Emulsifying properties of high methoxyl pectins in binary systems of water-ethanol.

The purposed mechanism for the effects of ethanol on the chain conformation and the emulsifying properties of high methoxyl pectin. • The pectin chain conformation is compressed in a binary solvent of water/ethanol. • Ethanol reduces the electrostatic repulsion and promotes pectin aggregation. • Condensation of pectin chain is beneficial to its adsorption at the O/W interface. • The pectin in binary solvent has better emulsion stability. Pectin is widely distributed in plant cell wall, most of which have limited emulsifying properties. Ethanol could alter the solubility of pectin, and affect its emulsifying properties. No creaming and breaking of emulsion appeared in 21% (v/v) ethanol contained emulsion. This project investigated the influence of ethanol (0%–35%, v/v) on conformation and emulsifying properties of pectin. Results shown that ethanol could reduce the helix conformation and zeta potential of pectin chain, which leading to compact conformation and enhanced interaction among pectin molecules. Although emulsion droplet diameter increased with ethanol content, the most stable emulsion was found in 21% (v/v) ethanol. CLSM also indicated over-aggregated pectin have a poor adsorption capacity on the interface of O/W. All results manifested the emulsifying properties of pectin can be improved by 21% (v/v) ethanol. This study provides a new strategy to improve the emulsifying property of pectin by changing its conformation. [ABSTRACT FROM AUTHOR]