Abstract:The effects of two organic acids on the quality of Sagittaria trifolia starch were investigated.L-Tartaric acid and citric acid were added to S.trifolia starch at different amounts.The effects of organic acid addition on the transparency,color difference,freeze-thaw stability,digestive properties,solubility,swelling power,and coagulability of S.trifolia starch were studied.The quality of S.trifolia starch was measured by electron microscopy observation,cross-polarized light observation,infrared spectrometry,and X-ray diffraction.The results showed that the transparency of acid-modified S.trifolia starch was significantly improved compared with that of the original starch.The addition of 15 g L-tartaric acid increased the transparency of S.trifolia starch by 32.03% and promoted the increase in rapidly digestible starch（RDS）.However,acid modification reduced the freeze-thaw stability and disrupted the structure of the starch without altering crystal morphology,leading to particle reorganization and enlargement.High concentrations of organic acids moderately improved the retrogradation properties of S.trifolia starch.The solubility and swelling capacity of S.trifolia starch were significantly increased at 65 ℃.In conclusion,organic acid modification was a mild modification method that can optimize the main processing characteristics of S.trifolia starch,demonstrating great application potential in production.