Polysaccharides from the Cell Walls of Pineapple Fruit

Cell wall material from pineapple fruit was obtained and sequentially extracted with 50 mM NaOH at 2°C, 1 M KOH at 2 and 20°C, and 4 M KOH at 20°C. From the 4 M KOH-soluble fraction, a >neutral> polysaccharide and an acidic one were isolated by chloride anion exchange chromatography. The >neutral> fraction was composed of xylose, arabinose, glucose, galactose, and minor quantities of mannose. The infrared spectra showed an absorption band at 900 cm-1 of β-linked polysaccharides. The methylation analysis revealed the main glycosidic linkages of the >neutral> polysaccharide: 1,4-linked xylose with branching points in C3 and C2, 1,4-linked glucopyranose with branching points in C6, and terminal glucopyranosyl, arabinofuranosyl, and arabino/xylopyranosyl residues.