Sugar beet pectins as food emulsifiers – Influence of molecular structure and conformation on the emulsification properties

Various food, beverage, pharmaceutical, and cosmetic products are formulated as emulsions, with their physical stability relying on suitable emulsifiers. Driven by the increasing demand for natural, eco-friendly, and sustainable products, the industry is seeking to replace synthetic and animal-derived emulsifiers with natural and vegan alternatives such as pectins. This dissertation aims to systematically investigate all relevant aspects of sugar beet pectins (SBPs), from extraction and modification to the influence of molecular structure, formulation, and process conditions on their emulsifying properties. Research shows that SBPs' colloidal, interfacial, and emulsifying properties are influenced by environmental conditions. Compact pectin conformations lead to faster adsorption kinetics, a higher number of adsorbed molecules, and thicker adsorption layers, crucial for stabilizing oil droplets. Emulsions with varying oil and pectin concentrations demonstrate that droplet size distribution and stability depend on the pectin-to-oil ratio and conformation. High pectin-to-oil ratios and compact conformations optimize droplet stabilization. The study's findings suggest that molecular features, such as the presence of hydrophobic groups, molecular size, and particularly the content of arabinan side chains, are crucial for droplet stabilization. SBPs are tested under unfavourable conditions, including heat and salt addition at various pH levels, in model emulsions. Results indicate greater sensitivity to salt than heat, with physical instabilities at low pH mitigate by higher pectin concentrations. Further, beverages and salad dressings formulated with SBPs demonstrate emulsion stability over extended storage periods. Overall, SBPs show substantial promise as food and beverage emulsifiers. This research provides a foundation for optimizing industrial extraction and developing post-extraction modification methods to enhance pectin functionality.