An ultrasound-microwave-assisted extraction (UMAE) approach was optimized using response surface methodology (RSM) to attain the maximum extraction yield (13.1%) of grape pomace pectin (GPP) by integrating 28.58 min sonication time, 600 W microwave power, 12.67 min irradiation time, and a liquid-to-solid ratio of 21.71 mL/g. The esterification degree, galacturonic acid (GalA) content, and molecular weight of the purified GPP were 72.5%, 67.9%, and 6.108 × 105 Da, respectively. The most abundant monosaccharides in the structure of GPP after GalA were glucose, galactose, arabinose, and rhamnose, respectively.
