The modulatory effect of oolong tea polyphenols on intestinal flora and hypothalamus gene expression in a circadian rhythm disturbance mouse model

The interaction between host circadian rhythm and gut microbes through the gut-brain axis provides new clues for tea polyphenols to improve host health.Our present research showed that oolong tea polyphenols(OTP)improved the structural disorder of the intestinal flora caused by continuous darkness,thereby modulating the production of metabolites related to pyruvate metabolism,glycolysis/gluconeogenesis,and tryptophan metabolism to alleviate the steady-state imbalance.After fecal microbiota transplantation from the OTP group,the single-cell transcriptomic analysis revealed that OTP significantly increased the number of hypothalamus cell clusters,up-regulated the number of astrocytes and fibroblasts,and enhanced the expression of circadian rhythm genes Cry2,Per3,Bhlhe41,Nr1d1,Nr1d2,Dbp and Rorb in hypothalamic cells.Our results confirmed that OTP can actively improve the intestinal environmental state as well as internal/peripheral circadian rhythm disorders and cognitive impairment,with potential prebiotic functional characteristics to notably contribute to host health.

Selenium-enriched oolong tea(Camellia sinensis)extract exerts anti-inflammatory potential via targeting NF-κB and MAPK pathways in macrophages

Both tea polyphenols and selenium(Se)have been suggested to exert the health benefits via the regulatory capacities of chronic inflammation,which make Se-enriched oolong tea a promising beverage as an anti-inflammatory diet.The aim of this study is to investigate the anti-inflammatory effects of Se-enriched oolong tea extract(Se-TE)and underlying mechanism in lipopolysaccharide(LPS)-induced RAW264.7 cells.Se-TE treatments(50 and 150μg/m L)significantly suppressed the over-production of nitric oxide(NO)and prostaglandin E2(PGE2)in LPS-stimulated macrophages via downregulating the expression of nitric oxide synthase(i NOS)and cyclooxygenase-2(COX-2).Moreover,Se-TEs also effectively inhibited the productions of inflammatory cytokines,such as tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),and interleukin-1β(IL-1β).Furthermore,Se-TE could block mitogen-activated protein kinase(MAPK)and nuclear factor-kappa B(NF-κB)signaling pathways through the inhibition of the phosphorylation of key proteins(IκB-α,p65,p38,ERK,and JNK)and the translocation of the p65 subunit into the nucleus.Collectively,our results indicated that Se-TE may have the potential to be used as a novel food ingredient for the development of various anti-inflammatory foods and the treatment and prevention of chronic inflammation-related diseases.

Multifunctional health-promoting effects of oolong tea and its products

Oolong tea,partially fermented from Camellia sinensis leaves,exhibits significant antioxidative,anti-inflammatory,and anti-cancer activities as indicated in several in vitro and in vivo studies.However,studies on health promoting effects of oolong tea and its characteristic compounds are limited.The potential efficacy of bioactives derived from oolong tea and their roles as promising anticancer agents,their cardio-protective benefits during hypoxic conditions,effects in treating allergic disorders,potential prebiotic activities,improvement of blood lipid status in human beings,effectivity as oral hypoglycemic agent in the treatment of type 2 diabetes,and their potentials to reduce the risk of obesity have been discussed in this review.These promising studies mainly gained from animal studies might broaden the consumption and usage of the phenolic-enriched oolong tea and its products in food and pharmaceutical industries.However,potential health beneficial effects of oolong tea in humans should be further complemented by large-sized,randomized double-blind and placebo-controlled trials to consolidate potential therapeutic applications.

Effect of Different Drying Methods on the Volatile Compounds Jinmudan Oolong Tea

Jinmudan,a new tea variety from Fujian Province has an excellent quality with a unique aroma like magnolia frogrance.To monitor the changes in the tea volatile compounds during the Jinmudan Oolong tea manufacturing(drying) process,the volatiles of tea samples were extracted and analyzed.Characteristic volatile compounds in Jinmudan Oolong tea were nerolidol,α-farnesene,linolenic acid,palmitic acid,indole,phenylacetaldehyde,cisjasmone,β-phenylethanol,etc.The content of nerolidol was the highest in four tested samples.The composition of the volatile compounds in microwave drying sample was simple,but its concentration was high,in which the main volatile compounds were alcohols and esters.The processing with combination of traditional drying craft and modern aroma-improvement technique could obviously improve the tea aroma,especially in level of epoxy linalool and jasmine lactone.

A Study on Effects of Turn-over Technology on the Quality of Jinmudan Oolong Tea

This paper reported the effect of oolong tea processing procedure of turn-over on quality of the Jinmudan Oolong tea,including taste components and volatile compounds.The content of the water extractable solids was gradually increased,but the content of amino acid decreased and then increased,and the content of the soluble sugar and tea polyphenols increased after the first turn-over processing.The major volatiles of the three tested Jinmudan Oolong tea samples were nerolidolcistrans,α-farnesene,palmitic acid,indole and 9,12,15-octadecatrienoicacid and methyl ester.The sensory evaluation results showed that an appropriate increase in the number of turn-over was helpful to quality of the Jinmudan Oolong tea.

Development and experiment of the mechanism for oolong tea stirring motion based on the manual stirring characteristics analysis

In this study,the motion characteristics of manual stirring were analyzed to achieve the goal of realizing a highquality mechanized imitation of manual stirring for oolong tea.A test bench for collecting the motion characteristics of manual stirring was designed,and the standard manual stirring motion characteristic curve was obtained.According to the requirements of the stirring motion characteristics,a variable-speed and variable-amplitude stirring mechanism was proposed,the kinematics model and reverse design model of the stirring mechanism were established,auxiliary analysis and design software were written,and the non-circular gear pitch curve and cam profile curve were obtained.A three-dimensional model of the stirring machine was established,a virtual prototype of the stirring machine was built,and the simulation experiment was completed by using the ADAMS software.A prototype of the stirring machine was developed,and the stirring experiment was conducted on the prototype.The maximum deviation of the pitch angle is 2.8772°,and the maximum deviation of the roll angle is 1.5948°according to the analysis and comparison of the actual curve data and the theoretical data curve.The experimental results showed that the simulation angle curve and the actual angle curve were consistent with the theoretical standard manual stirring motion characteristic curve,which verified the correctness of the design and modeling of the stirring mechanism.The tea was mechanically stirred by the stirring mechanism to achieve the desired stirring effect,which verified the feasibility of the stirring machine.

Beneficial Effects of Oolong Tea Consumption on Diet-induced Overweight and Obese Subjects

Objective:To determine the anti-obesity effects of oolong tea on diet-induced overweight or obesity.Methods:A total of 8 g of oolong tea a day for 6 weeks was ingested by 102 diet-induced overweight or obese subjects.The body fat level of the subjects was determined at the same time by taking body weight, height and waist measurements.The thickness of the subcutaneous fat layer was also determined on the abdomen 3 cm to the right of the navel by the ultrasonic echo method.On the other hand,effects of oolong...

Relation of tea ingestion to salivary redox and flow rate in healthy subjects

The biochemistry of human saliva can be altered by food intake.The benefits of tea drinking were extensively studied but the influence of tea ingestion on human saliva has not been revealed.The work aimed to investigate the immediate and delayed effect of vine tea,oolong tea and black tea intake on certain salivary biochemistry and flow rate.The saliva samples of healthy subjects were collected before,after and 30 min after tea ingestion.The chemical compositions and antioxidant capacity of tea samples were analyzed to correlate with salivary parameters.Principal component analysis indicated that the effects of vine tea consumption were dominated by increasing salivary flow rate(SFR),production rate of total protein(TPC),thiol(SH),malondialdehyde,catalase activity and antioxidant capacity(FRAP)in saliva.The antioxidant profile of studied tea samples(FRAP,polyphenols,flavonoids)was positively correlated with salivary SFR,TPC,SH and FRAP but negatively correlated with salivary uric acid concentration in saliva.

早青与晚青乌龙茶的挥发性成分差异

为探明鲜叶不同采摘时段对乌龙茶香气化学特征的影响,本研究将铁观音早青与晚青按传统工艺加工成乌龙茶,运用气相色谱-质谱法分析鲜叶和乌龙茶的挥发性成分,比较早青茶与晚青茶中挥发性成分的差异。结果表明,晚青茶所含挥发性组分总量比早青茶少28.3%,醇类化合物的含量及占比均处优势,尤其是异植醇和反-橙花叔醇。挥发性成分在鲜叶与乌龙茶中的组成特征差异较大,醇类和酸类化合物在鲜叶中的占比相近,但在乌龙茶中二者差异较大;早青与晚青包含56种共有挥发性成分,比其乌龙茶的共有成分多4种,但在鲜叶与乌龙茶共有42种成分中十六烷酸、二氢猕猴桃内酯、反-橙花叔醇、异植醇等受加工工艺的影响明显,且变化幅度较大。可见晚青与早青中挥发性成分的分布特征相异,晚青茶优于早青茶且清香突出。

茶树新品系‘福茗2号’区域试验报告

【目的】选育早生、高产、高香茶树新品种,满足消费需求的多样化。【方法】以‘黄棪’为对照,在福建福安、松溪、福州3个区试点对‘福茗2号’新品系的种植成活率、物候期(一芽一叶、一芽二叶和一芽三叶期)、鲜叶产量、制茶品质、抗性等方面进行为期6年(2016—2021年)的茶树品种区域试验。【结果】‘福茗2号’新品系种植成活率高,达89%以上;物候期比对照早1~2 d;鲜叶产量比对照高5%左右;制乌龙茶品质比对照高出0.5~1.1分;耐寒、耐旱性强,茶炭疽病和茶小绿叶蝉抗性均表现为抗。【结论】‘福茗2号’是一个早生、高产、优质、高抗的乌龙茶新品种,适宜在福建福安、松溪、福州及相似乌龙茶地区种植和推广应用。

响应面法优化乌龙茶提取茶多糖的工艺研究

以乌龙茶为原料,选用回流法提取茶多糖,根据Plackett-Burman实验设计考察提取温度、提取时间、提取次数、料液比等多种因素对茶多糖提取率的影响;在单因素实验基础上,运用Box-Behnken实验设计进行响应面剖析.实验结果显示,当提取温度100℃、提取时长80 min、料液比1∶50时,乌龙茶茶多糖的提取率显著增加,得率是6.13%.对最佳提取工艺开展验证,结果显示实测均值与模型估计值相近,表明该提取工艺平稳可行.

基于SBSE-GC-O-MS技术的3个代表性乌龙茶品种关键香气成分分析

为探究3个代表性乌龙茶品种关键香气成分,采用搅拌棒吸附萃取结合气相色谱-嗅闻-质谱(gas chromatography-olfactory-mass spectrometry,GC-O-MS)联用技术对黄旦、铁观音、金观音3个代表性乌龙茶品种关键香气成分进行鉴定和描述,结合香气活性值(odor activity value,OAV)、香气特征影响值和感官审评进行对比分析。感官审评表明,3个品种乌龙茶各表现出明显的品种特征香气,黄旦花香显,略带奶香,铁观音花香浓郁,金观音具甜果香,略带木质香。结合OAV及GC-O-MS鉴定结果表明,香叶醇、植醇、茉莉酸甲酯、反式-橙花叔醇、2-壬酮、苯乙醇等物质是黄旦的关键香气成分,赋予黄旦花香清高、奶香显的香气特征;铁观音中的芳樟醇、3,5-辛二烯-2-酮、氧化芳樟醇、顺式茉莉酮、脱氢芳樟醇、α-松油醇等物质呈多元性的花香,与其品种特征香气密切相关;金观音中的关键香气成分包括芳樟醇、藏花醛、香叶基丙酮、顺式茉莉酮、异丁子香酚等物质,是形成其甜果香与木质香品种特征香气的关键物质。

乌龙茶茶树品种制白茶的风味特征及特征组分分析

为探究乌龙茶品种所制白茶与传统白茶的风味品质差异,以紫玫瑰等8种乌龙茶品种所制白茶为研究对象,以福鼎大毫茶所制传统白茶为对照,结合感官审评、生化检测和多元统计分析手段进行分析。结果表明:乌龙茶品种所制白茶的外形、汤色较传统白茶暗,观感欠佳;而滋味和香气优于传统白茶。生化成分检测分析发现电导率、pH值、可溶性糖含量、游离氨基酸含量、没食子儿茶素没食子酸酯含量以及表没食子儿茶素没食子酸酯含量的差异是导致传统白茶与乌龙茶品种所制白茶滋味迥异的重要因素。挥发性物质检测表明:反式-2-壬醛、顺-3-壬烯-1-醇、棕榈酸甲酯、芳樟醇、亚油酸甲酯、柏木脑、甲酸香叶酯、苯乙醇、橙花醇、水杨酸甲酯、邻苯二甲酸二丁酯和植酮是影响传统白茶与乌龙茶品种所制白茶香型呈现的关键差异香气成分。本研究揭示了乌龙茶品种所制白茶与传统白茶间的风味品质差异,证明了乌龙茶品种具有开发花香型白茶的潜力,可为白茶风味进一步多元化提供理论参考。

不同烘焙程度‘春闺’闽北乌龙茶风味品质分析

采用感官审评、生化分析、超高效液相色谱三重四极杆串联质谱(UPLC-QqQ-MS)及顶空固相微萃取法结合气相色谱-飞行时间质谱联用技术(HS-SPME-GC-TOF-MS)对不同烘焙程度‘春闺’闽北乌龙茶进行检测分析,通过建立偏最小二乘判别分析模型、趋势模型探究其感官品质、常规生化成分、儿茶素组分、氨基酸组分及挥发性物质等方面的差异。结果表明:轻火‘春闺’感官审评总分为(91.3~93.65),略低于中火‘春闺’(93.6~94.15);生化成分中,轻火‘春闺’的氨基酸含量显著高于中火(P<0.05),中火‘春闺’的的茶黄素、茶褐素含量及酚氨比显著高于轻火火‘春闺’(P<0.05);对氨基酸组分进行TAV值计算得到,轻火‘春闺’主要呈味贡献氨基酸为半胱氨酸、天冬氨酸、谷氨酸及茶氨酸,中火‘春闺’为半胱氨酸、谷氨酸及茶氨酸;在主要差异挥发性物质中,轻火‘春闺’的橙花叔醇、吲哚、α-法尼烯及顺-茉莉酮等花香类挥发性物质含量显著高于中火‘春闺’(P<0.05);中火‘春闺’的顺-芳樟醇氧化物、茶吡咯、2,5-二甲基吡嗪、糠醛、脱氢-β-紫罗兰酮及二氢猕猴桃内酯含量显著高于轻火‘春闺’(P<0.05)。‘春闺’闽北乌龙茶适合采用中火烘焙工艺,其滋味醇爽浓厚有花香,香气类型呈现为花香馥郁,综合品质较优。本研究为‘春闺’闽北乌龙茶配套加工工艺和风味品质提供一定的理论依据。

不同品种乌龙茶烘焙前后化学成分差异及体外活性

为研究不同乌龙茶原料经烘焙处理后物质基础变化规律及活性差异,分析了不同乌龙茶原料烘焙前后中的总多酚、总黄酮茶多糖、儿茶素组分及咖啡碱含量差异,采用体外酶生化反应手段,考察不同乌龙茶原料及成品对α-葡萄糖苷酶、脂肪酶和黄嘌呤氧化酶的抑制能力。结果显示,茶多酚含量(质量分数)由原料中的13.75%~15.59%下降至成品的12.41%~14.14%,铁观音、肉桂高于老枞水仙、三印水仙和大红袍(P<0.05);原料中总黄酮含量(质量分数)在0.71%~1.00%之间,铁观音原料总黄酮含量最低,与其他原料相比有显著差异(P<0.05),除铁观音外,其余乌龙茶样品总黄酮含量在烘焙处理前后差异不显著(P>0.05);原料中茶多糖含量(质量分数)为1.14%~1.82%,烘焙后上升到成品的1.64%~2.12%。所有样品均表现出对于α-葡萄糖苷酶、脂肪酶和黄嘌呤氧化酶的抑制能力,且烘焙后的成品对于α-葡萄糖苷酶、脂肪酶的抑制能力减弱,肉桂表现出较高的抑制α-葡萄糖苷酶及脂肪酶活性的能力。乌龙茶烘焙后对于黄嘌呤氧化酶的抑制能力增强,IC50值由13.21~17.42 mg/mL降低为成品的10.26~14.38 mg/mL。

植物基鹰嘴豆茶乳饮料的研制及其稳定性分析

以鹰嘴豆和乌龙茶为主要原料制作植物基茶乳饮料,以静置分层率和感官评分为指标,在单因素试验的基础上通过响应面法优化茶乳饮料配方,并对其品质进行分析。结果表明:茶乳饮料的最优配方为以茶乳饮料质量为基准,茶汤添加量14.90%、豆乳添加量55.30%、赤藓糖醇添加量7.20%、单甘酯添加量0.01%,在此条件下制备的茶乳饮料的感官评分为84.50、静置分层率为25.79%,茶乳饮料的口感细腻,带有豆乳味和茶香味,色泽均匀无杂质。

模糊数学综合评价法结合正交试验优化乌龙茶饮浸提工艺

[目的]优化乌龙茶浸提工艺。[方法]以感官评价和理化指标为评价指标,通过模糊数学综合评价法构建综合评价体系,以模糊综合评价得分为评价指标,在单因素试验结果的基础上,通过正交试验法优化乌龙茶浸提工艺。[结果]各因素对乌龙茶浸提工艺的影响表现为时间>料液比>温度>β-环状糊精添加量,乌龙茶浸提最优工艺为浸提温度75℃,β-环状糊精添加量0.1%,浸提时间30 min,料水比1∶100。[结论]经验证试验表明,在该条件下模糊综合评价得分最高,该法科学、稳定、可行,能为乌龙茶浸提工艺的研究实践提供一定的理论支持和指导。

福建地区乌龙茶铝污染状况调查及暴露风险评估

为了解福建地区乌龙茶中铝含量情况,用电感耦合等离子体质谱法对市售的1456批次乌龙茶中铝含量进行了测定,并对膳食暴露风险进行评估。结果显示,乌龙茶中铝含量水平较高,范围在121.6 mg/kg~2368.2 mg/kg,平均值为936.8 mg/kg,不同产地乌龙茶的铝含量差异明显,具有统计学意义。茶汤中溶出的铝对饮茶人群存在潜在的风险,因此开展茶叶中铝的风险评估十分必要。

青枣芒果乌龙茶复合饮料的研制及贮藏

漳州地区种植的青枣品种是“牛奶枣”和“五十”,2个品种一起种植有利于授粉结果。但是,品种“五十”鲜果往往销售情况不好,加工成饮料可以提升其价值。以青枣、芒果、乌龙茶为原料,研究青枣芒果乌龙茶复合饮料的加工与贮藏。通过单因素试验和正交试验,确定青枣芒果乌龙茶饮料的最佳味道组合,即青枣和芒果的果肉质量比为4∶6(总量以100 g计),乌龙茶汤添加量50%,糖酸比90,可溶性固形物含量9%。在此组合下,现调出的饮料颜色呈现鲜亮黄色,酸甜适中,香气宜人。在贮藏方面,添加一定量的护色剂抗坏血酸和色素β-胡萝卜素,并用含铝的复合包装材料,能够长时间护色。羧甲基纤维素钠∶黄原胶比为1∶2,果肉∶水在1∶5~1∶3,饮料几乎不分层。

铁皮石斛花乌龙茶复合饮料制备工艺研究

随着消费者对健康饮品需求的日益增长,复合饮料因其丰富的营养价值和独特的口感而受到广泛关注。铁皮石斛花和乌龙茶作为传统的中草药和茶叶,具有多种保健功能。现代研究表明乌龙茶具有降血脂、抗氧化、减脂减肥、消炎抑菌、提神、利尿等功效。基于此,本文主要根据铁皮石斛花特有的功效与作用,以铁皮石斛花为原料,通过相应的技术流程加工方法步骤而制成铁皮石斛花乌龙茶复合饮料,旨在探索铁皮石斛花与乌龙茶复合饮料的制备工艺,为开发新型健康饮品提供参考。