Résumé
During wheat dough processing, a large part of the interactions with water are governed by wettability properties of flour. The wettability properties of wheat materials (flat slices of wheat endosperm, flour-based pellets, and gluten-based pellets) were assessed by the measurement of contact angles of a sessile drop of three reference liquids (water, diiodomethane, and formamide) and estimated by equilibrium properties (contact angles and surface tension properties) and drop penetration rates. The surface tension (γ[s]) of wheat materials was measured between 49.6 and 55.3 mJ/m[-2]. The present work permitted the evaluation of specific wheat types (hard wheat vs. soft wheat) and evaluation of the influence of material structure (flat slices of endosperm vs. flour-based pellets), and material nature (flour-based pellets vs. gluten-based pellets) on the wettability properties. The surface tension properties were considered with regard to the nonideal structure of sample surfaces by considering surface roughness and material porosity.