The fabrication of emulsions with pectin polysaccharides from diverse plant sources for enhancing the stability and biological activity of Lycium Barbarum extract

Complex-structured pectin polysaccharides are efficient natural food-grade emulsifiers and stabilizers. However, the relationship between the structure features of pectin polysaccharides from different plant sources and their emulsifying properties remains unclear, limiting the fabrication of stable pectin emulsions and their application. In this study, pectin polysaccharides were extracted from sunflower disk, beet root, apple pomace, grapefruit peel and citrus peel. Of the five polysaccharides, citrus pectin (CP) was found to exhibit the best emulsifying performance, which was attributed to its higher content of polysaccharides-covalently bound protein, higher degree of methyl-esterification, and higher branching degree in RG-I region. CP emulsions with varying CP concentrations (c) and oil volume fractions (φ) were prepared and analyzed for the structure and stability. When φ ≤ 30%, 2.0% CP emulsion with smaller particle size exhibited higher storage stability. When φ > 30%, the stability of 1.0% CP emulsion was relatively higher. In particular, c2.0%-φ20% emulsion exerted the highest stability against heating and ionic strength, which also had a high encapsulation efficiency (84.09% ± 0.53) for Lycium barbarum extract (LBE). LBE-loaded CP emulsion showed no cytotoxicity, and demonstrated higher antioxidant activity and inhibition rates against tyrosinase, elastase and hyaluronidase activities, which holds promise as a novel anti-aging emulsion for cosmetic application.