Effect of radio frequency heating on nutritional quality and protein solubility of corn

In this study, radio frequency heat treatment at varying temperatures (50, 55, and 60°C) was applied to investigate its impact on the nutritional quality and protein solubility of corn. The nutritive value was measured in terms of crude protein content, in vitro protein digestibility, bioavailability of Fe and Ca, and antinutritional factors, tannins and total polyphenols contents. No significant change in total and digestible protein of corn flour was observed after treatments. On the other hand, the availability of Ca and Fe was significantly increased, whereas the antinutritional factors, tannins and total polyphenols contents were decreased after radio frequency heating. Moreover, protein solubility was found significantly (P < 0.05) higher in treated corn than in control sample. Regarding these results, radio frequency heating at controlled temperature up to 60°C might be used as postharvest method to enhance the nutritional quality of corn.