Influence of High-Intensity Ultrasound on Drying Kinetics of Persimmon

Abstract

Drying persimmon pieces is recognized as a way to preserve and add value to the excess production of the fruit in Spain. To this end, air drying kinetics of persimmon cylinders (30 mm height and 13 mm diameter) were determined under different drying conditions: 8 air drying velocities (0.5, 1, 2, 4, 6, 8, 10, and 12 m/s) with and without application of high-intensity ultrasound (21.8 kHz and 154.3 dB). The drying process was modeled using two diffusion models with and without the influence of external resistance to drying. From the effective diffusivity and the mass transfer coefficient identified from the data it was concluded that high-intensity ultrasound increased the drying rate at the lowest air velocities tested, affecting both external and internal resistances.

Keywords:

• Acoustic drying
• Air velocity
• Diffusive model
• Diffusivity
• External resistance
• Internal resistance
• Kaki

ACKNOWLEDGEMENTS

The authors acknowledge the financial support of the Spanish Ministry of Science and Technology (AGL2001-2774-CO5-01) and the Generalitat Valenciana (Ref. GV04A-689).