酚基木聚糖对面团特性及馒头品质的影响

以小麦粉为原料,采用0.5%、1.0%、1.5%、2.0%四个添加量添加酚基木聚糖,研究酚基木聚糖对面团特性及馒头品质的影响。结果表明:随着酚基木聚糖添加量的增加,面团的吸水量、弱化度增大,形成时间、稳定时间和粉质指数先增大后减小,酚基木聚糖显著地改善了面团的粉质特性;面团的弹性模量G'呈下降趋势,黏性模量G"呈先升后降趋势,损耗角正切tanδ呈上升趋势;馒头的色泽、比容、硬度、黏附性、胶黏性和咀嚼性下降,凝聚性和回复性无显著差异。在酚基木聚糖添加量为0.5%时,馒头的综合评价最高。随着馒头储藏时间的延长,馒头的硬度呈上升趋势,弹性和回复性呈下降趋势,酚基木聚糖能减缓馒头硬度上升幅度和回复性下降幅度。馒头的老化主要集中在储藏前24 h内,酚基木聚糖的添加能减缓馒头的老化程度。     

肉桂酰化聚木糖改善APMP浆性能的研究

探讨了不同取代度聚木糖衍生物肉桂酰化聚木糖(CX)对碱性过氧化氢机械浆(APMP)性能的改善。结果表明,添加CX可以明显提高APMP浆的性能和配抄效果。较理想的CX取代度为0.18,CX较理想的添加条件为混合时间15 min和用量1.0%,此条件下添加CX的APMP浆抄造纸张的裂断长、耐破指数、撕裂指数、白度分别较未添加的提高了37.4%、90.5%、19.0%、3.7%。将KP浆与APMP浆配抄,不同配抄比例下添加CX的APMP浆均有较好的配抄效果;在达到相近物理性能条件下,可以显著降低KP浆的配抄比例。扫描电镜和红外光谱分析表明,CX吸附留着在纤维表面,减少了纤维之间的空隙,改善了纸张表面的均匀性。     

白腐菌对甘蔗渣木质纤维的降解及其影响因子(Ⅰ)--木聚糖对木质纤维不同组分降解的影响

在培养的过程中,加入木聚糖的白腐菌的生长明显优于空白对照样,白色的菌丝较早地覆盖在处理样品的表面;加入木聚糖,促进了木素的生物降解,大量的木素降解发生在培养的前期,而后期木素的降解量明显减少.木聚糖对酸溶木素含量变化没有明显的影响.木聚糖的加入使纤维素降解有所下降,但由于半纤维素含量较少,可以认为木聚糖的加入对半纤维素降解的影响很小.     

纤维化学组分变化对纸张物理强度的影响研究

对半纤维素和木素在非木材纤维的纸张抄造过程中的作用进行了阐述,指出了脱除和保留一定量的半纤维素和木素对纸张物理强度和纸页性能的影响。     

超声波辅助提取小麦麸皮酚基木聚糖的研究

以小麦麸皮为原料,研究了超声波超声功率、超声时间、碱液质量分数、碱提时间、碱提温度对小麦麸皮中水溶性酚基木聚糖和总酚基木聚糖得率的影响,同时分析了小麦麸皮水溶性酚基木聚糖的抗氧化特性和总酚含量.结果表明,小麦麸皮中酚基木聚糖提取的最佳工艺条件是超声功率300 W,超声时间30 min,碱液质量分数2％,碱提时间2h,碱提温度55℃,在此条件下,酚基木聚糖得率为38.73％,水溶性酚基木聚糖得率为29.05％.对提取的麸皮水溶性酚基木聚糖的抗氧化性的研究表明,水溶性酚基木聚糖对羟自由基有明显的清除作用,并呈现明显的量效关系.水溶性酚基木聚糖的总酚含量为12.27mg/g.     

Comparative study of carbohydrates in the two major species of jute (Corchorus capsularis and Corchorus olitorius

Unretted and retted bark and stem of Corchorus olitorius L and retted stem of C capsularis L, two species of jute, were analysed for ash, lignin, low molecular weight carbohydrates and polysaccharides. The results are compared with those from C capsularis published earlier. The unretted bark and stem of C olitorius contained less low molecular weight carbohydrates than the corresponding fractions of C capsularis. C olitorius bark contained less cellulose and more hemicellulose than C capsularis, particularly after retting. Xylans isolated from the retted fibre and stem of C olitorius were found to have a similar composition to those from C capsularis.     

Behavior of Eucalyptus Wood Xylans across Kraft Cooking

Abstract

The 4-O-methylglucuronoxylans isolated from wood, pulp, and black liquor from six eucalyptus wood species were characterized. The ¹H nuclear magnetic resonance (NMR) studies revealed that all eucalyptus wood xylans contain O-2-substituted 4-O-methylglucuronic acid (MeGlcA) groups with hexose residues (9–26%). Their molecular weight (Mw) and polydispersity varied in the range of 26,083–28,405 g.mol^?1 and 1.13–1.17, respectively. The xylan retention during pulping increased with increasing degree of MeGlcA substitution in the xylose ring. An average of 54% xylans was retained in the pulp and the remaining 46% were degraded and/or dissolved in the black liquor (39% degraded and 7% dissolved). The average Mw of the xylans retained in the pulp and dissolved in the black liquor is influenced by pulp kappa number and averaged 20,134 and 14,778 g.mol^?1, respectively, at kappa 17. The average substitution degree of uronic acids, including MeGlcA and hexenuronic acids (HexA) in the xylans isolated from pulps (kappa 17) and black liquors were 1.05 and 1.13/10 xyloses, respectively. Of the total uronic acids present in the six original woods, an average of 36% w/w was retained in the pulps.     

木聚糖酯化衍生物的合成、性能及应用研究进展

综述了近年来木聚糖酯化衍生物的合成途径,包括羧酸酯化、硫酸酯化和芳香酯化等。分析了木聚糖酯化衍生物的性能以及应用,同时讨论了木聚糖硫酸酯化衍生物的结构与功能之间的关系,并对木聚糖酯化改性及应用发展趋势进行了简要阐述。     

Cell wall compositions of raw and cooked corms of taro (Colocasia esculenta)

The monosaccharide compositions of parenchyma cell walls of raw and cooked corms of taro, Colocasia esculenta cv Tausala Pink, were determined. The cell wall constituents were sequentially extracted using CDTA, Na₂CO₃, 1 M KOH, 4 M KOH and water to leave a final residue (α‐cellulose). The monosaccharide compositions of the cell walls and cell wall fractions from the raw and cooked corms were consistent with the presence in these cell walls of large amounts of cellulose and pectic polysaccharides. The monosaccharide composition of the cell walls of the raw corms resembled the monosaccharide compositions of primary cell walls of other non‐commelinoid monocotyledons and dicotyledons. Cooking of the corms resulted in alteration of the cell walls, with solubilisation of pectic polysaccharides occurring earlier in the sequential fractionation and possibly changes in the extractability of xyloglucans and/or xylans. © 2000 Society of Chemical Industry     

功能性木聚糖醚化衍生物的研究进展

综述了近年来功能性木聚糖醚化衍生物的合成途径，包括羧甲基化、季铵化、甲基化和芳香醚化等。介绍了木聚糖醚化衍生物的功能特性以及应用，讨论了季铵化木聚糖衍生物的结构与功能之间的关系。指出了木聚糖醚化改性及应用研究的发展方向。