The components of flax (Linum usitatissimum) stems are described and illustrated, with reference to the anatomy and chemical makeup and to applications in processing and products. Bast fiber, which is a major economic product of flax along with linseed and linseed oil, is described with particular reference to its application in textiles, composites, and specialty papers. A short history of retting methods, which is the separation of bast fiber from nonfiber components, is presented with emphasis on water retting, field retting (dew retting), and experimental methods. Past research on enzyme retting, particularly by the use of pectinases as a potential replacement for the current commercial practice of field retting, is reviewed. The importance and mechanism of Ca2+ chelators with pectinases in retting are described. Protocols are provided for retting of both fiber-type and linseed-type flax stems with different types of pectinases. Current and future applications are listed for use of a wide array of enzymes to improve processed fibers and blended yarns. Finally, potential lipid and aromatic coproducts derived from the dust and shive waste streams of fiber processing are indicated. 1. Introduction of Flax and Linen Fiber The history of flax (Linum usitatissimum L.) is long and important. The translation of its scientific name, “linen most useful” [1, 2], aptly describes its versatility and importance to world economy. Linen, the long, strong fibers from flax stems, is considered one of the earliest successes in textiles [3]. While evidence does not exist on how early people learned to separate fibers from the stems, flax as a major textile in ancient Egypt is well documented in depictions of its cultivation and processing [4]. Linen samples have been reported in the remains of Swiss lake dwellings dating back some 10,000 years [3]. Production and use expanded beyond the Mediterranean countries to central and northern Europe, making its way to Great Britain about 2,000 years ago from the Middle East by Phoenician traders [3]. Linen, as one of the primary fibers for Europe throughout the Middle Ages and the Renaissance period, was used extensively for clothing. Linen was important to Russia and its economy through various stages of its political history [5]. Flax became the greatest export item and the basis of economic life in Russia in the late 1800s and into the twentieth century. At one time, Russia produced about 80% of the world’s fiber flax crop and before 1936 was the greatest exporter of flax. Fiber flax came to North America by European
References
[1]
V. S. Borland, From Flower to Fabric, Textile World, 2002.
[2]
P. G. Tortora and B. J. Collier, Understanding Textiles, Prentice-Hall, New Jersey, NJ, USA, 5th edition, 1997.
[3]
I. T. Hamilton, “Linen,” Textiles, vol. 15, pp. 30–34, 1986.
[4]
R. R. Franck, “The history and present position of linen,” in The Biology and Processing of Flax, H. S. S. Sharma and C. F. van Sumere, Eds., pp. 1–9, M. Publications, Belfast, Northern Ireland, 1992.
[5]
R. Pfefferkorn, Oregon Fiber Flax for an American Linen Industry, O. S. C. Cooperative Association, Corvallis, Ore, USA, 1944.
[6]
G. R. Stephens, “Connecticut fiber flax trials,” Bulletin 932, The Connecticut Agricultural Experiment Station, New Haven, Conn, USA, 1996.
[7]
B. B. Robinson and T. B. Hutcheson, Circular 231, United States Department of Agriculture, Washington, DC, USA, 1932.
[8]
W. M. Hurst, E. G. Nelson, J. E. Harmond, L. M. Klein, and D. W. Fishler, Station Bulletin 521, Oregon Agricultural Experiment Station and United States Department of Agriculture, Corvallis, Ore, USA, 1953.
[9]
R. Kozlowski, “Producing for the market,” in Proceedings of the 4th European Regional Workshop on Flax, pp. 1–6, Institut Technique du Lin, 1996.
[10]
R. Kozlowski, “Euroflax newsletter,” Tech. Rep. 2 (36), Institute of Natural Fibres & Medicinal Plants, Poznan, Poland, 2011.
[11]
M. Machkiewicz, J. Barriga-Bedoya, J. Mankowski, and I. Pniewska, “Global flax market situation. Fiber foundations—transportation, clothing, and shelter in the bioeconomy,” in Proceedings of the International Conference on Flax and Other Bast Plants, pp. 408–412, Saskatoon, Canada, July 2008.
[12]
R. Dodes, “Hemmed in by cotton, Hanes eases into flax,” Wall Street Journal. In press.
[13]
J. B. Rodie, “Flax unshackled,” Textile World. In press.
[14]
D. D. McAlister III, J. A. Foulk, D. E. Akin, and P. A. Annis, “Cotton fibres: proportion and interaction with flax fibres in blends: focus on rotor spun yarn,” in Proceedings of the 26th International Cotton Conference, pp. 207–211, Faserinstitut Bremen, Bremen, Germany, 2002.
[15]
D. R. Berglund, “Flax: new uses and demands,” in Trends in New Crops and New Uses, J. Janick and A. Whipkey, Eds., pp. 358–360, ASHS Press, Alexandria, Va, USA, 2002.
[16]
in Proceedings of the 59th Meeting of the Flax Institute of the United States, Institute of the United States, Fargo, ND, USA, March 2002.
[17]
J. F. Carter, “Potential of flaxseed and flaxseed oil in baked goods and other products in human nutrition,” Cereal Foods World, vol. 38, pp. 753–759, 1993.
[18]
D. E. Akin, “Flax fiber,” in Kirk-Othmer Encyclopedia of Chemical Technology, John Wiley & Sons, New York, NY, USA, 2012.
[19]
“Fiber foundations—transportation, clothing and shelter in the bioeconomy,” in Proceedings of the International Conference on Flax and other Bast Plants, pp. 21–23, Saskatoon, Canada, July 2008.
[20]
T. H？nninen and M. Hughes, “Historical, contemporary and future applications,” in Industrial Applications of Natural Fibres, J. Müssig, Ed., pp. 385–395, John Wiley & Sons, Chichester, UK, 2010.
[21]
S. Nandy and G. G. Rowland, “Dual purpose flax (Linum usitatissimum L.) improvement using anatomical and molecular approaches, fiber foundations—transportation, clothing and shelter in the bioeconomy,” in Proceedings of the International Conference on Flax and Other Bast Plants, pp. 31–39, Saskatoon, Canada, July 2008.
[22]
K. W. Dormier, “An overview of the flax fibre industry in North America,” in Proceedings of the 59th Flax Institute of the United States, pp. 89–91, North Dakota State University, Fargo, ND, USA, 2002.
[23]
W. H. Morrison III and D. E. Akin, “Chemical composition of components comprising bast tissue in flax,” Journal of Agricultural and Food Chemistry, vol. 49, no. 5, pp. 2333–2338, 2001.
[24]
D. E. Akin, G. R. Gamble, W. H. Morrison III, L. L. Rigsby, and R. B. Dodd, “Chemical and structural analysis of fiber and core tissues from flax,” Journal of the Science of Food and Agriculture, vol. 72, pp. 155–165, 1996.
[25]
W. H. Morrison III, D. E. Akin, D. S. Himmelsbach, and G. R. Gamble, “Chemical, microscopic, and instrumental analysis of graded flax fibre and yarn,” Journal of the Science of Food and Agriculture, vol. 79, pp. 3–10, 1999.
[26]
D. E. Akin, W. H. Morrison III, G. R. Gamble, L. L. Rigsby, G. Henriksson, and K. E. L. Eriksson, “Effect of retting enzymes on the structure and composition of flax cell walls,” Textile Research Journal, vol. 67, no. 4, pp. 279–287, 1997.
[27]
W. H. Morrison III, D. D. Archibald, H. S. S. Sharma, and D. E. Akin, “Chemical and physical characterization of water- and dew-retted flax fibers,” Industrial Crops and Products, vol. 12, no. 1, pp. 39–46, 2000.
[28]
D. E. Akin, W. H. Morrison III, L. L. Rigsby, and R. B. Dodd, “Plant factors influencing enzyme retting of fiber and seed flax,” Journal of Agricultural and Food Chemistry, vol. 49, no. 12, pp. 5778–5784, 2001.
[29]
C. C. Chen, R. Adolphson, J. F. D. Dean, K. E. L. Eriksson, M. W. W. Adams, and J. Westpheling, “Release of lignin from kraft pulp by a hyperthermophilic xylanase from Thermatoga maritima,” Enzyme and Microbial Technology, vol. 20, no. 1, pp. 39–45, 1997.
[30]
D. E. Akin, D. Slomczynski, L. L. Rigsby, and K. E. L. Eriksson, “Retting flax with endopolygalacturonase from Rhizopus oryzae,” Textile Research Journal, vol. 72, no. 1, pp. 27–34, 2002.
[31]
D. E. Akin, L. L. Rigsby, and W. Perkins, “Quality properties of flax fibers retted with enzymes,” Textile Research Journal, vol. 69, no. 10, pp. 747–753, 1999.
[32]
D. E. Akin, J. A. Foulk, and R. B. Dodd, “Influence on flax fibers of components in enzyme retting formulations,” Textile Research Journal, vol. 72, no. 6, pp. 510–514, 2002.
[33]
D. E. Akin, J. A. Foulk, R. B. Dodd, and D. D. McAlister III, “Enzyme-retting of flax and characterization of processed fibers,” Journal of Biotechnology, vol. 89, no. 2-3, pp. 193–203, 2001.
[34]
J. A. Foulk, D. E. Akin, and R. B. Dodd, “Influence of pectinolytic enzymes on retting effectiveness and resultant fiber properties,” BioResources, vol. 3, no. 1, pp. 155–169, 2008.
[35]
D. E. Akin, B. Condon, M. Sohn, J. A. Foulk, R. B. Dodd, and L. L. Rigsby, “Optimization for enzyme-retting of flax with pectate lyase,” Industrial Crops and Products, vol. 25, no. 2, pp. 136–146, 2007.
[36]
J. D. Evans, D. E. Akin, W. H. Morrison III, D. S. Himmelsbach, D. D. McAlister, and J. A. Foulk, “Modifying dew-retted flax fibers and yarns with a secondary enzymatic treatment,” Textile Research Journal, vol. 73, no. 10, pp. 901–906, 2003.
[37]
C. F. van Sumere, “Retting of flax with special reference to enzyme-retting,” in The Biology and Processing of Flax, H. S. S. Sharma and C. F. van Sumere, Eds., pp. 157–198, M Publications, Belfast, Northern Ireland, 1992.
[38]
D. E. Akin, “Flax—structure, chemistry, retting, and processing,” in Industrial Applications of Natural Fibres, J. Müssig, Ed., pp. 89–108, John Wiley & Sons, Chichester, UK, 2010.
[39]
K. R. Stern, S. Jansky, and J. E. Bidlack, Introductory Plant Biology, McGraw-Hill, New York, NY, USA, 9th edition, 2003.
[40]
D. E. Akin, L. L. Rigsby, and W. H. Morrison III, “Oil red as a histochemical stain for natural fibers and plant cuticle,” Industrial Crops and Products, vol. 19, no. 2, pp. 119–124, 2004.
[41]
W. B. Achwal and N. Roy, “Rapid staining test to assess residual wax in pretreated cotton fabrics,” 1985.
[42]
D. S. Himmelsbach, S. Khahili, and D. E. Akin, “Near-infrared—fourier-transform—Raman microspectroscopic imaging of flax stems,” Vibrational Spectroscopy, vol. 19, no. 2, pp. 361–367, 1999.
[43]
G. Henriksson, D. E. Akin, R. T. Hanlin et al., “Identification and retting efficiencies of fungi isolated from dew-retted flax in the United States and Europe,” Applied and Environmental Microbiology, vol. 63, no. 10, pp. 3950–3956, 1997.
[44]
D. E. Akin, L. L. Rigsby, G. Henriksson, and K. E. L. Eriksson, “Structural effects on flax stems of three potential retting fungi,” Textile Research Journal, vol. 68, no. 7, pp. 515–519, 1998.
[45]
G. Henriksson, D. E. Akin, L. L. Rigsby, N. Patel, and K. E. L. Eriksson, “Influence of chelating agents and mechanical pretreatment on enzymatic retting of flax,” Textile Research Journal, vol. 67, no. 11, pp. 829–836, 1997.
[46]
W. H. Morrison III, R. Holser, and D. E. Akin, “Cuticular wax from flax processing waste with hexane and super critical carbon dioxide extractions,” Industrial Crops and Products, vol. 24, no. 2, pp. 119–122, 2006.
[47]
R. A. Holser and D. E. Akin, “Extraction of lipids from flax processing waste using hot ethanol,” Industrial Crops and Products, vol. 27, no. 3, pp. 236–240, 2008.
[48]
K. V. Sarkanen and C. H. Ludwig, “Definition and nomenclature,” in Lignins: Occurrence, Formation, Structure, and Reactions, K. V. Sarkanen and C. H. Ludwig, Eds., pp. 1–18, Wiley-Interscience, New York, NY, USA, 1971.
[49]
K. Ross and G. Mazza, “Characteristics from flax shives as affected by extraction conditions,” International Journal of Molecular Science, vol. 11, pp. 4035–4050, 2010.
[50]
R. A. Blanchette, E. W. Krueger, J. E. Haight, M. Akhtar, and D. E. Akin, “Cell wall alterations in loblolly pine wood decayed by the white-rot fungus, Ceriporiopsis subvermispora,” Journal of Biotechnology, vol. 53, no. 2-3, pp. 203–213, 1997.
[51]
W. E. Marshall, L. H. Wartelle, and D. E. Akin, “Flax shive as a source of activated carbon for metals remediation,” BioResources, vol. 2, no. 1, pp. 82–90, 2007.
[52]
K. T. Klasson, L. H. Wartelle, I. M. Lima, W. E. Marshall, and D. E. Akin, “Activated carbons from flax shive and cotton gin waste as environmental adsorbents for the chlorinated hydrocarbon trichloroethylene,” Bioresource Technology, vol. 100, no. 21, pp. 5045–5050, 2009.
[53]
J. W. Kim and G. Mazza, “Extraction and separation of arbohydrates and phenolic compounds in flax shives with pH-controlled pressurized low polarity water,” Journal of Agricultural and Food Chemistry, vol. 57, no. 5, pp. 1805–1813, 2009.
[54]
M. Sohn, F. E. Barton II, W. H. Morrison III, and D. E. Akin, “Prediction of shive content in pilot plant processed flax by near infrared reflectance spectroscopy,” Journal of Near Infrared Spectroscopy, vol. 12, no. 4, pp. 251–258, 2004.
[55]
M. Sohn, F. E. Barton II, D. E. Akin, and W. H. Morrison III, “A new approach for estimating purity of processed flax fibre by NIR spectroscopy,” Journal of Near Infrared Spectroscopy, vol. 12, no. 4, pp. 259–262, 2004.
[56]
D. E. Akin, “Standards for flax fiber,” Standardization News, vol. 33, no. 9, pp. 22–25, 2005.
[57]
D. E. Akin, “Flax—ASTM standardization and harmonization,” in Industrial Applications of Natural Fibres, J. M. Müssig, Ed., pp. 371–379, John Wiley & Sons, Chichester, UK, 2010.
[58]
J. A. de Haseth, D. E. Akin, and F. E. Barton II, “Sensors and chemometrics for flax fiber quality and for processing, fiber foundations—transportation, clothing and shelter in the bioeconomy,” in Proceedings of the International Conference on Flax and Other Bast Plants, pp. 10–15, Saskatoon, Canada, July 2008.
[59]
F. E. Barton II, D. E. Akin, W. H. Morrison III, A. Ulrich, and D. D. Archibald, “Analysis of fiber content in flax stems by near-infrared spectroscopy,” Journal of Agricultural and Food Chemistry, vol. 50, no. 26, pp. 7576–7580, 2002.
[60]
S. Khalili, D. E. Akin, B. Pettersson, and G. Henriksson, “Fibernodes in flax and other bast fibers,” Journal of Applied Botany, vol. 76, no. 5-6, pp. 133–138, 2002.
[61]
R. H. Peters, “The chemistry of fibers,” Textile Chemistry, vol. 1, pp. 168–174, 1963.
[62]
G. Buschle-Diller, S. H. Zeronian, N. Pan, and M. Y. Yoon, “Enzymatic hydrolysis of cotton, linen, ramie, and viscose rayon fabrics,” Textile Research Journal, vol. 64, no. 5, pp. 270–279, 1994.
[63]
B. Focher, A. Marzetti, and H. S. S. Sharma, “Changes in the structure and properties of flax fibre during processing,” in The Biology and Processing of Flax, H. S. S. Sharma and C. F. van Sumere, Eds., pp. 329–342, M. Publications, Belfast, Northern Ireland, 1992.
[64]
H. L. Bos, M. J. A. van den Oever, and O. C. J. J. Peters, “Tensile and compressive properties of flax fibres for natural fibre reinforced composites,” Journal of Materials Science, vol. 37, no. 8, pp. 1683–1692, 2002.
[65]
D. E. Akin, G. Henriksson, J. D. Evans, A. P. S. Adamsen, J. A. Foulk, and R. B. Dodd, “Progress in enzyme-retting of flax,” Journal of Natural Fibers, vol. 1, no. 1, pp. 21–47, 2004.
[66]
C. Morvan, C. Andème-Onzighi, R. Girault, D. S. Himmelsbach, A. Driouich, and D. E. Akin, “Building flax fibres: more than one brick in the walls,” Plant Physiology and Biochemistry, vol. 41, no. 11-12, pp. 935–944, 2003.
[67]
T. A. Gorshkova, S. E. Wyatt, V. V. Salnikov et al., “Cell-wall polysaccharides of developing flax plants,” Plant Physiology, vol. 110, no. 3, pp. 721–729, 1996.
[68]
D. Stewart, G. J. McDougall, and A. Baty, “Fourier-transform infrared microspectroscopy of anatomically different cells of flax (Linum usitatissimum) stems during development,” Journal of Agricultural and Food Chemistry, vol. 43, no. 7, pp. 1853–1858, 1995.
[69]
R. Girault, I. His, C. Andeme-Onzighi, A. Driouich, and C. Morvan, “Identification and partial characterization of proteins and proteoglycans encrusting the secondary cell walls of flax fibres,” Planta, vol. 211, no. 2, pp. 256–264, 2000.
[70]
T. A. Gorshkova, V. V. Salnikov, N. M. Pogodina et al., “Composition and distribution of cell wall phenolic compounds flax (Linum usitatissimum L.) stem tissues,” Annals of Botany, vol. 85, no. 4, pp. 477–486, 2000.
[71]
G. D. Love, C. E. Snape, M. C. Jarvis, and I. M. Morrison, “Determination of phenolic structures in flax fibre by solid-state 13C？NMR,” Phytochemistry, vol. 35, no. 2, pp. 489–491, 1994.
[72]
W. H. Morrison III, D. S. Himmelsbach, D. E. Akin, and J. D. Evans, “Chemical and spectroscopic analysis of lignin in isolated flax fibers,” Journal of Agricultural and Food Chemistry, vol. 51, no. 9, pp. 2565–2568, 2003.
[73]
H. S. S. Sharma and C. F. van Sumere, “Enzyme treatment of flax,” The Genetic Engineer and Biotechnologist, vol. 12, pp. 19–23, 1992.
[74]
G. R. Gamble, M. E. Snook, G. Henriksson, and D. E. Akin, “Phenolic constituents in flax bast tissue and inhibition of cellulase and pectinase,” Biotechnology Letters, vol. 22, no. 9, pp. 741–746, 2000.
[75]
S. Bandyopadhyay-Ghosh, S. B. Ghosh, and M. Sain, “Cellulose nanocomposites,” in EdIndustrial Applications of Natural Fibres, J. Müssig, Ed., pp. 457–480, John Wiley & Sons, Chichester, UK, 2010.
[76]
D. E. Akin, “Chemistry of plant fibres,” in Industrial Applications of Natural Fibres, J. Müssig, Ed., John Wiley & Sons, Chichester, UK.
[77]
T. Sakai, T. Sakamoto, J. Hallaert, and E. J. Vandamme, “Pectin, pectinase, and protopectinase: production, properties, and applications,” Advances in Applied Microbiology, vol. 39, pp. 213–294, 1993.
[78]
E. A. Davis, C. Derouet, C. H. du Penhoat, and C. Morvan, “Isolation and an N.M.R. study of pectins from flax (Linum usitatissimum L.),” Carbohydrate Research, vol. 197, pp. 205–215, 1990.
[79]
W. J. M. Meijer, N. Vertregt, B. Rutgers, and M. van de Waart, “The pectin content as a measure of the retting and rettability of flax,” Industrial Crops and Products, vol. 4, no. 4, pp. 273–284, 1995.
[80]
H. S. S. Sharma, “Chemical retting of flax using chelating compounds,” vol. 113, pp. 159–165, 1988.
[81]
D. S. Himmelsbach, S. Khalili, and D. E. Akin, “FT-IR microspectroscopic imaging of flax (Linum usitatissimum L.) stems,” Cellular and Molecular Biology, vol. 44, no. 1, pp. 99–108, 1998.
[82]
C. Andeme-Onzighi, R. Girault, I. His, C. Morvan, and A. Driouich, “Immunocytochemical characterization of early-developing flax fiber cell walls,” Protoplasma, vol. 213, no. 3-4, pp. 235–245, 2000.
[83]
I. His, C. Andème-Onzighi, C. Morvan, and A. Driouich, “Microscopic studies on mature flax fibers embedded in LR White: immunogold localization of cell wall matrix polysaccharides,” Journal of Histochemistry and Cytochemistry, vol. 49, no. 12, pp. 1525–1535, 2002.
[84]
A. Jauneau, M. Quentin, and A. Driouich, “Micro-heterogeneity of pectins and calcium distribution in the epidermal and cortical parenchyma cell walls of flax hypocotyl,” Protoplasma, vol. 198, no. 1-2, pp. 9–19, 1997.
[85]
A. Jauneau, A. Cabin-Flaman, M. C. Verdus, C. Ripoll, and M. Thellier, “Involvement of calcium in the inhibition of endopolygalacturonase,” Plant Physiology and Biochemistry, vol. 32, no. 6, pp. 839–846, 1994.
[86]
I. A. Ansari, G. C. East, and D. J. Johnson, “Structure-property relationships in natural cellulosic fibres. Part I: characterisation,” Journal of the Textile Institute, vol. 90, no. 1, pp. 469–480, 1990.
[87]
A. E. Brown, H. S. S. Sharma, and D. L. R. Black, “Relationships between pectin content of stems of flax cultivars, fungal cell wall-degrading enzymes and pre-harvest retting,” Annals of Applied Biology, vol. 109, pp. 345–351, 1986.
[88]
A. M. Bochek, N. M. Zabivalova, I. I. Shamolina, and S. A. Grishanov, “Isolation of pectins from flax pedicels and fibers and their characterization,” Russian Journal of Applied Chemistry, vol. 75, no. 9, pp. 1517–1521, 2002.
[89]
C. Sultana, “Scutching of retted-flax straw,” in The Biology and Processing of Flax, H. S. S. Sharma and C. F. van Sumere, Eds., pp. 261–274, M. Publications, Belfast, Ireland, 1992.
[90]
T. Ross, “Preparing and spinning of flax fibre,” in The Biology and Processing of Flax, H. S. S. Sharma and C. F. van Sumere, Eds., pp. 275–296, M. Publications, Belfast, Ireland, 1992.
[91]
A. Daenekindt, “Flax, hemp, and allied fibres in the world,” Euroflax Newsletter, vol. 21, no. 1, pp. 6–9, 2004.
[92]
H. S. S. Sharma and G. J. Faughey, “Comparison of subjective and objective methods to assess flax straw cultivars and fibre quality after dew-retting,” Annals of Applied Biology, vol. 135, no. 2, pp. 495–501, 1999.
[93]
A. E. Brown, “Epicoccum nigrum, a primary saprophyte involved in the retting of flax,” Transactions of the British Mycological Society, vol. 83, no. 1, pp. 29–35, 1984.
[94]
D. L. Easson and E. N. J. Long, “Pre-harvest retting of flax with glyphosate,” in The Biology and Processing of Flax, H. S. S. Sharma and C. F. van Sumere, Eds., pp. 213–228, M. Publications, Belfast, Ireland, 1992.
[95]
A. M. Goodman, A. R. Ennos, and I. Booth, “A mechanical study of retting in glyphosate treated flax stems (Linum usitatissimum),” Industrial Crops and Products, vol. 15, no. 2, pp. 169–177, 2002.
[96]
H. S. S. Sharma, “The role of bacteria in retting of desiccated flax during damp weather,” Applied Microbiology and Biotechnology, vol. 24, no. 6, pp. 463–467, 1986.
[97]
M. Horne, R. Harwood, P. McCormick, and J. Harwood, “The commercial production of short-fibre flax for cottonization, fiber foundations—transportation, clothing, and shelter in the bioeconomy,” in Proceedings of the International Conference on Flax and Other Bast Plants, pp. 129–136, Saskatoon, Canada, July 2008.
[98]
A. Dujardin, Vlas-roten, De Westvlaamsche Boekhandel s.v. Groeninghe, Kortrijk, Belgium.
[99]
G. Henriksson, K. E. L. Eriksson, L. Kimmel, and D. E. Akin, “Chemical/physical retting of flax using detergent and oxalic acid at high pH,” Textile Research Journal, vol. 68, no. 12, pp. 942–947, 1998.
[100]
H. S. S. Sharma, “Studies on chemical and enzyme retting of flax on a semi-industrial scale and analysis of the effluents for their psycho-chemical components,” International Biodeterioration, vol. 23, no. 6, pp. 329–342, 1987.
[101]
M. J. A. van den Oever, N. Bas, L. J. M. van Soest, C. Melis, and J. E. G. van Dam, “Improved method for fibre content and quality analysis and their application to flax genetic diversity investigations,” Industrial Crops and Products, vol. 18, no. 3, pp. 231–243, 2003.
[102]
H. Costard, “Process for treating sclerenchyma fibers, in particular flax,” U.S. Patent # 5,666,696 Sept, 16, 1997.
[103]
H. Zimmer and K. D. Kloss, “Ultrasonic break down of hemp,” in Proceedings of the Bioresource Hemp Symposium, Frankfurt, Germany, March 1995.
[104]
M. Tubach and R. W. Kessler, “Interdisciplinary approach for new flax products: examples of applied research at the IAF,” in Proceedings of the World Fibre Flax Symposium, pp. 71–86, Connecticut Agricultural Experiment Station, 1994.
[105]
M. Sotton and M. Ferrari, “Le lin ultra-affine par le traitement hydrolyse flash,” L’Industrie Textile, vol. 1197, pp. 58–60, 1989.
[106]
R. W. Kessler, U. Becker, R. Kohler, and B. Goth, “Steam explosion of flax—a superior technique for upgrading fibre value,” Biomass and Bioenergy, vol. 14, no. 3, pp. 237–249, 1998.
[107]
V. G. Yachmenev, E. J. Blanchard, and A. H. Lambert, “Use of ultrasonic energy in the enzymatic treatment of cotton fabric,” Industrial and Engineering Chemistry Research, vol. 37, no. 10, pp. 3919–3923, 1998.
[108]
C. F. van Sumere and H. S. S. Sharma, “Analyses of fine flax fibre produced by enzymatic retting,” Aspects of Applied Biology, vol. 28, pp. 15–20, 1991.
[109]
H. S. S. Sharma, “Screening of polysaccharide-degrading enzymes for retting flax stem,” International Biodeterioration, vol. 23, no. 3, pp. 181–186, 1987.
[110]
H. S. S. Sharma, J. Lefevre, and J. Boucaud, “Role of microbial enzymes during retting and their effect on fibre characteristics,” in The Biology and Processing of Flax, H. S. S. Sharma and C. F. van Sumere, Eds., pp. 199–212, M. Publications, Belfast, Ireland, 1992.
[111]
H. S. S. Sharma and C. F. van Sumere, Eds., The Biology and Processing of Flax, M. Publications, Belfast, Ireland, 1992.
[112]
G. Henriksson, D. E. Akin, D. Slomczynski, and K. E. L. Eriksson, “Production of highly efficient enzymes for flax retting by Rhizomucor pusillus,” Journal of Biotechnology, vol. 68, no. 2-3, pp. 115–123, 1999.
[113]
A. P. S. Adamsen, D. E. Akin, and L. L. Rigsby, “Chelating agents and enzyme retting of flax,” Textile Research Journal, vol. 72, no. 4, pp. 296–302, 2002.
[114]
A. P. S. Adamsen, D. E. Akin, and L. L. Rigsby, “Chemical retting of flax straw under akaline conditions,” Textile Research Journal, vol. 72, no. 9, pp. 789–794, 2002.
[115]
ASTM D 1445-95, “Standard test method for breaking strength and elongation for cotton fibers (flat bundle method),” Annual Book of Standards, sec. 7 Textiles, ASTM, West Conshohocken, Pa, USA, 1997.
[116]
ASTM D 1448-90, “Standard test method for breaking strength and elongation for cotton fibers,” Annual Book of Standards, sec. 7 Textiles, ASTM, West Conshohocken, Pa, USA, 1997.
[117]
International Standard 2370, Textiles—determination of fineness of flax fibres, 2nd ed., ref # ISO 2370-1980 (E). International Organization of Standardization, Switzerland, 1980.
[118]
J. A. Foulk, D. E. Akin, and R. B. Dodd, “Miniature spinning enzyme-retted flax fibers,” Journal of Natural Fibers, vol. 6, no. 1, pp. 1–13, 2009.
[119]
D. E. Akin, R. B. Dodd, W. Perkins, G. Henriksson, and K. E. L. Eriksson, “Spray enzymatic retting: a new method for processing flax fibers,” Textile Research Journal, vol. 70, no. 6, pp. 486–494, 2000.
[120]
J. A. Foulk, D. E. Akin, and R. B. Dodd, “Processing techniques for improving enzyme-retting of flax,” Industrial Crops and Products, vol. 13, no. 3, pp. 239–248, 2001.
[121]
D. E. Akin, W. H. Morrison III, L. L. Rigsby, J. D. Evans, and J. A. Foulk, “Influence of water presoak on enzyme-retting of flax,” Industrial Crops and Products, vol. 17, no. 3, pp. 149–159, 2003.
[122]
D. E. Akin, R. B. Dodd, and J. A. Foulk, “Pilot plant for processing flax fiber,” Industrial Crops and Products, vol. 21, no. 3, pp. 369–378, 2005.
[123]
D. E. Akin, H. H. Epps, D. D. Archibald, and H. S. S. Sharma, “Color measurement of flax retted by various means,” Textile Research Journal, vol. 70, no. 10, pp. 852–858, 2000.
[124]
H. H. Epps, D. E. Akin, J. A. Foulk, and R. B. Dodd, “Color of enzyme-retted flax fibers affected by processing, cleaning, and cottonizing,” Textile Research Journal, vol. 71, no. 10, pp. 916–921, 2001.
[125]
D. K. Durden, J. N. Etters, A. K. Sarkar, L. A. Henderson, and J. E. Hill, “Advances in commercial biopreparation of cotton with alkaline pectinase,” AATCC Reviews, vol. 1, no. 8, pp. 28–31, 2001.
[126]
J. N. Etters, A. K. Sarkar, L. A. Henderson, and J. Liu, “The influence of biopreparation of cotton with alkaline pectinase on dyeing properties,” AATCC Reviews, vol. 1, no. 5, pp. 22–24, 2001.
[127]
V. Antonov, J. Marek, M. Bjelkova, P. Smirous, and H. Fischer, “Easily available enzymes as natural retting agents,” Biotechnology Journal, vol. 2, no. 3, pp. 342–346, 2007.
[128]
J. Marek, V. Antonov, M. Bjelkova, P. Smirous, H. Fischer, and S. Janosik, “Enzymatic bioprocessing—new tool for extensive natural fibre source utilization, fiber foundations—transportation, clothing, and shelter in the bioeconomy,” in Proceedings of the International Conference on Flax and Other Bast Plants, pp. 159–169, Saskatoon, Canada, July 2008.
[129]
J. D. Evans, D. E. Akin, and J. A. Foulk, “Flax-retting by polygalacturonase-containing enzyme mixtures and effects on fiber properties,” Journal of Biotechnology, vol. 97, no. 3, pp. 223–231, 2002.
[130]
J. Zhang, G. Henriksson, and G. Johansson, “Polygalacturonase is the key component in enzymatic retting of flax,” Journal of Biotechnology, vol. 81, no. 1, pp. 85–89, 2000.
[131]
D. S. Himmelsbach, S. Khalili, and D. E. Akin, “The use of FT-IR microspectroscopic mapping to study the effects of enzymatic retting of flax (Linum usitatissimum L) stems,” Journal of the Science of Food and Agriculture, vol. 82, no. 7, pp. 685–696, 2002.
[132]
J. Zhang, G. Johansson, B. Pettersson et al., “Effects of acidic media pre-incubation on flax enzyme retting efficiency,” Textile Research Journal, vol. 73, no. 3, pp. 263–267, 2003.
[133]
F. Brühlmann, M. Leupin, K. H. Erismann, and A. Fiechter, “Enzymatic degumming of ramie bast fibers,” Journal of Biotechnology, vol. 76, no. 1, pp. 43–50, 2002.
[134]
D. Rho, J. Yang, M. -J. Lorrain et al., “Processing of flax fibers for biocomposites using a thermostable pectate lyase, fiber foundations—transportation, clothing, and shelter in the bioeconomy,” in Proceedings of the International Conference on Flax and Other Bast Plants, pp. 201–210, Saskatoon, Canada, July 2008.
[135]
A. . Foulk, D. Rho, M. M. Alcock, C. A. Ulven, and S. Huo, “Modifications caused by enzyme-retting and their effect on biocomposite performance,” Advances in Materials Science and Engineereing, vol. 2011, Article ID 179023, 9 pages, 2011.
[136]
W. Hu, M.-T. Ton-That, J. Denault, D. Rho, J. Yang, and P. C. K. Lau, “Comparison between dew-retted and enzyme-retted flax fibers as reinforcing material for composites,” Polmer Engineering and Science, vol. 52, no. 1, pp. 165–171, 2012.
[137]
C. Ekblad, B. Pettersson, J. Zhang, S. Jernberg, and G. Henriksson, “Enzymatic-mechanical pulping of bast fibers from flax and hemp,” Cellulose Chemistry and Technology, vol. 39, no. 1-2, pp. 95–103, 2005.
[138]
J. D. Evans, D. E. Akin, W. H. Morrison III, D. S. Himmelsbach, and J. A. Foulk, “Modifying dew-retted flax fibers by means of an air-atomized enzyme treatment,” Textile Research Journal, vol. 72, no. 7, pp. 579–585, 2002.
[139]
H. Fischer, J. Müssig, and C. Bluhm, “Enzymatic modification of hemp fibres for sustainable production of high quality materials: influence of processing parameters,” Journal of Natural Fibers, vol. 3, no. 2-3, pp. 39–53, 2006.
[140]
W. H. Morrison III, D. E. Akin, G. Ramaswamy, and B. Baldwin, “Evaluating chemically retted kenaf using chemical, histochemical, and microspectrophotometric analyses,” Textile Research Journal, vol. 66, no. 10, pp. 651–656, 1996.
[141]
G. N. Ramaswamy, C. G. Ruff, and C. R. Boyd, “Effect of bacterial and chemical retting on kenaf fiber quality,” Textile Research Journal, vol. 64, no. 5, pp. 305–308, 1994.
[142]
D. E. Akin, A. Sethuraman, W. H. Morrison III, S. A. Martin, and K. E. L. Eriksson, “Microbial delignification with white rot fungi improves forage digestibility,” Applied and Environmental Microbiology, vol. 59, no. 12, pp. 4274–4282, 1993.
[143]
D. E. Akin, W. H. Morrison III, L. L. Rigsby, G. R. Gamble, A. Sethuraman, and K. E. L. Eriksson, “Biological delignification of plant components by the white rot fungi Ceriporiopsis subvermispora and Cyathus stercoreus,” Animal Feed Science and Technology, vol. 63, no. 1–4, pp. 305–321, 1996.
