Investigating carotenoid loss after drying and storage of

12
1. Literature review
provitamin A content compared to boiled and mashed roots and grated raw roots in
different products. Bread and mandazi from mixed flour (20% OFSP: 80% wheat flour)
have been formulated (Kósambo 2004). Porridge prepared with OFSP-sorghum
composite (70%/30%) flour (similar to atapa) had significant "-carotene in the final
product (Kósambo 2004). These trials therefore indicated that products rich in
provitamin A can be produced from OFSP flour.
Substituting cassava flour with sweet potato flour was evaluated in a small-scale
processing industry for the making of Kabakagala, a Ugandan traditional deep fried
pancake made from a mixture of cassava flour and banana pulp. Considerable interest
was shown by low and middle income consumers (Owori et al. 2001). Some attempts to
prepare Ugali, a kind of stiff porridge widely consumed in Kenya mainly made from
white cornmeal or sorghum flour, with sweet potato flour, have been reported (Gakonyo
1992, Oyunga-Ogubi et al 2000a; 2000b). Gakonyo (1992) however found that Ugali
was too sweet with sweet potatoes. Promotion is considered to be needed to help
develop the market for these new products (Owori and Agona 2003). Some of processed
products from sweet potato are shown in Figure 1-5.
Figure 1-5: Examples of sweet potato processed products from Eastern and Central
Africa. Owori et al. (2007) Sweet potato Recipe Book. Left to right: Top: boiled fresh
roots; bread; mandazi. Bottom: cookies, crisps, juice.
Owori et al. (2007) described the processing of OFSP, soya and maize flours by Kasawo
Grain millers in Kampala. These products were developed in collaboration with National
Agricultural Research Laboratories (NARL), Kawanda. Dehulled roasted maize and