Engineering properties and optimization of the dehulling process for hairless canary seed.

 This work aimed to determine the engineering properties of hairless canary seeds ( L.) of the variety "CDC Maria" and the optimum combination of operating conditions of the dehulling process with a pilot-scale centrifugal dehuller. The engineering properties analyzed in this study were the principal dimensions, length (4.8 mm), width (1.95 mm) and thickness (1.41 mm); geometric mean diameter (2.36 mm); the sphericity (49.2%); apparent and true densities (752 and 1191.47 kg/m, respectively); the porosity (0.37); 1000 grains weight (7.28 g); angle of repose (15.89°) and the static coefficient of friction (galvanized steel, 0.325; plywood, 0.372; aluminium, 0.316). For the process optimization, a two-variable Doehlert design was used, analyzing the effect of impact dehuller rotor speed (peripheral speed 30.4 to 47.1 m/s) and seed moisture content (10 to 14% d.b.) by maximizing the dehulling ability (DA) and maintaining the production of fines by 3%. Under the experimental conditions of 36.7 m/s (peripheral speed) and 10% d.b. (seed moisture), with a double pass through the dehuller, the optimum value of DA (94%) was obtained, with a fine production of 3%. The optimized dehulling process allows removing a large percentage (98%) of the canary seed hull.