Orthodox Black Tea Research Articles

Constraints and Compliances of Traceability in Low Grown Orthodox Black Tea Manufacturing Process

Traceability practices and their compliances in low grown orthodox black tea manufacturing process were examined, while proposing possible solutions for identified major drawbacks. The physical traceability in supply chain was considered one step forward and one step backward from the point of manufacturing, starting from auction/buyer back to supplier. Randomized stratified sampling was used. The traceability was evaluated using a checklist, end product sampling, open ended interviews, observations and internal document studies. The orthodox process was more complicated unlike other production processes due to the different separation techniques employed for grading and variety of grades produced because the sifting/grading was the key to number of different tea varieties. Major traceability issues were observed in leaf collection and grading operations due to complexity of separation through Myddleton, Chota, Michie and Winnower, which reduced the specific amounts produced, where bulking and blending process further extended complexity, while increasing the mixing of different made tea together with increased number of suppliers. Considering 1st, 2nd, 3rd dhool and big bulk with given separation techniques during grading; a single tea leaf could pass many paths before it end up in a specific product due to weight, size and shape of the leaf of a shoot based on the way it was rolled in orthodox rollers, where traceability up to tea bush, grading, blending and traceability of sample back to supplier was not fully complying. Nevertheless, supplier records, traceability after packing, traceability at dispatch and after dispatch were in full compliance, and other factors had varying degree of traceability compliances which make the compliances unachievable. Alternatively, if made tea is considered as bulk material, use of emerging technologies like Radio Frequency Identification (RFID) tags or/and DNA barcoding may be potential tools in rectifying such drawbacks and further research is needed to assess their efficacy in the field.

A Quartz Crystal Microbalance Sensor for Detection of Geraniol in Black Tea

Geraniol is one of the important qualities determining volatile components of black tea. This paper presents a quartz crystal microbalance sensor to detect geraniol from black tea aroma. The sensor is developed using β-cyclodextrin (β-CD). β-CD is a flavor encapsulating material with toroidal bucket-like structure, whose inside-cavity is hydrophobic and the outside is hydrophilic and it is found to be a suitable coating material for detecting geraniol. Extensive experiments have been carried out with the β-CD sensor and it is observed that the sensor offers better sensitivity for geraniol in comparison with other important constituents of black tea such as linalool, linalool oxide, methyl salicylate, and trans-2-hexenal. Experiments with ten Darjeeling orthodox black tea samples have been carried out with the developed sensor and a correlation factor of 0.9925 has been obtained with the corresponding gas chromatography mass spectrometry analysis.

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.

Determinants of net sale average (NSA) of orthodox black tea factories in high elevation, Sri Lanka

Secondary data proved that high grown teas are losing their position as the highest Elevation Average (EA) recorded over the years. As EA is determined by the factory Net Sale Average (NSA), factors affecting NSA are responsible for fluctuations of EA. This study attempts to identify those factors which affect NSA of orthodox black tea factories in high elevation. Data were collected for tea factories representing agro climatic regions in high elevation. Fixed effect panel data regression analysis was employed for the econometric analysis. Results revealed that NSA is determined by main grade percentage, own leaf quantity, best leaf standard, quality certification of factories and number of brokers involved in the selling process. However, Udu Pussellawa sub region shows negative relationship for own leaf and best leaf standard whereas Uva sub region shows negative relationship only for the main grade percentage. The overall results indicate that high elevation factory NSA is determined by the quality of the raw material and final output.The Kelaniya Journal of Management, Vol. 3(1); 2014: 63-85

ANALISIS DAYA SAING DAN DAMPAK KEBIJAKAN PEMERINTAH TERHADAP KOMODITAS TEH (STUDI KASUS: PTPN VIII AFDELING RANCABALI III)

Rancabali III department, National Plantation VIII produces tea with national and international standard of quality. The purpose of this study are to analyze the effect of government policies, increase of output price, increase of chemical fertilizer price, and production number decline to orthodox black tea competitiveness at Rancabali III department, National Plantation VIII. The methods are Policy Analysis Matrix and sensitivity analysis. The result shows that government policies, output price, chemical fertilizer price and production number affect the competitiveness of orthodox black tea at Rancabali III department National Plantation VIII.

Fractionation and identification of minor and aroma-active constituents in Kangra orthodox black tea

The aroma constituents of Kangra orthodox black tea were isolated by simultaneous distillation extraction (SDE), supercritical fluid extraction and beverage method. The aroma-active compounds were identified using gas chromatography–olfactometry–mass spectrometry. Geraniol, linalool, (Z/E)-linalool oxides, (E)-2-hexenal, phytol, β-ionone, hotrienol, methylpyrazine and methyl salicylate were major volatile constituents in all the extracts. Minor volatile compounds in all the extracts were 2-ethyl-5-methylpyrazine, ethylpyrazine, 2-6,10,14-trimethyl-2-pentadecanone, acetylfuran, hexanoic acid, dihydroactinidiolide and (E/Z)-2,6-nonadienal. The concentrated SDE extract was fractionated into acidic, basic, water-soluble and neutral fractions. The neutral fraction was further chromatographed on a packed silica gel column eluted with pentane and diethyl ether to separate minor compounds. The aroma-active compounds identified using gas chromatography–olfactometry–mass spectrometry were 2-amylfuran, (E/Z)-2,6-nonadienal, 1-pentanol, epoxylinalool, (Z)-jasmone, 2-acetylpyrrole, farnesyl acetone, geranyl acetone, cadinol, cubenol and dihydroactinidiolide. AEDA studies showed 2-hexenal, 3-hexenol, ethylpyrazine, (Z/E)-linalool oxides, linalool, (E/Z)-2,6-nonadienal, geraniol, phenylethanol, β-ionone, hotrienol and dihydroactinidiolide to be odour active components.

Induction of Apoptosis and Cytotoxic Activities of Iranian Orthodox Black Tea Extract (BTE) Using in vitro Models.

Plant-derivate therapeutic agents can perform cancer chemotherapeutic activity through triggering apoptotic cell death. Our aim was to investigate the cytotoxic effects, induction of apoptosis, and the mechanism of cell death of Iranian orthodox black tea extracts (BTEs) and hydro methanolic purified fractions (40, 60, 80 and 100%) in KB cells (oral squamous cell carcinoma). In order to analyze the cytotoxic activity of the BTEs, MTT (3-(4, 5- dimetylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide) and Trypan-blue assays were performed in oral squamous cell carcinoma (KB). Furthermore, the apoptosis inducing action of the extracts was determined by TUNEL, DNA fragmentation and cell death detection analysis. Dichloromethane BTE and hydro methanol fractions (40 and 60%) extract showed no cytotoxic effects; however, hydro methanol crude and hydro methanol fractions of BTE (80 and 100%) significantly inhibited cell growth and viability in a dose and time dependent manner. In addition, Cell death assay, TUNEL, and DNA fragmentation indicated induction of apoptosis by hydro methanol 80 and 100% fractions of BTE in KB cells. Statistical significance was determined by analysis of variance (ANOVA), followed by Duncan test and p value ≤0.05 was considered significant. The results from the present study suggests that the hydro methanol crude and hydro methanol fractions of BTE (80 and 100%) are significant source of compounds with the anti proliferative and cytotoxic activities, and this may be useful for developing potential chemo preventive substances.

Chemometric assisted RP-HPLC for fingerprinting of Indian orthodox black tea

In view of the large variation in tea quality, this study aims to fingerprint the best quality of Indian orthodox black tea depending upon the production region, variation of seasons, mechanical grading and processing with different fermentation times. A HPLC method reported by us earlier has been adapted to separate biochemical constituents in various tea samples, in which Thermo Hypersil ODS column has been found to be more efficient in terms of resolution and retention time. Even black tea processed from the same region but processed in different seasons or mechanically graded resulted in significant compositional changes. The average data from HPLC was subjected to chemometric analysis i.e. principal component analysis (PCA). Different clusters were obtained for each type of tea which can act as a fingerprint for further analysis and interpretation of tea quality for its ranking. Thus, HPLC integrated with chemometrics can be explored as a routine diagnostic tool for online monitoring of black tea quality.

Detection of linalool in black tea using a quartz crystal microbalance sensor

Linalool is one of the most important volatile constituent that contributes significantly in the aroma of brewed, dry or extracted tea. Thus it is very essential to sense the linalool content in orthodox black tea as that may lead to rapid quality estimation. Quartz crystal microbalance (QCM) type gas sensors are very sensitive and are increasingly being used for many applications. It can be easily fabricated, has less response time and fast recovery characteristics and can be coated with a variety of materials to obtain different sensitivities and selectivities. In the present work, a QCM sensor has been developed with polyethylene glycol (PEG) to detect linalool gas in black tea. Extensive experiments have been carried out with various concentrations of linalool gas and the sensitivity, repeatability and reproducibility of the developed sensors were determined. The sensors were observed to be sensitive and selective to linalool. The developed sensors were exposed to the orthodox black tea aroma and significant correlation is obtained with gas chromatography mass spectrometry (GCMS) estimations.

Effect of decaffeination conditions on quality parameters of Kangra orthodox black tea

Effect of extraction temperature and pressure on the removal of caffeine from Kangra orthodox black tea using supercritical carbon dioxide was investigated. Maximum caffeine as well as volatile flavor components was extracted at 35°C/170bar using 60g/min flow rate for 90min extraction in dynamic mode. Satisfactory decaffeination and quality retention were achieved at extraction at 60°C/90bar. The quality of extracts reduced at higher extraction temperature and pressure combinations. Maximum amounts of theaflavins (88.88%), thearubigins (81.18%) and catechins (73.53%) were retained at these extraction conditions. Volatile components in original (caffeinated) and decaffeinated black teas were isolated by simultaneous distillation extraction (SDE), and analyzed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). 2-Hexenal, 3-hexenol, phenylacetaldehyde, cis-linalool oxide, linalool, trans-geraniol, nerolidol, methyl salicylate, α- and β-ionones decreased in decaffeinated black teas compared to untreated control. β-ionone (1.77%), trans-linalool oxide (5.36%), linalool (7.84%), trans-geraniol (4.32%) and methyl salicylate (1.90%) were retained in satisfactory amount in decaffeination at 60°C/90bar. Application of aroma extract dilution analysis revealed 11 odor active compounds with flavor dilution (FD) factor ranging from 8 to 512 and odor quality investigated by GC-FID, GC–MS. Some unknown compounds quantitatively reduced or disappeared during decaffeination process. Although there was considerable loss of theaflavins and thearubigins as well as volatile flavor components, SFE extraction at 60°C/90bar for 90min appears as the method suitable for selective removal of caffeine from the Kangra orthodox black tea.

Priority PAHs in orthodox black tea during manufacturing process

Orthodox black tea is obtained from fresh leaves followed by withering, rolling, fermentation and drying. The presence of 16 priority polycyclic aromatic hydrocarbons (PAHs) was studied in fresh leaves and at various stages of manufacturing. Benzo(a)pyrene (2A: probable human carcinogen) was found in dried tea leaves only whereas, naphthalene (2B: probable human carcinogen) was present during all the stages of manufacturing. Dry tea leaves showed higher content of total 16 PAHs (∑PAHs) about 3 and 211 times than present in withered and dried leaves, respectively. Chrysene, benzo[g,h,i]perylene, indendo[1,2,3-c,d]pyrene, dibenzo[a,h]pyrene and benzo[a]antracene were not found during manufacturing stages of tea.

Enhancing electronic nose performance: A novel feature selection approach using dynamic social impact theory and moving window time slicing for classification of Kangra orthodox black tea (Camellia sinensis (L.) O. Kuntze)

This paper presents a novel multiobjective wrapper approach using dynamic social impact theory based optimizer (SITO) and moving window time slicing (MWTS) for the performance enhancement of an electronic nose (EN). SITO, in conjunction with principal component analysis (PCA) and support vector machines (SVMs) classifier, has been used for the classification of samples collected from the single batch production of Kangra orthodox black tea (Camellia sinensis (L.) O. Kuntze). The work employs a novel SITO assisted MWTS (SITO-MWTS) technique for identifying the optimum time intervals of the EN sensor array response, which give the maximum classification rate. Results show that, by identifying the optimum time slicing window positions for each sensor response, the performance of an EN can be improved. Also, the sensor response variability is time dependent in a sniffing cycle, and hence good classification can be obtained by selecting different time intervals for different sensors. The proposed method has also been compared with other established techniques for EN feature extraction. The work not only demonstrates the efficacy of SITO for feature selection owing to its simplicity in terms of few control parameters, but also the capability of an EN to differentiate Kangra orthodox black tea samples at different production stages.

A novel approach using Dynamic Social Impact Theory for optimization of impedance-Tongue (iTongue)

This paper presents a novel multiobjective wrapper approach using Dynamic Social Impact Theory based optimizer (SITO). A Fuzzy Inference System in conjunction with support vector machines classifier has been used for the optimization of an impedance-Tongue for the classification of samples collected from single batch production of Kangra orthodox black tea. Impedance spectra of the tea samples have been measured in the range of 20 Hz to 1 MHz using a two electrode setup employing platinum and gold electrodes. The proposed approach has been compared, for its robustness and validity using various intra and inter measures, against Genetic Algorithm and binary Particle Swarm Optimization. Feature subset selection methods based on the first and second order statistics have also been employed for comparisons. The proposed approach outperforms the Genetic Algorithm and binary Particle Swarm Optimization.

Fate of imidacloprid and acetamiprid residues during black tea manufacture and transfer into tea infusion

The objective of this paper is to investigate the loss/stability of neonicotinoids (imidacloprid and acetamiprid) residues during the manufacture of black tea and to study the transfer of these pesticides from made tea to its infusion. For orthodox black tea, the manufacturing process involves leaf harvesting (plucking two leaves and a bud), withering, rolling, fermentation (oxidation), and drying. Initial withering and final drying resulted in the loss of pesticide residues, but no significant reduction in residue levels resulted from the rolling and fermentation steps. The drying process resulted in a residue transfer of 64–70% and 69–74% of the initial level, whereas the brewing process resulted in a residue transfer of 37–39% and 45–49% of imidacloprid and acetamiprid, respectively, from dried tea into the infusion. The decrease in acetamiprid levels during drying was also significant (8–13%), whereas the total loss during the manufacturing process ranged from 26 to 31%. Further, brewing for longer periods (an extended brewing time) resulted in higher transfer (up to 44% for imidacloprid and 53% for acetamiprid) of pesticides to tea infusion. Further, the extent of pesticide leaching depends on its water solubility, partition coefficient, and the brewing time.

Penerapan Logika Fuzzy Pada Penilaian Mutu Teh Hitam Orthodox

In testing quality process of the orthodox black tea by using tea organoleptic expert, there is often found a problem of tester sensoric restriction. Based on this conditon the research has been carried out by using fuzzy modelling technique, which aimed to explore ruther more about how fuzzy method can concordance with fuzzy range value on black olthodox tea assesment. So that, it could be more objective on quality evalualion. The research has beld on May to June 2005 in tea plantation facility of PTPN Vlll Malabar. Pangalengan, and Tea and Cinchona Research Center (Pusat Penelitian Ten dan Kina -PPTK) Gembung, Cieidey, West Java. This fuzzy method can keep a record experience of the orthodox black tea tester and also correct the result of the determination done by the tester, Based on the parametrik LSD test and non-parametrik Mann-Whitney, there is no significant value diference In the result of the determination done by the tester and by using the fuzzy logic. So that the fuzzy logic method can be used as a method in orthodox black tea quality determination. But The method can not be used if there is a far diference in the tea determination between one tester to the others. Tbe best defuzzification method for tea quality detemination in this occasion is Smallest of Maximum (SOM) method.Keyword: Fuzzy Logic, Orthodox Black Tea, Quality Determination. Diterima: 30 Juli 2007; Disetujui: 22 Agustus 2007

Characterization of volatile components of Kangra orthodox black tea by gas chromatography-mass spectrometry

To characterize Kangra tea flavour, volatile components of Kangra orthodox black tea ( Camellia sinensis (L.) O. Kuntze) were isolated by two different methods viz. simultaneous distillation extraction (SDE) and hydrodistillation, and analysed by GC–MS. The composition of the volatile components extracted by the two methods differed considerably. A total of 101 compounds were tentatively identified in Kangra tea by matching EI mass spectra and retention indices with the literature data. Fifty compounds, constituting the major part of the volatiles (98.4 ± 0.4%) were detected in all the three replicates of made tea obtained by SDE. Major volatile components identified in Kangra tea were ( E)-2-hexenal, 1-pentene-3-ol, and ( Z)-3-hexenol among non-terpenoids and linalool, linalool oxides (furanoid), geraniol, methyl salicylate, 3,7-dimethyl-1,5,7-octatrien-3-ol, and epoxylinalol among terpenoids. The total volatile oil yield was about 0.02% by Clevenger type apparatus. SDE was found to be a more efficient technique than the other distillation processes for characterizing volatile components in terms of sample size and components extracted, and the extracted flavour was also closer to Kangra made tea.

How manufacturing processes affect the level of pesticide residues in tea

AbstractTea (both green and black) is consumed throughout the world, both for pleasure and therapeutic purposes. Most people will be unaware of their involuntary exposure to residues of pesticides lingering in processed tea and so possibly transferring into infusions of tea. The purpose of this work was to study the effect of green tea and orthodox black tea manufacturing processes on the fate of pesticides sprayed onto tea bushes (Camellia sinensis). The fates of residues of dimethoate, quinalphos, dicofol and deltamethrin in these two different types of tea manufacturing processes were compared. For black tea, the manufacturing process involves leaf harvesting, withering, rolling, fermentation and drying; and for green tea, leaf harvesting, microwave heating, rolling and drying. The two processes resulted in the same concentration factor of plant material into the dried commodity, while the decreases in residue levels were different for different pesticides. Initial microwave heating and dehydration in the green tea manufacturing process resulted in greater loss of pesticide residues than did withering and dehydration in black tea; no significant reduction in residue level resulted from the rolling and fermentation steps in black tea. Residue levels in both green and black teas were reduced during final drying. Copyright © 2004 Society of Chemical Industry

Seasonal variations in theaflavins, thearubigins, total colour and brightness of Kangra orthodox tea (Camellia sinensis (L) O Kuntze) in Himachal Pradesh

Variations in theaflavins, thearubigins, total colour and brightness of orthodox black tea were studied for four consecutive years (1993–1996) with a view to evaluating the effects of changing weather conditions on the quality of Kangra tea. A degree of withering of 600–650 mg g−1 during the first, second and fourth seasons was optimal for the development of significantly higher brightness and total colour characteristics. The quality of rainy season teas suffered owing to high chlorophyll content and low degree of withering. Hot air circulation through the withering troughs to assist evaporation of leaf moisture increased the brightness and total colour of rainy season teas. High atmospheric demand during the dry season assisted loss of green leaf moisture, but withering and brightness exhibited significant negative correlations with high relative humidity and rainfall. Summer season teas were superior in their total colour and brightness. © 2000 Society of Chemical Industry

Seasonal variations in theaflavins, thearubigins, total colour and brightness of Kangra orthodox tea (Camellia sinensis (L) O Kuntze) in Himachal Pradesh

Variations in theaflavins, thearubigins, total colour and brightness of orthodox black tea were studied for four consecutive years (1993–1996) with a view to evaluating the effects of changing weather conditions on the quality of Kangra tea. A degree of withering of 600–650 mg g−1 during the first, second and fourth seasons was optimal for the development of significantly higher brightness and total colour characteristics. The quality of rainy season teas suffered owing to high chlorophyll content and low degree of withering. Hot air circulation through the withering troughs to assist evaporation of leaf moisture increased the brightness and total colour of rainy season teas. High atmospheric demand during the dry season assisted loss of green leaf moisture, but withering and brightness exhibited significant negative correlations with high relative humidity and rainfall. Summer season teas were superior in their total colour and brightness. © 2000 Society of Chemical Industry

In vitro studies on antifungal activity of tea (Camellia sinensis) and coffee (Coffea arabica) against wood‐rotting fungi

AbstractThe present study reports the sensitivity of ten different wood‐rotting fungi towards eight samples of tea and two samples of coffee. The tea samples included five CTC black teas, one orthodox black tea and two green teas. The different fungi tested were sensitive to different tea and coffee samples to variable levels. Green tea caused the maximum growth inhibition and it was 100% in case of Phanerochaete chrysosporium and Sporotrichum pulverulentum. Of the black tea samples, orthodox black tea was more effective inhibitor for all the fungi tested. Phlebia radiata was the most sensitive fungus to all the black tea samples except Lipton Cheers. The growth of Daldinia concentrica was least affected by all the black tea samples. The two coffee samples showed better inhibition than CTC black tea samples. The inhibitory effect of tea and coffee extracts was greatly reduced on their filtration. All the tea and coffee samples tested showed more than 50% reduction in their inhibitory activity. The inhibitory effect was completely lost in spent black tea leaves. The antifungal effect of pure caffeine was tested at different concentrations. Majority of the fungi were totally inhibited at a concentration of 0.3% whereas, D. concentrica, P. radiata and P. palustris showed complete inhibition at a concentration of 0.5 percent.