Abstract: The research was designed to investigate the interactions of tartary buckwheat starch (TBS) and wheat starch (WS) with tartary buckwheat polyphenols (TBP) at low levels (1%.4%) during gelatinization and their effect on starch paste transparency, retrogradation and pasting properties, textural properties, resistant starch content and microstructure. The results showed that adding TBP could significantly decrease the transparency and sedimentation volume of TBS and WS paste, and accelerate starch paste retrogradation. The pasting temperature and enthalpy of both starches were decreased, indicating that the starches were prone to be pasted. Compared with the control without added TBP, addition of 4% TBP led to a decrease in the hardness of TBS and WS gels by 19.74% and 54.18%, respectively, and a significant increase in resistant starch content (by 15%.30%). The scanning electronic micrographs (SEM) indicated that TBP could accelerate the aggregation and cross-linking of starch granules. The changes in physicochemical properties of starch after TBP addition can be regarded as a physical modification method to increase resistant starch. Tartary buckwheat flour can be used as a high quality ingredient of foods high in resistant starch.

Key words: tartary buckwheat polyphenols, starch, pasting properties, textural properties