Effects of salts on physicochemical, microstructural and thermal properties of potato starch

The objective of this study was to determine the effects of salts on the physicochemical, microstructural and thermal properties of potato starch. The salting-out ions were able to decrease the solubility, swelling power, transparency and particle size of potato starch significantly (p < 0.05), while the salting-in ions increased these properties significantly (p < 0.05). The microstructure of potato starch granules, observed by a light microscopy at 50 °C and 70 °C, was consistent with the above results. Differential scanning calorimetry (DSC) analysis demonstrated an increase in gelatinization temperature and enthalpy with the addition of salting-out ions, whereas there was a reverse trend for the addition of salting-in ions. The effects of anions on these properties of potato starch follow the order of SCN− > I− > NO3- > Br− > Cl− > SO42- > F−, while effects of the cations follow the order of Li+ > Na+ > K+, matching to the order of the Hofmeister series.