Above-atmospheric Hydration of Corn

Abstract

Hydration tests were conducted under pressure in the range of 0 to 14 MPa at 25 to 55° C for 0.025 to 2.0 h using two corn varieties air-dried at 25 and 60° C. Hydration of corn kernels increased with increased soaking pressure, time, and temperature, and initial drying air temperature. Soaking at 0.70 MPa was found more beneficial than at other pressures. Higher hydration rate was observed for corn kernels soaked under 0.70 MPa at different initial moisture contents, soaking temperatures and drying air temperatures over atmospheric soaking. Effects of combined application of high pressure and high temperature in reducing the soaking time were more pronounced than when high pressure or high temperature was applied alone. Two hydration models were developed to predict the moisture content of corn kernels dried at 25 and 60° C for various soaking time, temperature, and pressure.