Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 25, 1996
Publication Date: N/A
Interpretive Summary: The US is dependent upon foreign countries to supply flax fiber for textiles. Improved methods for separating fiber from the stem (a process called retting) and tests for determining fiber quality are needed to make the flax fiber production economical and to reintroduce flax fiber production to the US. Research was undertaken to obtain fundamental information on the chemical components and plant structure of flax that limit fiber separation through enzymatic retting and on the properties that can be used to determine and monitor quality of fiber. This fundamental information is essential in establishing subsequent research projects involving new enzymes and new organisms for improved enzymatic retting of flax fiber towards the long term goals of establishing new uses of crops in the US and in enhancing crop quality.
Technical Abstract: Samples of flax (Linum usitatissimum) stems from the cultivars Natasja' and Ariane' were separated into fiber and core fractions and analyzed by gas-liquid chromatography, 13**C CPMAS NMR spectrometry, histochemistry, electron microscopy, and UV absorption microspectrophotometry to fill gaps in information concerning the structure and composition of cell walls related to quality and utilization. Analyses from chromatography and NMR gave similar results for carbohydrate and phenolic constituents in various samples and in the lower, more mature regions of the stem. Amounts of uronic acids and xylose were lower while amounts of mannose, galactose, and glucose were higher in fiber vs. core fractions. Quantities of phenolic constituents were significantly higher in the core, with groups representative of both guaiacyl and syringyl lignins; amounts of phenolic acids were low. NMR showed a low intensity signal for aromatics in fiber, and it is possible that such signals arise from compounds in the cuticle rather than the fiber. Microscopic studies indicated that aromatic constituents were present in core cell walls, cuticle of the epidermis, and cell corners and middle lamellae of some regions within the fiber tissues. The lignin in fiber appeared to be of the guaiacyl type and may be too low in concentration to be unambiguously detected by NMR. Aromatic compounds were not observed in the epidermis or parenchyma cell walls.