title: Characterization of Cell Wall Components and Their Modifications during Postharvest Storage of Asparagus officinalis L.: Storage-Related Changes in Dietary Fiber Composition.
abstract: Changes in cell wall composition during storage of plant foods potentially alter the physiological effects of dietary fiber components. To investigate postharvest cell wall modifications of asparagus and their consequences in terms of insoluble dietary fiber structures, asparagus was stored at 20 and 1 °C for different periods of time. Structural analyses demonstrated postharvest changes in the polysaccharide profile, dominated by decreased portions of galactans. Increasing lignin contents correlated with compositional changes (monolignol ratios and linkage types) of the lignin polymer as demonstrated by chemical and two-dimensional nuclear magnetic resonance (2D-NMR) methods. Depending on the storage time and temperature, syringyl units were preferentially incorporated into the lignin polymer. Furthermore, a drastic increase in the level of ester-linked phenolic monomers (i.e., p-coumaric acid and ferulic acid) and polymer cross-links (di- and triferulic acids) was detected. The attachment of p-coumaric acid to lignin was demonstrated by 2D-NMR experiments. Potential consequences of postharvest modifications on physiological effects of asparagus dietary fiber are discussed.
authors.affiliation: Institute of Applied Biosciences, Department of Food Chemistry and Phytochemistry, Karlsruhe Institute of Technology (KIT) , Adenauerring 20a, 76131 Karlsruhe, Germany.
authors.forename: Judith
authors.initials: J
authors.lastname: Schäfer
authors.affiliation: Institute of Applied Biosciences, Department of Food Chemistry and Phytochemistry, Karlsruhe Institute of Technology (KIT) , Adenauerring 20a, 76131 Karlsruhe, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Wagner
authors.affiliation: Max Rubner-Institut (MRI) , Department of Safety and Quality of Fruit and Vegetables, Haid-und-Neu-Straße 9, 76131 Karlsruhe, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Trierweiler
authors.affiliation: Institute of Applied Biosciences, Department of Food Chemistry and Phytochemistry, Karlsruhe Institute of Technology (KIT) , Adenauerring 20a, 76131 Karlsruhe, Germany.
authors.forename: Mirko
authors.initials: M
authors.lastname: Bunzel
mesh_terms: D027761:Asparagus Plant / Q000737:chemistry* / Q000378:metabolism; D002473:Cell Wall / Q000737:chemistry* / Q000378:metabolism; D004043:Dietary Fiber / Q000032:analysis* / Q000378:metabolism; D061353:Food Storage; D015394:Molecular Structure; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism; D014675:Vegetables / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004043:Dietary Fiber; D011134:Polysaccharides
keywords: cell wall composition; cell wall cross-links; dietary fiber; hydroxycinnamic acids; lignin structure; pectins; postharvest modifications; white asparagus