Starch ordered structures control starch reassembly behaviors during heat–moisture treatment for modulating its digestibility

This study investigated the effect of starch crystallinity on starch reassembly behaviors during the heat–moisture treatment (HMT) using starches with A-type crystal content of 0.00%–19.03%. The results showed that HMT reduced the native starch crystal content from 19.03% to 15.02% and increased starch thermostability, leading to a decrease in rapidly digestible starch (RDS) content from 86.91% to 76.71%. Moreover, starches containing a crystal content of 2.51%–8.11% exhibited significant reassembly during the HMT, and the resulting modified starches had more crystals and less RDS of 63.43%–69.31%. Interestingly, starches lacked A-type crystals but had some helical structures exhibiting A-type crystalline structures and lower digestibility after HMT. These findings verified that starch could significantly reassemble to form crystalline structures during the HMT. Controlling the crystal content of starch granules, particularly between 2.51% and 8.11%, was a promising approach for promoting starch reassembly during HMT and reducing starch digestibility.