White and Green Teas (Camellia sinensis var. sinensis): Variation in Phenolic,Methylxanthine, and Antioxidant Profiles

Abstract: Recent investigations have associated white teas with anti-carcinogenic, immune-boosting, and antioxidative properties that may impact human health in a manner comparable to green teas. An in-depth chemical analysis of white tea types was conducted to quantify polyphenols and antioxidant potential of 8 commercially available white teas, and compare them to green tea. Extraction and HPLC protocols were optimized and validated for the quantification of 9 phenolic and 3 methylxanthine compounds to examine inter- and intra-variation in white and green tea types and subtypes. A sampling strategy was devised to assess various subtypes procured from different commercial sources. Variation in antioxidant activity and total phenolic content (TPC) of both tea types was further assessed by the 1-1-diphenyl-2-picrylhydrazyl (DPPH) and Folin–Ciocalteau (F–C) assays, respectively. Total catechin content (TCC) for white teas ranged widely from 14.40 to 369.60 mg/g of dry plant material for water extracts and 47.16 to 163.94 mg/g for methanol extracts. TCC for green teas also ranged more than 10-fold, from 21.38 to 228.20 mg/g of dry plant material for water extracts and 32.23 to 141.24 mg/g for methanol extracts. These findings indicate that statements suggesting a hierarchical order of catechin content among tea types are inconclusive and should be made with attention to a sampling strategy that specifies the tea subtype and its source. Certain white teas have comparable quantities of total catechins to some green teas, but lesser antioxidant capacity, suggesting that white teas have fewer non-catechin antioxidants present. Practical Application: In this investigation white and green teas were extracted in ways that mimic common tea preparation practices, and their chemical profiles were determined using validated analytical chemistry methods. The results suggest certain green and white tea types have comparable levels of catechins with potential health promoting qualities. Specifically, the polyphenolic content of green teas was found to be similar to certain white tea varieties, which makes the latter tea type a potential substitute for people interested in consuming polyphenols for health reasons. Moreover, this study is among the first to demonstrate the effect subtype sampling, source of procurement, cultivation, and processing practices have on the final white tea product, as such analysis has previously been mostly carried out on green teas.     

Analysis of the theaflavin composition in black tea (Camellia sinensis) for predicting the quality of tea produced in Central and Southern Africa

A parameter of black tea that correlates with quality is highly desired. Twenty good and 20 poor quality tea clones were selected from the breeding programme at the Tea Research Foundation (Central Africa) (TRF(CA)). The theaflavin (TF) composition of the black tea manufactured from each clone was analysed by capillary electrophoresis and correlated with total scores and valuation from two tea tasters with regression analysis. The significance of the differences between the 20 good and 20 poor quality tea clones was determined with the Student t‐test and the distribution‐free Kruskal–Wallis test. The sum of the TFs of the black tea correlated well (r = 0.785, P = 0.0002) with the value of the tea. Of the individual TFs determined in the black tea, the highest correlation was obtained with TF‐3′‐monogallate (TF‐B) (r = 0.788, P = 0.0016), TF‐3‐monogallate (TF‐A) (r = 0.741, P = 0.0004) and free TF (TF‐f) (r = 0.705, P = 0.0002). TF‐B (m = 24.90) followed by TF‐A (m = 12.48) showed the steepest slopes against value, making them good indicators for value. The TF‐digallate (TF‐dg) content did not show significant correlation with value (r = 0.316, P = 0.358). The individual TF content thus can be used for optimising the black tea manufacturing process in Central and Southern Africa. © 2002 Society of Chemical Industry     

Uptake of fluoride by tea plant (Camellia sinensis L) and the impact of aluminium

Tea plant (Camellia sinensis L) accumulates large amounts of fluoride in mature leaves from soils of normal fluoride availabilities, but the properties of fluoride absorption by this plant species are not well understood. The present study examined the characteristic of fluoride uptake by tea plants and the impact of Al with solution and soil experiments. The results showed that the fluoride taken up by tea plants was largely and readily transported, in particular to the leaves. The fluoride in leaves increased linearly with fluoride concentrations in the uptake solution (R² = 0.75, P < 0.001) or in the soil (R² = 0.88, P < 0.001), whereas those in root and stem were only marginally influenced. Including Al in solution or adding Al to the soil apparently increased the uptake and translocation of fluoride to the leaves. The concentrations of fluoride in the leaves were significantly (P < 0.05) increased by 19.1% or 37.7% when 18.5 µmol l^?1 Al or 74.1 µmol l^?1 Al respectively was included in the uptake solution, compared with the control without Al during an uptake period of 22 h. Similarly, Al application (100 mg kg^?1) to soil led to significantly higher fluoride concentrations in mature leaves and new shoots (one bud with three leaves). By contrast, the concentrations of Al in leaves in solution and soil experiments were not affected by fluoride and Al treatments. Nevertheless, higher Al concentrations after Al and fluoride additions were observed in the new shoots in soil experiments. Copyright © 2003 Society of Chemical Industry     

柑橘-红茶咀嚼片的研制及其体外模拟消化中酚类化合物稳定性和抗氧化能力的评价

目的 研制柑橘-红茶咀嚼片并探究体外模拟消化前后酚类化合物的稳定性和抗氧化活性。方法 以柑橘、红茶粉作为材料,采用单因素实验得出柑橘-红茶咀嚼片的最佳配比,随后进行体外模拟消化即模拟口腔、胃、肠消化,对消化前后的总酚、总黄酮以及1,1-二苯基-2-苦基肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基、2,2’-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt,ABTS]阳离子自由基清除能力、还原力进行研究。结果 柑橘-红茶咀嚼片最佳配比为:茶柑混合物25%、麦芽糊精40.6%、赤藓糖醇33.3%、硬脂酸镁1.1%。该条件下制备的柑橘-红茶咀嚼片感官评分、硬度、脆碎度和崩解度分别为(83.3000±0.7149)分、(38.6667±0.5774) N、(7.2000±0.0000) min和(25.7367±0.5326) min。在体外模拟消化后总酚含量整体上逐渐减小,总黄酮含量呈现先减少后增加的趋势;DPPH自由基清...     

茶树白花和紫花的挥发性代谢物分析

目的 探究茶(Camellia sinensis)树白花和紫花中的挥发物质及其组成差异。方法 利用气相色谱-质谱法分析鸟王种茶树的白花和变异紫花的挥发性代谢组。结果 在两种茶树花中检测出挥发性代谢物共152个,主要为芳烃类、烃类、醇类、酮类、醛类、酚类、酯类、萜类和杂环化合物类等。筛选出差异代谢物共12种,其中有7种在紫花中上调,含量较高的有甲基丁香酚、α-紫罗兰酮;5种在紫花中下调,其中在白花中含量较高的有3-异丙烯基-2,5-二甲基-3,4-己二烯-2-醇、反式-3-己烯基乙酸酯、五甲基-苯。结论 本研究揭示了甲基丁香酚和α-紫罗兰酮是茶树紫花香气特征中,与白花相比最主要的差异成分,紫花的香气较白花更芬芳;为进一步探究不同颜色的茶树花的呈香机制、以及对相关资源的开发利用提供了一定的参考。     

Molecular evidence for maternal inheritance of the chloroplast genome in tea,Camellia sinensis (L.) O. Kuntze

BACKGROUND: Tea is the most consumed beverage worldwide after water. Yet very little is known about the genetics of tea in comparison with other crop species. Here we have taken advantage of the polymorphic nature of microsatellite DNA to investigate the mode of chloroplast inheritance in tea, Camellia sinensis (L.) O. Kuntze. This is important for the correct interpretation of phylogeny and introgression data as well as assessing the suitability of chloroplast transformation as a means for transgene containment in tea. RESULTS: The study was based on six Japanese tea cultivars, namely Aj2, CK23, Hatsumomiji, Nka05, Yamanoibuki and Kanayamidori used to generate four informative families. The parental pairs in the crosses differed at a single chlroroplast locus with respect to an imperfect microsatellite repeat of 16 nucleotide bases. In agreement with earlier cytological studies, all 61 progeny displayed a cpDNA profile that was consistent with the maternal inheritance of chloroplasts in tea. CONCLUSIONS: The data generated here provide the first molecular evidence of the plastid inheritance in tea. However, we suggest that additional families and polymorphic markers be screened for increasing the confidence in the observed maternal inheritance of chloroplasts in this important crop species. Copyright © 2011 Society of Chemical Industry     

Diversity among various forms of catechins and its synthesizing enzyme (phenylalanine ammonia lyase) in relation to quality of black tea (Camellia spp.)

BACKGROUND: Quality of tea depends on the cultivar and climatic conditions. Biochemical pathways within the plant and climatic factors can result in noticeable changes in chemical composition, which determine the quality of tea. Black tea quality attributes are influenced by various forms of catechins, namely gallated, non‐gallated, dihydroxylated and trihydroxylated catechins and their ratios. Hence the variations in grouped catechins and their synthesizing enzyme in relation to quality of south Indian black tea grown in different seasons and different cultivars were studied. RESULTS: Gallated, non‐gallated, dihydroxylated, trihydroxylated catechins and catechin index were significantly higher in crop shoots harvested during summer. A significant and wide diversity in various forms of catechins was noticed among the cultivars tested. Among the cultivars, UPASI‐3 registered the higher amount of various forms of catechins and activity of phenylalanine ammonia lyase (PAL), followed by UPASI‐9 and UPASI‐17 respectively, while the lowest amount was exhibited by ‘Assam’ seedlings and TRI‐2043. CONCLUSION: Overall quality as evaluated by tea tasters was positively correlated to the cultivars and seasons tested. This positive correlation can be attributed to higher levels of grouped catechins and PAL activity. Thus the contents of various forms of catechins could be the most important quality parameter of the south Indian black teas. Copyright © 2010 Society of Chemical Industry     

Understanding the biosyntheses and stress response mechanisms of aroma compounds in tea (Camellia sinensis) to safely and effectively improve tea aroma

Abstract

Metabolite formation is a biochemical and physiological feature of plants developed as an environmental response during the evolutionary process. These metabolites help defend plants against environmental stresses, but are also important quality components in crops. Utilizing the stress response to improve natural quality components in plants has attracted increasing research interest. Tea, which is processed by the tender shoots or leaves of tea plant (Camellia sinensis (L.) O. Kuntze), is the second most popular beverage worldwide after water. Aroma is an important factor affecting tea character and quality. The defense responses of tea leaves against various stresses during preharvest (tea growth process) and postharvest (tea manufacturing) processing can result in aroma formation. Herein, we summarize recent investigations into the biosyntheses of several characteristic aroma compounds prevalent in teas and derived from volatile fatty acid derivatives, terpenes, and phenylpropanoids/benzenoids. Several key aroma synthetic genes from tea leaves have been isolated, cloned, sequenced, and functionally characterized. Biotic stress (such as tea green leafhopper attack) and abiotic stress (such as light, temperature, and wounding) could enhance the expression of aroma synthetic genes, resulting in the abundant accumulation of characteristic aroma compounds in tea leaves. Understanding the specific relationships between characteristic aroma compounds and stresses is key to improving tea quality safely and effectively.

     

茶叶籽中总黄酮的提取及结构的初步鉴定

研究茶叶籽中总黄酮的提取工艺,在单因素实验基础上,选取液料比、提取温度和乙醇体积分数3个影响因素,以总黄酮含量为评价指标,通过Box-Benhnken的中心组合设计原理和响应面分析法优化提取工艺,确定最佳提取条件为:液料比26∶1(mL∶g),乙醇体积分数58%,提取温度82℃,提取时间2h,茶叶籽中总黄酮含量为11.174mg/g。通过颜色反应和紫外光谱特征,初步鉴定茶叶籽黄酮为二氢黄酮类化合物。     

Influence of age after pruning on the levels of flavanols and other bioconstituents in tea (Camellia sinensis)

The influence of age after pruning on the biochemical constituents such as catechin fractions, the key enzyme phenylalanine ammonia lyase (PAL) and other compounds which contribute to black tea quality as well as root carbohydrates was investigated. Analyses were done consecutively for 4 years after pruning. The concentration of total catechins was found to be highest in the ‘Cambod’ cultivar UPASI‐17, followed by UPASI‐3 and UPASI‐9 representing ‘Assam’ and ‘China’ jats respectively, under prevailing conditions. A concomitant increase in total catechin content was found up to 3 years followed by a decrease in the fourth year of the pruning cycle, irrespective of the cultivar. PAL, the precursor of catechin biosynthesis, also increased up to 3 years and showed a sharp decrease thereafter. On the other hand, the root carbohydrate reserve and the caffeine content of tea leaves increased steadily up to the fourth year. All the genotypes studied showed the same trend. However, variability in catechin contents was prominent in different clones. Copyright © 2005 Society of Chemical Industry     

Lead contamination in different varieties of tea plant (Camellia sinensis L.) and factors affecting lead bioavailability

BACKGROUND: There has been increasing concern in recent years about the concentration of lead (Pb) in tea. However, little research has been done to address questions concerning the distribution of Pb in different varieties of tea plant and the differences among tea plant varieties in their uptake and accumulation of Pb from the soil. Therefore the aim of this study was to investigate the accumulation of Pb in different tea plant varieties and the factors affecting Pb bioavailability. RESULTS: Three patterns of Pb distribution could be observed in different plant parts among the eight tea varieties surveyed, as well as a linear relationship between the Pb concentration in fine roots and the exchangeable Pb fraction in the corresponding soil. The uptake of Pb by fine roots increased significantly as the soil pH decreased. The average ratios of Pb concentration in fine roots to those in young stems and young leaves were 5.18 and 31.80 respectively. In fine roots the Pb concentration varied from 22.7 to 61.6 mg kg^?1. CONCLUSION: The results indicated that the uptake, transport and accumulation of Pb by tea plant organs were strongly governed by soil conditions and tea variety, thus providing tea producers with useful information on variety selection for the production of quality teas containing low levels of Pb. Copyright © 2010 Society of Chemical Industry     

Isolation and identification of spermidine derivatives in tea (Camellia sinensis) flowers and their distribution in floral organs

BACKGROUND: Recently, tea (Camellia sinensis) flowers have attracted increasing interest because of their content of bioactive compounds such as catechins. The aim of this study was to investigate the occurrence of some characteristic compounds in tea flowers. RESULTS: A principal component analysis of metabolites using ultra‐performance liquid chromatography/time‐of‐flight mass spectrometry showed differences in metabolite profile between flowers and leaves of C. sinensis var. Yabukita. Four spermidine derivatives were isolated from tea flowers. One of them was determined as N¹,N⁵,N¹⁰‐tricoumaroyl spermidine based on NMR, MS and UV data. The other three were identified as feruoyl dicoumaroyl spermidine, coumaroyl diferuoyl spermidine and triferuoyl spermidine based on MSⁿ data. Tricoumaroyl spermidine as the major spermidine conjugate was not detected in tea leaves. Furthermore, it decreased during floral development and mainly occurred in anthers. CONCLUSION: This study has provided the first evidence that spermidine‐phenolic acid conjugates occur in tea flowers in considerable amounts. Their presence should prompt a reconsideration of the ecological role of tea flowers. From an economic point of view, tea flowers might be suitable as a raw material in the healthcare food and pharmaceutical industries. Copyright © 2012 Society of Chemical Industry     

A comprehensive review of polyphenol oxidase in tea (Camellia sinensis): Physiological characteristics,oxidation manufacturing,and biosynthesis of functional constituents

Polyphenol oxidase (PPO) is a metalloenzyme with a type III copper core that is abundant in nature. As one of the most essential enzymes in the tea plant (Camellia sinensis), the further regulation of PPO is critical for enhancing defensive responses, cultivating high-quality germplasm resources of tea plants, and producing tea products that are both functional and sensory qualities. Due to their physiological and pharmacological values, the constituents from the oxidative polymerization of PPO in tea manufacturing may serve as functional foods to prevent and treat chronic non-communicable diseases. However, current knowledge of the utilization of PPO in the tea industry is only available from scattered sources, and a more comprehensive study is required to reveal the relationship between PPO and tea obviously. A more comprehensive review of the role of PPO in tea was reported for the first time, as its classification, catalytic mechanism, and utilization in modulating tea flavors, compositions, and nutrition, along with the relationships between PPO-mediated enzymatic reactions and the formation of functional constituents in tea, and the techniques for the modification and application of PPO based on modern enzymology and synthetic biology are summarized and suggested in this article.     

Occurrence and distribution of lipoxygenase in Camellia sinensis (L) O Kuntze and their changes during CTC black tea manufacture under southern Indian conditions

The optimal activity of tea lipoxygenase was found to be at pH 7·5 and 9·0, indicating the presence of two types of isoenzymes. Tea lipoxygenase was inhibited by cyanide and a small fraction appeared to be quite heat stable. Clonal and seasonal variations in lipoxygenase activity was significant. An increase in lipoxygenase activity was observed with leaf maturity. The lipoxygenase activity decreases with age from pruning and increases with an increase in plucking interval. The changes of lipoxygenase activity during CTC manufacture revealed that it increased with the degree of withering and upon rolling. However, a gradual decline was recorded during the fermentation and drying processes. The residual lipoxygenase activity in black tea is expected to affect its quality on storage. © 1998 Society of Chemical Industry.     

Reactions with phenolic substances can induce changes in some physico-chemical properties and activities of bromelain – the consequences for supplementary food products

Bromelain was allowed to react with phenolic compounds. The activity and selected physico‐chemical properties of the resulting derivatives were characterized. In vitro experiments showed that the proteolytic activity of bromelain was inhibited. Bromelain also serves as a food protein, because food stuffs based on pineapple contain relatively high concentrations of bromelain. In vitro digestion of bromelain derivatives with the main proteolytic enzymes of the gastrointestinal tract was also adversely affected. A covalent attachment of the phenolic compounds was identified at the tryptophan, free amino (lysines and N‐terminal) and thiol groups of bromelain. A decrease in solubility of the derivatives was observed. The isoelectric point was shifted to lower pH values and high molecular weight fractions were identified. All effects observed depended on the reactivity of the phenolic substances. Two supplementary food products containing both bromelain and quercetin were also tested in terms of their proteolytic activity and digestibility.     

Effect of weather conditions on concentration of calcium,manganese, zinc,copper and iron in green tea (Camellia sinensis (L) O kuntze) leaves of North-Western India

Variations of calcium, manganese, zinc, copper and iron contents in green tea leaves due to weather conditions were studied for three cropping seasons with a view to provide information on nutritional requirements to boost productivity. The concentrations of these micronutrients were related to the uptake capability of tea plants as affected by different weather parameters. High temperature and high atmospheric evaporative demand assisted calcium uptake whereas high humidity and high rainfall reduced it. Low temperature and high humidity reduced manganese uptake. High weekly evaporation, weekly relative humidity and accumulated rainfall depressed the uptake of zinc, copper and iron in green tea shoots.     

Micronutrients (B,Co, Cu,Fe, Mn,Mo, and Zn) content in made tea (Camellia sinensis L.) and tea infusion with health prospect: A critical review

Tea (Camellia sinensis L.) is a perennial acidophilic crop, and known to be a nonalcoholic stimulating beverage that is most widely consumed after water. The aim of this review paper is to provide a detailed documentation of selected micronutrient contents, viz. boron (B), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn) in made tea and tea infusion. Available data from the literature were used to calculate human health aspect associated with the consumption of tea infusion. A wide range of micronutrients reported in both made tea and tea infusion could be the major sources of micronutrients for human. The content of B, Co, Cu, Fe, Mn, Mo, and Zn in made tea are ranged from 3.04 to 58.44 μg g^?1, below detectable limit (BDL) to 122.4 μg g^?1, BDL to 602 μg g^?1, 0.275 to 13,040 μg g^?1, 0.004 to 15,866 μg g^?1, 0.04 to 570.80 μg g^?1 and 0.01 to 1120 μg g^?1, respectively. Only 3.2 μg L^?1 to 7.25 mg L^?1, 0.01 μg L^?1 to 7 mg L^?1, 3.80 μg L^?1 to 6.13 mg L^?1, 135.59 μg L^?1 ?11.05 mg L^?1, 0.05 μg L^?1 to 1980.34 mg L^?1, 0.012 to 3.78 μg L^?1, and 1.12 μg L^?1 to 2.32 μg L^?1 of B, Co, Cu, Fe, Mn, Mo, and Zn, respectively, are found in tea infusion which are lower than the prescribed limit of micronutrients in drinking water by World Health Organization. Furthermore, micronutrient contents in tea infusion depend on infusion procedure as well as on the instrument used for analysis. The proportion of micronutrients found in different tea types are 1.0–88.9% for B, 10–60% for Co, 2.0–97.8% for Cu, 67.8–89.9% for Fe, 71.0–87.4% for Mn, 13.3–34% for Mo, and 34.9–83% for Zn. From the results, it can also be concluded that consumption of three cups of tea infusion per day does not have any adverse effect on human health with respect to the referred micronutrients rather got beneficial effects to human.