Authors: Jean-Christophe Habeck, Jason Morrison
Published in: CSBE-SCGAB Technical Conferences » 5th CIGR and AGM Quebec City 2021 » Regular Sessions
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Description: While Canadian agriculture currently grows Hemp (Cannabis sativa L.) primarily for seed/food, stems are cultivated elsewhere for fibres. These cellulosic fibres must be loosened from the waste straw?s binding matrix of pectin, hemicellulose and lignin. Typical ?retting? processes used to loosen the fibers include: dew retting, water retting and chemical/enzymatic retting. The goal of this study is to assess Infrared (mid-IR) measurements on matched hemp fibre samples obtained using raw stems, water retted and dew retted stems and then measured using gravimetric methods to obtain non-polar extracts, cellulose, hemicellulose and lignin contents. Non-polar extract contents confirm that water retted hemp fibres are significantly lower in this respect than both dew and unretted hemp fibres. Notably, these results are not in agreement with mid-IR measurements at the typical 1733cm-1 carbonyl (C=O) stretch characteristic of pectin. The typical mid-IR methodology of identifying absorbances from spectra of pure standards is problematic in a bonded mixture. Case in point, a peak shift between 1590cm-1 and 1625cm-1 was observed showing a clear division between unretted, dew retted, and water retted fibres. The peak at 1590cm-1, carbon (C=C) aromatic stretch, is observed in both lignin and pectin while the 1625cm-1 peak, O-H stretch of adsorbed water, is observed in cellulose. This peak shift likely represents the transition of unretted fibres containing contaminants (e.g., pectin) to cleaner cellulose fibres and may present a novel way of estimating fibre purity.
Conference name: 5th CIGR International Conference and CSBE-SCGAB AGM 2021, Quebec City,QC, 11-14 May 2021.
Session name: Waste Management 1 - Bioproducts
Publication type: Presentation
Language 1: en
Rights: Canadian Society for Bioengineering