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Traditional starch sources for food and nutrition security
Introduction
Root and tuber crops are an important source of carbohydrates in Kenya, second to cereals. A number are considered traditional as they are part of the local traditional cuisines. These include cassava, sweet potato, taro (arrow root) and yam. Up to 15 other types of edible root and tuber plants occur in the wild where they may be an important source of water and carbohydrates especially for herders. Likewise, plantains are packed with starch unlike their kin, the banana which has a high percentage of sugar. Like the potato, plantains find a lot of use in local cuisines, but this potential is yet to be exploited. This article explores the potential of these underutilized organically produced starchy foods for both nutritional and food security.
Cassava
Cassava is generally a minor crop in Kenya but an important crop in the coastal and western regions of Kenya, and particularly Busia County. Many local varieties exist and are known by different names in different areas. A popular variety at the coast is Kibanda meno, with a reddish brown coat. It is sweet with a dry consistency. Other popular types include Binti Asmani (Binti Athumani) and Tajirika, a new variety with higher yields but not as tasty.
Roots can be peeled and eaten raw but can also be dried and milled and the flour used to make a wide variety of products including crisps, cakes and ugali. In the latter case, it is often milled together with other cereals such as maize, finger millet and sorghum. Eating raw cassava needs z good knowledge of its preparation to avoid poisoning by cyanogenic glycosides naturally associated with the roots.
Cassava is a rich source of energy but also a good source of dietary fiber, vitamin C and potassium. It also contains some protein and calcium. Cassava leaves are used as a vegetable and are quite nutritious.
Sweet potato
Sweet potatoes are a common breakfast food in Kenya. Some have white or cream-colored flesh while others (recent types) have yellow or orange flesh.
Sweet potatoes are an important source of starch. Orange or yellow fleshed types are rich in beta-carotene, a precursor of vitamin A. Vitamin A not only helps keeps our eyes healthy but also our immune system. Sweet potatoes are also good sources of other vitamins (C and B vitamins), and minerals (calcium, magnesium, iron, phosphorus, zinc).
In Kenya, sweet potatoes are used raw, roasted or boiled and can be made into a variety of products including chips and crisps.
Taro, coco yam
Taro or cocoyams (nduma – Colocasia esculenta) is grown where there is a good supply of moisture and nutrients especially along streams. The corms (tubers) are now much sought after as they are a popular snack and are commonly included in breakfast. They are eaten boiled or fried or in form of crisps and can also be made into stew. Young taro leaves are used as a vegetable.
Taro is a well-balanced food nutritionally and is an excellent source of dietary fiber, minerals, vitamins and energy. It has good amounts of potassium, copper, phosphorus, manganese, magnesium and vitamins B6, E and C. These vitamins have good antioxidant effects.
Yams (Gikwa, kikwa, kiazi-kikuu)
Yams (Dioscorea spp.) were important in the past and are now rare. They are twining plants with prickly slender stems. The tubers are reddish brown, and could be up to 40 cm long with several finger-like projections. A mature plant may yield a sacksful of tubers (about 50 kg).
Another type of yam found in Kenya is the aerial yam or air potato (litugu, liruku) or Dioscorea bulbifera. It is also a twinning plant but the tubers (bulbils) grow on the thin stems above ground rather than below ground. It is mainly grown in the western part of Kenya where it is both used as food and medicine. Air potatoes are grown from the mature bulbils.
Yams have many health benefits. They are rich in energy, vitamins, minerals, and fiber. They are particularly rich in potassium and manganese. Aerial yams are rich in carbohydrates (73%) and are good sources of protein (7.5%) besides other nutrients.
Plantains
Plantains or cooking bananas are widely consumed in East Africa. They are mainly eaten cooked but may also be left to ripen. Plantains tend to be longer and larger in size than bananas, and have a thicker skin/peel. Plantains are also starchier and lower in natural sugar than bananas and mainly used in savoury dishes. They are primarily eaten steamed, boiled, fried, or baked. Green plantains are a perfect substitutes for potatoes and can make great fried plantain chips. They become sweet as ripening progresses from green to yellow then dark brown.
Besides starch, plantains are rich in potassium and carbohydrates but also magnesium, vitamin C, fibre, and many forms of antioxidants.
While bananas are mainly made into sweet banana breads, muffins, cakes and cupcakes, plantains are normally cooked for savoury meals such as Katogo but can also be made into pancakes and chips.
Sweet plantains may be eaten straight but can also be made into an excellent snack by peeling them then roasting on charcoal fire or baking in an oven.
Sweet plantains can also be peeled, chopped and fried.