Effect of Cooling,and Freezing on the Digestibility of Debranched Rice Starch and Physical Properties of the Resulting Material

Ten percent non‐waxy and waxy starch suspensions were debranched with pullulanase followed by heating and cooling (1 °C) to crystallize and/or gel. Products with a range of textures can be made depending on the type (waxy and non‐waxy) of starch used. The water holding capacity was 35% and 84% for waxy and non‐waxy cooled debranched starch, respectively, at 4 h of cooling and did not change. The hardness of the debranched waxy and non‐waxy starch continued to increase beyond 24 h up to 45 g and 245 g of force, respectively. The particle size of precipitates of non‐waxy and waxy debranched starch was 45 μm and 4 μm after 4 h of cooling and did not change. Cooling of debranched non‐waxy starch at 1 °C for 12 h without agitation decreased digestibility by 59%; with stirring digestibility decreased by 42% after 24 h of cooling. Freezing of debranched cooled waxy and non‐waxy starch does not effect the decreases in digestibility. Particle size of debranched, cooled/freeze‐thawed, dried, and milled starch affects digestibility.