Structure and Chemical Composition of Bast Fibers Isolated from Developing Hemp Stem

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• 作者：David Crô ; nier ; Bernard Monties ; and Brigitte Chabbert
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2005
• 出版时间：October 19, 2005
• 年：2005
• 卷：53
• 期：21
• 页码：8279 - 8289
• 全文大小：1086K
• 年卷期：v.53,no.21(October 19, 2005)
• ISSN：1520-5118

文摘

Microscopic and chemical changes of hemp bast fibers were studied during the maturation fromvegetative to grain maturity stages at both apical and basal regions of the stems. The content ofprotein was the main factor related to fiber maturation, whereas increased proportions of mannoseand glucose and decreasing levels of galactose were also highly significant. Enhanced glucosedeposition in apical fibers could be related to the gradual thickening of the fibers, whereas in basalregions the thickness of the fibers nearly reached the maximum at vegetative stages. In contrast, theextent of lignification remained close to 3-4% during plant growth. Hemp fiber lignins were rich inguaiacyl units and would be rather condensed in nature. In addition, the proportion of p-hydroxyphenylunits displayed a constant decline during maturation. A progressive chemical fractionation of hempfibers provided further insights to the occurrence and nature of noncellulosic polysaccharides. Notably,these data pointed out that maturation is accompanied by a significant increase in water- and alkali-soluble components containing glucose- and mannose-related polymers and a decrease in arabinoseand galactose components disrupted by diluted hydrochloric acid. Taken together, chemical featuresof the noncellulosic components suggest that the architecture of hemp fibers differs slightly from thatof the more widely studied flax fibers.Keywords: Hemp; Cannabis sativa L.; maturation; cell wall; lignin; glucomannans