The Application of Kudeme as Fermentable Modifiers in Nixtamalized Maize
Date
2002-12
Authors
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Publisher
University of Ghana
Abstract
Fermentation and nixtamalization have been used to enhance the quality and nutritional
value of cereals. “Kudeme” a product of microbial and biochemical disintegration of
cassava was inoculated into nixtamalized maize dough and fermented, to study the
influence of the addition of kudeme on the characteristics of nixtamalized maize dough.
The functional and physico-chemical indices were monitored. A 4 x 5 factorial design of
kudeme level by fermentation time was used in pre-testing the system and a central
composite design with k = 3, then used to optimize physico-chemical and functional
responses. Preliminary results indicated almost constant moisture levels of 55%, pH
dropped from 8.17 to 3.90 with corresponding increase in titrable acidity from 0.0077 to
0.2160g /lOOgLA. There was no significant difference in water absorption at 25°C and
70°C, which ranged between 49.37 to 93.55%. Pasting temperatures ranged between 68.5
and 86.4°C and temperature at peak viscosity between 70.0 and 92.5°C, and these as well
as viscosity, increased with increasing kudeme levels and fermentation time. Viscosity
ranged between 80 to 470 BU. R2 values of indices; an indication of the degree to which
variations in dependent variables were explained by independent variables for regression
models ranged between 18.24 and 99.73% for biochemical responses, 11.04 to 90.76%
for water absorption and swelling index, 23.34 to 85.18% for colour and 28.39 to 87.61%
for 7 and 8% slurry viscosity and cooking temperatures. No lacks of fit for most models
were observed. Response surface plots as well as two dimensional plots for various
parameters indicated that kudeme level and duration in fermentation influenced trends in
these parameters to varying increasing or decreasing orders. Particle size decreased with
increasing kudeme levels. And this was believed to be the major factor influencing the
outcome of other parameters studied. There were high positive correlation between
kudeme level and Amylograph indices studied. Blanched kudeme was not an effective
modifier, compared to roasted kudeme. The modifications of quality indices, induced by
kudeme on fermentation of nixtamalized maize could be exploited to promote fineness,
better physico-chemical and functional properties of nixtamalized maize, making it
traditionally relevant to Africans.
Description
Thesis ( MPhil) - University of Ghana, 2002