Extraction and analysis of the parietal polysaccharides of acorn pericarps from Quercus trees

Abstract Acorns produced by Quercus trees are currently underexploited and undervalued. To evaluate the commercial and health benefits of acorns, we examined the cell wall components of acorn pericarps from Quercus suber and Quercus ilex, growing in North-Western Algeria. Acorn pericarps were sequentially extracted and the polysaccharide fractions were analyzed by gas liquid chromatography and Fourier-transform infrared spectroscopy. The lignocellulosic fraction was the major component of Q. suber and Q. ilex cell walls (37.19% and 48.95%, respectively). Lower amounts of pectins and hemicelluloses were also found in both species. Hemicellulose extracts from the two species contained xylose as the major monosaccharide (ranging from 36.7% to 49.4%). Galacturonic acid was the major component of hot water- or ammonium oxalate-extracted pectins from both species (ranging from 20.6% to 46.8%). The results reported in this paper reveal that acorn pericarp cell walls from these two oak could be potential sources of bioactive compounds.