Shear
Shear is a mechanical force in which one plane of a material slides against a neighbouring plane, causing deformation in the direction of the force. In food processing, shear is everywhere: mixers shear doughs, homogenizers shear fat droplets into tiny sizes, and extruders shear starchy masses. Controlling shear determines texture, stability, and structure in countless products. Too much shear can damage delicate structures; too little leaves mixtures uneven. Engineers design equipment around shear behaviour. It is fundamental to food rheology.