Properties of butyrylated lotus seed starch with butyryl groups at different carbon positions

The objectives of this study were to investigate the properties of butyrylated lotus seed starch (LSB). LSB was prepared using an aqueous phase method and the substitution occurred at C2, C3, and C6. The surface of starch esters with high DS became rougher and more broken. Fourier transform infrared spectroscopy proved that the carbonyl group was successfully incorporated into the starch. The degree of crystallinity and molecular weight decreased as DS increased. Moreover, the thermal analysis and viscosity showed a lower gelatinization enthalpy and final viscosity of LSB compared with the unbutyrylated starch (LSB-0). The in vitro digestion characteristics showed that with different distributions at C2, C3, and C6, the content of resistant starch increased, indicating that LSB with higher DS had stronger resistance to digestion. This study revealed that the distribution of butyryl groups at different carbon positions was related to the properties.