Analysis of chemical and structural changes in kiwifruit (Actinidia deliciosa cv Hayward) through the osmotic dehydration

Osmotic dehydration experiments of kiwifruit (Actinidia deliciosa cv Hayward) were carried out in order to apply a nonlinear irreversible thermodynamic model. Samples were immersed into 65% (w/w) sucrose aqueous solution at 30 °C during 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 250, 320, 400, 720, 1440 min. Some physical–chemical parameters were measured in fresh, treated and reposed (24 h at 30 °C) samples. It was possible to apply the enthalpy–entropy compensation coupled to a nonlinear thermodynamic model, obtaining the apparent bulk modulus and explaining the elastic answer of the tissue throughout the osmotic process. The osmotic dehydration also produces losses in the native compounds of kiwifruit such as citric acid and Calcium and Potassium.