Effects of different pretreatments on specific heat of forage maize

In order to determine the heat and mass transfer properties of corn-based feedstuffs during the process of conditioning, extrusion and cooling，the effects of drying temperature (45-105℃)，moisture content (12%-16%) wet basis, particle size (0.2-0.6 mm) on the specific heat of corn grain were investigated using a continuous differential scanning calorimeter (DSC) method. The experiments in three factors with five levels were designed by quadratic orthogonal rotation approach. A model of specific heat of corn grain versus dry temperature, moisture content and particle size was established by regression analysis and response surface methodology (RSM). The results showed that the minimum specific heat of corn grain was obtained(2051 J/(kg·K)) under the processing condition of drying temperature 45℃, moisture content 12% wet basis , and particle size 0.6 mm. This model can be used to evaluate the specific heat of corn grain processing in different conditions and to provide a reference for thermal processing of similar feedstuffs.