Designing of Efficient Solar Dehydrator to Curtail Food Wastage in Uganda
Hadijah Nantambi,1 Sylvia Namazzi 1, Ali Alnasser 2, John Eichmann 2, Takahisa Kitagawa 2 and Kendra Sharp 2
1 EcoLife Foods, Mattuga, Wakiso- Uganda.
2 School of Mechanical, Industrial and Manufacturing Engineering (MIME) Oregon State University
ABSTRACT: Low to middle income (LMI) countries are faced with over 50% of food losses due to lack of post-harvest handling and preservation technologies. In regards to fruits and vegetables, the losses are more visible during rainy seasons where excess is produced than what can be consumed. Associated with this is wastage of these fruits and vegetables due to lack of preservation methods hence causing their scarcity during times of peak demand. It is against this background that EcoLife (a social enterprise in Uganda geared towards reducing food losses among small holder farmers) worked with Oregon State University (OSU)-capstone project to design, construct and test a cost effective solar dehydrator with raw product capacity of 10 kg. The dryer was made from locally available materials with the racks that handle food products being constructed from recommended food grade materials. The device was constructed with wheels for easy transportation and the solar collector box was made detachable for easy storage and transportation. The dehydrator box was provided with enough space to ease cleaning and the dryer can be operated by any gender.
The temperatures inside the drying chamber were between 45oC-50oC as compared to ambient temperatures of 25oC-28oC. The drying efficiency of the dryer was tested using pineapple, strawberry, kiwi, apple and mango fruits and their water loss after drying were 45.07%, 79.6%, 90.0%, 97.2% and 87.6% respectively. The average drying time inside the dryer reduced by 6 h when compared to sun drying time. The total material cost of the dry was US$ 306 (Polycarbonate top) or US$ 267 (Poly bag top) hence making the drier relatively affordable in Uganda.
Key words: Solar dehydrator, Design Process, Drying time, Fruits and Vegetables