Before we export yam

The recent controversy stirred by the Minister for Agriculture, Chief Audud Ogbeh that Nigeria has started exporting yam tubers is understandable, at least to the discerning minds. Tat the country is by far the world’s largest producer of yams, accounting for over 70–76 percent of the world production is an economic advantage we should leverage on but we have not done so.

According to the Food and Agricultural Organisation(FAO) report, in 1985, Nigeria produced 18.3 million tonnes of yam from 1.5 million hectares, representing 73.8 percent of total yam tuber production in the African continent. Yam, a tropical crop in the genusDioscorea, has as many as 600 species out of which six are economically important staple species.

According to 2008 figures, the yam production in Nigeria has nearly doubled since 1985.The figure then was that Nigeria was producing 35.017 million metric tonnes, with value equivalent of US$5.654 billion. As at 2014 the amount had jumped to 45,004,340 metric tonnes according to FAO Statistics on 5,416,400 hectares. Comparably, the world’s second and third largest producers of yams, Côte d’Ivoire and Ghana, only produced 6.9 and 4.8 million tonnes of yams in 2008 respectively.

The crux of the matter is that our policy makers seem to be putting the cart before the horse. We produce crude oil but export much of it while we do little refining as the four refineries remain comatose. Instead, we import the finished products and by-products at astronomical costs to our economy. Ditto for most of our agricultural products such as cocoa, coffee, cashew, cassava and yams. It does not make economic sense as we would have gained much more if we were exporting the finished products rather than the raw materials.

Also, not much has been done by way of mass enlightenment on the industrial and nutritional uses of yam to man. For instance, in Nigeria yam is used in production of high quality bread and cakes. Yam, sweet in flavour, is consumed as boiled yam (as cooked vegetable) or fufu or fried in oil and then consumed. It is often pounded into a thick paste after boiling and is consumed with soup. It is also processed into flour for use in the preparation of the paste. The yam chips and pellets can also play the same function as cassava chips and pellets in the production of livestock feeds. Yam Starch has a lot ofindustrial uses.

On the nutritional front yam tuber is the main part of the yam plant which has highcarbohydrate content (low in fat and protein) and provides a good source of energy. It provides some 200 calories of energy per capita daily. Unpeeled yam has Vitamin C. Yam is a good source of energy and each 100 grams contain 118 calories. It is mainly composed of complex carbohydrates and soluble fiber. It is an excellent source of B complex vitamins like Vitamin B6, Vitamin B1, riboflavin, folic acid, pantothenic acid and niacin. It also contains a good amount of antioxidants and Vitamin C.  It provides around 20% of the required Vitamin C in the body per 100 grams. It also contains small amounts of Vitamin A and beta carotene levels. It is a rich source of minerals like copper, potassium, iron, magnesium, calcium and phosphorus. 100 grams of yam provides 816 mg of Potassium.

Yam is a good source of Vitamin B6 which is needed by the body to break down a substance called homocysteine, which can damage blood vessels walls. High levels of homocysteine can also lead to heart attack despite having low levels of cholesterol.

Thus, having a good supply of Vitamin B6 in the body is believed to reduce the risk of developing heart diseases. Potassium is an important component of cell and body fluids and controls heart rate and blood pressure by countering the hypertensive effects of sodium. Low intake of potassium-rich food can also lead to hypertension. Dioscorin, a storage protein found in yam is known to benefit people suffering from hypertension. Dioscorin inhabits aniotensin converting enzyme which therefore leads to increased kidney flow and reduced blood pressure.

Its medicinal use as a heart stimulant is attributed to its chemical composition, which consists of alkaloids of saponin and sapogenin. Its use as an industrial starch has also been established as the quality of some of the species is able to provide as much starch as in cereals.

Yam has been used as a traditional medicine in China, Korea and Japan for centuries. It contains allantoin, a cell proliferate that expedites the healing process when applied topically on ulcers, boils and other skin diseases. Its decoction is also known to stimulate and relieve bronchial irritation, cough and other respiratory problems.

Medicinal properties of wild yam include bringing calm and peace to the consumer. It has no poison as it benefits the spleen, nourishes the lung and kidney, protects the brain, boosts sperm and beautifies the skin. Besides, it is anti-aging, anti-tumor, anti-fatigue and stress and prevents damage from allerge. It also adjusts metabolism, boosts the immune system, prompts cell growth and adjusts internal secretion. It regulates the functions of heart and kidney, exciting blood system and adjusting mental systems.

Considering the industrial uses yam is part of several pharmaceutical tablets. It is also used as an industrial fuel. Back in 2006, China imported 145 million tons of crude oil, accounting for 44% of its consumption of oil. With the rapid growth in vehicle sales in China, consumption of fuel oil for vehicles accounted for 35% of oil consumption in 2006. And demand for fuel oil in China continues to grow at the rate of 15-16% per year. To satisfy domestic demand for vehicle fuel, control its dependence on foreign sources of oil and attempt to moderate fuel costs, China has embarked on a robust effort to ramp up fuel ethanol development.

Now that Beijing has successfully steered ethanol development away from grain-based feedstock, there are signs that China is poised for scale development of non-grain based ethanol using yam.

What should be done now is for the Minister of agriculture to liaise with the Ministry of Science and Technology and leverage on the findings at the Federal Institute of Industrial Research (FIIRO), Oshodi and the universities to add value to yam before talking about export. Nigeria stands to make much more revenue that way.

 

Ayo Oyoze Baje