Study on starch-protein interactions and their effects on physicochemical and digestible properties of the blends.

The aim of this study was to characterize the influence of starch-protein interactions on physicochemical properties and starch digestibility in corn starch-whey protein isolate (WPI) blends during cooking. The results studied by differential scanning calorimetry (DSC) and dynamic viscoelasticity revealed that the swelling process of starch granule was restricted by protein. While recrystallization after cold storage was accelerated by protein addition. The short-range structure in Fourier transform infrared spectroscopy (FTIR) favored by protein was in negative correlation to the rapidly digestible starch content. Studies on rheological properties showed that the interaction force was mainly through hydrogen bonds. Additionally, confocal laser scanning microscopy analysis indicated that whey protein formed a surrounding or encapsulation of starch granules and acted as a physical barrier toward starch digestibility following cooking.