, allowing components such as 2-methoxycinnamaldehyde to be more easily enriched

in cinnamon oils than in other oils.