Effects of drying methods and temperatures on protein, pasting, and thermal properties of white floury corn

Abstract

The objective of this study was to investigate the effects of drying methods (tempering–10 min, tempering–30 min, fixed-bed, and infrared radiation) and drying air temperature (70 °C and 90 °C) on proteins, thermal, and pasting properties of white floury corn. When proteins were extracted with sodium dodecyl sulfate (SDS) only, the grains dried at 90 °C in the tempering–10 min and tempering–30 min methods showed higher absorbance on β-glutelin fraction. Regardless of the drying method, increasing the drying temperature from 70 °C to 90 °C reduced soluble protein, peak viscosity, breakdown, final viscosity, and setback. In both temperatures, a higher gelatinization enthalpy (∆H) of corn flour was observed in the tempering–10 min. The fixed-bed drying method (70 °C and 90 °C) resulted in higher soluble protein, lipase activity, peak viscosity, and breakdown, and lower acidity compared to other methods. Practical applications This study suggests that drying white corn at 70 °C by the fixed-bed method, aiming to maintain protein solubility and pasting properties. Infrared radiation drying has proved to be an alternative method for the industry, mainly due to its potential to inactivate lipases without changing the pasting properties.