EFFECT OF DRYING METHODS ON MALTING OF FINGER MILLET (RAGI,ELEUSINE CORACANA)

摘要

Effect of various dehydration methods on drying kinetics,nutritional and optical properties of sprouted finger millet were evaluated.Drying included heat pump drying (37oC),microwave vacuum drying (at 250 W,350 W and 450 W),vacuum drying (at 50oC,60oC,70oC and 80oC),infrared drying (at 3 kW/m2,3.6 kW/m2 and 4.2 kW/m2).Vacuum dryer,heat pump dryer showed falling rate periods whereas microwave vacuum dryer and infrared dryer showed constant as well as falling rate periods.The time taken for drying from 56 ％ db to 10 ％ db was in the order of microwave vacuum dryer < infrared dryer < vacuum dryer < heat pump dryer.The effective diffusivity was maximum for the infrared dried (4.2 kW/m2) and minimum for heat pump dried sprouted finger millet.The infrared (4.2 kW/m2) dried sprouted finger millet underwent greater colour degradation.Overall colour of heat pump dried sprouted finger millet was maintained well after drying as compared to vacuum and infrared dried sprouted finger millet.Retention of protein of sprouted finger millet was in the order of heat pump dryer,infrared dryer,vacuum dryer and microwave vacuum dryer.However,infrared drying seems to be a promising method for drying sprouted finger millet,when comparing the lower drying time and good quality product to the faster microwave drying.The malted finger millet perceived easy digestibility achieved through lowered viscosity,rendering it ideal for geriatric and weaning formulations.