Emulsification properties of sugar beet pectin: The synergistic effect of homogalacturonan and rhamnogalacturonan-Ⅰ

In recent years, sugar beet pectin has been shown to exhibit excellent emulsifying properties compared to commercial citrus peel pectin and apple pectin, with emulsifying properties similar to those of gum arabic. However, due to the highly complex molecular structure, the emulsification mechanism of sugar beet pectin is still unclear. In this study, the RG-Ⅰ region of sugar beet pectin was successfully isolated and characterized by chemical composition, FT-IR, TG/DTG, XRD and 1H NMR analyses. In addition, multiscale characterization techniques showed that RG-Ⅰ could form a much thicker and more elastic interfacial film than HG. This highly elastic interfacial film is crucial for the long-term emulsion stability. Moreover, our studies also showed that HG and RG-Ⅰ alone could not form an interfacial film as elastic as that of sugar beet pectin. This indicates that the smooth HG region and hairy RG-Ⅰ region of sugar beet pectin molecules are both necessary to form a thick and highly elastic interfacial film, and thus obtain a long-term stable emulsion.