Study on Correlation between the Starch Content of Potato Tuber and its Viscoelastic Characteristics

When potato tubers had received the exogenic action, water and starch in tubers generated tougor pressure which would act on cell walls in the tuber tissue, so starch content and water ratio have an obvious effect on the mechanical characteristics of potato tubers. In order to provide a mechanical method for detecting the starch content of potato tubers, correlation between viscoelastic characteristics and starch content of tubers was studied. In the research, the tubers of Desiree potato were compressed by cylindrical probe, and showed nonlinear stress-strain curves. The viscoelastic model of potato tuber was established, and its viscoelastic parameters were determined. Meanwhlie, the starch content and water ratio of potato tuber were detected after mechanical tests, and the correlation between viscoelastic parameters and starch content was analysed. According to the results of correlation analysis, viscosity coefficient which had been obtained from the viscoelastic model was significantly correlated with starch content and water ratio. Finally, the regression equation of starch content and the viscosity coefficient was determined.