A PRELIMINARY CHARACTERIZATION OF SOME PECTINS FROM QUINCE FRUIT (CYDONIA-OBLONGA MILL) AND PRICKLY PEAR (OPUNTIA-FICUS-INDICA) PEEL

The preliminary characterization of a hot acid extracted pectin from q uince (Cydonia oblonga Mill.) and from prickly pear (Opuntia ficus ind ica) peel was carried out. The yield of the extraction, the galacturon ic acid content and the neutral sugar composition were determined and compared with published data on apple and lemon pectins The pectin yie ld from quince was on average 0.53% on fresh weight, which is of a sim ilar order to apple. The quince pectin had a high galacturonic content (about 78%), and a degree of methoxylation of about 59% corresponding to a medium-high methoxyl pectin. The prickly pear pectin yield was 0 .12% on fresh weight. This pectin had a galacturonic acid content of 6 4%, a low degree of methoxylation (10%), a high acetyl (10%) and neutr al sugar content (51% galacturonic). It might be related to similar po lygalacturonides present in the mucilages of other Cactaceae.