栲胶法变换气脱硫工艺

介绍了栲胶法脱硫的原理，工艺流程及规整填料在脱硫塔中的应用。     

Effects of viscosity on the bitterness and astringency of grape seed tannin

To examine the separate effects of viscosity and sweetness on astringency, aqueous solutions of grape seed tannin (GST) were thickened with carboxymethyl cellulose (CMC) from 2 to 45 cP (experiment 1) or sweetened with 0 to 1.8 g/L aspartame (experiment 2). Trained subjects continuously rated astringency and bitterness in duplicate. Subjects were categorized by the salivary flow induced by citric acid and ability to taste n-propyl thiouracil (PROP). In experiment 1, maximum intensity and total duration of astringency were significantly decreased as viscosity rose, although time to maximum intensity of astringency was not affected. Maximum intensity and total duration of bitterness were not significantly affected by increasing viscosity; however, the onset of bitterness was significantly delayed. In experiment 2, increasing sweetness had no affect on any astringency parameter, although maximum intensity of bitterness was significantly decreased. Neither PROP nor salivary flow-status had any effect on perception of bitterness or astringency in either experiment.     

Degradation of Leaf Litter Phenolics by Aquatic and Terrestrial Isopods

To investigate species-specific decomposition rates of litter from native (Quercus faginea) and introduced (Eucalyptus globulus) tree species in Portugal, we monitored changes in the phenolic signature of leaf litter during decomposition as mediated by an aquatic, Proasellus coxalis (Isopoda: Asellota), and two terrestrial, Porcellio dispar and Eluma caelatum (Isopoda: Oniscidea), detritivores. Although the litter of Eucalyptus and Quercus did not differ in overall protein precipitation capacity, we detected differences in terms of contents of particular phenolic compounds and phenol oxidation products. Accordingly, we observed food-specific consumption rates in Proasellus, but not in the terrestrial isopods. Proasellus digested Eucalyptus at significantly higher rates than Quercus, whereas the opposite was the case for Eluma, and Porcellio digested both litter types equally well. Despite slight differences in detail, effects of Proasellus on changes in the signature of litter phenolics were similar for both litter types, whereas terrestrial isopods—Porcellio and Eluma, although they differed from each other—digestively degraded phenolic compounds in Eucalyptus and Quercus litter, respectively, in different ways. Overall, however, degradation of litter phenolics was similarly effective on both litter types. From these data, we conclude that decomposition of Eucalyptus litter does not proceed more slowly than of litter from native Portuguese trees.     

分光光度法测脱硫溶液中栲胶、“888”含量

用分光光度法同时测定脱硫溶液中栲胶和“888”含量,结果表明,吸收波长分别为450nm和650nm,栲胶、“888”在使用浓度范围内,符合线性关系。该方法操作简易,结果准确。     

Effects of sample drying and storage,and choice of extraction solvent and analysis method on the yield of birch leaf hydrolyzable tannins

In this study, I investigated the effects of different methods of sample drying and storage, and the choice of extraction solvent and analysis method on the concentrations of 14 individual hydrolyzable tannins (HTs), and insoluble ellagitannins in birch (Betula pubescens) leaves. Freeze- and vacuum-drying of birch leaves were found to provide more reliable results than air- or oven-drying. Storage of leaves at –20C for 3 months before freeze-drying did not cause major changes in tannin content, although levels of 1,2,3,4,6-penta-O-galloylglucose and isostrictinin were altered. Storage of dried leaf material at –20C is preferred because 1 year storage of freeze-dried leaves at 4C and at room temperature decreased the concentration of the pedunculagin derivative, one of the main ellagitannins of birch. Furthermore, storage at room temperature increased the levels of isostrictinin and 2,3-(S)-HHDP-glucose, indicating possible HT catabolism. Of the extraction solvents tested, aqueous acetone was superior to pure acetone, or aqueous or pure methanol. The addition of 0.1% ascorbic acid into 70% acetone significantly increased the yield of ellagitannins, presumably by preventing their oxidation. By comparing the conventional rhodanine assay and the HPLC–ESI-MS assay for quantification of leaf galloylglucoses, the former tends to underestimate total concentrations of galloylglucoses in birch leaf extract. On the basis of the outcomes of all the method and solvent comparisons, their suitability for qualitative and quantitative analysis of plant HTs is discussed, emphasizing that each plant species, with its presumably unique HT composition, is likely to have a unique combination of ideal conditions for tissue preservation and extraction.     

钻井泥浆稀释剂塔拉磺甲基化单宁(SMT-T)性能的研究

对塔拉豆荚壳经浸提、磺甲基化、络合等工艺制备的塔拉磺甲基化单宁(SMT-T)的性能进行了初步研究,结果表明:SMT-T用于钻井泥浆稀释剂是可行的;SMT-T的干燥方式及其添加量即 0.5% 和 2.0% 对钻井泥浆降黏率无明显差异;当温度为 180℃、加入 2% 的盐,其降黏率在 80% 以上;当温度在200~220℃时,其降黏率为 82.5%~86.4%;SMT-T质量指标测定超过现行行业标准SY/T 5091-1993《钻井液用磺化栲酸》。SMT-T适宜在180~220℃ 的深井、气井、高密井等使用。     

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。     

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。     

栲胶-硫酸锰体系的脱硫研究

以氧化栲胶(Teos)-MnSO4为脱硫剂,采用氧化-还原电位方法进行脱除硫化氢的研究,考察了该体系用于脱硫的热力学可行性、MnSO4对氧化再生性能、脱硫液电位和脱硫过程的影响。结果表明:Teos-MnSO4碱性溶液脱硫在热力学上是可行的;影响脱硫液贫液电位的主要因素是Teos,随Teos浓度1 g/L～3 g/L增加而降低;MnSO4 0.025g/L无需另加入络合剂能稳定存在,模拟氧化再生过程实验表明锰盐能改善栲胶脱硫液的氧化再生性能,络合剂柠檬酸0.25 g/L的加入对此影响不明显;模拟脱硫过程实验表明脱硫液电位与所含H2S浓度的对数成线性关系,而脱硫液硫容较低,欲提高其硫容须添加其它变价金属组份。     

The role of acidity,sweetness, tannin and consumer knowledge on wine and food match perceptions

The purposes of this study were to (1) explore significant differences in perception of match for a variety of food and wine styles; (2) evaluate the impacts of wine sweetness level, wine acidity level, and wine tannin level on perception of match; and (3) investigate the impact of food and wine expertise on perceived level of match. The highest perceived wine matches for each food item were: Sauvignon Blanc and chêvre, Chardonnay and brie, Cabernet Sauvignon and spicy Italian salami, and Port and milk chocolate. Wine sweetness, acidity, and tannin levels all significantly impacted the level of match with certain food items. Food and wine expertise also significantly impacted the level of match, indicating differences between the more expert and novice participants in the role wine sweetness, acidity, and tannin had on level of match.