Design and Development of Microwave Assisted Raisin Making Grape Dryer for its Drying Constant

The raisin trade in international market is increasing day by day. USA and Turkey together produce almost 80% of the total raisins of the world. India has achieved the production level in the range of 55,000 to 65,000 t of raisins, which is next to Turkey at world level. Efforts on improvement in quality of the Indian raisins have been initiated to promote the export of this product in world market. As the overall investment in raisin grape production is considerably less as compared to table grape production for export, hence the raisin exporters are expected to accrue better price realization out of this product in terms of superior cost: benefit ratio. India’s export of raisins is 314 Mt with the value of 0.473 million US dollars. Over the past two decades, there has been an increasing interest in microwave drying to reduce drying time and increase the removal of water from agricultural products. Microwave drying has several advantages such as higher drying rate, shorter drying time, decrease energy consumption, and better quality of the dried products. Improving drying processes by reducing energy consumption and providing high quality with minimal increase in economic input has become the goal of modern drying. Any single technique using this technology cannot by itself achieve this target. A combination of existing drying techniques should be considered.