Understanding properties and digestibility of starch sodium octenyl succinate derived from high-amylose wheat starch

Abstract

Starch-based emulsifiers, with multifunctional properties such as high viscosity, high gelling, and low digestibility, have gained increasing interest. This study aimed to understand the properties and digestibility of high-amylose wheat (HAW) starch sodium octenyl succinate (SSOS). HAW-SSOS had slightly lower peak gelatinization temperatures (T_p1: 71.5 °C, T_p2: 97.3 °C), conclusion temperature (104.3 °C), and relative crystallinity (16.7 %) compared to its counterpart. HAW starch exhibited increasing viscosities during pasting at 50 °C–95 °C-50 °C, while HAW-SSOS displayed high peak (564.5 cP), trough (492.0 cP), and final (1225.0 cP) viscosities. When pasting at 50 °C–140 °C-50 °C, the peak, trough, and final viscosities of HAW-SSOS decreased to 473.5 cP, 35.0 cP, and 170.0 cP, respectively. The gel prepared from pasting HAW-SSOS starch at 50 °C–95 °C-50 °C showed lower hardness (11.0 cP), gumminess (7.0 cP), and chewiness (49.0 cP) compared to the HAW starch gel (129.0 cP, 49.0 cP, and 310.5 cP, respectively). Both HAW starch and HAW-SSOS gels prepared from pasting at 50 °C–140 °C-50 °C showed increased hardness, gumminess, and chewiness. HAW-SOSS exhibited a higher resistant-starch content compared to HAW starch. These results suggested that the introduction of OS groups into HAW starch disrupted the double-helical crystallites, increased pasting viscosity and enzymatic resistance, and reduced gelatinization temperatures and gel hardness.