Effect of continuous and intermittent ultrasound on drying time and effective diffusivity during convective drying of apple and red bell pepper

Effect of continuous and intermittent ultrasound on drying time and effective diffusivity during convective drying of apple and red bell pepper

2012

E04512

A new approach of ultrasound-assisted convective drying was tested in this study using a screen as product support and sound transmitting surface. Red bell pepper and apple cubes were dried at 70 °C in a laboratory scale hot-air drying oven. In addition to continuous ultrasound used for both products, intermittent ultrasound was applied for apple drying reducing net sonication time to 50% and 10%. Significant improvements of drying characteristics were observed for continuous sonication and intermittent ultrasound at 50% net sonication time. Experimental data were fitted with eight models, among which the Midilli model resulted in the best fit with R2 > 0.9988 and reduced χ2 0.0002. The influence of ultrasound on drying time to reach 20% and 30% residual moisture content as well as on effective moisture diffusivities and drying periods is discussed

108(3):103-110, JOURNAL OF FOOD ENGINEERING

Research > Published Articles