Effect of Different Pre-Treatments and Temperatures on Drying Characteristics of Beetroot Slices

Abstract

An experimental study was carried out to study the effects of different pretreatments and drying methods on beetroot slices. Drying is widely used and primary method for preservation. Dried beetroot slices were made by treating the slices with different pretreatments (control, KMS, blanching and KMS plus blanching). The drying was done under natural convection in direct sun drying method and under forced convection in cabinet tray drying at temperatures 50⁰C, 60⁰C and 70⁰C. Moisture content, drying rate and moisture ratio were computed to study the drying characteristics of beetroot slices. The study revealed that the highest drying rate and lowest final moisture level was recorded in hot air tray drying of beetroot slices at air temperature of 70⁰C. The total drying time for beetroot slices dried under tray drying at 70°C took 240-360 min to be dried completely depending upon treatments. Sun drying took maximum drying time of 480 min. The increase in drying air temperature increased the drying rate in all the methods.