Specialty Teas Research Articles

Studying and enhancing the hypoglycemic effect of Pingyang Yellow Soup and preliminary exploration of its internal mechanisms in a zebrafish model

Yellow tea belongs to specialty tea, and it is loved by consumers because of its unique flavor and taste. Herein, Pingyang Yellow Soup (PYS, a kind of yellow tea) was chosen. In this study, we investigated the effects of PYS on the hypoglycemic effect of the zebrafish model and explored its potential mechanism of action. Results showed that PYS had very strong and definite hypoglycemic biological activity. Meanwhile, different water/material ratios, extraction temperatures, and extraction times had significant influence on the hypoglycemic performance of PYS, and the strength of influence was ranked as extraction temperature > extraction time > water/material ratio. In addition, results showed that the removal rate of tea polyphenols (TPs) in PYS had a strong linear correlation to the degree of decreased hypoglycemic performance, indicating the hypoglycemic performance was closely related to TPs levels. The comprehensive analysis revealed that the nor-sugar rate of PYS had a variety of regression relationships with its components, and the best hypoglycemic performance does not require the highest content levels of each component but depends on what it is, and there exists a relative optimal value, which provides basic information for exploring the internal mechanism of action of hypoglycemic effects and developing functional tea drinks of PYS.

Insights on the Nutraceutical Properties of Different Specialty Teas Grown and Processed in a German Tea Garden.

European countries have recently started experimenting with growing and producing their own teas in small quantities, mainly for the specialty tea sector. To characterize European teas, this study investigated a set of five tea types obtained from different Camellia sinensis varieties/cultivars, representing various oxidation grades (green, white, yellow, oolong, black), all grown and processed in the only tea garden in Europe (in Germany) that focuses on all five types. Hot and cold brews were studied by measuring the total phenolic (TPC) and flavonoid contents (TFC), the antioxidant capacity and UV-Vis spectra, also with the objective of discriminating between the different tea types and the different plant varieties. The dried leaves were analyzed to measure the content of essential and toxic elements and by ATR-FTIR spectroscopy to determine a chemical fingerprint for identifying the tea varieties and types. The average levels of TPC (hot brew = 5.82 ± 2.06; cold brew = 5.4 ± 2.46 mM GAEq), TFC (hot brew = 0.87 ± 0.309; cold brew = 0.87 ± 0.413 mM CAEq), and antioxidant capacity (ORAC assay-hot brew = 20.9 ± 605; cold brew = 21.8 ± 8.0 mM TXEq, ABTS assay-hot brew = 15.2 ± 5.09; cold brew = 15.1 ± 5.8 mM TXEq, FRAP assay-hot brew = 9.2 ± 3.84; cold brew = 10.4 ± 5.23 mM AAEq) observed compared well with those from other parts of the world such as China, Africa, and Taiwan. The hazard quotient <1 and the hazard index of 0.14 indicate that there is no non-carcinogenic risk from consumption of these teas. The obtained information is essential for elucidating the characteristics and the impact of tea processing and tea variety on the health benefits of these tea products coming from a single European tea garden. This multifaceted approach would help tea growers in Europe increase their knowledge on the health attributes of the teas they grow, ultimately leading to optimization of the nutraceutical properties of these teas.

Ted's Teas: A Two‐Part Accounting and Audit “Crossover Case”*

AbstractThis fictional case is based on a real specialty tea company in Nova Scotia. Ted's Teas is a two‐part crossover case that illustrates the integration of financial accounting and audit learning outcomes applied to real‐world scenarios. In Part 1, students assume the role of an internal accountant and apply knowledge of the Chartered Professional Accountants (CPA) of Canada's CPA Way to identify how to treat leases, changes in policy, and estimates as part of accounting knowledge under both Accounting Standards for Private Enterprises and IFRS frameworks. In Part 2, students “cross over” and change roles, so they are now external auditors for Ted's Teas, tasked to provide an analysis of risk of material misstatement, recommend an audit approach, and develop substantive procedures. This two‐part case presents opportunities for students to demonstrate technical competence in multiple areas, either separately in two different courses or combined in one “capstone” or case course. The case and teaching notes, including the marking rubrics, were adapted from principles used to train and evaluate CPA Professional Education Program candidates, tailored to an appropriate level for undergraduate and graduate learners.

Characterization of Some Perennial Pigmented Tea Accessions of Assam

Tea leaves has high antioxidant activity mainly due to presence of high amount of flavonoids and to some extent presence of pigments and has been a potential important raw material for the pharmaceutical industry. Therefore a study had been under taken to evaluate twenty (20 nos.) pigmented tea accessions exhibiting morphological variations of Experimental Garden for Plantation Crops, Assam Agricultural University, Assam to profile based on shoot growth and biochemical characters by field survey and laboratory investigation during the period 2017-18. Post hoc analysis was used to test the significance level and correlation similarity co-efficient matrix was used to analyze the genetic relationship among clones.&#x0D; The plucking point density which is an important criteria from yield point of view was found to be highest in THT 028 (0.158 g) with maximum fresh weight of young shoot for both Light Prune (LP) and Medium Skiff (MS) years whereas the maximum dry weight was found in THT 035 (0.036 g) followed by THT 028 (0.035 g) in both LP and MS years. An increasing trend of, antioxidant and total catechin content observed from rain flush to autumn flush in all the germplasms. The germplasms with purple young shoot colour THT 024, THT 032 and THT 039 had the highest anthocyanin content (39 mg/l, 43.7 mg/l and 40.56 mg/l respectively) and they can be further studied for development of specialty tea. The germplasms with higher catechin content (THT 027, THT 030 and THT 034) can be studied for development of parent material for green tea manufacturing. On hierarchical cluster analysis based on dendogram, THT 024, THT 032 and THT 039 formed discriminated clusters on the basis of shoot characters and biochemical characters which can be selected for future breeding programme.

Evaluation of Sensory Quality for Taiwanese Specialty Teas with Cold Infusion Using CATA and Temporal CATA by Taiwanese Consumers.

The market size of varied carbonated teas and bottled ready-to-drink tea products in Taiwan has surpassed that of traditional Taiwan tea with hot infusion. The consumption behavior of Taiwanese consumers for new and varied types of cold infusion tea products has also differed from that of traditional hot infusion ones. More kinds of Taiwan tea with different fermentation levels are gradually being used as raw materials for various cold infusion tea products. Therefore, to study consumers’ responses towards cold-brewed tea has become more important for the market of tea in Taiwan. This study recruited Taiwanese consumers to taste seven Taiwanese specialty tea infusions with various degrees of fermentation, and their opinions were gathered by questionnaires composed of check-all-that-apply (CATA), and temporal check-all-that-apply (TCATA) questions and hedonic scales. We found that both CATA and TCATA data agreed that the sensory features of unfermented and lightly semi-fermented tea infusions could be plainly distinguished from the ones of heavily semi-fermented and fully fermented teas based on correspondence analyses. Through CATA and TCATA, the sensory characteristics of the cold-brewed tea of various fermentation degrees could be clearly identified. The first-hand information of cold tea beverages analyzed through this study could be useful for the development of the market in Taiwan. The proper level of bitterness, astringency, fresh tea leaf flavor, and late sweetness were the essential qualities of cold infusions brewed from lightly fermented teas, which could be the best raw materials for production of cold tea beverages to satisfy as many consumers as possible.

Using Sensory Wheels to Characterize Consumers' Perception for Authentication of Taiwan Specialty Teas.

In the context of fair trade and protection of consumer rights, the aim of this study was to combat adulteration, counterfeiting, and fraud in the tea market, and rebuild the image of high-quality Taiwan teas. Experts at the Tea Research and Extension Station, Taiwan (TRES), are engaged in promotion of the systems of origin identification (AOC) and grading for authentication of Taiwan’s premium teas. From tea evaluation competitions (bottom-up quality campaign), the flavor descriptions and consumers’ perceptions were deconvoluted and characterized for the eight Taiwan specialty teas, namely, Bi-Luo-Chun, Wenshan Paochong, High-Mountain Oolong, Dongding Oolong, Tieh-Kuan-Yin, Red Oolong, Oriental Beauty, and Taiwan black tea. Then, according to the manufacturing processes, producing estates and flavor characters, the specialty teas were categorized into six sensory wheels. The flavor descriptors of the sensory wheels were also recognized in consumers’ feedback. In recent years, the performance of international trade in tea also demonstrates that the policy guidelines for authentication of specialty teas are helpful to the production and marketing. Furthermore, the development of sensory wheels of Taiwan’s specialty teas is the cornerstone to the establishment of the Taiwan-tea assortment and grading system (TAGs) for communication with the new generation consumers, enthusiasts, sellers, and producers.

Black and Green Tea as Well as Specialty Teas Increase Osteoblast Mineralization with Varying Effectiveness.

Many human studies suggest a benefit of tea consumption on bone health. The study objective was to compare the ability of different tea types to promote mineralization. Saos-2 cells underwent mineralization (5 days) in the presence of tea (white: WT, green: GT, black: BT, green rooibos: GR, or red rooibos: RR; 1 μg/mL of polyphenols) or control. Total polyphenol content (TPC, Folin-Ciocalteu's reagent), antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl [DPPH] scavenging), mineralization (Alizarin Red staining), gene expression quantitative reverse transcription PCR (RT-qPCR), and cell activity (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay) were determined. TPC was highest in GT and BT. The ability of each tea to inhibit DPPH also differed (WT, GT > RR) after normalizing for polyphenol quantity. Each tea increased mineralization and differences were observed among types (GT/BT/GR/RR > WT, GT = BT = GR, RR > BT/GT). mRNA expression of alkaline phosphatase (ALP) and ectonucleotide pyrophosphatase/phosphodiesterase (NPP1) remained unchanged, whereas osteopontin (OPN) and sclerostin (SOST) were reduced in cells treated with tea, regardless of type. At 24- and 48-h postexposure to tea, cell activity was greater in cells receiving any of the teas compared with vehicle control. Supplementation increased mineralization regardless of tea type with both rooibos teas and black tea stimulating greater mineralization than WT, whereas green tea is similar to the others. While future study is needed to confirm in vivo effects, the results suggest that consuming any of the teas studied may benefit bone health.

Important Sensory, Association, and Postprandial Perception Attributes Influencing Young Taiwanese Consumers' Acceptance for Taiwanese Specialty Teas.

For hundreds of years, Taiwan has been famous for its various specialty teas. The sensory features of these teas have been well specialized and standardized through sensory evaluations performed by tea experts in yearly competitions throughout history. However, the question arises of whether young Taiwanese consumers, whose dietary behaviors have become Westernized, agree with the conventional sensory standards and association/postprandial concepts in the traditional tea market of Taiwan. To study young Taiwanese consumers’ ideas towards traditional specialty teas, this research recruited 109 respondents, younger than the age of 30, to taste seven Taiwanese specialty tea infusions of various degrees of fermentation, and their opinions were gathered by questionnaires composed of check-all-that-apply (CATA) questions and hedonic scales. Through statistical analyses, we found that several tea sensory attributes which were emphasized in experts’ descriptive sensory evaluations were not appreciated by the young Taiwanese people. Instead, tea aroma and late sweetness/palatable/smooth/refreshing mouthfeels were the most important sensory attributes contributing to their tea preference. Overall, there would generally be no problem in serving young Taiwanese consumers lightly-fermented oolong teas that generate the highest digestive and lowest heartburn postprandial perceptions.

Insights into the Genetic Relationships and Breeding Patterns of the African Tea Germplasm Based on nSSR Markers and cpDNA Sequences.

Africa is one of the key centers of global tea production. Understanding the genetic diversity and relationships of cultivars of African tea is important for future targeted breeding efforts for new crop cultivars, specialty tea processing, and to guide germplasm conservation efforts. Despite the economic importance of tea in Africa, no research work has been done so far on its genetic diversity at a continental scale. Twenty-three nSSRs and three plastid DNA regions were used to investigate the genetic diversity, relationships, and breeding patterns of tea accessions collected from eight countries of Africa. A total of 280 African tea accessions generated 297 alleles with a mean of 12.91 alleles per locus and a genetic diversity (HS) estimate of 0.652. A STRUCTURE analysis suggested two main genetic groups of African tea accessions which corresponded well with the two tea types Camellia sinensis var. sinensis and C. sinensis var. assamica, respectively, as well as an admixed “mosaic” group whose individuals were defined as hybrids of F2 and BC generation with a high proportion of C. sinensis var. assamica being maternal parents. Accessions known to be C. sinensis var. assamica further separated into two groups representing the two major tea breeding centers corresponding to southern Africa (Tea Research Foundation of Central Africa, TRFCA), and East Africa (Tea Research Foundation of Kenya, TRFK). Tea accessions were shared among countries. African tea has relatively lower genetic diversity. C. sinensis var. assamica is the main tea type under cultivation and contributes more in tea breeding improvements in Africa. International germplasm exchange and movement among countries within Africa was confirmed. The clustering into two main breeding centers, TRFCA, and TRFK, suggested that some traits of C. sinensis var. assamica and their associated genes possibly underwent selection during geographic differentiation or local breeding preferences. This study represents the first step toward effective utilization of differently inherited molecular markers for exploring the breeding status of African tea. The findings here will be important for planning the exploration, utilization, and conservation of tea germplasm for future breeding efforts in Africa.

Antioxidant Capacity and Anti-diabetic Activity of Wild Berry Stem Infusions

The potential health benefits of green tea sand herbal teas have led to an increased demand of specialty tea products in the food market. Aims: To determine the proximate composition, phytochemical compositions and hypoglycemic potentials of the methanol and hot water extracts of the stems of wild berries from Eastern Canada. Study Design: Extraction of the air - dried stems of wild berries with bot h methanol and hot water, and testing the various extracts for the proximate composition, phytochemical composition and hypoglycemic potentials in comparison to green tea and rose - hip fruit. Place and Duration of Study : The stems of wild blueberry, raspber ry and blackberry along with rose - hip fruits were collected from the wild habitats of Windsor area of Nova Scotia, Canada in the year 2013; while the commercial green tea was purchased from a local store (Bulk B arn, Truro, Nova Scotia). Methodology: Phenol ic composition and characterization was done using spectrophotometric analyses and UPLC - ES I - MS. Carotenoid and caffeine content were measured using HPLC - PDA. The antioxidant capacities were evaluated using ferric reducing ability of plasma (FRAP), 2,2 diphenyl - 1 - picrylhydrazyl (DPPH)and oxygen radical absorbance capacity (ORAC) assays. The Original Research Article

Studies on quality of orthodox teas made from anthocyanin-rich tea clones growing in Kangra valley, India

Recently anthocyanin-rich purple tea varieties have been developed. The quality of these new purple tea varieties developed in Kangra valley was assessed, and compared with the quality of tea from standard Kangra clone. Purple tea shoots (PL) recorded higher amount of polyphenols compared to standard green tea shoot (GL) while epigallocatechin gallate (EGCG) recorded higher levels in GL. Higher levels of theaflavins were recorded in orthodox black tea from purple shoots (BTP) compared to black tea (BT) made from green shoots. Both theanine and caffeine recorded higher levels in GL. Volatile flavour profiles of these teas showed qualitative and quantitative differences. Aroma extract dilution assay showed higher dilution factors in BTP than BT. Orthodox teas from purple shoots exhibited higher antioxidant activity compared to standard black tea. Strong correlation of total quality scores with aroma and infusion colour was observed. Tea from anthocyanin-rich cultivars can become specialty teas with high antioxidant activity.

Varietal identification of tea (Camellia sinensis) using nanofluidic array of single nucleotide polymorphism (SNP) markers.

Apart from water, tea is the world’s most widely consumed beverage. Tea is produced in more than 50 countries with an annual production of approximately 4.7 million tons. The market segment for specialty tea has been expanding rapidly owing to increased demand, resulting in higher revenues and profits for tea growers and the industry. Accurate varietal identification is critically important to ensure traceability and authentication of premium tea products, which in turn contribute to on-farm conservation of tea genetic diversity. Using a set of single nucleotide polymorphism (SNP) markers developed from the expressed sequence tag (EST) database of Camilla senensis, we genotyped deoxyribonucleic acid (DNA) samples extracted from a diverse group of tea varieties, including both fresh and processed commercial loose-leaf teas. The validation led to the designation of 60 SNPs that unambiguously identified all 40 tested tea varieties with high statistical rigor (p<0.0001). Varietal authenticity and genetic relationships among the analyzed cultivars were further characterized by ordination and Bayesian clustering analysis. These SNP markers, in combination with a high-throughput genotyping protocol, effectively established and verified specific DNA fingerprints for all tested tea varieties. This method provides a powerful tool for variety authentication and quality control for the tea industry. It is also highly useful for the management of tea genetic resources and breeding, where accurate and efficient genotype identification is essential.

HPTLC Methods for Identification of Green Tea and Green Tea Extract

For centuries, the leaves of Camellia sinensis have been used to make green, black, and special types of tea; it has been the basis for one of the most popular beverages all over the world. More recently, green tea has become the raw material for extracts which are used in various beverages, health foods, dietary supplements, and cosmetic items. In view of the Good Manufacturing Practice (cGMP) for dietary supplements, mandating proper identification of raw materials and finished products, it is very important to have the necessary analytical tools at hand. This paper presents HPTLC methods for identification of green tea and green tea extract. On silica gel 60 with ethyl formate, toluene, formic acid, water (30:1.5:4:3) as mobile phase, the flavonoid fingerprint of green tea can give information about the geographical origin of the material. The mobile phase toluene, acetone, formic acid (9:9:2) allows the discrimination of green tea from black and other specialty teas, based on the polyphenol pattern. The latter method has been validated, addressing specificity, stability, reproducibility, and robustness. For additional quality control of extracts, ethyl acetate, methanol, and water (20:2.7:2) can be used as mobile phase to investigate the alkaloid profile, whereas, 1‐butanol, acetone, acetic acid, water (7:7:2:4) provides an amino acid profile.

HPLC Analysis of Catechins, Theaflavins, and Alkaloids in Commercial Teas and Green Tea Dietary Supplements: Comparison of Water and 80% Ethanol/Water Extracts

ABSTRACT: To help meet the needs of consumers, producers of dietary tea supplements, and researchers for information on health‐promoting tea compounds, we compared the following conditions for the extraction of tea leaves and green tea‐containing dietary supplements: 80% ethanol/water at 60 °C for 15 min and boiled water for 5 min. The following 7 catechins, 4 theaflavins, and 3 alkaloids were separated in a 70‐min single HPLC analysis: (−)‐epigallocatechin, (−)‐catechin, (+)‐epicatechin, (−)‐epigallocatechin‐3‐gallate, (−)–gallocatechin‐3‐gallate, (−)‐epicatechin‐3‐gallate, (−)‐catechin‐3‐gallate, theaflavin, theaflavin‐3‐gallate, theaflavin‐3′‐gallate, theaflavin‐3,3′‐digallate, caffeine, theobromine, and theophylline. The following ranges of concentrations of flavonoids (catechins plus theaflavins) in the tea leaves extracted with 80% ethanol were observed (in mg/g): in 32 black teas, 19.8 to 115.1; in 24 green teas, 12.3 to 136.3; in 14 specialty teas, 4.9 to 118.5; in 7 herbal teas, 0 to 46.0. Total alkaloids in all teas ranged from 0 to 32.6 mg/g. Significantly greater amounts of flavonoids were extracted from the tea leaves with aqueous ethanol than with boiled water. Levels of tea catechins in 10 capsules sold as dietary supplements were about 50 to 75% lower than the amounts listed on the labels. Catechin content of 4 commercial green tea extracts ranged from 96 to 696 mg/g. The results make it possible to maximize the extraction of tea compounds to better relate the flavonoid and alkaloid content of teas and dietary tea supplements to their health‐promoting effects.