Abstract:
In an effort to evaluate the nutritional value of cowpea -
fortified maize-dough, and to assess the availability and
utilization of cowpeas in the Ga - district, this study was
carried out. The study was designed to ascertain the socioeconomic
factors associated with cowpea production,
consumption, Post-harvest handling and distribution, as well
as the nutritional benefit and efficacy of using cowpea as a
fortifying-agent in fermented maize dough, a popular base for
both traditional weaning gruel and coastal staple diets in
Ghana.
Eighty-nine (89) cowpea farming households, drawn from 23
rural communities in the Ga - district of the Greater Accra
Region, were involved in the study (interviewed with their
consent).
Four (4) cowpea fortified fermented maize doughs
(CFFMD's), two each of a 60:40 maize : cowpea constitution by
weight, were prepared by the traditional and an "improved"
method of fermentation, respectively, for the nutritional
evaluation; using wistar moll rats. The outcome of the study suggested that Cowpea production
in the study area was beset with numerous problems pertaining
to cultivation, crop management, storage and marketing. This
accounted for the observed low yields and short household
cowpea stock durations, in other words, household cowpea
availability for consumption, in the farming communities
studied. Farmers in the study population regarded, and hence
treated cowpea as a secondary crop to maize and cassava which constituted their staple foods.
In addition, cowpea consumption rate was high, that is,
when available in the population studied. Furthermore,
indigestion, diarrhoea and flatulence were identified as the
common problems associated with cowpea consumption.
The method of fermentation used; traditional or
"improved", seemed to have an effect on the resultant protein
quality of the cowpea-fortified maize doughs. The observed
improvement in protein quality was slightly higher in the
maize doughs traditionally fermented. Nonetheless,
fortification with dehulled cowpea flour did improve the
protein quality of all the maize doughs considerably.
Relative to ordinary maize dough, high protein digestibility
and utilisation values were obtained for the CFFMD's, though
found limiting in lysine and tryptophan. The following range
of values were obtained -
Essential amino acid total of 289.68 - 314.89 mg/g crude
protein; Apparent digestibility .of 83 - 86%; True
digestibility of 100 - 103%; Biological value of 82 - 86%;
Balance values of 54 59%; and Net Protein Utilization values
of 81 - 88%. The range of Chemical Scores of limiting amino
acids Lysine and Tryptophan obtained were 57.33 - 63.33%
and 58.18 80.36% respectively.