Though the mechanism of the formation of nonmethyl ester linkages is still unclear, the apparent
increase in non-methyl ester linkages could be attributed
to the interactions between free carboxyl groups in C6of
D-galacturonic acids and hydroxyl groups in intra- and/
or inter-pectin molecules. In addition, the size of pectin
fragments in jelly curd was relatively large with flakelike structure, while those of pectin fragments from
heated achenes was smaller and porous (Fig. 2), suggesting the importance of PE and calcium to jelly curd
formation of pectin