CHAPTER ONE
1.0INTRODUCTION
1.1BACKGROUND
Cassava which is known biologically as “manihotesculentacrantz” is a crop which has many varieties. Cassava, is a perennial woody shrub in the Euphorbiaceous (Spurge family) native to South America, but now grown in tropical and sub-tropical areas worldwide for the edible starchy roots  (tubers) which are a major food source in the developing world, in equatorial regions including Africa, South America, and Oceania. Also known has yucca, manioc, and tapioca.
It is a major food crop in Nigeria (kim, 2009). It supplies about 70% of the daily calorie of over 50 million people (Agbetoye, 1999) and about 500 million people in the world. It is a basic staple food to more than 70% of Nigerian population and it is consumed at least once every day (Njoku and muoneke, 2008). It was probably the emancipated slaves who introduced the cassava crop into southern Nigeria, as they returned to the country from South America via the Islands of Sao Tome and Fernando Po. At that time there was Portuguese colonies off Nigeria shores (Ekanem, 1962). Cassava, however, did not become important in the country until the end of the nineteenth century when processing techniques were introduced, as many more slaves returned home.The cassava root is long and tapered, with firm, homogenous flesh encased in a detachable rind, about 1mm thick, rough and brown on the outside. Commercial varieties can be 5cm to 10cm in diameter at the top and around 15cm to 30cm long (FAO, 2003).
The cultivation of the cassava crop is by the propagation of stem cuttings. Roots can be harvested between 6 months and 3 years after planting depending on the cassava variety. It is rich in carbohydrates, calcium, vitamin B and C, and essential minerals.
The roots are dug up from the soil, removed from the plant and washed before being processed.
Gari is a processed fermented product from cassava and is consumed in Nigeria as well as in most countries of the West African coast and in Brazil.
In sub-Saharan Africa (SSA), cassava is mainly a subsistence crop grown for food by small Scale farmers, who sell the surplus(IITA, 2003). It grows well in poor soils (IITA, 2011). Nigeria is currently thelargestproducerof cassava in the world with an annual production of over 34 metrictons (Mt) of tuberous roots (FAO, 2002).Gari is a widely consumed Nigerian food; an estimated 4.2 million tons were produced in 2009 (NBS 2010).