The modulation of glucose release from noodles through the addition of low methoxyl pectin and sodium alginate

The worldwide prevalence of diabetes mellitus has increased substantially in recent years, posing a serious global public health challenge. Hydrocolloids are functional ingredients that increase the viscosity of gastrointestinal contents, which has been shown to reduce the absorption of digestible carbohydrates. In this study, delaying starch hydrolysis using low methoxyl pectin (LMP) and sodium alginate (SA) gels, mediated by calcium ions, were investigated to develop an ingredient of starch and SA-LMP composite (SC). LMP, SA and the combination were added to wheat flour (WF) to develop SCs with different compositions: 0% LMP & SA (Control), 2% LMP (Trial 1), 1% LMP & SA (Trial 2) and 3% SA (Trial 3). The SC physicochemical properties, such as proximate composition, color, pasting and rheological properties were evaluated. Incorporation of LMP and SA gels reduced the WF pasting profiles due to reduction of starch gelatinization. The addition of LMP and SA enhanced cross-link formation, resulting in higher composite gel strength and increased noodle hardness. The in vitro behavior of wheat noodles was influenced by the specific SC type. Trial 2 noodles showed the lowest reduction in glucose release as combination of LMP and SA gels formed thick wall gel networks, thus limited the enzyme accessibility to starch. Overall, the results showed that modulating glucose release from noodles using SA and LMP gels is a useful technique to reduce starch digestibility, thus lower the glycaemic index of wheat noodles. • Gelation of low methoxyl pectin (LMP) and sodium alginate (SA) were able to retard starch hydrolysis • Pasting profiles of wheat flour were lowered by addition of LMP and SA gels • LMP-SA gels enhanced wheat flour viscoelastic properties • Starch hydrolysis of LMP-SA gels was lower than that of LMP and SA gels