ABSTRACT
Drying, a process for food preservation involves subjecting a food commodity to high temperatures
that aid in the removal of moisture thereby making the food shelf stable. The objective of this study
was to design a greenhouse type solar dryer that would be used for the drying of cassava and other
foods and evaluate the characteristics of the dried products. The rationale behind this study was
that open sun drying has been the method of drying over the centuries but it is subjected to a lot of
challenges such as contamination from bird droppings and rodents, high moisture content due to
inconsistent temperature variations which contributes to microbial contamination as a result of the
slow or intermittent drying and no protection from rain or dew. The greenhouse type solar dryer
with a total volume and surface area of 20.335 m3
and 35.774 m2
respectively was designed and
constructed with locally available materials. Temperature and humidity were monitored in the
empty greenhouse type solar dryer (GTSD) and open sun drying (OSD) for a period of 14 days
showed that the GTSD recorded the highest temperature of 60oC occurring between 12:00 and
13:00 hours GMT. The highest relative humidity was recorded at 84 % and this was observed at a
later time in the day, 18:00 hours GMT. Cassava slices (0.47cm thickness) and chunks (4 cm length
× 2 cm breadth × 1.5 cm) and cocoa beans were dried. The total drying period for the two food
commodities was 156 hours. Generally, there was moisture removal in all the dried samples.
However the GTSD gave a faster drying rate of 3.361 g/g h for the slices occurring after 12 hours
of initial drying than the OSD. An Analysis of variance performed on the moisture data delineating
time of drying, drying method and sample size showed that the removal of moisture of the cassava
samples is dependent on the time for drying, the drying method and sample size. The data observed
for both moisture and drying rate of the cassava and cocoa samples depicted that drying does not
occur at nightfall but rather moisture absorption due to higher humidity levels observed at night.
Edu, F (2021). The Design And Evaluation of A Green House Type Solar Dryer And its Performance on Two Food Commodities; Cassava And Cocoa. Afribary.com: Retrieved April 16, 2021, from https://afribary.com/works/the-design-and-evaluation-of-a-green-house-type-solar-dryer-and-its-performance-on-two-food-commodities-cassava-and-cocoa
Frontiers, Edu. "The Design And Evaluation of A Green House Type Solar Dryer And its Performance on Two Food Commodities; Cassava And Cocoa" Afribary.com. Afribary.com, 06 Apr. 2021, https://afribary.com/works/the-design-and-evaluation-of-a-green-house-type-solar-dryer-and-its-performance-on-two-food-commodities-cassava-and-cocoa . Accessed 16 Apr. 2021.
Frontiers, Edu. "The Design And Evaluation of A Green House Type Solar Dryer And its Performance on Two Food Commodities; Cassava And Cocoa". Afribary.com, Afribary.com, 06 Apr. 2021. Web. 16 Apr. 2021. < https://afribary.com/works/the-design-and-evaluation-of-a-green-house-type-solar-dryer-and-its-performance-on-two-food-commodities-cassava-and-cocoa >.
Frontiers, Edu. "The Design And Evaluation of A Green House Type Solar Dryer And its Performance on Two Food Commodities; Cassava And Cocoa" Afribary.com (2021). Accessed April 16, 2021. https://afribary.com/works/the-design-and-evaluation-of-a-green-house-type-solar-dryer-and-its-performance-on-two-food-commodities-cassava-and-cocoa