In this study, superheated steam (SS) at different temperatures (110, 130, 150℃) was used to modified the tartary buckwheat whole flour (TBWF) and core flour (TBCF). And the pasting properties, thermal properties, in vitro digestion, phenolics content, and antioxidant abilities of tartary buckwheat flours (TBFs) after SS treatment were investigated. The result showed that SS could significantly increase the peak viscosity, trough viscosity of TBFs and decrease the setback of TBFs (P<0.05). Moreover, transition temperatures and gelatinization enthalpy (ΔH) of TBFs were significantly increased by SS treatment (P<0.05), and ΔH increased with the increase of treatment temperature. Contents of rapidly digestible starch and slowly digestible starch in TBFs were significantly decreased by SS (P<0.05). By contrast, the content of resistant starch in TBFs was significantly increased by SS (P<0.05). However, there were no significant differences among all TBFs treated by SS at different treatment temperatures (P>0.05). In addition, contents of soluble-conjugated phenolics and bound phenolics in TBFs were significantly increased by SS (P<0.05), contents of free phenolics, and total phenolics in TBFs were significantly reduced by SS (P<0.05). The trend of antioxidant abilities of TBFs was consistent with that of phenolics in TBFs. This study demonstrated that SS can significantly change the physicochemical properties of TBFs, reduce the in vitro digestibility of TBFs and improve its nutritional value. These results will provide new possibilities for its application in healthy functional foods.
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