Experimental Investigations on Electrical Heat Assisted Drying of Cashew Kernels

Abstract

Drying is an important process in food preservation. In cashew processing industries cashew kernels are dried for easy peeling of the thin brownish sticky layer known as testa. The average moisture content of 13% of the cashew kernels needs to be reduced to 5% for proper peeling action. Drying can achieved either by traditional drying methods or through dryers. Due to control of the air properties in indirect drying cashew kernels can be dried at faster rate and can retain their quality. Air flow passage also plays an important role in drying process. The objective of the study is to investigate experimentally the feasibility of drying chamber for drying of cashew kernels using electrically assisted heating. An electrical heat assisted drying system is designed and developed using locally available materials. The system uses three different drying chambers that are designed and tested for optimum drying rate of cashew kernels in three separate experiments. Drying chamber without baffle plates has resulted in reduction in moisture content to required level by 5% in three hours with drying rate of 2.8 kg/h against 6.5% and 6.8% in single tray version and four trays with baffle plate version. The drying efficiency of drying chamber is found to be 30.54%.