PROBLEM TO BE SOLVED: To provide heat and moisture-treated starch, that is producible at lowest cost and in greater quantity, having higher quality than in conventional methods.SOLUTION: Using a sealable container equipped with a heating device on the periphery for increasing temperature of inner walls, and a device for mixing starch inside, the starch is heated by introduction of superheated steam at a degree of superheat of 1-30°C. Heat and moisture-treated starch with excellent heat resistance and acid resistance, that is producible at lower cost and in greater quantity, while swelling is restricted, can thus be produced.
