Evaluation of quality of pumpkin and soy bean-seed blended maize flour
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Date
2023
Authors
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Publisher
SOKOINE UNIVERSITY OF AGRICULTURE,
Abstract
Maize is a major food staple in most of the sub-Saharan African countries. Maize flour is
mostly rich in carbohydrates, which provide energy to the human body. Nutritionally, maize
flour is deficient in the other major diet requirements of proteins, vitamins and essential
minerals. In this study, maize flour was enriched using pumpkin and soybean seed flours
and the sensory and nutritional qualities of the resulting composite flours were evaluated.
Four formulations of maize, soybean and pumpkin seeds flours were preparedby
compositing various proportions of each ingredient. The flours were produced by grinding
the seeds using a hammer mill to a particle size fine enough to pass through a 1 mm sieve
size. The composite flours were then used to prepare stiff porridges (ugali), which is the
popular format of preparation for this meal. Nutritional and sensory quality of the flours and
stiff porridges were evaluated. The nutritional quality parameters included crude protein,
which was found to increase from 8.1% (w/w) in the plain maize flour to up to 24.09% in
the blended flour formulations; crude fibre increased from 7.3% to13.45%; crude fat from
3.6% to 32.26%; ash from 1.09% to 3.44%; and moisture content was increased from 8.1%
to10.29%. Micronutrient parameters evaluated included Vitamin A which was found to
increase from 0.00μg/g to 78.82 μg/g; Folic acid from 2.5 μg/g to 5.33 μg/g; Vitamin C from
0.00 mg/100g to 12.23 mg/100g; Zinc from 1.8 mg/100g to 3.43 mg/100g; and Iron from
3.5 mg/100g to up to 20.81 mg/100g, in the formulations. Sensory attributes evaluated for
the composite flour ugali were aroma, color, texture, general appearance, smell, flavour,
hardness, springiness, oiliness, taste and general acceptability. A 9-point hedonic scale
was employed in the sensory evaluation, alongside instrumental evaluation using a
laboratory texture analyzer. There was no significant difference in smell, appearance,
texture, flavour, hardness, springiness across the four formulations among the panelists.
The mean score was above 5 for all parameters, which is in the middle of the 9- point
hedonic scale. These findings indicate that generally all the formulations were accepted.
Formulation F4 (8.47%) had the highest score among the formulations. The instrumentally
evaluated results indicated significant differences in hardness, cohesiveness and
springiness in the stiff porridge samples. From the human sensory evaluation, all samples
were accepted regardless of their instrumentally evaluated differences, indicating that the
differences were not enough to substantially influence the human sensory organs.
The effect of cooking was established by evaluating the vitamin A and B9 losses.
The vitamin A losses after cooking were established to vary in the range from a minimum
of 0.06% to a maximum of 0.88% among the formulations. The vitamin B9 losses after
cooking were established to vary by a minimum of 0.05% to a maximum of 1.04% among
the formulations.
Pumpkin and Soy bean seeds flour improved the nutritional quality of the stiff porridge
composite flours. The micronutrients compositions were increased due to the added
ingredients of soy bean and pumpkin seeds flour. The sensory evaluation of stiff porridge
from all formulations and control sample indicated that all formulations were acceptable.
Therefore the inclusions of pumpkin and soy bean seeds flour in the levels used in this
study improved maize flour stiff porridge but did not significantly affect the product
acceptability.
Description
Masters dissertations
Keywords
quality of pumpkin, soy bean, seed blended, maize flour, carbohydrates