Functionality
Pectins are mainly used as gelling agents, but can also act as a thickener, water binder and stabilizer. Low methoxyl pectins (<50% esterified) form thermoreversible gels in the presence of calcium ions and at low pH (3 - 4.5), whereas, high methoxy pectin's rapidly form thermally irreversible gels in the presence of sufficient (e.g. 65% by weight) sugars, such as sucrose and at low pH (<3.5). The lower the methoxy content, the slower is the setting. The degree of esterification can be reduced using commercial pectin methylesterase, leading to a higher viscosity and firmer gelling in the presence of Ca2+ ions. Highly acetylated pectin from sugar beet is reported to have considerable emulsification ability due to its more hydrophobic nature, but this may be due to associated protein impurities.