Pectic acid gelation

Pectins are generally classed according to their ester content as high methoxyl pectins (>50% of the carboxyl groups esterified) or low methoxyl pectins (<50% of carboxyl groups esterified) (pectic acid, methyl ester [9049-34-1]). Low methoxyl pectins, like algins, require calcium for gelation. 

Pectic Substances 46, 77). An important group of substances commonly called pectins is found in the primary cell wall and intercellular layers of all land plants, and, in some ways, seems to correspond to the hyaluronic acid of the ground substance of much animal tissue. Because of the immense gelling power of pectic substances, they are widely used for the gelation of fruit juices to form jellies. 

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