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

摘要

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.