Prediction and control of glass transition temperature for hydrogenated starch hydrolysates and its impact on the texture modification of gummy

The purpose of this study was to determine the relationship between the glass transition temperature (Tg) of hydrogenated starch hydrolysates (HSH, sugar alcohol mixtures) and the sugar alcohol composition. The Tg and heat capacity change induced by the glass transition (ΔCp) of anhydrous sugar alcohols (sorbitol, maltitol, maltotriitol, and maltotetraitol) were investigated using differential scanning calorimetry. The effect of molecular weight of the anhydrous sugar alcohol on the Tg was described by a stretching exponential function. The inverse of ΔCp for the anhydrous sugar alcohols showed a linear relationship with Tg. Based on the results, the Tg for anhydrous HSHs with and without co-solutes (xylitol, sorbitol, and sucrose) was calculated using the original Couchman-Karasz model from the composition. The predicted Tg values were in good agreement with experimentally determined values (the coefficient of determination, R2 = 0.931). This approach was also applicable to HSH-water systems (R2 = 0.816). The effects of HSHs with and without co-solutes on the Tg and texture (breaking force) of the gummy samples were investigated as a typical food application. The Tg and breaking force of the gummy samples strongly depended on the types of HSHs used. The breaking force increased linearly with Tg. Based on the composition, the Tg for the gummy could be predicted by the original Couchman-Karasz model (R2 = 0.940). In addition, the predicted Tg corresponded to the breaking force (R2 = 0.937). The predicted Tg will be practically useful for texture modification of sugar-based amorphous foods.