Chemical Constituents of Pu-erh Tea and Its Inhibition Effect on α-amylase in vitro

[Objective]The aim was to clarify the chemical substance basis of hypoglycemic and lipid-lowering effects of Pu-erh Tea. [Method]Pu-erh Tea was extracted with 95% ethanol,followed by petroleum ether,chloroform,ethyl acetate and n-butanol extraction,after the further purification and through the NKA-9 macroporous resin and many times of Sephadex column chromatography,two compounds were isolated,in the same time,the effect of Uracil and Gallic acid on α-amylase was studied. [Result]The Uracil and Gallic acid were isolated and identified respectively from Pu-erh Tea and the Uracil was firstly isolated from Pu-erh Tea; Gallic acid had strong inhibition on α-amylase. [Conclusion]It could provide some theories on the hypoglycemic and lipid-lowering effects of Pu-erh Tea.

Study on Pu-erh Tea Methanol Extracts on Antibacterial Activity of Several Plant Pathogens

[Objective] The aim was to study Pu-erh tea methanol extracts on antibacterial activity of several plant pathogens and provide reference for application of Pu-erh tea in agriculture disease prevention and control.[Method]The inhibitive effect of Pu-erh tea methanol extracts on several plant pathogens was studied by adopting mycelium growth rate method.[Result] The results showed that Pu-erh tea methanol extracts had inhibitive effects on Thanatephorus cucomeris(Frank)Donk,Fusarium oxysporum f.sp.niveum,Fusa...

Analysis of α-amylase Inhibitor Content Change in Pu-erh Tea During Pile-fermentation Process

The study was to investigate the changes of α-amylase inhibitor content in Pu-erh tea during pile-fermentation process. Pu-erh tea samples from two regions of Shuangjiang County and Jinggu Dai and Yi Autonomous County of Yunnan Province at various fermentation stages were used as experimental materials to investigate the effect of different fermentation stages on the inhibitory effect to α-amylase; and the change law of the inhibitory effect of c-amylase inhibitor during processing was meanwhile studied by determining the contents of tea polyphenol and amino acid. The results showed that crude meterial of Pu-erh tea presented strong inhibitory effect to α-amylase; this inhibitory effect assumed a de： creasing trend to the minimum at the middle stage of fermentation, whereafter it increased to some extent. Made tea also showed a strong inhibitory effect to α-amylase. During whole processing period, contents of tea polyphenol and amino acid generally assumed a remarkably decreasing trend. Our results provided references for further isolating co-amylase inhibitor from Pu-erh tea and discussing the mechanism of its health care function.

Factors Influencing the Effects of Theabrownin in Pu-erh Tea on Scavenging DPPH Radicals

[Objective] This study aimed to explore factors influencing the effects of theabrownin in Pu-erh tea on scavenging DPPH radicals. [Method] Taking Pu-erh tea as main research object, theabrownin in Pu-erh tea from tea piles with different times of mixture, stored for different years and processed by both the old and new techniques were extracted and isolated. And DPPH method was used to study the effects of theabrownin solution and tea liquor on scavenging radicals and their antioxidant activity. [Result] The result showed that the theabrownin content in Pu-erh tea from tea piles with one to four times of mixture revealed a first declining and subsequently rising trend. Under different pH conditions, the rates of DPPH radical scavenging of 1 mg/ml theabrownin solution made from tea piles with different times of mixture decreased gradually with the increase of pH, and all the rates were lower than that of the control vitamin C solution; the rates of DPPH radical scavenging of theabrownin from tea samples stored for different years and produced by different techniques dropped slowly within pH range 3.0-6.0; when pH was higher than 6.0, the rates of DPPH radical scavenging of theabrownin from tea samples produced by both new and traditional techniques in 2001 declined obviously, while the declining trend was not obvious in either the black tea or the Pu-erh tea produced by new technique in 2005. Under different theabrownin concentrations, the rates of DPPH radical scavenging of theabrownin solution made from tea piles with different times of mixture ascended as the concentration increased and the highest rate occurred in tea pile with four times of mixture, reaching up to 46.56%±0.88%; for tea samples stored for different years and produced by different techniques, the rates of DPPH radical scavenging of theabrownin rose gradually with the increase of the theabrownin concentration; the rate of radical scavenging of theabrownin in the black tea ascended obviously and that in Pu-erh tea was decreasing within the concentration range of 0.04 -0.06 mg/ml. At pH6.0, the DPPH radical scavenging ability of theabrownin in 0.1 mg/ml theabrownin solution and tea liquor containing 0.1mg/ml theabrownin from tea piles with different times of mixture ascended with the time of mixture; solution made from tea samples produced by different techniques in different years, the DPPH radical scavenging ability of theabrownin solution and tea liquor followed： Pu-erh tea produced by the new technique in 2001 ﹥ Pu-erh tea produced by the old technique in 2001﹥ Pu-erh tea produced by the new technique in 2005. And the DPPH radical scavenging ability of theabrownin in tea liquor containing 0.1 mg/ml theabrownin was higher than that in 0.1 mg/ml theabrownin Solution made from tea samples either with different times of mixture or produced by different techniques in different years. The above results indicated that many factor influenced the effects of theabrownin on eliminating DPPH radicals, including the time of fermentation, fermentation technique, years of storage, concentration and pH all had great influence on the effects of theabrownin on eliminating radicals. To ensure a good effect on scavenging radicals, it is better to prepare theabrownin at pH6.0 with concentration between 0.08 and 0.1 mg/ml for drinking. [Conclusion] Results of this study provide a basis for developing functional products of theabrownin from Pu-erh tea in the future.

Analysis of Monosaccharide Composition of Pu-erh Tea Polysaccaride by Pre-column Derivatization HPLC

[Objective] This study aimed to establish a pre-column derivatization HPLC method for the identification and analysis of monosaccharide composition of Pu-erh tea polysaccharide. [Method] Pu-erh tea polysaccharide was extracted using the wa- ter extraction method, further isolated and purified by DEAE cellulose-52 columns. The obtained tea polysaccharide and four components TPS1, TPS2, TPS3 and TPS, were first derived by 1-phenyl-3-methyl-5-pyrazolone （PMP）, and then the PMP derivatives of monosaccharide were analyzed by high performance liquid chromatog- raphy （HPLC）. [Result] Pu-erh tea polysaccharide contained eight kinds of monosac- chaddes （mannose, rhamnose, glucuronic acid, galacturonic acid, grucose, galactose, arabinose, fucose）, without xylose; so it was the same with TPS1; each of TPS2, TPS3 and TPS4 contained seven monosaccharides, while no fucose. [Conclusion] This method is simplified and rapid, which can be used to determine the monosac- charide composition of Pu-erh tea polysaccharide and monosaccharide content.

Characterization of aroma compounds of Pu-erh ripen tea using solvent assisted flavor evaporation coupled with gas chromatography-mass spectrometry and gas chromatography-olfactometry

Pu-erh ripen tea becomes popular worldwide owing to its unique taste and aroma.In the present study,volatile compounds from Pu-erh ripen tea were extracted using a solvent assisted flavor evaporation(SAFE)and analyzed with a gas chromatography-mass spectrometry(GC-MS)and a gas chromatography olfactometry(GC-O).Results demonstrated that 58 major volatile compounds and 24 aroma active substances of Pu-erh ripen tea were identified by GC-MS and GC-O analysis.Among volatile compounds identified,methoxyphenyl compounds were considered as the dominate compounds in the aroma of Pu-erh ripen tea.Further investigation showed that 6 methoxybenzenes were responsible for the aging aroma in Pu-erh ripen tea;α-ionone,3,4-dimethoxytoluene,1,3-dimethoxybenzene,etc.were responsible for the wood-like aroma.Linalool,α-terpineol,α-ionone,β-ionone,and benzeneacetaldehyde were responsible for the floral odor.Compared the odor detection threshold(ODT)among the 8 methoxyphenyl compounds in water,1,2,3-trimethoxybenzene showed the highest ODT,followed by 3,4-dimethoxyphenol.1,3-dimethoxybenzene(105μg/L)and 1,2,3-trimethoxy-5-methylbenzene(100μg/L)were present at relatively low odor threshold values.The result indicated that methoxyphenyl compounds play a vital role in the unique flavor of Pu-erh ripen tea.

Reducing oxidative stress and hepatoprotective effect of water extracts from Pu-erh tea on rats with high-fat diet

Reducing oxidative stress and hepatoprotective effect of Pu-erh tea water extracts on rats fed with high-fat diet were researched for explaining health care of Pu-erh tea.Fifty SD rats were divided into five groups.The body weight was measured once a day.The malondialdehyde(MDA)and glucose(Glu)levels and the activities of alanine aminotransferase(ALT),aspartate aminotransferase(AST),nitric oxide synthase(NOS),and pyruvate kinase(PK)in serum were determined.Furthermore,the hepatic glycogen level(HGL)and the activities of hepatic total superoxide dismutase(T-SOD),catalase(CAT),and glutathione peroxidase(GSH-Px)were also measured after continuous administration for 12 weeks.The result demonstrated that Pu-erh extract caused the decreases in body weight,fat index,MDA and NOS levels,and the increases in hepatic T-SOD,CAT and GSH-Px activities,indicating that the extract may be due to inhibiting the increases of body weight and fat index,reducing oxidant stress state and inhibiting lipid peroxidation,thus decreasing the activities of ALT and AST,and protecting the liver in rat.Meanwhile,the extracts could increase the production of hepatic glycogen and the activity of PK,and reduce glucose level,protecting the liver from the diseases associated with type II diabetes.

Detection of composition of functional component theabrownins in Pu-erh tea by degradation method

Habitual tea consumption can reduce the risk of ASCVD morbidity and mortality and all-cause mortality in China,and long-term adherence to this habit can provide greater protection.Pu-erh tea is one of the representatives of post-fermented teas,and the polymers in Pu-erh tea have anti-cancer and anti-hyperlipidemic activities,but their chemical composition is still unknown.In this study,the chemical composition of Pu-erh tea was investigated in detail and eight(1–8)known compounds were isolated.The polymers in Pu-erh tea were also degraded by thiol degradation,and the fragments of quercetin and(–)-epicatechin-3-O-gallate were found in the thiol degradation products of Pu-erh tea polymers by UPLC observation and separation and purification.This is the first time that this fragment was obtained in Pu-erh tea polymer.

Inhibitory Effects of Pu-erh Tea Leaves on Mouse Type IV Allergy

Pu-erh tea is one of post fermented tea manufactured through oxidative maturing by microorganisms. We investigated the preventive effects of pu-erh tea extract on oxazolone-induced type IV allergy in male (ICR) mice. Oral administration of 50 mg/kg water extract of pu-erh tea leaves resulted in significant preventive effects against mouse type IV allergy. The hydrophilic Theabrownin-like fraction (TBW-ND), with a high molecular weight of approximately 12,000 or higher, was prepared from pu-erh tea leaves by a solvent-extraction method, followed by Diaion HP-20 column chro-matography and dialysis. Oral and percutaneous administrations of TBW-ND at doses of 18.7 mg/kg and 0.037 mg/ear also resulted in significant preventive effects, which included preventing increases in levels of the proinflam-matory cytokine interleukin-12. The anti-allergic ingredients in TBW-ND were predicted to be highly complex compounds containing of polyphenols, polysaccharides and/or proteins. The results suggest pu-erh tea leaves could be a beneficial food for protecting against delayed-type allergy.

Anti-Obesity, Anti-Atherosclerotic and Anti-Oxidant Effects of Pu-Erh Tea on a High Fat Diet-Induced Obese Rat Model

Pu-erh tea, a traditional Chinese beverage, has been believed to have many benefits to human health and without side effects. In this study, we systematically analyzed the main active components of Pu-erh tea and investigated its anti-obesity, anti-atherosclerotic and anti-oxidant effects using an obese rat model. Obesity was induced by feeding a high-fat diet and subsequently the experimental obese mice were fed with high-fat diet supplemented with low (2.5%), medium (5%) or high (7.5%) doses of Pu-erh tea powder for 6 weeks respectively. As result, the body weight gain of the rats was decreased by medium and high doses of Pu-erh tea treatments. Furthermore, the levels of serum total cholesterol (TC), triglyceride (TG) and atherosclerosis index (AI) were significantly lowered by Pu-erh tea compared to the control group. Conversely, high density lipoproteincholesterol (HDL-C) level of the rats was significantly elevated by Pu-erh tea treatments. In addition, Pu-erh tea treatments increased the activities of anti-oxidative enzymes such as superoxide dismutase (SOD) and glutathione peroxides (GSH-Px), whereas reduced the level of lipid peroxidation product malondialdehyde (MDA) in obese rats. Collectively, our find-ings revealed that Pu-erh tea exerts comprehensive benefits in anti-obesity, anti-atherosclerotic and anti-oxidant effects, therefore can be used as a promising functional food in obesity management.

Pu-erh tea: A review of a healthful brew

Pu-erh tea has been used for thousands of years to treat metabolic diseases.Recognized in Shen Nong's Herbal Classic,a compendium kept by the first traditional Chinese practitioners,it is still highly valued for its hypocholesterolemic and hypolipidemic effects.This review reports the processing and bioactive components of pu-erh tea.Recent human and animal studies of pu-erh tea and its potential therapeutic mechanisms have also been summarized.The interaction of liver and gut microbiome regulates the puerh tea biotransformation and endogenous metabolism,and thus contributes to the health benefits.

Characteristics of Superfine Green Tea Powder and Its Application in Food Industry

Superfine green tea powder is a new kind of tea product that can be eaten directly.It provided most of the benefits of whole green tea leaves,with all of the bioactive ingredients.This paper highlighted the characteristics and health benefits of superfine green tea powder,and its applications in food industry.

Evaluation of the Anti-Proliferative Effects of a Green Tea and <i>Capsicum</i>Powder Extract in Cancer Cell Lines

In recent years the use of natural supplements in order to prevent, treat or delay recurrence of cancer or reduce chemotherapy toxicity has attracted much?attention. One such supplement is Capsol-T which consists of de-caffeinated green tea and chili pepper extracts. The aim of the study was the evaluation of Capsol-T effect on the proliferation of various cancer cell lines representing different cancer types. Cell lines that were used in the study were: DU145, LNCap,?MCF7, HCT116 and MOR. The effect of various concentrations and incubation times of Capsol-T on cell viability was determined using the MTT method. The results do not show a common anti-proliferative pattern in all cancer cells.?In some cell lines and certain concentrations cell growth was significantly decreased at 24 hr which became more evident at 48?hr. The role of Capsicum?powder in cancer is unclear since both cancer cell proliferation and growth arrest have been demonstrated. Green tea on the other hand was found to decrease certain drugs’ bioavailability. Our results suggest that an anti-proliferative?effect in certain types of cancer should not be generalized to other types as well.?Different concentrations also affect the net result often having opposite effects. Overall, caution should be taken when using natural supplements for their anti-cancer effects.

Qingshan Brand Milk Powder with Tea

Qingshan brand milk powder with teais produced by the Inner Mongolia QingshanMilk Holdings Co.Ltd.It is prepared on thebasis of the original taste of Inner Mongolianmilk with tea and a folk tonic prescription.The fresh milk and fine pressed tea areprocessed into a powder through sterilizing,vacuum-condensing and dry spraying.

茶叶、袋装茶以及茶粉中15种金属及类金属含量及健康风险评估

目的研究茶叶、袋装茶以及茶粉的茶汤中Li、Al、Cr、Mn、Fe、Ni、Cu、Zn、As、Se、Mo、Cd、Sb、Ba、Pb 15种金属及类金属含量情况,评估饮用茶汤对人群健康的风险。方法随机抽取不同的茶叶、袋装茶以及茶粉共39份样品,用100℃水冲泡茶叶、袋装茶以及茶粉60min,3种茶汤用电感耦合等离子体质谱法(inductively coupled plasma-mass spectrometry,ICP-MS)直接测定15种金属及类金属溶出量。运用单项污染评价、内梅罗法综合污染评价,靶标危害系数(target hazard quotient,THQ)和危害指数(hazard index,HI),以及美国环境保护署(U.S.Environmental Protection Agency,US EPA)和国际致癌研究署(International Agency for Research on Cancer,IARC)推荐的健康风险评价模型对3种茶汤进行健康风险评价。结果茶叶、袋装茶以及茶粉3种茶汤中单项污染指数和内梅罗综合污染评价指数均小于0.7,污染等级分别为优良、安全。THQ值和HI值均小于1。HI排名依次是绿茶茶粉>红茶茶粉>乌龙茶粉>绿茶袋装茶>红茶茶叶>乌龙袋装茶>乌龙茶茶叶>绿茶茶叶>红茶袋装茶,HI中占比较大的元素整体上为Al、Mn、Ni、Cu。茶汤中个人健康危害年风险总和为9.01×10^(–6)~3.73×10^(–5)a^(–1),低于USEPA和国际辐射防护委员会(International Commissionon Radiological Protection,ICRP)推荐的最大可接受风险水平。结论茶叶、袋装茶以及茶粉茶汤中15种金属及类金属对暴露人群的健康风险较低。茶叶、袋装茶以及茶粉均处于安全饮用范围。

米糠绿茶低热量曲奇饼干的配方优化

为开发营养低热量的曲奇饼干,拓展米糠的应用领域,研究在单因素试验基础上,以感官评分为响应值,以米糠粉添加量、绿茶粉添加量、赤藓糖醇添加量和黄油添加量为考察因素,通过Box-Behnken试验设计进行响应面优化分析,确定最佳制作配方。结果表明,当米糠粉添加量为11%、绿茶粉添加量为3%、赤藓糖醇添加量为38%、黄油添加量为89%时,感官评分最高,为92.9分。在此条件下制得的曲奇饼干色泽自然、香味浓郁、花纹清晰且口感酥脆。

红茶粉对鲜湿米粉品质的影响

为探究红茶粉对鲜湿米粉食用品质影响及作用机理,考察不同添加量的红茶粉(质量分数为0%、1%、2%、3%)对鲜湿米粉食用品质的影响,并通过糊化特性、热特性、结晶特性和微观结构分析红茶粉对鲜湿米粉品质影响的作用机理。结果表明:适度添加红茶粉可以提高鲜湿米粉的弹性和硬度,降低黏附性,蒸煮损失率和断条率,其中红茶粉质量分数为1%时,蒸煮品质改善明显,与未添加红茶粉相比,断条率降低50.58%,蒸煮损失率降低24.74%。同时鲜湿米粉的颜色随着红茶粉的加入逐渐向红色和黄色转变,抗氧化能力显著提高。糊化特性表明红茶粉能够降低米粉崩解值和回生值,赋予米粉更好的热稳定性和抗剪切能力。热特性和X射线衍射分析表明红茶粉能够抑制米粉重结晶,延缓老化。扫描电镜观察到,适当添加红茶粉能够赋予米粉更加稳定致密的网络结构。

抹茶菌群多样性分析

为了解抹茶菌群多样性,以不同企业不同等级的抹茶为试验材料,采用CTAB法提取样品总DNA,分别测定样品中微生物的16SrDNA基因V3、V4区序列。测序数据经质量控制、嵌合体过滤、高质量数据统计后,利用QIIME2软件获得扩增子序列变体ASVs特征表和特征序列,进行ASVs分布、α多样性、β多样性、物种和物种关系分析。结果表明,45个抹茶样本中有9个样本的菌群丰度极低,集中在高等级产品中。Z企业和Y企业的抹茶菌群ASVs数目、Chao1和Observed-species指数均与抹茶等级呈负相关性,而J企业抹茶的上述指标与抹茶等级不成相关性。Shannon指数表明影响各抹茶中菌群多样性的因素基本一致。抹茶组内样本间群落结构相近,企业内部样本间群落结构相近,同一企业不同批次但等级相同的样本菌群结构相近,产品微生态稳定性较好。36个抹茶样中共检测到物种29门、71纲、176目、345科、902属、1577种,其中变形菌门(Proteobacteria)和厚壁菌门(Firmicutes)为各组样本的绝对优势菌门,二者在ZA、ZB、ZC、YA、YB、JA、JB和JC中的丰度之和分别为96.34%、95.85%、96.06%、95.53%、95.31%、95.91%、96.06%和95.27%。鞘氨醇单胞菌属(Sphingomonas)、甲基杆菌属(Methylobacterium)和假单胞杆菌属(Pseudomonas)为各组的共有优势菌属(丰度≥2.00%),优势菌属在上述各组中的丰度之和分别为64.71%、65.61%、60.04%、70.65%、69.20%、72.98%、75.92%和76.57%。各组的共有优势菌属均属于变形菌门(Proteobacteria),ZB的第一优势菌属链球菌属(Streptococcus)属于厚壁菌门(Firmicutes)。本试验结果为阐明抹茶菌群多样性提供理论参考。

响应面法优化超微岩茶粉糙米无糖蛋糕的研制

利用超微粉碎技术制得超微武夷山岩茶粉,以蛋糕粉和糙米粉为主要原料,添加超微岩茶粉和赤藓糖醇制作一款戚风蛋糕。通过单因素试验,考查超微岩茶粉、糙米粉、赤藓糖醇和蛋清添加量对蛋糕感官评价和质构的影响,并在单因素试验结果的基础上,以综合评分为指标,利用响应面法优化确定蛋糕最佳工艺配方为:以糙米粉与蛋糕粉总质量为基准,按烘焙百分比计,糙米粉添加量78.3%,超微岩茶粉添加量5.6%,赤藓糖醇82.5%,蛋清添加量224.8%。以此配方制得的超微岩茶粉糙米无糖蛋糕呈淡棕绿色,组织松软细腻,茶香馥郁且具稻米香气,营养价值高于普通戚风蛋糕。

过氧化氢酶、多酚氧化酶及其组合对白芽奇兰速溶茶粉香气品质的影响

本研究采用顶空固相微萃取-气相色谱-质谱联用技术和香气活性值(odor activity value,OAV)分析,探究过氧化氢酶、多酚氧化酶及复合酶处理对特色乌龙茶白芽奇兰速溶茶粉香气成分的影响。结果表明,经过氧化氢酶、多酚氧化酶及复合酶处理后,白芽奇兰速溶茶粉的香气成分和含量均发生了显著变化。过氧化氢酶处理组的香气成分含量最高且OAV提高最多,新生成了反式芳樟醇氧化物(呋喃糖)、顺式-己酸-3-己烯基酯和反式-β-法呢烯,且与未经处理的茶样相比反式-2-壬烯醛、β-环柠檬醛、反式-2-癸烯醛和反式香叶基丙酮的OAV均显著增加;多酚氧化酶处理组新生成了顺式-己酸-3-己烯基酯、反式-β-法呢烯、反式-β-紫罗兰酮和β-环氧紫罗兰酮,且反式-2-壬烯醛、芳樟醇和反式-β-紫罗兰酮的OAV显著增加;过氧化氢酶和多酚氧化酶复合处理组的香气成分种类最多,新生成了顺式-3-己烯-1-醇、反,反-2,4-庚二烯醛、顺式-β-罗勒烯、反式-2-辛烯醛、反,反-3,5-辛二烯-2-酮、壬醛、5-乙基-6-甲基-3-庚烯-2-酮、丁酸己酯、戊酸叶醇酯、2-甲基丁酸己酯、顺式-己酸-3-己烯基酯、己酸己酯、反式-β-法呢烯和反式-β-紫罗兰酮,且芳樟醇的OAV显著增加。这些酶处理引起的香气成分变化可能与类胡萝卜素氧化降解、脂质过氧化、萜醇类前体糖苷键断裂等机制相关。本研究发现了过氧化氢酶和多酚氧化酶复合处理对白芽奇兰速溶茶粉香气具有协同增效作用,可为提高速溶茶粉的香气品质提供理论依据。