title: Characterisation of cell-wall polysaccharides from mandarin segment membranes.
abstract: In an attempt to develop a process of enzymatic peeling of mandarin segments suitable for use on an industrial scale, the cell wall fraction of the segment membrane of Satsuma mandarin fruits was extracted to obtain a chelating agent-soluble pectin fraction (ChSS), a dilute sodium hydroxide-soluble pectin fraction (DASS), a 1M sodium hydroxide-soluble hemicellulose fraction (1MASS), a 4M sodium hydroxide-soluble hemicellulose fraction (4MASS) and a cellulose-rich residue (3.1, 0.9, 0.4, 0.7 and 1.6%w/w of fresh membrane, respectively). The ChSS pectin consisted mainly of galacturonic acid followed by arabinose and galactose. The DASS fraction contained less galacturonic acid and more neutral sugars than ChSS. Eighty-nine percent of the galacturonic acid present in the segment membranes was recovered in the above two pectin fractions. The two hemicellulosic fractions consisted of two different molecular weight populations, which also differed in their sugar composition. Arabinose, xylose, mannose, galactose and glucose were the main sugar constituents of these hemicellulose fractions. In addition to an (arabino)xylan and a xyloglucan, the presence of an arabinogalactan is suggested by the sugar composition of both hemicelluloses. The pectin fractions were also characterised by their degradability by the pectic enzymes polygalacturonase, pectinmethylesterase and rhamnogalacturonan hydrolase. However the degree of degradation of the pectin fractions by enzymes differed, and the amount of the polymeric materials resistant to further degradation and the oligomeric products also differed. Using pectic enzymes it is possible to obtain peeled mandarin segments ready to eat or for canning.
authors.affiliation: Laboratorios ECOSUR, Polígono Industrial Base 2000-San Martín, 30564 Lorquí, Murcia, Spain. Electronic address: direccion@laboratoriosecosur.es.
authors.forename: Luis
authors.initials: L
authors.lastname: Coll-Almela
authors.affiliation: Department of Agrofood Technology, Miguel Hernández University, 03312 Orihuela, Alicante, Spain. Electronic address: dsaura@umh.es.
authors.forename: Domingo
authors.initials: D
authors.lastname: Saura-López
authors.affiliation: Department of Food Science & Technology and Human Nutrition, University of Murcia, 30100 Murcia, Spain. Electronic address: laencina@um.es.
authors.forename: José
authors.initials: J
authors.lastname: Laencina-Sánchez
authors.affiliation: Food Carbohydrate Biochemistry, Laboratory of Food Chemistry, Wageningen University, AXIS Building 118, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands. Electronic address: henk.schols@wur.nl.
authors.forename: Henk A
authors.initials: HA
authors.lastname: Schols
authors.affiliation: Food Carbohydrate Biochemistry, Laboratory of Food Chemistry, Wageningen University, AXIS Building 118, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands. Electronic address: fons.voragen@wur.nl.
authors.forename: Alfons G J
authors.initials: AG
authors.lastname: Voragen
authors.affiliation: Department of Food Science & Technology and Human Nutrition, University of Murcia, 30100 Murcia, Spain. Electronic address: jmros@um.es.
authors.forename: José María
authors.initials: JM
authors.lastname: Ros-García
mesh_terms: D002473:Cell Wall / Q000737:chemistry; D002482:Cellulose / Q000032:analysis; D002957:Citrus / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D010368:Pectins / Q000032:analysis; D011134:Polysaccharides / Q000032:analysis / Q000737:chemistry*
chemical_list: D011134:Polysaccharides; D010368:Pectins; D002482:Cellulose
keywords: Cell-wall polysaccharides; Citrus unshiu Marc.; Enzymatic degradation; Pectic enzymes; Satsuma mandarin; Segment membrane