Abstract: Sugar beet pectin (SBP) is an acidic anion polysaccharide extracted from beet pulp. The backbone of SBP is comprised of rhamnose and galacturonic acid, which are rich in neutral sugar side chains, including rhamnose, arabinose, galactose and fructose. The proteins are covalently attached to the end of the neutral sugar side chains, contributing to the excellent emulsifying properties of SBP. This paper focuses on a comparison of the emulsifying properties of SBP and citrus pectin (CP). The effects of the growing area of sugar beet pulp, pectin concentration, pH, thermal treatment and storage time on the emulsifying properties (including drop size distribution, average particle size, zeta-potential, and turbidity) of the pectin were investigated. It was found that the geographical origin of sugar beet pulp showed a great influence on the protein composition in SBP. The drop size of the emulsion prepared with citrus pectin was much larger than that of SBP emulsion, and the former also exhibited poorer emulsifying activity. Emulsions coated with 10–25 mg/mL sugar beet pectin maintained good stability during the storage period (four weeks), while the droplet size of citrus pectin emulsion increased significantly. Emulsion droplet size remained stable in the swrange of pH 2–6. The droplet size of CP emulsion increased significantly during thermal treatment (25–85 ℃). This study verified that SBP exhibited excellent emulsifying activity and emulsion stability.

Key words: sugar beet pectin, geographical origin, citrus pectin, emulsifying activity, emulsion stability