Hot-air drying characteristics and mathematical model of cantaloupe slices

Abstract

Objective: In order to improve the quality of cantaloupe production and shorten the drying period. Methods: Use different blanching time (0.5, 1.0, 1.5, 2.0, 2.5 min), impregnation liquid (0.1%, 0.2%, 0.3%, 0.4%, 0.5% citric acid solution) to pretreat cantaloupe slices, and study different hot air temperature (35, 45, 55, 65, 75 ℃), air velocities (0.5, 1.0, 1.5, 2.0, 2.5 m/s), and slice thicknesses (2, 4, 6, 8, 10 mm) on the hot air drying characteristics and moisture diffusivity coefficient of cantaloupe slices, different thin-layer drying mathematical models were fitted. Results: 0.4% citric acid pretreatment yields the best quality dried product, and the temperature and thickness influenced slice drying significantly. There was no constant drying stage in cantaloupe slices drying with the effective moisture diffusivity coefficients of 1.134 8×10-7~4.908 0×10-7 m2/s and activation energy of 28.15 kJ/mol. Conclusion: The optimal hot air drying process of cantaloupe slices drying is as followed: hot air temperature of 55 ℃, air velocities of 2.0 m/s, slice thickness of 6 mm, under the conditions, Page model has the highest R2 value and the lowest root mean square error, which is more suitable for evaluating the moisture removal law of hot-air drying of cantaloupe slices.

Keywords

• cantaloupe
• hot-air drying
• drying characteristics
• mathematical model
• heat and mass transfer