DESIGN, FABRICATION AND EVALUATION OF ROTARY HOT-AIR DRYER FOR THE VALUE ADDITION OF FRUIT WASTE

Citrus waste is solid residue that remains after fresh fruits are squeezed for their juices. Pakistan is among the top ten citrus producing countries in the world. Pakistan is contributing 2.16 million tons per annum in fruit waste generation. Fresh food waste is often used locally to feed animals as milk enhancer. When fresh fruit are squeezed, a solid residue is produced which is commonly known as citrus waste. Fresh citrus waste has a natural acidity, but it is still a perishable product due to its high moisture content and soluble sugar. Dehydration method is usually applied for the removal of moisture content up to less than 10 % to increases the shelf life for easy handling and transportation. The present study enables the design of a rotary-hot air dryer having an internal rotating body. The drying efficiency increased with the increase in the internal temperature and the air flow rate in the rotary drum, while the drying efficiency decreases with increasing the drum speed. The drying process provided the optimal results with respect to drying time and Vitamin C concentration. The present designed hot-air dryer provides fundamentals for fruit pulp industry who can easily adopt this technology. This dryer can be installed within pulp industry and waste can be processed at source point. The dehydration process increases the shelf life of citrus fruit waste and it will be available throughout the year around the country. The dehydrated material can enhance the milk quantity of animal.