高单宁桉树栲胶的研制

以桉树树皮压榨液为原料,采用络合还原工艺制取高单宁桉树栲胶,其单宁含量高达84.98%(以干基计),达到工业栲胶的国家标准(GB 1086—2010)。     

马占相思树皮单宁含量的影响因素研究

研究了产地、树龄、部位以及贮存时间对马占相思树皮单宁含量的影响。结果表明:不同产地的该种树皮的单宁含量差异较大;树龄对树皮的单宁含量影响较明显,随着树龄的增加,单宁含量逐渐减少;从主干的根部往顶部,树皮的单宁含量逐渐降低,非单宁含量逐渐增加;贮存时间的延长,单宁含量减少,因此,贮存时间不能过长。研究结果表明马占相思树皮是适合工业生产的一种优良栲胶原料。     

马占相思树皮单宁含量的影响因素研究

研究了产地、树龄、部位以及贮存时间对马占相思树皮单宁含量的影响。结果表明：不同产地的该种树皮的单宁含量差异较大；树龄对树皮的单宁含量影响较明显，随着树龄的增加，单宁含量逐渐减少；从主干的根部往顶部，树皮的单宁含量逐渐降低，非单宁含量逐渐增加；贮存时间的延长，单宁含量减少，因此，贮存时间不能过长。研究结果表明马占相思树皮是适合工业生产的一种优良栲胶原料。     

广西不同产地板栗壳斗的分析

采用LY/T 1083-2008栲胶原料分析试验方法,对广西不同产地及不同品种的板栗壳斗的总抽出物、单宁、总颜色进行了分析测定。结果表明,同一品种不同产地及不同品种板栗壳斗的总抽出物、单宁、总颜色值有一定差异,其中单宁含量差异不大,总抽出物和总颜色值差异较大。板栗壳斗平均总抽出物为31.7%、单宁18.0%、总颜色28.4,其单宁含量和总颜色值与我国林业行业标准LY/T 1325-2012毛杨梅树皮合格品的质量指标相近,具有作为栲胶原料开发利用价值。     

胶体滴定法测定橡椀栲胶中的单宁含量

用胶体滴定法测定了橡椀栲胶中的单宁含量。实验结果表明,pH值为5,橡椀栲胶中单宁质量在0.6～3.0 mg范围内,栲胶的电荷量(以滴定值表示)与单宁质量呈良好的线性关系。样品XK-2和XK-3的平均回收率分别为101.1%、103.4%,RSD分别为5.4%和1.5%,皮粉法和胶体滴定法测定的单宁含量的差值小于2.1%。与皮粉法相比,胶体滴定具有快速、简便、样品用量少的特点。     

甲醛缩合法检验落叶松树皮栲胶单宁含量

介绍了甲醛缩合法检验落叶松要树皮栲胶单宁含量的测定方法，与皮粉法对比结果表明，完全可以代替皮粉法的测定，是一种对落叶松树皮栲胶单宁含量测定快速，准确的方法。     

橡椀栲胶简介

一、橡椀栲胶生产概况: 栲胶是林业化工产品,是从含有单宁的树皮、根、茎、叶、果实或果壳做原料,经过浸提浓缩、干燥等工序加工制成的。橡椀栲胶是用麻栎、栓皮栎(俗名又叫橡树)的果壳(又叫橡椀)为原料加工制成的。我国栲胶资源极为丰富,有几十种植物可以浸提栲胶,主要有落叶松树皮、橡椀、化香果、红根、解树皮、木麻黄树皮、杨梅树皮、余柑树皮、板栗壳和黑荆树皮等,在     

栲胶新原料——肥木树皮

本文报道了肥木树皮生产栲胶和上海沪光制革厂用该栲胶鞣制猪底革试验。该树皮单宁是一种混合类单宁,约4.5吨树皮生产一吨栲胶,这种栲胶渗透速度很快,皮革能在24小时内完全渗透。猪底革颜色和理化性能令人满意。     

山槐栲胶鞣革性能试验报告

山槐树在我国许多地区都有生长,树皮含单宁量较高。广西百色栲胶厂从1975年开始生产山槐树皮栲胶,产品经上海、重庆、武汉、南宁、广州等地制革厂试用,得到一致好评。为了进一步鉴定山槐树皮栲胶质量及其鞣革性能,百色栲胶厂与上海沪光制革厂协作,共同进行了大型鞣革试验,现将试验结果叙述如下。     

相思树皮栲胶鞣革性能的研究

相思树是含羞草科(Mimosaceac)金合欢属(Acacia)的树种之一,树皮供作鞣料。大家知道,由本属各种树皮制的栲胶,颜色淡红,色泽浅鲜,渗透性快,收敛性温平,鞣革性能好,单宁含量一般为62～63%。即是各种树种生长地区不同,所制的栲胶在一定程度上性能亦相似。国际市场闻明,产销量大的荆树皮栲胶(象牌)是这类栲胶有代表性的品种。     

马占相思栲胶浓胶波美度与浓度换算关系及浸提、磺化工艺研究

研究了马占相思栲胶主要生产工序的工艺参数。结果得出：马占相思栲胶浓胶在20 ℃时的波美度（y,°Bé）与浓度（x,kg/L）的关系式为： y=1.2+40x。不同温度（T,℃）下,实测波美度（y’）换算为20 ℃时的波美度（y,°Bé）与温度的关系式为： y=y’+（T-20）/15;浸提工艺：马占相思树皮400 g,吸水率210%,头步加水1 200 mL,以后每步加水800 mL,浸提首罐温度100 ℃,尾罐温度128 ℃,浸提时间12 h,添加焦亚硫酸钠量助浸为气干原料质量的1.8%,栲胶得率为 81.9%,单宁得率为90.6%。磺化工艺：在 85 ℃下,添加焦亚硫酸钠（Na₂S₂O₅）量为栲胶绝干质量的6%,反应时间为 2 h,磺化后得栲胶产品的单宁含量为67.8%,不溶物为3.2%,pH值为4.5,总色度为9.6。其他工艺同杨梅栲胶生产工艺。     

Influence of ultrasound on Avaram bark (Cassia auriculata) tannin extraction and tanning

Efficient processing methodologies such as ultrasounds which would achieve significant enhancements in processes thereby minimizing sectional stream wastes in one hand and bring about economic benefits on other are necessary. Hence, research studies on application of ultrasound in process industries such as leather, textiles and chemicals are gaining importance. In this regard, a case study has been presented in this paper for solid–liquid tanning extraction and tanning from a plant material. For this purpose, Avaram bark (Cassia auriculata) which contains ingredients such as polyphenolics, useful in stabilization of collagen, which is the main constituent of skins/hides. Avaram bark tannin come under the group of ‘condensed tannins’ useful in main tanning process of leather making. The influence of various process parameters such as ultrasonic power, time and agitation on extraction has been studied. The results show significant 1.6-fold improvement for total extract due to the use of ultrasound, 100 W as compared to magnetic stirring control process, suggesting better mass transfer enhancement in leaching of strongly bound tannins from avaram bark due to ultrasound. Efficacy of tannin extract (10% or 20% offer) has been analyzed through application in tanning process and found to be useful. There has been significant improvement in rate of tannin uptake for ultrasonic extract as compared to control extract by the bovine pelt, suggesting diffusion enhancement of tanning agent through the pelt matrix. Use of ultrasound in avaram extract tanning has also been studied and found to be useful. Therefore, the present study clearly indicates the use of ultrasound in Avaram bark tannin extraction and tanning as a viable option with added advantages even dispensing with external heating.     

Soy-based,tannin-modified plywood adhesives

In this research, two different types of commercial tannins, namely a hydrolysable tannin (chestnut) and a condensed flavonoid tannin (mimosa), were used to prepare two types of soy-based (soy flour (SF) and soy protein isolate) adhesives for making plywood. Thermogravimetric properties (TGA) and its derivative as function of temperature (DTG) of different soy-based adhesive were measured in the range 40°C–300°C. Thermomechanical analysis (TMA) from 25°C to 250°C was done for the different resin formulations. Duplicate three-ply laboratory plywood panels were prepared by adding 300 g/m² of the adhesives’ total resin solid content composed of SF or isolated soy protein (ISP), urea, chestnut, and mimosa tannin extracts with hexamine as hardener. Based on the results obtained, tannins can improve SF adhesion properties. The TMA showed that chestnut tannin extract appeared to react well with SF, while mimosa tannin extract appeared to react well with ISP. Matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry also showed that among other reactions, the soy protein amino acids reacted with the tannins. Furthermore, delamination and shear strength test results showed the good water resistance of plywood bonded with soy-based tannin modified adhesive.     

杜仲叶渣中杜仲胶提取工艺的研究

以提取过药用成分的杜仲叶渣为原料,提取杜仲胶。研究了分别用碱水解和酶解预处理杜仲叶渣,然后用溶剂提取杜仲胶,以及直接用溶剂提取杜仲胶的工艺。实验结果表明最佳工艺条件为:杜仲叶渣直接用正己烷作溶剂提取杜仲胶,原料与溶剂比例为1:20(g:mL),机械搅拌并加热回流浸提2h,趁热过滤,滤液放入冰箱在-20℃条件下冷却析晶1h,真空抽滤后自然干燥得到浅绿色杜仲胶产物,提取得率为4.42%。用丙酮多次精制得到白色的杜仲胶。对白色杜仲胶产物做红外光谱测定,确定为反式1,4-聚异戊二烯(TPI)。     

紫外法和皮粉法测定塔拉单宁含量的对比研究

分别采用紫外法和皮粉法对5种不同含量的塔拉单宁进行对比研究,并利用SPSS软件对单宁含量测定结果进行显著性检验,结果表明：高纯度塔拉单宁（93%）分别用紫外法和皮粉法测定单宁含量时实验结果并未显著差异（P>0.05）,而4种纯度为60%左右塔拉单宁的实验结果均具有显著性差异（P < 0.05）,皮粉法测得的单宁含量均比用紫外法测得的结果高,差值约为1.5%~2.0%,并由此计算出紫外法测定塔拉单宁含量计算公式中的矫正常数p为1.03。紫外-可见吸收光谱与HPLC分析结果表明：塔拉单宁与五倍子单宁的最大吸收峰均为276 nm,同质量浓度下塔拉单宁的吸收峰强度高于五倍子单宁,塔拉单宁成分出峰时间主要在20~40 min,五倍子单宁主要在30~45 min。     

Thermal Degradation of Condensed Tannins from Radiata Pine Bark

Abstract

In order to understand the influence of the inherent chemistry on the relative thermal stability of condensed tannins, the thermal degradation behaviors of various radiata pine bark extracts have been investigated using thermogravimetric analysis (TGA). Generally, results suggest pine bark extract fractions may be readily processed at temperatures below 200°C if co-extracted polysaccharides contents are minimized. Those extracts possessing greater carbohydrate content and lower tannin purity tend to have decreased thermal stability. The initial onset temperature for degradation of relatively crude extracts with high proportions of carbohydrate contents were relatively low (ca. 150°C), whereas extract purification to < 5% carbohydrate content gave increases in thermal stability of at least 50°C. The complicity of the carbohydrate content in the degradation of the tannin samples was also supported by calculated Ozawa activation energies and modulated TGA experiments. While no increase in the thermal stability was gained by acetylating the pendant hydroxyl groups of the pine bark tannin extract, chemical variations such as sulfonation have a large effect on thermal degradation, promoting lower degradation temperatures.     

表面活性剂在芡实栲胶提取中作用的初步研究

研究了表面活性剂在芡实栲胶提取中的作用。试验条件为 :6 5 %的乙醇水溶液 ,原料呈粒度为 0 .3cm方块 ,浸提温度 6 0℃ ,浸出时间 2h ,乙醇水溶液中的水使用蒸馏水 ,加入适量的表面活性剂 ,浸提液呈中性 ,结果可得栲胶 9%