African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6800

Full Length Research Paper

Changes in lignin structure with maturation of alfalfa leaf and stem in relation to ruminants nutrition

Jordan P. Marković1*, Ratibor T. Štrbanović1, Dragan V. Terzić1, Dragoslav J. Djokić1, Aleksandar S. Simić2, Miroslav M. Vrvić3 and Sanja P. Živković4
  1Institute for Forage Crops, Kruševac, 37251 Globoder, Serbia. 2Department of Crop Science, Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11080 Belgrade-Zemun, Serbia. 3Faculty of Chemistry, University of Belgrade, 11158 Belgrade, Studentski Trg 16, P. O. Box 51, Belgrade, Serbia. 4Department of Phytomedicine, Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11080 Belgrade-Zemun, Serbia.  
Email: [email protected]

  •  Accepted: 16 December 2011
  •  Published: 31 January 2012



In the present investigation, the major chemical constituents in leaf and stem of alfalfa (Medicago sativa L.) cv Elena at three different stages of maturity were studied. The experiment was designed as a randomized block replicated three times. During growth and development, crude protein content decreased and cell wall constituents (Neutral Detergent Fiber-NDF, Acid Detergent Fiber-ADF and ADL- Acid Detergent Lignin) increased in both plant anatomical fraction of alfalfa. Lignin is a poorly characterized polymer and its exact properties vary depending on both the species of the plant and its location within the plant. Three stages of maturity taken from alfalfa leaf and stem were examined. The investigation was concentrated on the determination of chemical changes in the lignin during growth and development by the Attenuated Total Reflectance-Furior Transform Infrared (ATR-FTIR) spectrometric technique. The predominant component of lignin from alfalfa leaf was guaiacyl-type lignin. Despite the leaf, the predominant component of lignin from alfalfa stem was guaiacyl-syringyl-type lignin. A comparison between the signals from lignin in different development stages revealed the appearance of new peaks, which are indications of new bonds and changes in the structure of the lignin.


Key words: Alfalfa, cell-wall, lignin, attenuated total reflectance-furior transform infrared (ATR-FTIR) spectroscopy.