ISOLATION AND CHARACTERIZATION OF SOLUBLE POLYSACCHARIDES AND INSOLUBLE CELL-WALL MATERIAL OF THE PULP FROM 4 MANGO (MANGIFERA-INDICA L) CULTIVARS

Mature green fruits from monoembryonic (Amelie and Palmer) and polyemb ryonic (M'Bingue and Tete de Chat) mango cultivars were initiated to r ipen with ethylene (10 ppm, 24 h) and then left to reach full ripeness (6 days). After elimination of skin and kernel, pulp was added with H EPES (1/5, w/w) and centrifuged. Soluble polysaccharides were obtained from the supernatant by precipitation with ethanol and freeze-drying. Cell wall material (CWM) was isolated from the pellet by the buffered phenol procedure and further enzymatically destarched. Soluble polysa ccharides (similar to 0.5-0.8%/pulp fresh weight) were essentially hig hly esterified pectic substances (uronic acids content similar to 50-6 0%; degree of methyl esterification similar to 89-97%) and their molec ular weights were higher in the polyembryonic cvs. CWM, similar to 1%/ pulp fresh weight, was mainly built of cellulose (similar to 20%) and highly esterified pectic substances (uronic acids similar to 13-24%; d egree of esterification similar to 63-73%). Hemicellulosic glucans wer e more abundant in the monoembryonic (similar to 9%) than in the polye mbryonic (similar to 4%) cultivars.