ASSESSMENT OF NUTRITIONAL COMPOSITION AND CYANOGENIC CONTENT OF GARI SOLD IN IBADAN, OYO STATE.
Chapter One 1.1 Background to the study
Cassava (Manihot esculenta Crantz) is to African villager farmers as rice is to Asian farmer, or potato and wheat to European farmers (Montagnac et al.,2009). It has so many names aside from cassava, such as manioc, mandioca a.d it is the most important food in terms of carbohydrates (Ojo and Akande, 2013). Cassava is eaten daily in various forms such as gari, fufu and tapioca (Okechukwu and Okoye, 2010). Gari is a lactic acid fermented product of cassava root that can be processed with palmoil rich in carotenoid ("yellow garri") or without palmoil. In Nigeria, gari is widely acceptable and consumed by both the poor, the middle men or average Nigerian, and also the rich because it serves as a major source of carbohydrate. Gari can be taken in Various forms; some people use it to make EBA or soak inside water along with groundnut, mashed beans or bean cake (Akara). The major problem of consuming gari is the toxicity which may arise from poor processing of cassava which is rich in cyanogenic glucosides. Consumption of cyanide and its accumulation in human body normally lead to cretinism, neurological disorders and goiter (Ojo and Akande 2013). Cyanide has been found to be greatly reduced during the processing of cassava to gari. Unit operations such as peeling, washing, grating, fermentation, dewatering and roasting have been found to effectively reduce the residual cyanide contents of the product (Ojo and Akande 2013). Chijioke et al. (2010) reported that the traditional method of gari production which requires the cassava slurry to be fermented for 72h during which the Cyanide's (linamarin and lotaustralin) are hydrolysed by linamarase enzyme to yield hydrocyanic acid which has low boiling point and easily escape during roasting render the gari safe for consumption. Cutting corners by so many processors for the sake of profit has led to production of gari with excess cyanide content (Ojo and Akande 2013). According to World Health Organization recommended safe level for cyanide is 10ppm. In addition, processing steps such as sun drying and solid-state fermentation coupled with storage of gari could provide favourable conditions for the growth of moulds and the production of mycotoxins (Abu et al., 2010).
1.2 Problem Statement
The major problem of consuming gari is the toxicity which may arise from poor processing of cassava which is rich in cyanogenic glucosides. Cutting corners by so many processors for the sake of profit gas led to production of gari with excess cyanide content (Ojo and Akande, 2013). The consumption of cyanide and its accumulation in human body normally lead to neurological disorders, cretinism and goiter (Ojo and Akande 2013). Hence there is need to assess the nutritional composition and cyanogenic content of gari sold in Ibadan, been the largest city in Nigeria.
1.3 Objectives of the Study
The major objectives of the study is the assessment of the nutritional composition and cyanogenic content of gari sold in Ibadan. This is to achieved through the following specific objectives:
(i) The determination of the proximate composition of the gari samples,
(ii) determination of the functional properties of the gari samples,
(iii) determination of the mineral composition of the gari samples and
(iv) determination of the antinutritional factors present in the gari samples.
1.4 Research Questions
(1) what is gari?
(2) How is it produced?
(3) what is its nutritional composition?
(4) Does its consumption pose a risk to human health?
1.5 Significance of the Study
The research gives a clear into the nutritional composition and cyanogenic content of gari sold in Ibadan. The study will serve as preliminary study into the effect of consuming gari on human health. The findings of this research will show if the residual cyanogenic content level conform with the WHO recommended safe levels for cyanide.
1.6 Scope of the Study
The research focus on the assessment of the nutritional composition and cyanogenic content of gari sold in Ibadan.
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Chijioke, A., A. Aderibigbe, T.O. olarewaju, A.M. Makusidi, and A E. Oguntoyibo. 2010. Prevalence and pattern of cystic kidney diseases in Ilorin, Nigeria, Saudi J. Kidney Dis. Transplant. 21: 1172-1178.
Ojo, A., and E.A. Akande. 2013. Quality evaluation of gari produced from cassava and potato tuber mixes. Africa.J. Biotechnology. 12:4920-4924.
Okechukwu, D.E., and I.C. Okoye. 2010. Evaluation of soaking time on the cyanide content of 'Abacha' slices. Pp 136-137.