Drying characteristics and quality of lemon slices dried under Coulomb force-assisted heat pump drying

Abstract

In this research, a Coulomb force-assisted heat pump (CF-HP) dryer was invented for the purpose of improving the drying characteristics and product quality of biomaterials. As compared to HP drying alone, the assistance of Coulomb force in HP dryer enhanced the drying rate and effective moisture diffusivity of lemon slices up to 26%, which eventually shortened the total drying time by 40%. This saved the total energy consumption of HP drying by 31.5%. CF-HP drying method preserved most of the vitamin C and total phenolics content, at the same time minimized shrinkage and browning of dried lemon slices.

Keywords:

• Coulomb force-assisted heat pump drying
• vitamin C
• total phenolics content (TPC)
• shrinkage
• browning

Additional information

Funding

This study was supported by the Exploratory Research Grant Scheme (ERGS), Ministry of Education Malaysia, under Grant [ERGS/1/2012/TK05/UTAR/02/5].