The effect of sucrose and mannitol addition to low-acyl (LA) gellan gum gels at both the molecular and macroscopic levels prior to, and after freeze-drying has been investigated. It has been shown that the gel network order as well as the mechanical properties are changed with the solute content, especially in the case of sucrose. The freeze-dried gel structure, containing either mannitol or sucrose, was studied, reporting for the first time the interaction of mannitol with the gellan gum gel. The generated freeze-dried gel network was evaluated in terms of porosity, pore size and wall thickness distributions. The solute physical state was correlated the water activity trend as a function of the solute content. Since mannitol is crystalline, the water activity decreases, in contrast with the amorphous sucrose. The rehydration mechanism was investigated and associated with the solute release from the structure. Specifically, the material properties (surface and bulk) as well as the role of the dissolution medium over time were assessed. It was found that the rehydration for both the gellan/sucrose and gellan/mannitol systems was highly influenced by the additive content, as an increase in water uptake was measured up to 10 wt%. A further increase in solute led to a considerable drop in the rehydration rate and extent due to the change in the freeze-dried structure, with smaller pores and with higher wall thickness values.

中文翻译：

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冻干凝胶系统中甘露醇和蔗糖与结冷胶的相互作用。

已经研究了在冷冻干燥之前和之后在分子和宏观水平上将蔗糖和甘露醇加到低酰基（LA）吉兰糖胶中的作用。已经表明，凝胶网络顺序以及机械性能随溶质含量而改变，特别是在蔗糖的情况下。研究了含有甘露醇或蔗糖的冻干凝胶结构，首次报道了甘露醇与结冷胶的相互作用。根据孔隙率，孔径和壁厚分布评估生成的冻干凝胶网络。溶质的物理状态与水活度趋势与溶质含量的函数相关。由于甘露醇是结晶的，因此与无定形蔗糖相比，水活性降低。研究了再水化机理，并与溶质从结构中释放有关。具体而言，评估了材料特性（表面和体积）以及溶出介质随时间的作用。已经发现，吉兰糖/蔗糖和吉兰糖/甘露糖醇系统的再水化都受添加剂含量的影响，因为测得的吸水量增加至10wt％。溶质的进一步增加由于冻干结构的变化，孔隙较小和壁厚较高而导致复水率和水合度显着下降。已经发现，吉兰糖/蔗糖和吉兰糖/甘露糖醇系统的再水化都受添加剂含量的影响，因为测得的吸水量增加至10wt％。溶质的进一步增加由于冻干结构的变化，孔隙较小和壁厚较高而导致复水率和水合度显着下降。已经发现，吉兰糖/蔗糖和吉兰糖/甘露糖醇系统的再水化都受添加剂含量的影响，因为测得的吸水量增加至10wt％。溶质的进一步增加由于冻干结构的变化，孔隙较小和壁厚较高而导致复水率和水合度显着下降。