Influence of moisture content on the wheat kernel mechanical properties determinedon the basis of shear test

摘要

The results of moisture content impact on thewheat kernel mechanical properties determined on the basis ofshear test are presented. Four common wheat cultivars differing inkernel hardness were used for tests. The samples of wheat weretempered by adding water or by drying to adjust moisture content.The individual kernels were placed in the hole of a special accessoryand cut down by using universal testing machine ZWICKZ020/TN2S. The increase in moisture content caused linear decreaseof the shear force and force-to-deformation ratio.The relation betweenthe moisture content and the deformation up to the failure ofthe kernel was non-linear. The highest changes of deformation wereobserved at the moisture of kernels ranged from 16 to 20%. Whenthe moisture of kernels was 10 and 12% the significant higher valuesof shear force were obtained for hard wheat varieties than forsoft ones. The moisture content has no significant influence on theshear energy. This parameter average ranged from 11.7 to 14.0 mJ.