Near-Infrared Fourier-Transform Raman Spectroscopy of Flax (<i>Linum usitatissimum</i> L.) Stems

Abstract

Samples of flax (Linum usitatissimum L.) stem and its anatomical parts were studied by near-infrared Fourier transform Raman (NIR-FT-Raman) spectroscopy to determine if the major chemical components of each could be detected by this method. The Raman spectra of reference compounds from relatively pure materials served as models for the chemical components. Bands for cellulose were greatest in the fibers. Hemicellulosic polysaccharides were observed to be prevalent in bast tissue and fibers. Weak signals for pectins were observed in the bast, cuticle/epidermis, fibers, and stem. Bands for aromatic rings were detectable in all materials. Bands from waxes/fatty acid esters were detectable in the cuticle/epidermal tissue. The results indicated that NIR-FT-Raman could be used detect the major chemical components in flax in situ and provide a simple, rapid, and noninvasive assessment of their relative amounts and location within the tissues of the flax plant. Keywords: Fourier transform; Raman; flax; carbohydrates; phenolics; wax; fiber; bast; core; cuticle; epidermis