Preparation and properties of starch phosphates using waxy, common, and high-amylose corn starches. I. Oven-heating method

The structure and physicochemical properties of waxy, common, and high-amylose corn starch phosphates prepared by oven heating were studied. Starch phosphates prepared by either slurry or dry-mixing treatment before oven heating were also compared. The slurry treatment more efficiently incorporated phosphorus into starch relative to the drymixing treatment under the reaction conditions studied. In general, the phosphorylated starch prepared by the slurry treatment exhibited a lower gelatinization temperature, a higher peak viscosity, a lesser degree of retrogradation, and improved freeze-thaw stability compared with those prepared by the dry-mixing treatment. Phosphorylation occurred probably in both amylose and amylopectin, and the amount and location of incorporated phosphate groups varied with starch types likely due to their different amylose and amylopectin contents. Waxy starch was more prone to phosphorylation, followed by common and high-amylose starches, respectively.