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
(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.
Abu J.O, G.I.O Badifu, and M.A.
Akpapunan. 2006. Effect of crude palmoil inclusions on some physic of
chemical properties of gari, fermented cassava food product. J. Food
Sci. Technology. 24:73-79.
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.