Perubahan Konsentrasi Larutan Gula pada Dehidrasi Osmotik Irisan Mangga (Mangifera indica L.) dan Pengaruhnya Terhadap Kebutuhan Daya Pengadukan

Abstract

During osmotic dehydration, water leaving the product may dilute the osmotic solution, especially for conditions having low product solution ratio. The main objectives of this study were to obtain the characteristic of sugar solution concentration during osmotic dehydration of mango and its effect on stirring power requirement. Solution concentration used in this study was 61o brix. Three level of solution temperature, i.e 30 oC, 40 oC, 50 oC and three levels of stirring speed, i.e 100 rpm, 300 rpm and 500 rpm were used as the process variables. Stirring speed and high temperature solution will increase the water loss, while the final moisture content of the sample will be lower. Highest water loss by 70% and the lowest final moisture content of 35.3% wb occur at 30oC temperature treatment and stirring speed 500 rpm. Solid gain at high stirring speed increased temperatures 30oC (4.59%), 40oC (7.92%) and 50oC (11.9%), while the solid gain with medium and low stirring speed did not increase. High stirring speed (500 rpm) at a temperature of 30oC solution, 40oC and 50oC produces Reynolds number greater than the low (100 rpm) and medium (300 rpm) stirring speed for 8 hours. The decresing osmotic solution concentration due to the water leaving the mango during the osmotic process provided the reduction solution viscosity. These conditions caused in the stirring rotation speed increased, so the need for stirrer motor power decreased during the osmotic dehydration process.