Protein, hydrophobic nature, and glycan profile of sugar beet pectin influence emulsifying activity

Sugar Beet Pectin (BP) was sequentially fractionated with increasing isopropanol into six fractions from a commercial BP control (BP2-C) and denoted as BP2-F1 to BP2-F6. Fractions of BP2 were categorized based on physico-chemical characteristics of similar protein and ferulic acid content, varying galacturonic acid, surface hydrophobicity, degree of esterification and molecular weight. Glycan-directed monoclonal antibodies response showed intense binding for homogalacturonan, rhamnogalacturonan I and arabinogalactan epitopes that varied between early and later precipitating fractions, and between lots of BP. In a 14-day study of rice bran oil-in-water emulsion, the particle size (2 +/- 0.3 mu m) and zeta-potential (-34 +/- 3 mV) remained stable for BP2-F3 and B2-F4. Fractions that precipitated at lower alcohol concentrations likely have more amphiphilic properties, compared to later precipitating fractions that provide more steric stabilization.