FE - DCTP | Documentos por Auto-Depósito
Permanent URI for this collection
Browse
Browsing FE - DCTP | Documentos por Auto-Depósito by Author "Gaiolas, Carla Sofia Cardona Jorge"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
- Determination of sugar content in Pinus pinaster and its corresponding hollocellulose, cellulose and kraft pulpsPublication . Duarte, Ana Paula; Gaiolas, Carla Sofia Cardona Jorge; Belgacem, Mohamed Naceur; Simões, RogérioThis paper deals with the study of the polysaccharide complex from Portuguese Pinus pinaster, as well as from its main components, i.e., holocellulose, cellulose and pulps obtained using different cooking conditions. Nordic Pinus sylvestris was also studied in order to compare it with Portuguese pine. Two methods were used: one consisted of the hydrolysis of polysaccharides with trifluoroacetic acid (TFA) and quantification of the amount of each sugar using High Performance Liquid Chromatography (HPLC). The latter approach used here consisted of the hydrolysis of the samples under scrutiny by sulphuric acid and converting it into alditols, which were then esterified before injecting to Gas Chromatography coupled with Mass Spectrometry. Myo-inositol was used as an internal standard. The results obtained by the two methods showed that the TFA procedure prevents monosaccharide degradation, comparatively with the sulphuric acid one. In fact, the overall sugar yield was found systematically higher than 93% for TFA hydrolysis, whereas that corresponding to H2SO4 treatment never exceeded 77%. The sugar composition of both pines was found very similar and the sulfidity level (from 10 to 55%) did not affect the pulp sugar composition. The glucose/mannose and xylose/arabinose ratios were found to be around 3.5 for both Portuguese and Nordic pines. Finally, kraft pulping of Pinus pinaster was found to affect drastically galactose, mannose and arabinose.