Nutrition / Research Uptake

African Traditional Foods and nutrition: making consumption of orange-fleshed sweet potatoes a big deal.

In this interviews edition, we caught up with Dr. Francis Kweku Amagloh, a researcher from the University for Development Studies in Ghana who shared with us about his work on sweet potatoes and child nutrition.


Dr. Francis Kweku

You are one of the panelists in the ongoing African Potato Association 9th triennial conference for the session focusing on “New evidence concerning nutritional value and changing behavior” Could you please tell us about your study?
I will be presenting a paper on a study that I have been doing on sweet potatoes for complementary feeding for children. Previous research has shown that sweet potatoes are a good source of vitamin A but also low in phytate, an anti-nutrient that inhibits iron, calcium and zinc absorption. Typically, in Africa, complementary foods are based on cereals, and in advancement, legumes are added so as to improve on protein and energy levels. However by doing this, we are combining two food crops that are high in phytate and so a typical cereal-legume blend limits iron and calcium absorption. There is a study in Ghana that shows these cereals and legumes blended given to babies does not improve their iron status as well as vitamin A, which are important nutrients for babies. The good news is that now there are orange-fleshed sweet potatoes (OFSP) that are high in vitamin A.  My study looked at the possibility of using sweet potato in combinations with soya beans and fish at the household level in Africa, for communities that will accept it as an alternative complementary food. The product is named Complementary Food for Africa (ComFa), a product based on sweet potatoes, soya beans, and fish. The results showed that ComFa is high in vitamin A and low in phytate compared to a typical cereal-legume blend. Based on this, we can suggest that the product may likely enhance higher iron, calcium and zinc absorption, and of course improve the vitamin A status of the children, better than cereal-legume blends.

The ComFa product that you are talking about must consist of sweet potato combined with another product like the soya bean?
Yes, because sweet potato on its own will not be suitable for infant feeding hence the reason why we encourage blending it with soya beans and fish to increase the protein content. In addition, we have also developed an industrial product similar to cerelac, i.e. with skimmed milk in its composition, targeting consumers and communities which will not accept fish in their diets.
The other issue with the cereal-legume blend is that it forms a very thick viscous porridge and this is what I will be my presentation will focus on. Due to this, for mothers to reduce the viscosity, and get the product appropriate for complementary feeding, they have to add more water. From a nutritional point of view, if you take one gram of flour to process the food, and add more water to it, you are effectively diluting the all nutrients. We investigated if the sweet potato based product we have developed will have similar viscosity. There was basis for us to think it will have a low viscosity because: during processing, most of the starch is converted to maltose. If the product has low level of starch, it will be difficult for it to form a high viscous porridge. However we had to subject it to a laboratory analysis where we used a Rapid Viscous Analyzer to assess its viscosity profile. We found that sweet potato-based complementary food forms a very low viscous porridge compared to the typical cereal-legume blend. The nutritional advantage is that mothers can add more flour, and in so doing, enhances the nutrient content unlike in the cereal-legume blend.

How is the acceptability of sweet potato as an alternative food in Ghana?
The study was done in New Zealand, but we carried out a sensory acceptability study using mothers from sub-Saharan Africa with experience in baby feeding and they all rated sweet potato high as a complementary food. In addition, due to the fact that sweet potatoes are naturally sweet, and babies like sweet food, the acceptability among babies is likely to be high. We have developed a good product and the adoption will depend very much on how we are going to promote it. We need to engage everyone involved in policy making to advocate for consumption of sweet potatoes and especially for complementary feeding. I know in Kenya there is a law that states the need for fortifying foods with vitamin A. In my opinion, we do not even need to go that route, because countless evidence is coming up to show that OFSP is a good source of vitamin A and is used in addressing vitamin A deficiency.  For example in developed countries like New Zealand they do not fortify babies’ foods with vitamins, but vitamin A deficiency among babies is not a public health concern.

Is it just the OFSP only or other sweet potatoes also contain vitamin A?
The OSFP contains a higher level of vitamin A compared to the white-fleshed varieties, which are devoid of vitamin A. I therefore do not advise mothers to use the white-fleshed ones. There is a radio interview that I did in New Zealand in which I spoke of a new product that we have also developed and is very easy to prepare.

Today we are told that nearly one billion people are hungry but at the same time, another one billion people are overweight. Hunger and obesity are both associated with poor diet and nutritional problems. These are challenges seen in Africa, yet Africa is home to some nutritionally rich foods, good soils; what is your comment on this?
It is a very big dilemma. Basically if one is obese, that means the amount of food taken and the higher energy they are getting is not all being utilized, so you tend to accumulate fats which build up and lead to obesity. We are now advising people especially those in the urban centres, to have at least a 30 minute walk a day.

There is also the issue of lack of knowledge and awareness about the nutritional content of our foods, which is a major contributor to poor diet. For example there is a lot of emphasis especially in Africa on the cereal-legume based blends which like you say may not necessarily be very nutritious after all. What can you say about that?
Education is the major factor. The major thing that has to be done is getting the right information out.  We need to advocate for a behavioral change for farmers to diversify their production and more communication to promote root and tubers especially in Africa. For infants, OFSP is far much better than cereal-based porridge.

What should be done to support small-scale farmers in adopting such innovations as cultivating and consuming nutrient rich crops like OFSP?
During this conference, the breeders and agronomists in attendance have emphasized the need for farmers to use clean and good quality vines for them to realize good yields. There is need to have sustainable seed production and distribution systems that are accessible to farmers. If the Government has programs or policies that provide for subsidies in planting materials for crops such as maize, then these should also be adopted for the sweet potatoes.

Any final comments?
My comment is to advise mothers especially in the in the rural household communities where the OSFP is grown, to take it up as a complementary food to provide vitamin A. We have to take infant nutrition very seriously, if we want to influence the future generation and increase their productivity and poverty eradication in Africa.

What kind of arrangements have you put in place for spreading this information, to the mothers out there because they cannot access the journal articles you have produced.
I am currently on the National Advisory Board for Farm Radio International, and we are doing a campaign on utilization of OFSP; I am looking to use the opportunity to specifically talk about the ComFa product.

Dr. Francis Kweku Amagloh gave the best oral presentation at the African Potato Association 9th triennial conference.


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