Interpretation of the force deformation curves of soaked red kidney beans (Phaseolus vulgaris L.)

In this study, the textural patterns of red kidney beans soaked in water at 20, 30, 40 and 60 °C are reported. Texture (hardness) was measured instrumentally by cutting with a wedge-type blade mounted on an Instron Universal Testing Machine at a speed of 200 mm min ¹. The general trend of the force deformation curves was similar for all of the soaking temperatures studied throughout the soaking process. At initial stages of hydration, textural changes were a function of the soaking time. However, once the hydration process attained equilibrium, changes in texture became minimal and were within the range of 34 ± 2 N, regardless of the soaking temperature and hydration time. The force deformation curves were influenced by the presence of a large cavity between the two cotyledons of red kidney beans. Interpreting textural patterns of soaked beans would provide a better control of the water absorption process, which subsequently influences changes in texture.