水解类单宁可生物降解性的研究

以橡单宁为原料 ,通过培养、分离筛选出了一种对单宁具有显著降解作用的菌株 ,经鉴定为内孢霉。通过研究外加碳源、氮源、碳氮比、诱导物及表面活性剂对该菌降解单宁的影响 ,发现这几个因素均明显影响微生物对单宁的降解。该菌在以蔗糖为外加碳源 ,以硝酸钠为氮源 ,碳氮比为 10∶ 1的条件下单宁的降解率最高 ,并发现添加 0 .3× 10 -3 mol/ L的诱导物 2 - 2连氮 - 3-乙苯 -二噻唑 - 6硫酸 (ABTS)、0 .2 g/ L的表面活性剂吐温 - 80 (Tw- 80 )及十二烷基磺酸钠 (SDS)有助于单宁的降解     

黑色单宁染料的研究

本文以单宁和铁盐的显色反应为基础，对栲胶改性做黑色染料进行了研究。在亚硫酸钠改性栲胶的基础上，利用铁盐和单宁显色，通过改变与铁盐配位的配体种类和数量，对栲胶改性作黑色染料的可能性及方法进行了探索。     

黑木相思树皮单宁含量的分析研究及其栲胶的试制

对广西种植的4年生黑木相思树皮的单宁含量进行分析研究和黑木相思栲胶的试制.结果显示,黑木相思树皮单宁属于缩合类单宁,总固物为38.2％,单宁含量为26.0％(纯度为71.6％),其单宁含量与马占相思树皮相当,略低于黑荆树皮;生产1 t栲胶的树皮消耗量约为2.5 t,栲胶单宁含量达68.1％,纯度为70.5％.黑木相思树...     

Asperniger LQ125 降解水解单宁特性的研究

对菌株AspernigerLQ1 2 5产生降解酶适宜条件进行了研究。在起始 pH5 .0的 1 0 0mL/2 5 0mL培养液中 ,加入水解单宁 (橡单宁 ) 5 .0 g/L、蔗糖 2 0 g/L、蛋白胨 6g/L ,在 3 0℃、1 2 0r/min摇瓶中培养 48h ,单宁酶活力达到最大 ;外加碳源有利于菌株对单宁的利用。     

铬--橡椀复鞣剂的制备及应用研究

水解类植物鞣质在酸性条件下能降解,其降解产物可起到还原、蒙囿以及与金属盐络合的作用.利用这些性质,制备铬--橡椀复鞣剂.按常规铬鞣剂制备方法,先配制红矾钠-硫酸溶液,硫酸用量按理论碱度40%加入,一次性加入红矾钠质量43%的橡椀栲胶,然后在75～80℃条件下保温4h,经喷雾干燥得到粉状铬--橡椀复鞣剂.复鞣试验结果表明该复鞣剂具有铬和栲胶复鞣的优点,成革柔软、丰满、粒面细致;缺点是对油脂吸收有影响,加入氯化稀土,可以改善复鞣革的加油性能.     

我国常用植物鞣剂薄层色谱特征的研究

本文研究了落叶松、木麻黄、柚柑、杨梅、橡椀、和荆树皮胶液的薄层色谱特征。初步确定了这些鞣液中鞣质和非鞣质成分与薄层色谱上R_f值的关系。这些数据对扩大薄层色谱技术在植鞣剂研究中的应用是非常有益的。     

植-醛结合鞣法机理的计算化学研究

以 (+) -儿茶素和 (+) -儿茶素为模型化合物 ,应用从头计算法 (abinitiocalculation)中的Hartree -Fork和MP2方法 ,对凝缩类单宁和醛的反应进行了研究。结果表明 :从原子电荷和前线轨道分布来看 ,A环是凝缩类单宁结构单元中的亲核中心 ,对亲电试剂具有较高的活性。通过比较中间体和产物的稳定性发现 :对于 (+) -儿茶素而言 ,C - 6和C - 8具有相近的活性 ,这和核磁共振试验得出的结论基本吻合 ;而对于 (+) -儿茶素 ,在C - 8反应得到的中间体和产物都比在C - 6位稳定 ,表明儿茶素和醛反应可能具有一定的选择性 ,相对更容易在C - 8上发生反应。儿茶素和儿茶素在C - 6和C - 8不同的反应选择性 ,与由B环差异产生的HOMO(highestoccupiedmolecularorbital,最高已占分子轨道 )分布不同有关     

The Extractable and Bound Condensed Tannin Content of Leaves from Tropical Tree,Shrub and Forage Legumes

The extractable, protein-bound and fibre-bound condensed tannin (CT) concentrations in the leaves of tropical legumes grown in both Colombia and Northern Australia were determined by the butanol–HCl method, whilst extractable CT was also determined by the vanillin–HCl method. With the exception of Senna siamea all species contained CT. The very high CT concentration found in many plants growing in Colombia may have been partly due to soil fertility being much lower at the Colombian than the Northern Australian site. Acacia boliviana , Arachis pintoi , Centrosema latidens , Senna velutina and Gliricidia sepium contained <55 g total CT kg⁻¹ DM, which suggests that they could comprise a reasonable proportion of ruminant diets. All other species grown in South America contained 100–240 g CT kg⁻¹ DM, which suggests that they should only be fed in small amounts as supplements to dilute the CT concentration. Leucaena species and Calliandra calothyrsus grown in Northern Australia contained intermediate concentrations of total CT (60–90 g kg⁻¹ DM). Most species contained 70–95% of total CT as extractable CT, with the exception of Flemingia macrophylla , where 60% was extractable and 40% bound, and Gliricidia sepium , where almost all the CT was bound to protein. Values for Flemingia macrophylla differed between accessions. Extractable CT determined with vanillin–HCl was generally higher than extractable CT determined with butanol–HCl. Three accessions showed negligible (<1 g kg⁻¹ DM) extractable CT with butanol–HCl but 10–12 g extractable CT kg⁻¹ DM with vanillin–HCl. Two accessions showed undetectable levels of extractable CT but substantial levels of protein-bound CT, illustrating the importance of using a bound CT method for identifying forages containing CT. Relative to freeze drying, oven drying of Leucaena species reduced the concentration of extractable CT and increased concentrations of bound CT. The significance of the results for the nutrition of ruminant livestock are discussed, including the possible roles of protein-bound and fibre-bound CT.     

Impact of exogenous tannin additions on wine chemistry and wine sensory character

Tannins are an important part of wine quality and are frequently added during winemaking. Tannin additives and their impact on wine are poorly documented. This work sought to characterize a range of enological tannins and their contribution to wine quality. Enological tannins were analysed for protein precipitable tannins and iron reactive phenolics. One tannin product was added to a Merlot wine during barrel ageing, at a range of concentrations from 60 to 300 mg/l. Condensed and hydrolysable tannins were added to Cabernet Sauvignon wine post-pressing at a recommended and excessive rate. Wines were analysed for anthocyanin, small and large polymeric pigment, precipitable tannin, iron reactive phenolics and sensory character. Enological tannins contained 12-48% tannin and recommended additions had little impact on wine tannin. High tannin additions were readily measured in the wines and were discriminated in sensory analysis with lower intensities of most parameters except brown colour, bitterness and earthy character. Recommended addition rates are too low to impact the measured tannin concentration of Merlot and Cabernet Sauvignon wines from Washington (USA). High enological tannin additions had a measureable impact on final wine had a negative impact on sensory character. Tannins are added to wines for a range of reasons and represent one of many input costs in an industry increasingly seeking efficiencies in response to global economic circumstances, over-supply and an ongoing price point squeeze. This research suggests many tannin additions may be unjustified and have limited or negative impacts on quality.     

柿子单宁优化提取工艺探讨

探讨了柿子果肉中总酚和缩合单宁的优化提取工艺,采用Folin-Denis法和改良的香草醛-盐酸法分别进行总酚和缩合单宁含量的测定。通过正交实验确立了含1%盐酸的无水甲醇是最佳提取溶剂,提取最佳条件为提取时间40min、提取温度90℃、料液比1∶12、提取3次。     

Quantification of condensed tannins by precipitation with methyl cellulose: development and validation of an optimised tool for grape and wine analysis

A precipitation assay is presented that enables tannin measurement in matrices of red wine, 50% ethanol grape extract and aqueous tannin solutions. By exploiting the polysaccharide polymer methyl cellulose to precipitate tannins, the absorbance of phenolics at 280 nm before and after tannin precipitation (subtractive approach) can be obtained, thus enabling selective measurement of tannin only. This methyl cellulose precipitable (MCP) tannin assay allows complete precipitation of tannin from red wine and from grape homogenate extracts. The subtractive assay is both simple and robust, selective for condensed tannins and does not suffer interference from other 280 nm-absorbing phenolics such as anthocyanins or catechins. Matrix effects have only minimal impact on the assay performance and validation parameters indicate a robust performance. There was good correlation between tannin measured by reverse-phase HPLC and the MCP tannin assay for 121 Australian red wines ( r = 0.74) and also 54 grape extracts ( r = 0.79). We envisage that the technical simplicity of this tannin assay will enable widespread research and field applications. In addition, an alternative format that requires re-solubilisation of the tannin-polymer pellet in acetonitrile is reported, which is particularly suitable for measurement of smaller tannin concentrations. Notwithstanding that option, technical requirements of the re-solubilisation step lead us to suggest that the subtractive format would be simple for adoption by wine industry practitioners.     

碳酸钠-苯酚溶液测定柿子中单宁含量方法的研究

根据儿茶素与柿子单宁结构相似,及柿汁-碳酸钠-苯酚溶液与儿茶素-碳酸钠-苯酚溶液相同的反应显色过程,并在相同波长(420nm)处有最大吸收峰值,首次提出和研究了一种操作简便、测定周期短和更安全的柿子单宁含量测定方法。经分析,碳酸钠-苯酚溶液对柿子中的单宁有特异显色作用,可以较好地排除其它物质的干扰;与无水甲醇法测定柿子单宁含量法相比较,测得数值相近,且两种方法相关性较好。因此,可得出结论:用碳酸钠-苯酚溶液法测定柿子单宁含量是可行的,此法用儿茶素作为标准物质,测定波长420nm。     

植物单宁的提取方法

单宁是制革用栲胶的主要成分,具有重要的应用价值。简要介绍了植物单宁的提取方法,并对其发展做了进一步的展望。     

马占相思栲胶的性质及应用研究

对广西百色林化总厂试生产的马占相思栲胶的物理化学性质及应用特点进行了研究。结果表明,马占相思栲胶的性质与进口的荆树皮栲胶相似,收敛性中等,粘度低,鞣制过程中沉淀少,渗透速度快,成革颜色浅淡,可用于生产重革,也可用于轻革的复鞣。用其复鞣蓝湿皮,革的丰满性、柔软性和粒面细致度等各项性能均优于余柑杨梅栲胶,接近荆树皮栲胶,可以代替进口的荆树皮栲胶。     

栲胶型CT中和复鞣剂的应用研究

CT-中和复鞣剂是以栲胶为主要原料 ,经催化亚硫酸化制得。通过不同用量的中和复鞣剂在渗透性、中和 p H值、增厚率、成革性能等方面的性质对比 ,确定了中和复鞣剂中和应用方案。试验表明 :CT中和复鞣剂具有良好的中和能力和缓冲性 ,能够满足铬革中和的要求。用 CT中和复鞣剂中和能使成革粒面细致、粒纹清晰、松面率下降 ,成革利用率提高。CT中和复鞣剂用量为 3% - 5 % ,中和 1.5 - 2 h可达到要求。     

提取氯化血红素新工艺的研究

研究一种从猪血中提取氯化血红素的新工艺,将超声波细胞破碎应用于鞣酸法提取氯化血红素。应用红外光谱法对氯化血红素产品进行定性的鉴定,紫外光谱法进行产品中氯化血红素纯度的测定。该法所得产品的纯度为93.03%,得率为79.58%。     

植物单宁的应用及其研究进展

植物单宁广泛存在于植物体内,是具有重要开发利用价值的天然物质。本文主要综述了植物单宁的自然资源、理化性质、生理特性及其在饮料工业、食品工业、医药化工等工业中的应用现状及研究进展。     

栲胶在无铬少铬结合鞣中的应用

栲胶已在制革工业获得了广泛的应用。本文对各种以栲胶为基础的结合鞣法进行了综述,阐述了结合鞣的反应机理、工艺过程。同时,总结了有利于实施结合鞣的栲胶改性方法。     

水解类植物鞣质性质及其与蛋白质反应的研究 I.水解类植物多酚化合物制备和结构鉴定

本文详细报导了具有水解类鞣质结构特征的化合物α和β—3,6—二棓酰—D—葡萄糖(DriGG),β—1,3,6—三棓酰—葡萄糖(TriGG),β—1,2,3,6—四格酰—D—葡萄糖(TeGG)和β—1,2,3,4,6—五棓酰—D—葡萄糖(PGG)的制备和鉴定方法。该项工作是从分子水平认识植物鞣质结构和性质的关系以及植物鞣质与蛋质反应机理的基础。     

不同加工处理对卡亚中单宁含量影响

通过比色法研究不同加工处理对卡亚单宁含量影响,其中沸水焯烫处理效果最佳,处理后卡亚成熟叶、嫩叶单宁含量分别降至0.15%、0.05%,基本符合一般果蔬可食部分的单宁含量。