STARCH GELATINIZATION IN SUGAR SOLUTIONS

In limited water (<30%), the gelatinization temperature of starch incr eases as the moisture content decreases. When sugar is dissolved in wa ter, the sugar displaces part of the water. Therefore, the moisture co ntent of a wheat starch granule in a sugar solution is always less tha n 30%; thus, the gelatinization temperature is increased. When sugar i s dissolved in water, the Aw is decreased. This decreased Aw was shown to increase the onset melting point of crystallized dextrins. Thus, t he well known effect of sugar increasing the onset temperature of star ch gelatinization appears to be a result of the displacement of the wa ter inside the starch granule and the lower Aw.