The influence of different sugars on corn starch gelatinization process with digital image analysis method

The digital image analysis, integral optical density (IOD) method, combined with “the model of response difference of crystallite change (MRDCC)” was applied to dynamically analyze the influence of different sugars on the gelatinization of corn starch. All of the saccharides (ribose, fructose, glucose, sucrose, lactose, trehalose, maltose, raffinose and stachyose) proposed in our research showed protection effect on starch crystalline structure during gelatinization. The protection effect increased with the increase of sucrose concentration (0–20%). Trisaccharide and tetrasaccharide were more effective in inhibiting the gelatinization process than disaccharide; and the protection effect of disaccharides on starch was bigger than that of monosaccharide during gelatinization. The gelatinization inhibition effect had good relationship with nDHN (dynamic hydration number), and the increase of the equatorial OH (e−(OH)) group number of saccharides might increase the inhibition effect on starch gelatinization. However, in addition to the e−(OH) groups, the combination ability of sugar with water molecules might be also related to the size of the sugar molecules and their three-dimensional structure. We believed that owing to the helical structure which formed though hydrogen bonds, tetrasaccharide tended to decrease the hydration ability of saccharide and destabilized the water structure, thus the inhibitory effect of stachyose was almost the same as raffinose.