Convective dehydration kinetics and quality evaluation of osmo-convective dried beetroot candy

Abstract

The Beetroot cubes were osmotically pretreated in 60oB of sucrose solution at 55o C osmotic solution temperature for 180 min with fruit to solution ratio 1:4 (w/w).The osmotically dehydrated Beetroot cubes were further dehydrated convectively at different drying air temperatures of 55, 65 and 75oC up to final moisture content of 9±1%(w.b).Among the models investigated, the Page model fitted the experimental data for convective drying of natural and osmosed beetrooot cubes.. During convective dehydration, the effective moisture diffusivity of natural samples and osmosed samples at drying air temperatures ranging from 55 to 75 oC varied between 8.09917 × 10-9to 1.45785 × 10-8 m2s-1, between 1.13388 × 10-8 to 1.61983 × 10-8 m2s-1, respectively. The activation energy of convective dried natural beetroot cubes was 27.92 kJ mol-1 as compare to 16.98 kJ mol-1 for osmosed samples. Finally osmo-convectively dried beetroot cubes was coated with sucrose for candy preparation