Study on the physicochemical properties and antioxidant activity of hawthorn pectin extracted by ultrasound-assisted electrolysis of water.

This study systematically compared ultrasound-assisted electrolyzed water extraction (UAEWE), ultrasound-assisted extraction (UAE), traditional acid extraction (AE), and commercially available hawthorn pectin (CHP) in terms of pectin yield, physicochemical properties, structural characteristics, and antioxidant activity. The objective was to evaluate the feasibility of UAEWE as a sustainable alternative for hawthorn pectin production and explore its potential applications. Results indicated that UAEWE-extracted pectin achieved the highest yield (7.21 ± 0.13%) and galacturonic acid (GalA) content (87.35 ± 0.37 g/100 g), significantly surpassing UAE (5.96 ± 0.06%; 82.28 ± 0.49 g/100 g) and AE (4.53 ± 0.15%; 76.08 ± 0.96 g/100 g). However, UAEWE-extracted pectin exhibited lower esterification degree (63.13 ± 0.08%), weight-average molecular weight (223.92 ± 4.22 kDa), and particle size (3.56 ± 0.45 μm) than the other samples. Monosaccharide composition analysis revealed similar sugar profiles among all samples, although relative proportions differed. Microstructural characterization showed that UAEWE-extracted pectin possessed a highly porous architecture, consistent with its superior extraction yield. FTIR and NMR analyses confirmed no significant structural alterations among the pectin samples. Rheological measurements demonstrated that UAEWE-extracted pectin exhibited the lowest apparent viscosity at 1% concentration, pH 3, and low shear rates. Moreover, UAEWE-derived pectin showed enhanced antioxidant activity compared with UAE, AE, and CHP samples. These findings highlight UAEWE as a promising extraction strategy for hawthorn pectin, offering reduced acid usage, cost-effectiveness, and environmental sustainability. The resulting pectin, characterized by high GalA content and antioxidant capacity, shows potential for bioactive compound encapsulation and functional food applications.