CHAPTER ONE
1.0 INTRODUCTION
1.1 Background
Despite the dominant role of the petroleum sector as the major foreign exchange earner, agriculture remains the mainstay of Nigeria’s economy (Oyejide 1986). In addition to contribution to GDP, it is the largest non-oil export earner, the largest employer of labour, and a key contributor to wealth creation and poverty alleviation, as a large percentage of the population derives its income from agriculture and related activities (NEEDS, 2004). All over the world, the concept of evolving strategies for ensuring natural food security and sustainable livelihood especially for the developing countries has gained full prominence. In view of this, processing cassava into its derivatives for food and income has been the practice of many Nigerians in the rural areas. The current drive towards higher levels of commercialization of cassava processing under the presidential initiative on cassava requires that the scale of cassava processing be increased in Nigeria (Ekwe and Ekwe, 2005).
Cassava is one of the staple food crops grown in Nigeria. Nigeria grows 34,000 tonnes of cassava every year, which constitute the largest output of the crop from any country in the world (Adebayo and Sangosina, 2005). In 1982, Nigeria ranked number six in the world production of cassava with an output of 6.8 million tonnes per annum. Through the cassava multiplication programme (CMP) (1986-1996), Nigeria’s production of cassava increased from 41million tonnes in 2005 to 49million tonnes in 2008 (FAO, 2008).
Today the crop is grown in virtually all parts of the country and is now the focal food crop for foreign exchange earning (Isiorhaorja and Idoge, 2005). In Nigeria, cassava is consumed daily and sometimes more than once a day (Nweke, 2004) and it contributes more than 1000 calories per person per day to the diet of
many families. Cassava is consumed with a sauce made with ingredients rich in protein, vitamins and minerals. Some even eat cassava for breakfast, lunch and dinner (Haggblade and Zulu, 2003). In Nigeria, cassava is very important in the economy and nutrition of poor rural household (NRCRI, 1996). Cassava has other advantages such as ability to store well in the soil for several months as being tolerant to extreme conditions. This is why cassava has been called the “famine security crop” (Philip, 2005). Cassava is of two types; the bitter and the sweet cassava, and they contain cyanogenic glucosides, which break down into hydro-cyanic acid after it has been harvested. The acid makes raw cassava very poisonous for animal and human consumption. Processing of cassava is therefore important as means of removing this poison, increasing its palatability and the storage life.
Cassava processing is a household business as children help in peeling while the women are mostly engaged in the processing, which is done to stop physiological and microbial spoilage, reduce the cyanogenic glucosides content (Asiedu, 1989) and convert the roots to other products which are more acceptable. However, several constraints affect cassava processing which limit the contribution of the crop to the nation’s economy (Hawn, 1989; Henry, 1999 in Adebayo and Sangosina, 2005). For instance, the cynide content in cassava is a major limiting factor to its utilization, but can be reduced by appropriate processing innovations, (Oyewole and Aibor, 1992). Lack of fund and inadequate storage facilities also affect its processing.
Products derived from cassava include gari, starch, tapioca, fufu, pellets, flour and chip. International Institutes for Topical Agriculture (2004) survey of cassava utilization found that 70%, 15%, 10%, 5% of farmers respectively make gari, starch, fufu and tapioca from cassava.
Gari is cream white granular flour with slightly fermented and slightly sour taste made from fermented, gelatinized fried cassava tubers. The processing of cassava into gari involves certain units of operation. Fresh tubers are peeled, washed and grated. The grated pulp is put in porous sacks, which are weighed down with heavy stones for 3-4 days to expel the water from the pulp while it is fermenting. In some areas, hydraulic jacks are used to expel the water from grated cassava. The dewatered and fermented pulps are sieved and the resulting fine pulp is toasted in a frying pan. Palm oil is sometimes added during toasting with constant stirring so as to present all granules to the heat, to prevent the pulp from lumping and burning. This has an additional effect of changing the color of the product from white to yellow (Alinor, 2002).
