LAUSR

Abstract The effects of nineteen sugars and sugar alcohols on the gelatinization temperature (Tgel) of wheat starch were investigated. Starch Tgels in sweetener solutions were determined using differential scanning calorimetry; the solution and intrinsic properties of the sweeteners were then compared to the measured Tgels. The Tgel increased as sweetener concentration increased, but significant differences in Tgel were found between different sweetener types, even those containing the same number of carbons. On a molar basis, trisaccharides most increased the Tgel, while on a percent-solids basis disaccharides most increased the Tgel. Significant correlations existed between the Tgel and increasing sweetener solution water activities, solids contents, and viscosities, but these correlations were weaker when compared within similar sweetener concentrations. The amount of sweetener entering the starch granule depended on the solution solids content. The glass transition temperature of the amorphous water-sweetener-starch fraction did not have a direct effect on the starch Tgel. Sweeteners with more equatorial and exocyclic hydroxyl groups tended to increase the Tgel more, indicating that sweetener stereochemistry could be important. It was theorized that sweeteners increased the Tgel by forming sweetener-starch intermolecular interactions in the starch amorphous regions, with supporting evidence including how sweeteners affected starch annealing and how pH affected starch-glucuronic acid interactions and measured Tgels. A machine-learning model was developed that could predict the starch Tgel in a sweetener solution within 1.6%. To date this study is the most comprehensive investigation of the effects of a broad variety of sweeteners on the gelatinization temperature of wheat starch.