Studies on the starch and hemicelluloses fractionated by graded ethanol precipitation from bamboo Phyllostachys bambusoides f. shouzhu Yi

J Agric Food Chem. 2011 Mar 23;59(6):2680-8. doi: 10.1021/jf1045766. Epub 2011 Feb 22.

Abstract

Starch from bamboo Phyllostachys bambusoides f. shouzhu Yi evaluated by means of solid-state 13C CP/MAS NMR and X-ray diffraction showed a typical B-type pattern with a very low degree of crystallinity (10.9%). In addition to starch, alkali-soluble hemicelluloses were further fractionated by graded precipitation at ethanol concentrations of 0 (HA), 15, 30, 45, 60, and 75% (v/v). Chemical composition and structural features of the six hemicellulosic subfractions were investigated by a combination of sugar analysis, GPC, FT-IR, GC-MS, 1D (1H and 13C) and 2D (HSQC) NMR spectra, and thermal analysis. The results showed that the bamboo hemicelluloses were O-acetylated 4-O-methyl-glucuronoarabinoxylans (GAX) consisting of a linear (1→4)-β-D-xylopyranosyl backbone decorated with branches at O-3 of α-L-arabinofuranosyl (5-12 mol%) or at O-2 of 4-O-methylglucuronic acid units and acetyl groups (0.8-11 mol%). The molecular weights of these polysaccharides ranged between 13400 and 67500 g/mol, and the molar ratios of A/X and G/X increased with ascending ethanol concentrations. Moreover, xylo-oligosaccharides (XOS) with DP 1-6 were produced by enzymatic hydrolysis of hemicelluloses and the total yields of XOS were range of 21.5 to 40.6%. The structure-property relationships were also established in order to improve enzyme accessibility.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bambusa / chemistry*
  • Chemical Fractionation / instrumentation
  • Chemical Fractionation / methods*
  • Ethanol / chemistry
  • Plant Extracts / analysis
  • Plant Extracts / isolation & purification*
  • Polysaccharides / analysis
  • Polysaccharides / isolation & purification*
  • Starch / analysis
  • Starch / isolation & purification*

Substances

  • Plant Extracts
  • Polysaccharides
  • Ethanol
  • hemicellulose
  • Starch