1. A review of the drying systems and technologies in Nigeria
SOBUKOLA, O.P. (Ph.D.)
Federal University of Agriculture, P.M.B. 2240, Abeokuta, Nigeria

2. Issues in Post-harvest Losses (PHL)
Inefficient harvesting and drying methods,
delays in harvesting
poor processing techniques
inadequate method of storage and distribution, and even at the consumer end (Sanni, 1999)
Corruption

3. The way forward is through efficient and sustainable processing methods

4. Drying Technology as a viable option
It refers to the removal of water from materials, in most cases at temperature below boiling points (Sanni, 1999; Karim et al., 2008)
It preserves foods by removing enough moisture from food to prevent decay and spoilage (Sobukola et al., 2007)
Water content of properly dried food varies from 5 to 25% depending on the food.

5. Drying Phenomena
The evaporation of moisture from the surface of the materials and
The migration of moisture from the interior of a material to the surface (Sanni and Akingbala, 2000).

6. Sun drying system in Nigeria
This is exposing the food directly to the sun
Sun drying enhances the effects of the sun’s energy
Drawbacks of sun drying
inclement weather
slow drying rates
contamination of products with mycotoxins
Inconsistencies in product quality
Roadways sun drying
Raised pole
Blackened surface
Dried root slices

7. Solar drying Technology
Advantages of Solar Drying System
Better Quality of Products are obtained
It Reduces Losses and Better market price to the products.
Products are protected against flies, rain and dust; product can be left in the dryer overnight during rain, since dryers are waterproof.
Prevent fuel dependence and Reduces the environmental impact
It is more efficient and cheap.
Disadvantages of Solar Drying System
Quality of products are not obtained in some cases.
Adequate solar radiation is required.
It is more expensive as it require more time for drying.
(Toshniwal and Karale, 2013)

8. Solar cabinet dryer
Direct solar dryer
Indirect forced convection solar dryer
Forced Convection Solar Cabinet Dryer

9. Drum drying
Drum drying is a method used for drying out liquids from raw materials with drying drum.
Pureed raw ingredients are dried at relatively low temperatures over rotating, high-capacity drums that produce sheets of drum-dried product.
Some advantages of drum drying include the ability of drum dryers to dry viscous foods which cannot be easily dried with other methods.
Starches, breakfast cereals, baby foods etc.

10. Rotary drying

11. Rotary drying Produces about 380 kg of fried products per 8hours
Uses charcoal and electric coil as heat source
Very useful for odourless fufu, garri and tapioca

12. Uniqueness of Flash dryer
A flash dryer is a pneumatic type dryer with high temperature ( °C)
fuel usage (around 15 L/h) and short residence time (5 s).

14. Selected References
Karim, O. R., Awonorin, S. O. and Sanni, L. O Effect of pre-treatments on Quality Attributes of Air-Dehydrated Pineapple Slices. Journal of Food Technology 6 (4):
Sanni, L.O. (1999). Sanni, L. O Effective postharvest system in Nigeria. Nigerian Food Journal, 17: Published by Nigerian Institute of Food Science and Technology (NIFST).
 Sobukola, O.P., Dairo, O.U., Sanni, L.O., Odunewu, A.V. and Fafiolu, B.O. (2007). Thin layer drying process of some leafy vegetables under open sun. Food Science and Technology International 13(1): 35-40, Published by Sage Publications
 Sanni, L. O. and Akingbala, J. O Effects of drying methods on physicochemical and sensory qualities of fufu. Drying Technology-An International Journal, Canada, 18 (1& 2):
 Toshniwal, U. and Karale, S.R. (2013). A review on solar drying. International Journal of Engineering Research and Applications vol. 3(2),

15. Thanks for your Attention