Method of estimating the baking qualities of doughs

摘要

492,049. Testing dough. HALTON, P., and FISHER. E. A. March 23, 1937, No. 8542. [Class 58] Doughs are prepared to have a predetermined and similar elasticity modulus and are then tested for their viscosity elasticity modulus ratio and extensibility before tearing. The elasticity modulus is estimated by measuring the rate of extrusion through an aperture while under pressure and by measuring the rates of extrusion of doughs of different water content the amount of water required by a flour to give a dough of predetermined elasticity may be determined. The dough is placed in a vertical cylinder 11 having a small aperture 15 at the bottom and is compressed by a piston 16 to which is connected a weight 18. A pointer 19 indicates the downward movement of the dough due to its extrusion through the aperture. The viscosity and bearing properties are measured by impaling a ball of dough, made under standardized conditions and of predetermined elasticity modulus, symmetrically on two horizontal arms 21, 22, arranged in contact with each other. The lower arm 22 is mounted on a crosshead carried by vertical guides 24 and moved up and down by a screw-threaded rod 25 engaging with a threaded sleeve fastened to the crosshead. The rod 25 may be rotated by a motor 27 through belt and pulley gearing. The upper arm 21 is also carried on a crosshead carried by guides and is normally held against a stop by a wire 32 passing over and attached to a pulley 33 to which a weight 34 is secured by an arm 35. The upper arm is also connected to a stylus which records the vertical movement of the arm on a drum 37 rotated by gearing from the upper end of the rod 25. On starting the motor the upper arm will tend to be pulled downwards owing to the viscosity of the dough : ultimately the dough will tear and the stylus will record the point of rupture. The drum will thus show a record of the force required to stretch the dough and the elongation produced.