Graphene irradiation heating on corn grains: Effects on bioactive compounds, thermal, structural, and functional properties of corn flour

Abstract

Drying methods often suffer from high-temperature strategies that lead to overheating and uneven drying. However, graphene may provide significant improvements due to its ability to dry products at low temperatures and convert electro-thermal energy effectively. This study used a graphene far-infrared dryer to investigate the impacts of different corn varieties (ZD88 and RP909) at varying infrared temperatures of 35, 45, and 55 °C. It also analyzed the changes in various bioactive compounds, structural and functional properties of corn flour. The findings indicate a maximum reduction of relative crystallinity in RP909 by 20.19 %, and changes were observed in the structural order of protein content at 55 °C. The results observed a decrease in gelatinization enthalpy with an increase in gelatinization temperature. However, the in vitro digestibility for ZD88 shows that the slowly digestible starch recorded an increase of 14.15 %, while rapidly digestible starch and resistant starch observed a higher decrease of 9.38 % and 23.56 %. It was revealed that ZD88 recorded a higher phenolic value at 35 °C. Additionally, ZD88 and RP909 demonstrate a reduction in oil absorption capacity and water absorption capacity, while increasing their water absorption index and water solubility index on corn flour. This research highlighted that graphene irradiation heating systems could be a promising solution to enhance corn flour characteristics for industrial applications.