Structural strength analysis of partially crystalline trehalose

•The concept of strength was developed using partially crystalline trehalose systems.•Strength shows linear decreasing with increasing of crystalline content in a system.•Fractional water sorption analysis was used in partially crystalline systems.•DSC shows crystalline phase-independent glass transition temperature.

Strength concept, which is based on the Williams-Landel-Ferry (WLF) model, was developed using mixed structured powders containing amorphous and crystalline components. At the present study, semi-crystalline trehalose powders with various (100:0; 80:20; 60:40; 40:60; 20:80) amorphous to crystalline ratios were analyzed. Amorphous components were prepared from water solution by freeze-drying. Strength analysis, which included water sorption, differential scanning calorimetry, dynamic mechanical analysis and microscopy, was applied. The results indicated that water content significantly decreases glass transition (∼100 °C) and α-relaxation temperatures (∼90 °C) as well as structural strength parameter (∼10 °C), while, the effect of crystalline component is less pronounced. This study can be used in processing and characterization of various partially crystalline food products including nutritional formulations and infant formulas.