A prediction of the compressive deformabilities of multilayered gels and texturized fruit, glued together by three different adhesion techniques

The compressive force-deformation relationships of multilayered hydrocolloid gels composed of different combinations of agar, four galactomannans, xanthan, carrageenan and konjak mannan, and of gelled texturized fruits (based on banana, apple, kiwi and strawberry pulps and agar-LBG combinations), adhered via three different gluing techniques, were calculated from those of the individual layers. The gluing techniques consisted of: pouring hot hydrocolloid solution on a gelled layer, using melted agar as a glue between already gelled layers, or simultaneously pouring pre-gelled (gum solution before setting) hydrocolloid solutions. Two assumptions were made: that the normal force in the layers is the same, and that the deformations are additive. The effects of lateral stresses were considered negligible. The calculation was performed using a mathematical model previously developed for double-layered curdlan gels. The model constants were determined from the behavior of the individual layers. Good agreement was found between experimental and fitted results over a considerable range of strains. Thus the model's applicability to a given gel system was demonstrated, suggesting a very convenient tool to analyze and predict the compressive behavior of any number of arrays with different layer combinations.