Novel pectins extracted from Euryale ferox fruit peel by combined hydrothermal pretreatment and enzymatic hydrolysis exhibit potential as aqueous gels and antioxidant activities

Summary The present study provided new alternatives for recycling of Euryale ferox fruit peel to develop application of pectins in food industry. In this work, the physicochemical characteristics, thermal properties, rheological properties and antioxidant activities of novel pectins (Pectin Hp, Pectin Eh and Pectin Hp‐Eh) extracted from E. ferox fruit peel were explored. The results indicated that Pectin Hp‐Eh had the highest yield (122.48 mg g−1). Pectin HP, Pectin Eh and Pectin HP‐Eh, with strip, polygonal and irregular shaped structures, respectively, exhibited dominant elastic characteristics as aqueous gels. Compared to Pectin HP and Pectin HP‐Eh, Pectin Eh possessed better rheological properties. Moreover, Pectin Eh exhibited stronger scavenging activities of hydroxyl and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radicals than those of Pectin HP and Pectin HP‐Eh. The IC50 values of Pectin Eh for hydroxyl and DPPH radicals were determined to be 11.81 and 14.07 mg mL−1, respectively. Pectin Hp, Pectin Eh and Pectin Hp‐Eh were extracted from Euryale ferox fruit peel. The three pectins exhibited potential as aqueous gels and antioxidant activities.