Propriedades mecânicas e estrutura celular de melão desidratado osmoticamente em soluções de sacarose ou maltose, com adição de lactato de cálcio

Abstract

The purpose of this work was to study the influence of calcium lactate and sugar type on mechanical properties and cellular structure of osmodehydrated melon pieces. The process was carried out for two hours under controlled temperature (30° C) and agitation (120 rpm), using a 40°Brix sucrose or maltose solution containing calcium lactate (0 to 2,0%). Samples were analyzed with respect to water loss, solids and calcium gain, mechanical properties (stress and strain at rupture) and structure by light microscopy. Maltose treatments in combination with the salt action promoted higher water loss and lower solids gain rates. The calcium lactate addition in the sucrose or maltose solution resulted in higher stress at rupture values. This increase was more pronounced for sucrose treatments, due to the higher calcium uptake observed in these experiments. Calcium lactate was efficient in the maintenance of melon cellular structure when used at concentrations up to 1,0%. Maltose showed a higher protector effect in cellular membrane functionality, while the treatment performed only with sucrose solution as well as both treatments with salt concentration at 1,5% caused an intense cytoplasm plasmolysis and cell wall damages.