Effects of proanthocyanidins on the pasting, rheological and retrogradation properties of potato starch.

BACKGROUND Proanthocyanidins (PAS) were complexed with potato starch (PS) to prepare polyphenol-starch complexes. The pasting, rheological and retrogradation properties of the complexes were investigated. RESULTS The addition of PAS markedly affected the pasting, rheological and retrogradation properties of PS, especially at a concentration of 5% (w/w). Rapid viscosity analysis indicated that PAS significantly changed the viscosity, breakdown and setback value of PS. The rheological results showed that PAS decreased the flow behavior index and consistency coefficient, but increased the viscoelasticity of PS. Differential scanning calorimetry and X-ray diffraction indicated that PAS delayed the retrogradation of PS. Furthermore, scanning electron microscopy indicated that the morphologies of retrograded PS gels were greatly altered to a less compact structure with the presence of PAS. Moreover, Fourier transform infrared spectroscopy elucidated that PAS interacted with PS via a noncovalent interaction, and inhibited the retrogradation of PS. CONCLUSIONS The findings suggested that supplementing PS with PAS might be an effective and convenient method for modifying the physicochemical properties of PS. © 2021 Society of Chemical Industry.