Drying Kinetics of Fresh Green Peas by Microwave Cum Hot Air Drying

Abstract

Experiment was carried out to analyse the effect of microwave preheating time at selected power level and temperature for hot air oven drying on drying kinetics. The samples were analysed for various parameters such as moisture content, drying rate, moisture ratio, drying constant. The hot air oven drying of fresh green peas were carried out at three different temperature 60, 70 and 80°C. The microwave pre-heating time used were 3, 4 and 5 min at constant microwave power level of 450W.The initial moisture content of fresh green peas was (354.54% db) after preheating in microwave, reduce to moisture content level of (333.06% db) for 3 min duration, (323.73% db) for 4min duration, (313.16%db) for 5min duration respectively. Weight of the samples at different stages during drying process were recorded. The loss in weight was converted into corresponding moisture loss for calculating moisture content (% db). Drying rate curve were formed to study the drying characteristics at different microwave pre-heating times. Sample size of green peas chosen for drying was 200g. The weight loss was recorded at interval of 1hr. Fresh Green peas was dried under two drying modes i.e. fresh green peas dried without microwave pre-heating and microwave pre-heated green peas dried by hot air oven.