A Recent Approach on Process Optimization and Characterization of Gamma Irradiation Induced Variations in Functional Properties of Maize (Zea mays L.) Flour

The effect of particle size and high dose gamma irradiation on functional properties of maize flour was
studied. The maize flour at three levels of particle size (<177, <250 and <420 μm) obtained from
sieves of 80, 60 and 40 meshes respectively) was irradiated in transparent glass bottles at three
levels of gamma radiation dose (25, 50 and 75 kGy) using 60Co gamma source. A significant linear
increase in water holding and swelling capacities and bulk density and significant linear decrease in
emulsifying stability was observed in response to an increase in particle size of the flour. Gamma
radiation dose was found to show a significant linear positive effect on water holding capacity and
solubility but a significant linear negative effect on oil holding capacity, protein solubility and bulk
density values. These observed trends in functional properties of maize flour with the application of
gamma irradiation suggests that quality of maize flour, regarding the manufacture and packaging of
food products, may be improved by irradiation process. The particle size of the flour was found to be
directly associated with the water holding capacity, swelling capacity and bulk density of flour.
Moreover, gamma radiation influence favorably in improving the water and oil absorption, swelling and
emulsifying capacities of maize flour.