普洱茶茶褐素对大鼠肠道菌群的影响

本研究以普洱茶茶褐素(分子量50 k Da,TB)为研究对象,通过灌胃茶褐素后分析大鼠体内微生物变化,揭示普洱茶茶褐素对肠道菌群的影响。结果显示,茶褐素能显著改善抗生素的脱污染作用,调整肠道菌群失调,且具有促进大鼠肠道乳酸杆菌、双歧杆菌增殖,抑制大肠杆菌、肠球菌生长的作用,并随时间延长,效果愈加明显;而微生物的大量繁殖可加速茶褐素的分解代谢。     

普洱茶茶褐素对大鼠尿液影响的代谢组学研究

本研究采用核磁共振(NMR)代谢组学法研究普洱茶茶褐素(TB,分子量50 k Da)对大鼠尿液代谢的影响。将实验大鼠分为正常对照组、正常+TB组、高脂组和高脂+TB组,以生物核磁共振技术结合正交偏最小二乘-判别分析(OPLS-DA)研究灌胃高剂量普洱茶茶褐素后大鼠尿液内源性代谢物的变化。结果表明,正常+TB组与正常对照组,高脂+TB组与高脂组的尿液代谢谱有明显差异;筛选出缬氨酸、柠檬酸、牛磺酸、丙酸盐、α-酮戊二酸、β-羟基丁酸等6种普洱茶茶褐素标志性代谢物;普洱茶茶褐素对大鼠尿液的影响可能涉及到氨基酸代谢、能量代谢、三羧酸循环、脂类代谢和氧化应激反应。     

云南普洱茶中多酚类物质与品质的关系研究

实验结果表明,在普洱茶加工过程中茶多酚、儿茶素、黄酮类、荼黄素、荼红素的含量大幅度减少,茶褐素的含量大幅度增加,由2．53％增加为10．57％,它们与普洱茶感官得分的相关方程为Y=93．8930-0．4047X1-0．0654X2—5．4336X3—71．4532X4＋1．2114X5＋1．2761X6,复相关系数R^2=0．985;普洱茶的级别与茶多酚、儿茶素、黄酮类、茶黄素、茶红素、茶褐素的含量也密切相关,相关方程为：Y=73．6346＋3．4281X1-54．9145X2-4．5225X3＋164．0906X4＋7．2507X5＋1．9839X6,     

普洱茶色素类物质及其在沤堆过程中的变化

茶叶中的色素,大别为两类,一为脂溶性色素,如叶绿素a、叶绿素b、叶黄素、胡萝卜素等,另一为水溶性色素,如花黄素类、花色素类、黄烷醇类及其氧化产物等。这些成分在普洱茶的沤堆过程中变化很大,从而形成普洱茶茶汤具有的色香味,并与其它茶类有不同的饮效。一、脂溶性色素该类色素用丙酮提取,石油醚分离和纸上色层分析。曾比较了各种类型茶叶,其中鲜叶、普洱原茶和成茶的色层,按其吸附强弱离析的层次和层的宽度示于     

普洱茶主要氧化产物提取条件的优化及其抗氧化活性分析

以普洱茶为原料,研究溶剂pH值、浸提温度、时间、料液比对茶褐素（TBS）提取率的影响。结果表明,溶剂pH值、浸提温度、时间、料液比等都显著影响TBS的浸提效果,其中料液比、浸提温度、浸提时问达到了极显著水平,各因素影响效果的重要眭依次为：料液比〉浸提温度〉浸提时间〉溶剂pH值。同时得到茶褐素浸提的优化条件为：温度100℃,溶剂pH=7,料液比1：30,时间20min。茶褐素抗氧化活性分析结果显示,其抗氧化活性优于普洱茶水提物。     

人工接种真菌发酵普洱茶的化学成分变化研究

在传统普洱茶自然渥堆发酵的基础上,研究了人工接入黑曲霉、青霉和酵母3种真菌后普洱茶化学成分的变化。结果表明,茶多酚、儿茶素、茶黄素、茶红素、茶褐素、水溶性果胶、水溶性糖、水浸出物、咖啡碱、氨基酸和灰分这些化学成分的变化趋势均与自然渥堆发酵相一致,呈增加趋势的有茶黄素。茶褐素、咖啡碱、水溶性果胶和灰分,呈减少趋势的有茶多酚、儿茶素、茶红素、水溶性糖、水浸出物和氨基酸。由于人为增加了普洱茶渥堆发酵所需的优势菌种,从而在一定程度上导致了以上这些化学成分的变化幅度与自然渥堆发酵的存在着量上的差异性,人工接种真菌后,更有利于茶多酚、儿茶素、水浸出物、水溶性糖、茶红素的保留,有利于茶黄素、咖啡碱的积累,并生成适量的茶褐素。人工接种真菌渥堆发酵普洱茶．在方法上是可行的．但有关相应的技术参数还需进一步研究。     

云南晒青绿毛茶的微生物固态发酵及成分变化研究

研究了添加外源优势菌种固态发酵云南晒青绿茶过程中主要成分的变化规律。结果表明,随着发酵时间的延长,主要的化学品质成分含量均发生了明显变化,以多酚类、儿茶素、茶红素、茶褐素、寡糖和多糖的变化最明显。发酵40天后,多酚类物质下降了约60%,儿茶素类下降了80%,黄酮类下降了55%,茶红素下降了90%,水溶性寡糖下降了65%,水浸出物下降了25%,而茶黄素、水溶性总糖和灰分的变化不大。但茶褐素类物质增加了4.5倍,水溶性多糖也增加了5.7倍。这说明多酚类物质、儿茶素、茶红素、茶褐素类、寡糖及多糖类物质可作为云南普洱茶的特征成分用于品质判定。实验结果还表明,利用优势菌种发酵晒青绿茶可以在短时间内生产熟普洱茶,其理化成分含量可达到陈年普洱茶的水平。实验结果同时还表明,离开了微生物和湿热作用,晒青绿茶是难以形成普洱茶特有品质风格的。     

不同等级普洱茶的化学成分及抗氧化活性比较

选用高、中、低三类不同等级的普洱茶为研究对象,研究比较了它们的抗氧化活性、香气成分及其主要理化成分含量的差异。结果表明,高、低两类等级的普洱茶相比,总氧化活性、清除羟自由基活性、清除DPPH自由基活性、醇类香气成分总量、杂氧化合物香气成分总量、黄酮总量以及茶色素含量等,一般都存在显著性差异(P<0.05);而中等级的普洱茶与高或低等级的普洱茶相比,除总氧化活性、清除羟自由基活性、茶多酚含量和黄酮总量存在显著性差异外(P<0.05),其他理化成分的含量一般都不存在显著性差异(P>0.05)。主成分分析表明,抑制羟自由基活性、总抗氧化活性、黄酮总量、茶褐素含量以及醇类香气成分总量等是区分普洱茶等级的重要理化指标。     

不同等级普洱茶的化学成分及抗氧化活性比较

选用高、中、低三类不同等级的普洱茶为研究对象,研究比较了它们的抗氧化活性、香气成分及其主要理化成分含量的差异.结果表明,高、低两类等级的普洱茶相比,总氧化活性、清除羟自由基活性、清除DPPH自由基活性、醇类香气成分总量、杂氧化合物香气成分总量、黄酮总量以及茶色素含量等,一般都存在显著性差异(P＜0.05);而中等级的普洱茶与高或低等级的普洱茶相比,除总氧化活性、清除羟自由基活性、茶多酚含量和黄酮总量存在显著性差异外(P＜0.05),其他理化成分的含量一般都不存在显著性差异(P＞0.05).主成分分析表明,抑制羟自由基活性、总抗氧化活性、黄酮总量、茶褐素含量以及醇类香气成分总量等是区分普洱茶等级的重要理化指标.     

普洱茶立体小罐发酵加工工艺技术的应用研究

为了改善普洱茶生产的清洁化加工条件,提升自动化发酵水平,研究开发了普洱茶立体小罐发酵加工工艺技术。该技术通过将传统大堆发酵料分割成独立小单元,以小罐为载体进行封装,配套自动化控制系统,流水线作业完成装罐、发酵和出罐,发酵过程不翻堆、不补水,精准控制发酵温湿度,解决了传统渥堆发酵生产装备水平低、环境可控性差的难题,提升了普洱茶自动化发酵水平。结果显示,立体小罐发酵技术加工的普洱茶审评结果符合普洱茶国家标准,规模化自动发酵具有可行性;较传统发酵工艺,普洱茶立体小罐发酵加工工艺技术可提升单位面积产能40%,缩短发酵周期15~20 d,减少人工成本约75%;茶叶外形条索更完整,茶多酚、茶褐素、氨基酸态氮含量以及pH显著提高,品质稳定性明显提升。     

Mercerization in degassed sodium hydroxide solution

The application of a degassing system to mercerization process was investigated. It was found that the physical properties of cotton fabrics mercerized in the degassed NaOH solution were superior to those mercerized in NaOH solution. The degree of penetration of the degassed water was examined by measuring wicking height. The wicking height in the degassed water without the wetting agent is higher than that of the saturated water with 0.1 % of wetting agent.     

浸泡介质及浸泡条件对豆浆中抗营养因子及品质的影响

为了最大程度降低豆浆中抗营养因子含量的同时保证品质优良,以干豆制浆为对照,利用不同浸泡介质(水、柠檬酸溶液、NaHCO_3溶液)及不同浸泡条件,探究前处理工艺条件以及介质的改变对豆浆中抗营养因子及营养品质的影响。结果表明:浸泡处理能有效降低豆浆中胰蛋白酶抑制因子活性和植酸含量,但不同介质对不同抗营养因子的效果不同。经浸泡处理后的胰蛋白抑制因子的最低活性为30.88±1.35 TIU·mg^-1,相对于未处理组降低了54%;植酸最低含量为3.46±0.15 mg·mL^-1,相对于未处理组降低了77.4%;而经浸泡处理后的单宁含量却显著上升(P<0.05)。从降低胰蛋白酶抑制因子活性的效果来看,NaHCO_3>水>柠檬酸;从降低单宁含量的效果来看,柠檬酸>NaHCO_3>水;从降低植酸含量的效果来看,柠檬酸>水>NaHCO_3。除抗营养因子外,豆浆的品质指标也发生了显著变化,NaHCO_3浸泡组的总体品质最优,除了个别品质指标(蛋白质含量)与水浸泡组相比差异不显著(P>0.05),其它品质成分含量均显著高于水浸泡组,而柠檬酸浸泡组的品质为3组中最差。选取NaHCO_3溶液作为浸泡介质进行正交工艺优化,当浸泡温度为25℃,浸泡时间为16 h,浸泡豆水比为1∶4,NaHCO_3浓度为0.45%时,豆浆的抗营养因子的去除效果最好,品质最优。     

巴西香蕉苗静置水培营养液配方的初步筛选

采用静置水培法，使用4种不同的营养液配方，并以清水培养和椰糠基质栽培为对照，对巴西香蕉苗进行生长比较试验。结果表明：在香蕉苗增加的生物量方面，BXM配方(巴西木植物营养液)处理与椰糠栽培的差异不显著，但与日本园试配方、Hoagland植物营养液配方、1/2 MS培养基营养元素配方和清水培养的差异显著；在株高和叶面积方面，均以椰糠栽培的最大，BXM配方处理的居次，接下来依次是Hoagland植物营养液配方、日本园试配方、1/2 MS培养基配方和清水培养。综上所述，在这4种营养液配方中，BXM配方是巴西香蕉苗生长的最适营养液配方。     

Fabrication of meta-aramid fibrid by precipitation

“Fibrid”, a type of fibrous particle used for binding, and the meta-aramid fibrids were successfully prepared by injecting the meta-aramid solution into the high shearing coagulation bath in this paper. The meta-aramid solution was prepared by dissolving the meta-aramid fibers in LiCl/DMAc solving system, and the mixture of water and DMAc was used as coagulation bath. The rotating speed, concentration of meta-aramid solution and the concentration of water in the coagulation bath were the main factors on effecting the formation and morphology of fibrids. The results showed that the length of meta-aramid fibrid decreased with the rotating speed and the content of water in coagulation bath increasing, and increased with the concentration of meta-aramid solution increasing. The morphology of meta-aramid fibrid were observed by optical microscope, a lower thermal property of meta-aramid firbid than meta-aramid fiber was observed in TGA which was mainly due to the breaking of hydrogen bonding and crystalline structure of meta-aramid fiber during the dissolving process, the results in TGA were consistent with the XRD, and the XRD curves showed that the non-crystalline structure were observed in meta-aramid fibrid.     

pH值对茶树生理活动的影响

水培试验结果表明,硝态氮源茶树的适宜pH值为4.5—6.0,最适pH值为6.0;氨态氮源茶树的适宜pH值为4.5—6.5,最适pH值为5.5。硝态氮茶苗比氨态氮生长好,但叶色发黄。在适宜pH范围内,茶树对氮磷钾的吸收量多,水分代谢旺盛,光合效率高,呼吸作用随pH升高而增强;在适宜pH范围外,茶树的生理活动明显受到抑制,生长不良和伤害致死。在水培过程中,溶液的pH不断向酸性方向变化,表现了茶树的喜酸性特性,但在适宜pH范围内向酸性变化小,范围外变化大,氨态氮源较硝态氮源变化大。     

Salt-Induced Disaggregation/Solubilization of Gliadin and Glutenin Proteins in Water

The effect of salt concentration used in preparing gluten, on the subsequent dissolution of gluten in water, was examined. Flour from a Canadian hard red spring wheat cultivar, Katepwa, was used to prepare glutens using three different solvents, i.e. distilled deionized water (DDW), 0·2% NaCl solution and 2% NaCl solution. The isolated wet glutens were extracted sequentially with DDW, providing four water soluble fractions and an insoluble residue. The amount of protein in each fraction was determined and respective compositions were assessed electrophoretically under reducing and non-reducing conditions. Surprisingly, DDW extracts of gluten prepared with 2% NaCl contained almost all the gliadins, except some ω-gliadin components, and most of the polymeric glutenin. For the gluten prepared with 0·2% NaCl, most of the gliadin, but only a small portion of glutenin, was extracted. For gluten prepared with DDW, only part of the gliadins and almost no glutenin was extractable with water. The DDW solubilities of gluten proteins prepared in DDW, 0·2% NaCl and 2% NaCl were 27, 52, and 85%, respectively, after four sequential extracts with DDW. The large increases in the solubility of gliadin and glutenin proteins in DDW when the gluten is prepared in salt solution (after removal of most of the salt) can be explained on the basis of a salt-induced conformational change of the proteins, which renders water a more effective solvent.     

曲酸对小麦种子萌发及幼苗生长的影响

以小麦种子为试验材料,采用培养皿纸上发芽法,以清水和油菜素内酯作为对照,研究不同浓度曲酸溶液对小麦种子萌发及幼苗生长的影响。结果显示:不同浓度的曲酸溶液(50、100、200、300、400、500mg/L)处理后,小麦种子发芽势显著提高,以300mg/L效果最佳,优于清水对照组和20mg/L油菜素内酯处理;小麦幼苗的根长、株高、根冠比与对照组相比无显著差异;小麦幼苗的鲜重、地上部分干重、地下部分干重均有不同程度增加,浓度为200mg/L时达到峰值并高于对照组;幼苗叶绿素含量比油菜素内酯对照组高,以200mg/L促进效果最为明显。     

不同基因型玉米萌芽期的抗旱性研究

对4个玉米杂交种辽单24、丹413、沈丹16、沈农87进行了萌芽期的抗旱性研究。结果表明水分胁迫降低了杂交种的发芽势和发芽率,阻碍了胚根和胚芽的生长,也降低了叶片的蒸腾速率和光合速率。但不同杂交种在抗旱性上存在明显差异,在水分胁迫下,抗旱性强的杂交种仍然保持较高的发芽势和发芽率。水分胁迫下,玉米种子的吸水速率减小,但吸水速率与抗旱性间相关性不明显。各品种在20%PEG水分胁迫处理下的萌动吸水伤害率间差异明显,可以作为一个抗旱鉴定指标。研究表明,利用室内高渗溶液萌发法通过对玉米萌芽期抗旱性高度相关的性状的测定得出的萌芽期抗旱性鉴定结果与田间直接鉴定的结果基本相符,说明室内高渗溶液萌发法是鉴定玉米萌芽期抗旱性的一种快速、简便、准确的方法。     

Potato berry blackening and premature drop due to boron deficiency

A number of methods are used in potato programs to achieve successful crosses. The cut stem technique is used in many of them and it usually achieves good results. However sometimes berries turn black, produce sterile seed and drop off prematurely. No pathogen was associated with the disease. Six water sources were compared including potable water, water from a deep tubular well, water from a superficial well, Hoagland’s nutrient solution, distilled and deionized water. Flowering stems of cv Yungay were cut, pollinated with pollen from clones R 128.6 and placed in bottles with water from different sources. Hoagland’s nutrient solution and water sources with highest boron content produced lowest incidence of blackened berries. An additional experiment testing 6 macrometabolic and 6 micrometabolic elements including B produced the following results: Treatments containing B produced normal berries; whereas treatments without B produced around 90% of blackened berries and/or drop off. It was thus demonstrated that this abnormality was caused by B deficiency which could be corrected by addition of 2 ppm of boric acid. Solutions containing greater than 5 ppm caused phytotoxicity in leaves of flowering stems.     

蒸汽爆破处理对剑麻纤维组分分离的影响

采用高温、高压水蒸汽瞬间爆破处理剑麻纤维。通过处理前后剑麻纤维的水溶物、碱溶物、木质素含量、纤维素含量的比较,分析研究了蒸汽爆破处理条件对剑麻纤维组分分离效果的影响。试验结果表明:爆破前预处理、处理温度(压力)、维压时间是影响组分分离的重要因素:随着处理强度的增大,纤维中木质素含量降低,纤维素含量增大;爆破前的不同试剂预浸泡处理中,质量分数为17.5％的NaOH和质量分数为0.1％的H2SO4预浸泡处理效果较优,水和质量分数为1％的NaOH浸泡处理效果较差。