Modification of potato starch by using superheated steam.

Conventional hydrothermal modification of starches is a time- and energy-consuming process. In this study, superheated steam (SS) at different temperatures (100-160 ℃) was used to modify the structural and physicochemical properties of potato starch (PS). The long- and short-range molecular structures were disrupted without affecting the granular structure of PS and the degree of disruption could be regulated by simply changing the treatment temperature. The swelling power, solubility, transparency, peak viscosity and breakdown of PS were positively correlated with each other and were significantly decreased by SS treatment, while the pasting temperature, final viscosity and setback were significantly increased. Considerable amount (>9%) of slowly digestible starch was converted to resistant starch by SS treatment at 100 and 120 °C. Considering the high thermal efficiency of SS and the short treatment time (1 h) used in this study, SS treatment could be a superior alternative to conventional hydrothermal modification.