Abstract:Effects of drying temperature (50, 85, 95, 105, 120 ℃) on physicochemical, rheological properties and microstructure of black pearl waxy corn flour was investigated. The results showed that with the increase of drying temperature, the dispersion time of the flour increased from 13.4 s to 29.0 s, indicating the dispersion capacity of corn flour decreased. In addition, in comparison with the sample treated at room temperature (control), the loose bulk density and tap bulk density, particle density of the flour obtained at 120 ℃ increased significantly by 8.77%, 27.94% and 108.22%, respectively. The Carr's index, Hausner ratio, the angle of repose and slide also increased by 86.90%, 19.49%, 21.62% and 26.20%, and the porosity decreased by 9.89%. Other results also demonstrated that sample at high drying temperature (120 ℃) exhibited higher G′ and lower final tanδ value (0.54 vs. 0.15) compared to the control during the heating, indicating the dispersion capacity of corn flour treated at high temperature showed solid-like properties. Confocal micrograph (CLSM) results showed that heat treatment could effectively destroy the network structure of protein, thus destroying the combination of starch and protein. The results showed that drying temperature could affect the physicochemical, rheological properties and microstructure of the treated black pearl waxy corn flour, and therefore affect dispersion capacity of the obtained flour.