CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
The industrial processing of cassava into garri. Cassava is a very versatile commodity with numerous uses and by product. Each component of these plant can be valuable to its cultivator. The leaves may be consumed as a vegetable, or cooked as a soup ingredient or dried and used it to fed livestock as a protein feed supplement. The stem is used for plant propagation and grafting. The roots are typically processed for human and industrial consumption.
In Nigeria, the consumption pattern varies according to ecological zones. Garri is a roasted granule, is the dominant product and is widely accepted in both rural and urban areas. It can be consumed without any additives or it can be consumed with a variety of additives such as sugar, groundnut, fish, meat and stew. The north east also use the cassava as fufu/akpu, garri abacha. Fufu is a fermented wet paste from cassava is also consumed throughout the country especially in the southern zones how every most processors complain that the wet paste are ready to eat forms of fufu, that are currently sold, have a short sheaf life. Estimates of industrial cassava use suggest that approximately 16 percent of cassava root production was utilized as industrial raw materials in 2001 in Nigeria. Ten percent was used as chips in animal feed, 5 percent was processed into a syrup concentrate for soft drink and less than one percent was processed into high quality cassava flour used in biscuits and confectionary, destrin pre-geled starch for adhesive, hydrolysate for pharmaceuticals and seasonings.
Garri is cassava tuber should be free from microbial contamination garri should be processed within two days of harvest to prevent deterioration or loss of quality in garri. Garri is a creamy-white granular flour with a slightly fermented flavour and a slightly sour taste made from fermented gelatinized fresh cassava tubers. Fresh cassava tuber is most, low acid food that is susceptible to bacteria and fungi growth. Hygienic practices especially in the early stage of processing should therefore ensure minimal contamination, all waste material from the process should be removed from the site as they are produced to avoid contamination of the final product with peel sand.
fermentation must be properly controlled as to short period will result in incomplete detoxification. Fermentation consists of two distinct methods Aerobic and Anerobic fermentation for aerobic fermentation, the peeled and sliced cassava roots are first surface dried for 1-2 hours and then heaped together, covered with straw or leaves and left to ferment in air for 3-4 days until the pieces becomes moldy. The fermented moldy pieces are sun-dried. After the mold has been scrapped off. Theprocessed and dried pieces (called “Mokopa” in ugandal are then milled into flour, which is prepared into a “fufu” called “Kowan” in Uganda. The growth of mold on the root pieces, increases the protein content of the final products three to eight times. (Amey, 1987, Sauti et al, 1987). This fermentation method is also very popular in other parts of East Africa as Tanzania, Rwanda and Zaire.
A long period of too will result in given the product a strong sour tests. Both over-fermentation and under-fermentation also affect the texture of the final garri if too much liquid is press from the grinded cassava the gelatinization of starch, during sub-sequent roasting is affected and the product is white. It the sufficient liquid is not removed however the fermentation of granules during roasting is affected and the dough is more likely to form into lumps. The idea of moisture content is about 47-50% and this is assessed visually by experience to the starch, sieving is important because it enable one to obtain a higher quality product free of fibrous contaminated. The granules must be roasted to above 80oc/175oc to achieved partial gelatinization of the starch. If lower temperature are used the product simply dries and produces a dry white powder. Too high temperature will cause charring of the product and make it stock to the roasting pan.