Characteristics of granular cold-water-soluble potato starch treated with alcohol and alkali.

The characteristics of cold-water-soluble potato starch (CWSS) produced using alcoholic-alkaline treatment were determined using scanning electron microscopy, rapid visco analysis (RVA), X-ray diffraction, differential scanning calorimetry, storage modulus (G'), loss modulus (G″), and gel images. Scanning electron microscopy revealed a damaged crystalline structure when CWSS was suspended in ethanol. The RVA analysis of native starch showed a peak value of viscosity at high temperatures, whereas the viscosity of CWSS did not show such a peak. The DSC diagram of native starch showed a gelatinization peak temperature; however, no such peak was observed for CWSS. Cold-water solubility tremendously increased in CWSS owing to the loss of crystallinity. The values of G' and G″ in CWSS decreased with increasing temperature; the opposite was observed for normal potato starch. These results indicate that alcoholic-alkaline treatment affects the starch structure and produces totally different physicochemical properties from native starch; this makes CWSS feasible for use in a variety of food materials.