The effects of repeated heat-moisture treatment (RHMT) and continuous heat-moisture treatment (CHMT) on structural, physicochemical and digestibility properties of red adzuki bean starch have been investigated and compared. The results showed that the starch granules had many rupture and scallops and some of the polarization cross disappeared after CHMT and RHMT. The crystal type of CHMT and RHMT starches changed from C-type to A-type. The pasting temperatures and gelatinization transition temperatures of CHMT and RHMT starches increased, while the pasting viscosities (peak, trough, breakdown, final and setback viscosity), solubility and swelling power of CHMT and RHMT starches decreased compare to native starch. The RDS and SDS contents of starch samples were higher than native starch, which indicate that the digestibility was improved by CHMT and RHMT. On the whole, the RHMT measures have more advantages in the changes of starch structural, physicochemical and digestibility properties compared to CHMT ones.
Keywords: Crystallinity; Digestibility; Modification; Pasting; Swelling.
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