Support scientists to make sweetpotato serve our health needs

Sweetpotato ranks as the seventh most important food crop in the world. In East Africa, it is the third most important food crop.

However, despite the crop being a nutritious major staple crop throughout Africa, it remains one of the least marketed. This could be attributed to the long-held perception of sweetpotato as a poor man’s food. However, new evidence hold it that urban consumers in Africa are becoming health and nutrition conscious as the incidences of chronic diseases typical of western countries rise hence a shift to this food crop as a healthy alternative, shedding off its image as a poor man’s food.

Depending on the flesh colour, they are very nutritious crops rich in ß-carotene, anthocyanins, phenolic compounds, dietary fiber, ascorbic acid, folic acid and minerals. Biofortified orange fleshed sweetpotato (OFSP) is very high in beta-carotene a provitamin A carotenoid.

This biofortified one is a good source of vitamin A with 125g providing 100% of daily vitamin A requirements for children under five years old. It is now being promoted and implemented as a sustainable food based dietary strategy towards the alleviation of vitamin A deficiency in Africa.

That this variety has low glycemic index, a measurement carried out on carbohydrate-containing foods and their impact on our blood sugar lends credence to it being important for diabetic patients in Africa where the rates of type 2 diabetes are on the rise.

Traditionally people in Africa consume sweetpotato in the boiled or roasted forms. Consumers in Africa are used to and prefer the white or yellow fleshed varieties, which have high dry matter contents.

Most OFSP varieties have low dry matter and have been used for infant and young child feeding. For adults, its flour has been used for making bread, buns, chapatti, muffins, fried products and porridges. The use of its flour at commercial level is not economically and nutritionally advantageous.

In countries with a rapidly growing middle class and rates of urbanization, such as Kenya, the growing demand for innovative and healthy foods has generated a new bread market. Kenya imports most of the wheat used in bakeries. At the International Potato Center (CIP), OFSP puree, made by mashing steamed sweetpotato, is being promoted to replace 20-50% wheat flour requirements in bread, buns and cookies.

By using this particular puree at 40-50% wheat flour substitution level, the country will save a lot of foreign currency. Demand for the puree will generate employment at farm level and puree processing facilities and improve the livelihoods of farmers from the income generated. Urban consumers will have additional options to healthier and acceptable bakery products rich in the crops’ beta-carotene and fiber. 

However, there are still many obstacles to the nation-wide adoption of biofortified orange fleshed sweetpotato puree for bakery applications. Many people are not aware of its availability, and its nutritional benefits. In some East African countries, there are no national policies for biofortification and there has been insufficient effort to promote biofortified orange fleshed sweetpotato puree among investors and current bakeries in Kenya and the region.

Until these obstacles are addressed, its potential to improve the health and wealth of Kenyan and indeed African households will be missed. There is a need to promote its continued production and consumption among vulnerable rural households and also urban consumers. Cooking demonstrations in both settings will increase the diversity of biofortified orange fleshed sweetpotato utilization beyond roasting and boiling. Governments should therefore invest more in sweetpotato breeding and availability of clean planting materials. Government and financial institutions should increase financing options available to youths and women interested in its agribusiness development.

Dr. Tawanda Muzhingi, is the Regional Food Scientist at the International Potato Centre. This article was submitted as an editorial to Sayansi, a publication of the Media for Environment, Science, Health and Agriculture (MESHA) in Kenya.