Microwave Thin Layer Drying of Untreated and Osmotic-Pretreated Indian Gooseberries (Phyllanthus Emblica) (PDF)

Scientific Essay from the year 2016 in the subject Engineering - Chemical Engineering, , language: English, abstract: The thin layer drying characteristics of untreated and osmotic-pretreated Indian gooseberries were examined using a laboratory microwave dryer at five different powers. Hypertonic solutions like 10%NaCl and 20%NaCl were used for osmotic-pretreatment of Indian gooseberries. Drying was carried out until constant values were obtained. The drying curves obtained from the experimental data were fitted to different thin layer drying models. All the models were compared according to three statistical parameters ¿2, RMSE and R2.

The results showed that gooseberries pretreated in 20%NaCl solution took lesser drying time than gooseberries pretreated in 10%NaCl solution and untreated samples. Midilli model was found to be the best model for describing the drying curve of Indian gooseberries. Effective diffusivities and drying coefficient (k) for untreated and pretreated Indian gooseberries were calculated at five microwave powers using linear regression method. Biot number for untreated and pretreated Indian gooseberries was calculated using standard mass transfer equations.