Effect of microwave heating on the physiochemical characteristics, colour and pasting properties of corn (Zea mays L.) grain

Abstract

Microwave energy have been explored in the food industry for controlling pests in the stored commoditie. This study was undertaken to investigate the effect of microwave (300 W) heating at different temperatures (50, 55 and 60 °C) on the germination rate, colour, composition and pasting properties of corn grains with different initial moisture content 10, 14 and 18%. Microwave heating caused a significant reduction in germination rate of corn, however, it has no significant effect on its colour, starch, crude protein, crude oil and free amino acid content. Only the fatty acids Oleic and Linoleic showed significant changes among the fatty acids after microwave heating. Oleic acid increased to 29.0 and 29.4% when corn with 14 and 18% IMCs treated at 60 °C. However, similar treatment reduced Linoleic acid to 55.1 and 54.8%, respectively. Moreover, microwave heating caused a reduction (14.0–39.5%) on the free fatty acid content of corn and enhanced some of its pasting properties. Accordingly, it could be concluded that microwave heating at temperature up to 60 °C maintains the quality characteristics of corn and can be applied as an effective method in the food industries.