Ray Diffraction and Relative Crystallinity

Starch, when heated in the presence of excess water, undergoes an order-disorder phase transition called gelatinization over a temperature range characteristic of the 

Barley starch Gelatinization transition temperatured (°C) Enthalpy( /g) 

Barley starch Granule size Gelatinization transition temperatures3 (°C) T Tp Tc Ranee (°C) Tc-T0 Enthalpy (AH) Cl/g) U/g) 

The wide range in T0, Tp, Tc and AH among genotypes (Table 16.2) could be attributed to differences in cultivars,39,49,52 growth conditions,49,58 and thermal and mechanical conditions employed during starch isolation.66 DSC parameters of barley starches are generally lower than those reported for normal, waxy and high-amylose maize starches examined under identical conditions.28 

---