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 (25, 50 and 75 kGy) using 60Co gamma source. A significant linear increase in water holding and swelling capacities and bulk density values 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.