Octenylsuccinylation strategy to construct high-amylose maize starch-myristic acid complexes with high thermal...

Gelatinizing high-amylose maize starch (HAMSt) requires high temperatures to allow complexation with lipids, making it a challenging process. An octenylsuccinylation method was examined as a part of a strategy to decrease the gelatinization temperature of HAMSt, thereby promoting the complexation between HAMSt and myristic acid (MAc). Octenyl succinic anhydride (OSA) modification of HAMSt reduces the onset gelatinization temperature of HAMSt from 71.63 °C to 66.97 °C. Moreover, as the OSA concentration increased from 2 % to 11 %, the degree of substitution and molecular weights of the esterified HAMSt gradually increased from 0.0069 to 0.0184 and from 0.97 × 10⁶ to 1.17 × 10⁶ g/mol, respectively. Fourier transform infrared analysis indicated that the octenyl-succinate groups were grafted onto the HAMSt chains. The formation of HAMSt-MAc complexes improved the thermal stability of OSA-treated HAMSt (peak temperature increased by 0.11 °C-13.95 °C). Moreover, the diffraction intensity of the V-type peak of the 11 % sample was greater than that of other samples. Finally, the anti-retrogradation ability was in the order of OSA-HAMSt-MAc complexes > HAMSt-MAc complexes > HAMSt. Overall, our results indicate that octenylsuccinylation can be an effective strategy to promote the formation of OSA-HAMSt-MAc complexes and delay starch retrogradation.