R4D - Research For Development Logo

Project Record

An enterprise approach to commodity system improvement: sweet potato in Uganda and Kenya.

Download Project Record to Word
Print Project Record

 Crop Post Harvest
 Central Research Department (now Research and Evidence Division)

  Africa, Eastern Africa
  Kenya, Uganda

The project aims to identify factors contributing to success or failure of existing small enterprises, and determine technical factors that constrain potential entrepreneurs from starting processing and selling sweet potato-based food products. This will include comparing the returns from sweet potato with other crops (cassava, maize, sorghum, and millet) and with other similar small-scale enterprise activities.

Sweet potato has gained new importance in Uganda and Kenya, especially in regions already adversely affected by cassava mosaic disease. Identification of strategies, methods and technologies to improve the performance of enterprises using the crop, and the quality/marketability of sweet potato-based food products, provides a means of diversifying utilisation of the crop, enhancing food security, and contributing to poverty alleviation.

To determine the potential, in comparison with other activities, of sweet potato processing to contribute to income generation; to develop a strategy for further development of sweet potato based enterprises in the project areas; and to hold a planning workshop to discuss the potential of sweet potato processing and its contribution to income generation.

Strategies developed and promoted for the successful development of the small enterprise sector based on sweet potato products.
Research involving producers and consumers in rural and urban trading centres of Uganda and Kenya has demonstrated the feasibility of using fresh sweet potato or sweet potato flour (in mixture with other flours) in fried and baked snack food products. The availability of new orange-fleshed sweet potato varieties that are high in pro-vitamin A has given added impetus to this work, due to the enhanced nutritional value and attractive appearance of products produced. As a result of these efforts, small-scale businesses owned mostly by women, and selling home-cooked foods at local markets, have emerged at several locations in Kenya and Uganda. The survey of 28 such micro-scale enterprises indicated that the following factors have influence on their activities: lack of support for risk-taking (94%), lack of standard process and adapted equipment (75%), marketing (70%), consumers' needs (40%), local taxes (40%), and competition (50%).

The market study on processed sweet potato in the household economy of north-east Uganda (Kumi, Soroti, and Katakwi Districts) found that more than 80% of sweet potato was traded in the fresh form, and sweet potato flour was identified as a promising product for urban markets. Sweet potato flour of acceptable quality was produced at farm level in Soroti at a very attractive cost: $0.14/kg.

This project compared sweet potato with other major crops. The annual profit margins for producing major crops in Soroti, Uganda were determined. The analysis demonstrated that the investments in sweet potato, cassava and groundnuts were good ways of combatting proverty in the poorest households from the remote areas.

Technologies for improving products to meet market needs developed, evaluated and promoted.
Soroti area was identified as a favourable site for flour production, based on the current importance of the crop; the potential for increased production; the favourable climatic conditions for seasonal drying; and the existence of indigenous processing technology which served as a base for production of commercially-acceptable flour.

However, the current indigenous sweet potato processing technology was not profitable, due to high cost of labour and lack of adapted tools. This project introduced the sweet potato slicer into the farming system, which reduced the labour requirement by 10 times, and increased the profitability of processing sweet potatoes into dried chips by 4 times. More than 500 sweet potato slicers have been manufactured by a local private company and sold to farmers/processors in the Soroti area.

Ten of the 17 sampled farmers/processors who were exposed to the holistic process of producing clean dried sweet potato chips went ahead and started the processing of the product for their households and the neighbouring markets. The sanitation levels of the dried sweet potato products produced by local villagers using the new introduced and improved schema were found to have increased, and more than 95% of consumers found that the improved flour makes high quality local bread and porridge for their children. Efforts aimed at popularising products (chapatis and mandazis) having sweet potato as an ingredient, continued in Kenya, and three community-based organisations (CBO) in Busia, Siaya, and Teso Districts with a network of thousands of poor micro-scale sweet potato growers were involved.

The feasibility of producing a rural-based sweet potato flour was assessed in Soroti, Uganda. This was done by working (a) with smallholder farmers/processors to efficiently produce sweet potato flour of acceptable quality; (b) to establish flour quality standards and perfect practical recipes for products (buns, chapatis and mandazis) out of flour to be traded (c) with consumers to test the quality and market in the interaction with micro-enterprise customers. The low level of production by each household does not facilitate profitable processing, unless they work collaboratively by combining output. Current indigenous sweet potato processing technology was not profitable at the household level, due to high cost of labour. However, this problem was overcome by the introduction of a sweet potato slicer into the farming system, which increased the profitability of processing sweet potatoes into dried chips. Dried sweet potato was found to have a local and immediate market, particularly in the area of the nomadic Karamojongs and Katakwi District. Because of their pro-vitamin A content, dried orange-fleshed sweet potato from the variety Naspot 5, was of exceptional interest for existing NGO programmes, particularly those working in disaster relief in the far north of Uganda and southern Sudan. Bakers in Kampala were interested and willing to use sweet potato flour to process their products, provided that the price of sweet potato flour was motivating; a regular supply of quality sweet potato flour was assured; and the quality of products was not lowered. Consumers from Soroti, Kumi and Lira, Uganda; and Teso, Busia, Kenya; found the dried chips excellent for making their local product, atapa. Kampala and Nairobi consumers identified the major quality problems that sweet potato flour imparted onto the products: "off" odour, reduced volume of product during the processing, and short shelf life (disintegration of products). The project established the potential of sweet potato flour as an important component in urban baked products, but much developmental work involving the link between producers/ processors and users needs to be done with regard to the improvement of quality of the product, required by the urban consumers. Changes in packaging practice are needed to improve the quality of dried product, and hence its value and wider distribution. Overall, the project has contributed to the purpose by developing, testing, and promoting processing systems to add value to sweet potato production by poor households.


Hagenimana V and Low J (2000). Potential of orange-fleshed sweet potatoes for raising vitamin A intake in Africa. Food and Nutrition Bulletin, 21: 414-418

Nandutu A, Carasco J and Hagenimana V (2000). Using sweet potato amylase extracts for determination of starch in foodstuffs.
Journal of Food Technology in Africa, 5: 66-69

Van Hal M (2000). Quality of sweet potato flour during processing and storage. Food Reviews International, 16, 1-37

Carey EE, Hagenimana V, K'Osambo L, Oyunga MA, Benesi I, Smit N, Ocitti P'Obwoya C, Turyamureeba G, Ndolo PJ and Low J. (1999) Using orange-fleshed sweet potato varieties to combat vitamin A deficiency and enhance market opportunities for smallholder farmers in sub-Saharan Africa, pp 157-168. In: Food Security and Crop Diversification in SADC Countries: The role of cassava and sweet potato. Edited by Akoroda MO and Teri JM. SARRNET, Malawi

Fawzia A, Karuri EG and Hagenimana V. (1999). Sweet potato ketchup: Feasibility, acceptability, and production costs in Nairobi, Kenya. African Crop Science Journal 7: 81-89

Hagenimana V (1999). Micro-scale enterprise approach to sweet potato and potato improvement systems, pp 20-26. In: Kwarteng J (ed). Enhancing post-harvest technology generation and dissemination in Africa. Mexico City: Sasakawa Africa Association, viii + 79p.

Hagenimana V, Carey EE, Gichuki ST, Oyunga MA and Imungi JK. (1999). Carotenoid contents in fresh, dried and processed sweet potato products. Ecology of Food and Nutrition 37: 455-473.

Hagenimana V, K'Osambo LM and Carey EE. (1999). Potential of sweet potato in reducing vitamin A deficiency in Africa, pp 287-294. In: Impact on a Changing World. Programme Report 1997-1998. International Potato Centre, Lima, Peru. 458p

Hagenimana V, Karuri EG and Oyunga MA (1998). Oil content in fried sweet potato processed products. Journal of Food Processing and Preservation 22: 123-137

Hagenimana V, Oyunga MA, Low J, Njoroge SM, Gichuki S and Kabira J. (1999). The effects of women farmers' adoption of orange-fleshed sweet potatoes: Raising vitamin A intake in Kenya. ICRW/OMNI Research Programme, Research Report Series 3. International Center for Women, Washington, DC. 24p.

K'Osambo LM, Carey E, Misra AF, Wilkes J and Hagenimana V. (1998). Influence of age, farming site, and boiling on pro-vitamin A content in sweet potato (Ipomoea batatas (L) Lam) storage roots. Journal of Food Composition and Analysis 11: 305-321

NRB 9800 312/792/002