Modification of Potato Pectin with Energy-gathering Ultrasonic Treatment: Physico-chemical, Microstructural, and Emulsifying Properties

In order to clarify the potential relationship between the emulsifying properties, physico-chemical characteristics, and microstructure of potato pectin under different ultrasonic treatment conditions, the effects of different energy-gathering ultrasonic power densities (30, 40, 50 W/L) and time (10, 20, 30 min) on the physicochemical characteristics, microstructure, and emulsifying properties of potato pectin were explored. The results showed that energy-gathering ultrasonic modification disrupted the chain structure of potato pectin, leading to a reduction in particle size (D₅₀, D_4,3, D_3,2), degree of methylation (DM), degree of acetylation (DA), ζ-potential, and molecular weight (M_w). Meanwhile, the galacturonic acid (GalA) content increased significantly, ranging from 39.11% to 48.14%. Additionally, the emulsion stability and droplet size uniformity of emulsions prepared with modified potato pectin were significantly improved (P<0.05), in which the emulsions prepared by potato pectin modified under 30 W/L and 40 W/L for 20 min exhibited the best physical stability and lowest turbiscan stability index (TSI), achieving values of 46.00% (EGU30-20) and 5.25% (EGU40-20), respectively. These values were significantly superior to those of unmodified potato pectin (physical stability: 39.00%, TSI: 18.38). These findings highlighted the potential of ultrasound technology as an environmentally friendly, easy-to-operate, and effective approach to enhance the emulsifying properties of potato pectin, thereby broadening its application potential in the food industry.