Abstract:
Iron deficiency anaemia (IDA) has been a significant public health problem in the
developing world. Fortification has been identified as one o f the most cost-effective and
sustainable approaches for controlling IDA. Addition of various bionutritional substances
creates several technical challenges for the Food Technologists and therefore it is necessary
to maintain the overall quality o f the product in terms o f the bioavailability o f the fortifying
agent.
The main objective of this work is therefore to investigate the effects o f iron
fortification on the physical, functional and microbiological properties o f weaning foods. The
iron compounds used were ferrous sulphate and ferrous fumarate.
Oven drying at 60°C was used to reduce the moisture content o f the fermented maize
dough to produce dehydrated product. A 4x3x2x2 factorial experiment with, fermentation
time, iron compound, iron concentration and the mode o f iron addition as variables were
replicated. The indices measured were pH, titratable acidity, colour, fat acidity, water
absorption, viscosity, total iron content, energy content and microbiological study.
A roasted weaning food - maize/cowpea/groundnut blend was prepared and response surface
methodology studies using a central composite rotatable design for factor, k=3 ( iron
concentration, legume concentration and roasting temperature) conducted. Samples were packaged in polyethylene bags and stored for 4 months and analysed
for pH, titratable acidity, colour, water absorption and fat acidity.
Sensory evaluation/consumer acceptability test was performed on three iron-fortified cooked
products namely, dehydrated fermented maize dough, maize/cowpea dough and roasted
maize /cowpea/groundnut blend.
Even though iron fortification brings about relative increase in pH, the values (3.51-
v
4.11) were optimal for cereal phytase in fermented maize dough system. Breakdown of
triglycerides was high in both iron-fortified and non-fortified products. Fermentation and iron
addition were found to increase the total iron content o f the products. Energy content o f at
least 460 kcal/lOOg was recorded for all samples. This is higher than a recommended energy
for a quality weaning food. The concentration o f iron added before fermentation did not
interfere with the microbial growth o f the fermented maize signifying that the levels added
were not toxic to the microorganisms. Even though storage had significant effect on the indexes measured, there was not
much change in the characteristics when comparing the iron-fortified and the non-fortified
products.
Regression models developed to predict product characteristics o f roasted weaning
food were influenced by the process variables. These were mainly legume concentration and
roasting temperature. Iron addition however, affected the characteristics when legume
concentration was high. Storage o f the roasted blend was highly affected by iron addition.
Products were generally acceptable to mothers from the sensory evaluation and
consumer acceptability test conducted in five communities in the Central region.
