Physicochemical properties of hydroxypropylated and cross-linked starches from A-type and B-type wheat starch granules

The large (A-type) and small (B-type) wheat starch granules were characterized and used for hydroxypropylation and cross-linking. The A-type granules contained higher amylose content and exhibited lower gelatinization temperature and higher transition enthalpy as compared with the B-type granules. Hydroxypropylated starches (HS) and hydroxypropylated and cross-linked starches (HCS) from the A-type granules were more hydroxypropylated than were those from the B-type granules. Moreover, HS and HCS of A-type granules had higher swelling power and resulted in greater paste consistency and clarity than HS and HCS of B-type granules. Hydroxypropylation of starches increased swelling power, paste consistency and clarity. In contrast, cross-linking of the HS inhibited granule swelling and reduced paste viscosity and clarity. Both the HS and HCS decreased the gelatinization temperature but improved freeze–thaw stability as compared with the native starches.