EFFECT OF SEVERAL KINDS OF DIETARY POLYPHENOLS ON PHYSICOCHEMICAL PROPERTIES OF CORN STARCH

The interaction between starch and polyphenol can be used to improve starch properties and develop functional foods.In order to investigate the effect of 7 polyphenols on the physicochemical properties of corn starch,certain food source polyphenols were added in starch respectively to study the changes of solubility,swelling force,viscosity,thermodynamics and gel properties of corn starch.The results showed that ferulic acid and caffeic acid significantly reduced the solubility of starch in all polyphenols,and ferulic acid could also significantly reduce its swelling power.Additionally,these two kinds of acids also increased the attenuation value and reduced the retrogradation value of starch.Chlorogenic acid and caffeic acid had the most significant effect on attenuation and retrogradation value.Ferulic acid and caffeic acid significantly increased ΔH₁;7 polyphenols reduced the ΔH₂and R,and ferulic acid displayed the most significant effect on two aspects.All polyphenols could significantly reduce the starch gel strength and rupture distance,of which ferulic acid had the most significant effect on its gel strength,while ferulic acid,chlorogenic acid and caffeic acid displayed the most significant effect on rupture distance (P<0.05).In general,7 polyphenols could reduce the dissolution of amylose molecules in corn starch granules,destroy the thermal paste stability of starch paste during starch gelatinization,inhibit the retrogradation of starch,and prevent starch from gelling.Additionally,ferulic acid,chlorogenic acid,caffeic acid,gallic acid and catechin displayed more significant effects on the physicochemical properties of corn starch than that of proanthocyanidins and tannins.Our study provided a theoretical basis for modification of starchy products and development of related functional foods.