Abstract
Emulsions based on peanut protein isolate-high methoxyl pectin (PPI-HMP) with different occurrence states have diverse characteristics under ultrasound. This study aimed to explore the effects of ultrasound on the interfacial behavior and emulsion stabilization mechanisms of PPI-HMP with different occurrence states. Interface-adsorbed PPI and HMP contents and the structural properties of interface-adsorbed, and interface-unadsorbed components were investigated using fluorescence spectroscopy, Fourier transform infrared spectroscopy, a contact angle measuring instrument, and scanning electron microscopy. Ultrasound enhanced interface-adsorbed content of PPI at pH 5.0, 7.0, and 9.0. The structural properties of interface-adsorbed PPI showed that ultrasound facilitated the formation and interfacial accumulation of soluble PPI-HMP complexes at pH 5.0. Competitive adsorption between PPI and HMP was observed at pH 7.0. Analysis of interface-unadsorbed components showed that ultrasound enhanced the formation of hydrogen bonds among HMP molecules, resulting in network structures in the continuous phase at pH 7.0, and 9.0. The results provide a theoretical basis for applying PPI-HMP and ultrasound in the food industry.