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. (C) 2004 Elsevier Ltd. All rights reserved.