Synchrotron X-ray scattering analysis of the interaction between corn starch and an exogenous lipid during hydrothermal treatment

Lipids have an important effect on starch physicochemical properties. There exist few reports about the effect of exogenous lipids on native corn starch structural properties. In this work, a study of the morphological, structural and thermal properties of native corn starch with L-alpha-lysophosphatidylcholine (LPC, the main phospholipid in corn) was performed under an excess of water. Synchrotron radiation, in the form of real-time small and wide-angle X-ray scattering (SAXS/WAXS), was used in order to track structural changes in corn starch, in the presence of LPC during a heating process from 30 to 85 °C. When adding LCP, water absorption decreased within starch granule amorphous regions during gelatinization. This is explained by crystallization of the amylose–LPC inclusion complex during gelatinization, which promotes starch granule thermal stability at up to 95 °C. Finally, a conceptual model is proposed for explaining the formation mechanism of the starch–LPC complex.

► Interaction between corn starch and exogenous lipid was studied.
► Adding lipids in hydrothermal treatment affect the morphological structure of starch.
► Amorphous structure shows less water absorption by formation of complex starch-lipids.
► Thermal stability of granules maintenance until dissociation temperature of complexes.