CTC Tea Research Articles

Valorization of CTC tea waste through kombucha production and insight into GC-MS based metabolomics

This research paper is aimed to deliver a novel approach to prepare a popular probiotic beverage i.e., kombucha from infusion of tea waste to valorize the by-product of tea industry. In this study, a GC-MS based approach in combination with preliminary in vitro biochemical analysis was used to investigate the metabolic profiles, especially the antioxidant compounds produced during the fermentation of waste tea infusion. Waste tea infusion was found to be rich in xanthosine, the precursor of caffeine while the fermented sample was seen to be rich in more bioactive secondary metabolites derived from the substrate compounds i.e., xanthosine and sucrose. In addition, GC-MS based metabolomics helped to propose biosynthesis pathways of the metabolome which suggest the later breakdown of xanthosine and other substrate components into microbial metabolites during fermentation process. These findings are expected to be useful for further studies on production of bioactive formulations from tea waste.

In-vitro biotransformation of tea using tannase produced by Enterobacter cloacae 41.

Tannase is a widely used enzyme that improves the quality of tea by facilitating the release of water-soluble polyphenolic compounds, as well as reduces the formation of tea creams. The microbial tannase enzymes are often employed for tea biotransformation by hydrolyses esters of phenolic acids, including the gallated polyphenols found in blacks teas. The study was focused to investigate the tannase enzyme mediated biotransformation of black tea such as CTC-(Crush, tear, curl) & Kangra orthodox which are commonly used by the south Indian peoples. HPLC spectral analysis revealed that tannase treatment on tea cream formation (CTC & Kangra orthodox tea) allows the hydrolysis of the EGC, GA, ECG, and EGCG. A significant reduction in the formation of tea cream and increased antioxidant activity has been observed in the CTC (1.62 fold) and Kangra orthodox (1.55 fold). The results revealed that tannase treatment helps to improve the quality of black tea infusions with respect to cream formation, the intensity of colour, and sensory characteristics of tea. The result of this study indicates that E. cloacae 41 produced tannase can be used to improve the quality of both tea samples.

Effects of Processing Technologies on the Levels of Chlorogenic Acid, Gallic Acid and Theanine in Selected Kenyan Tea Cultivars by HPLC-PDA

Chlorogenic acid (CGA) one of tea biomolecules is a natural antioxidant that neutralizes free radicals in the body. It has also anti-obesity, anti-atherosclerotic and anti-cancer properties. Gallic acid exists in form of free acids and esters in plant material. This ubiquitous chemical is one of the many biologically active phenolic compounds of plant origin. Theanine a non-protein amino acid also called L-theanine is speculated to increase the levels of GABA, serotonin and dopamine. It has been used as a nutritional supplement in reducing stress, causing feelings of relaxation and improved mood. The aim of this study was to determine the variation of the levels of CGA, GA and theanine with processing technologies. Six tea cultivars TRFK 6/8, TRFK 11/4, TRFK 12/2, TRFK 31/8, TRFK 54/40 and TRFK 306/1 were selected for use in the study. Their leaf was processed to obtain CTC and orthodox tea products with green and black tea types being made. Profiling was done using High Performance Liquid Chromatography (Shimadzu Japan) equipped with photo-diode array detector (SPD-M20A). Graphical representation of the mean levels of Chlorogenic acid, Gallic acid and L-theanine contents was done using Microsoft® Excel, version 2010. Standard error of the mean was used to determine levels of significant differences. The result showed that TRFK 306/1 had the highest levels of CGA for both CTC and orthodox processing techniques while TRFK 12/2 had the lowest levels. In general, the levels were higher in black teas than in the green tea types. The levels of GA were in the range of 0.28-0.51% in green teas and 0.28-0.55% for the black tea types. At the cultivars level, black teas had significantly high levels of GA than the green teas. The theanine levels ranged at 0.97-1.87% for green teas and 0.79-1.47% for the black tea types.

스리랑카의 차산업 발전 방향에 대한 연구

Sri Lanka s tea industry is maintaining its position as the world s leading tea exporter, excluding CTC tea. Ceylon tea’s world-class quality has been achieved thanks to tea cultivation research by TRI and organized management by SLTB.
 Currently, Sri Lanka’s tea industry is facing some challenges to be solved: the aging of tea trees, limited tea cultivation areas and lack of skilled labor, which are causing the disruption of tea production. As a result, it is leading to a rise in unit cost of production and weakening the competitiveness in the international market. In such a situation, they need to adapt to universal trends while maintaining its wonderful traditions.
 First, more research needs to be done in terms of characteristic cultivation terrains to develop highly qualified tea and about the diversity of tea according to the
 preferences of various buyers.
 Second, more effective way of tea production should be adopted. They need to increase the production amount of CTC for milk tea, ice tea and tea bags, consumed the most in the world, and diversify their products instead of bulk exports.
 Finally, mechanization and education of tea cultivation and production are important. They could increase export volume and keep ruling over the international tea market.
 The future of Ceylon tea is very promising since Sri Lanka’s tea industry is the cleanest and the most environmentally-friendly on the planet. To keep its position as a tea maker for the mental, physical and social health of mankind and to survive in the harsh international tea market, continuous multi-modal studies are essential.

Effect of Tea on Gingivits: A Community-based Study

Pharmacological values of tea have been found by medical researchers in many countries. Catechin compounds found in tea impart several health benefits including mitigating dental ailments. However, whether dento-clinical properties of catechins are camouflaged by additive like milk or not has remained unexplored. A survey-based study involving community people suffering from gum disease (gingivitis) has been carried out to understand whether hot water extract of tea ( known as brew) without milk has any relevance in reducing gingivitis. The survey reveals a strong negative linear correlation ( r= -0.807** ) between drinking tea without milk and reduction of gingivitis. The results also reveal that frequency of gingivitis amongst people who drink tea with milk is more ( r= 0.696* ) as compared to the people who drink tea without milk. Tea made from Tinali 17/1/54 cultivar of Camelia sinensis L. O. Kuntze var, Assamica has been used in the study as this cultivar is ubiquitous in tea growing areas and can produce different categories of black tea – strong CTC tea, mild flavored orthodox tea and milder green tea.

Major tea processing practices in India.

Tea is the most popular beverage in the world and is the economical backbones of some countries like India, China, Kenya, Sri Lanka etc. Indian tea is very much popular among the world, specially Darjeeling tea which is famous for its flavour and taste. Among the various types of tea, orthodox tea is highly demandable for its quality. The present paper deals with various types of tea processing in India. Mainly three types of tea processing are practices in India. Among these, CTC tea processing is more common in Indian sub-continent followed by Green tea and Orthodox tea. In this paper, details manufacturing process and step wise pictorial viewed are presented. All the data are extracted from different world famous tea gardens of Darjeeling, terai and duars of Northern West Bengal.

EFFECT OF GREENLEAF QUALITY AND MOISTURE CONTENT ON PHYSICAL AND ORGANOLEPTIC OF THE CTC (Crushing Tearing Curling) TEA

PTPN VII (Persero) Pagaralam Business Unitstarted developing the processing of black tea (CTC). Only after several times the processing quality CTC teas produced unsatisfactory. The Company continues to optimize the performance ofthe processingand quality control of CTC tea. This study aims to determine the effect of the quality of shootsandwilting percentage of the physical and organoleptic properties of CTC tea. This research was conducted in PTPN VII (Persero) Act Pagaralam. The results showed that all of the top quality withvalue range 62% to 70% and the percentage of wilted 65% to 72% no real effect on the physical and organoleptic properties. The water content and density of CTC tea has fulfilled SNI and enterprise standards. CTC tea produced medium quality (Fair made).

Production of fungal pectinase enzyme through solid substrate fermentation of estate waste for improvement of enzymatic oxidation and increasing the quality of CTC tea

Enzymes, especially pectinase, plays an important role in the processing of tea that determines the quality and the color appearance of black tea. The main obstacle encountered in the application of enzymes in food processing in general, and in particular in the processing of black tea is the price of commercial enzyme that are still very expen­sive, because it is still imported. Indonesia has a high fungal diversitythat is potential as producer of commercial pectinase enzyme. To reduce the cost of production, fermentation was done using solid waste of plantation that rich of pectin content such as cocoa pod husk that has not been optimally utilized. The research aimed to develop the production technology for pectinase enzymes of fungi through solid substrate fermentation for applications in the processing of CTC black tea. Research includes the isolation and selection of local superior fungi producing enzymes pectinase, optimiza­tion of enzyme production by fungi isolates were selected through a solid substrate fermen­tation using cocoa pod husk waste, production optimization included optimization of fermen­tation time and substrate composition, enzyme extraction of fermented substrate, and appli­cation of pectinase enzyme extracts in the processing of CTC black tea and sensory test of fermented tea. The results showed that it has been obtained isolates of Aspergillus niger on Pectinase Screening Agar Medium (PSAM) which was capable of producing pectinase enzyme on growing media of mix cocoa pod husk and rice bran with additional of enrichment media. The optimum conditions of pectinase production was obtained in the composition of cacao pod husk: rice bran (80:20 w/w) plus enrichment media, the incubation time of 9 days, which produced pectinase activity of 125 U/mL. Applications of pectinase on enzymatic oxidation of CTC tea proved that it was capable of raising the quality of the tea flavor, though the tea gradedid not change.

Dynamics of production and export in transformation of tea plantation sector in India

The study was based on secondary published data with effect from 1971 to 2011 with an objective to examine the trends of production and export of tea and growth in India. It was observed that tea sector plays an important role contributing more than 200 crores to the GNP of the country. The major three producing regions are Darjeeling, Assam and Nilgiri. In the recent years, the sector has witnessed a stiff competition in the international export market affecting domestic production. It was observed that China produces 39.00% of world tea followed by India sharing 24.55% with an annual change of 2.87% during 1971–81 to 3.06% during 2001–11. Production of tea in the country was mainly due to increase of area and productivity. Replanted and replacement area could not influence the production of tea significantly. Number of tea estates was found to increase in between 1991–01 at the rate of 74.09% due to inclusion of small tea gardens and it declined from 5.29% to 3.64% during 1961 to 2011. Productivity change was higher in Assam, Tripura, Tamil Nadu and Kerala with high production change during the decades. The area growth during the decades was low. Production share of tea grades like CTC, Darjeeling and Green tea declined over years while share of Orthodox tea increased over years. The country witnessed high annual change of area of tea bushes under the age group of 5 to 10 years followed by below 5 years due to more area put under the small tea estates in the recent years. The export of tea bags as value added tea grew faster from 1971–72 to 2011–12 in terms of quantity and value followed by packet tea. Auction sale in the country declined. Employment generated per estate varied from 191 in Karnataka to 1011 in West Bengal in 2011. The emerging small tea sector has contributed from 5% in early 90’s to 31% during current year and is expected to touch 50% within next few years. It can be concluded that area could influence the production and it needs to be increased under replanting and replacement planting. Steps should also be taken to increase the export of value added tea in the country. The small tea sector should be organised and regulated to make it more productive.

Extraction Kinetics of phytochemicals and antioxidant activity during black tea (Camellia sinensis L.) brewing.

BackgroundTea is the most consumed beverage in the world which is second only to water. Tea contains a broad spectrum of active ingredients which are responsible for its health benefits. The composition of constituents extracted to the tea brew depends on the method of preparation for its consumption. The objective of this study was to investigate the extraction kinetics of phenolic compounds, gallic acid, caffeine and catechins and the variation of antioxidant activity with time after tea brew is made.MethodsCTC (Crush, Tear, Curl) tea manufactured in Sri Lanka was used in this study. Tea brew was prepared according to the traditional method by adding boiling water to tea leaves. The samples were collected at different time intervals. Total phenolic and flavonoid contents were determined using Folin ciocalteu and aluminium chloride methods respectively. Gallic acid, caffeine, epicatechin, epigallocatechin gallate were quantified by HPLC/UV method. Antioxidant activity was evaluated by DPPH radical scavenging and Ferric Reducing Antioxidant Power (FRAP) assays.ResultsGallic acid, caffeine and catechins were extracted within a very short period. The maximum extractable polyphenols and flavanoids were achieved at 6–8 min after the tea brew is prepared. Polyphenols, flavanoids and epigallocatechin gallate showed a significant correlation (p < 0.001) with the antioxidant activity of tea.ConclusionThe optimum time needed to release tea constituents from CTC tea leaves is 2–8 min after tea is made.

Total Polyphenols Content and Antioxidant Activity of Different Tea Commercially Produced in Nepal

This study was conducted to assess and compare the total polyphenol content (TPC), antioxidant activity of different tea varieties commercially produced in Nepal. Nine different brands of tea samples, three from each CTC, orthodox and green tea were collected from different parts of Kathmandu valley. TPC was analyzed as per folin-ciocalteu method and antioxidant activity as per DPPH (2, 2-diphenyl-1-picrylhrdrazine) free radical scavenging capacity. The TPC was found to be 4.60, 8.79, 18.20mg of phenol equivalent (PE)/gm of sample in CTC, orthodox and green tea respectively. Green tea Emerald and green tea Kanchanjunga contained the highest level of polyphenol. Antioxidant activity (for 0.36 mg of tea sample) was found to be 25.04, 43.86, and 72.39% for CTC, orthodox and green tea respectively. Moreover, some commercial brands of green tea (Emerald and Kanchanjunga) showed the highest antioxidant activity. The TPC and antioxidant activity of different commercial brands of tea were found to be positively correlated (r=0.97). J. Food Sci. Technol. Nepal, Vol. 6 (73-77), 2010 DOI: http://dx.doi.org/10.3126/jfstn.v6i0.8264

Study of Tea Aroma Based on Zinc Oxide Nanorod Sensing Element

Flavour type of tea liquor is a very important factor in identification of quality of Indian tea. Though the main aromatic ingredients in made tea are same, the quality of made tea mainly differ from their flavour types, which rely on their trace volatile components. CTC Tea is known for its strength and processed to retain its strong taste whereas Orthodox Tea is processed to retain mostly its aroma. Usually the Quality of tea is sensed by Tea Tasters and classified by smelling and very few devices are available to calibrate the Flavour. In this paper, resistance change of zinc oxide nanorods was investigated in an atmosphere of different types of tea infusion with an objective to produce a low cost alternative to classify tea by its quality. Zinc Oxide nanorods were fabricated on a glass substrate by sol-gel spin coating technique. The ZnO film possessed a columnar structure consisting of small crystals with an average grain size of around 5 nm. The sensing properties of the ZnO film were tested for two different Tea liquors, namely, Assam CTC Tea and Darjeeling Orthodox Tea. An obvious change in resistance of the ZnO film was observed when the sensor was exposed to gas mixture. The Nanostructured elements showed higher sensitivity than the larger sized grains and pores. The response time was quite fast with large value of signal-to-noise ratio. This work shows potential application of nanostructured zinc oxide as one of the sensing elements in a sensor array for monitoring the quality of Indian tea.The Himalayan Physics, Vol. 3, No.3, July 2012

Quality improvement of orthodox and CTC tea and performance enhancement by hybrid hot air–radio frequency (RF) dryer

Orthodox and CTC tea were dried in hot air, radio frequency and hybrid hot air – radio frequency (RF) dryers for comparisons of drying durations and quality parameters. Drying duration was the shortest for RF drying at 60min for orthodox tea where as for CTC tea it was 90min. Hybrid drying for CTC tea took total of 55min and the same for orthodox at 20kW power was 85min. Aroma index of made liquor increased at 16kW compared to 20kW RF power.

Development of Safety and Productivity Correlation Model for Tea Industries of Barak Valley, Assam

The tea industries of Assam, India, are more than 150 years old. Though tea is an important class of industry in terms of employment and foreign exchange earning, the industry faces challenges from work place safety and declining productivity. A poor safety standard primarily originates from the belief that safety and productivity are mutually exclusive objectives, one eating away the other. But in practice they are correlated. The knowledge of exact nature of dependence of productivity with safety and health in a tea industry is therefore highly significant in the context of efficient tea production. In this paper, a quantitative relation between safety and productivity has been developed for tea industries of Barak valley, Assam. For this, safety and health in a tea industry have been modeled as function of four inputs such as occupational safety (OS), occupational health (OH), behavioral safety (BS) and competency (C). Models for the assessment of the levels of these four inputs in a scale of 0 to 10 have been proposed. Data collected from 40 nos. of CTC tea manufacturing units situated in different locations of Barak valley, Assam, India. These data were regressed using regression software Eviews 3.1 to develop the correlation model between safety and productivity. The developed correlation, which is otherwise not available in the existing literature, would definitely contribute to change the management’s erroneous mindset of treating safety as a liability to the business.

Antioxidant activity of white, green and black tea obtained from the same tea cultivar

The present study explored what effect manufacturing has on the antioxidant properties of teas coming from a single cultivar but processed differently to give a white, two black (Orthodox and CTC) and two green (low-caffeine and non-decaffeinated) teas. Total phenol (TPC), flavonoids (TFC), theaflavins, individual catechins content, and chelating activity were also investigated. Using the ABTS, ORAC and LDL assays the following ‘antioxidant profile’ was obtained: green≥low-caffeine green>white≥black Orthodox>black CTC, with statistically significant correlation between ORAC and LDL assays (r2=0.444, p=0.0067), whereas TPC and TFC significantly correlate with the ABTS one (r2=0.871, p=0.000 and r2=0.438, p=0.007, respectively). Metal chelating activity, which was lowest in the green teas, does not correlate with antioxidant activity but appears to be influenced by theaflavins content. The results contribute to better understand how the manufacturing process influences the antioxidant activity of tea when variables (geographical region, environmental conditions, cultivar type, plucking techniques) are kept to a minimum. Secondly, we show that novel African green, white and black Orthodox teas, made from tea varieties typically used in black CTC tea production, may have potential health benefits comparable with commonly consumed teas.

ENZYMATIC TREATMENT OF BLACK TEA (CTC AND KANGRA ORTHODOX) USINGPENICILLIUM CHARLESIITANNASE TO IMPROVE THE QUALITY OF TEA

ABSTRACT Tannase mediated biotransformation of black tea (CTC and Kangra orthodox) was investigated. Black tea infusion treated with tannase showed that both epigallocatechin (EGC) gallate and epicatechin (EC) gallate of tea catechins were hydrolyzed by this enzyme into EGC and EC, respectively, accompanied by 11.2-fold (CTC tea) and 10.29-fold (Kangra orthodox tea) increase in gallic acid concentration. The tannase treated tea infusion showed reduction in tea cream formation and an increase in antioxidant activity to 1.73- and 1.61-fold, respectively. However, there was no change in the content and concentration of volatile compounds. Moreover, the results also showed that there was an improvement in the quality of tannase treated black tea infusion in relation to color, brightness, strength and flavor as compared with control. PRACTICAL APPLICATION The tannase mediated biotransformation of tea infusion (CTC and Kangra orthodox) improves the quality of tea in relation to reduction in tea cream formation. The reduction will help to produce a turbidity free, cold water soluble instant tea or tea extract. Furthermore, on tannase treatment, an increase in an antioxidant activity was also observed due to certain flavonoids present in tea that show potential health benefits against cardiovascular diseases and cancer. There was no significant change in the volatile compounds that thereby resulted in an improved color, brightness, strength and flavor of tea.

Aggregation of sensory data using fuzzy logic for sensory quality evaluation of food

A method of sensory evaluation using fuzzy logic has been proposed in this paper. The method was applied for evaluation of sensory quality of tea liquor made out of dried CTC tea. Linguistic data (e.g., excellent, very good, good, satisfactory, fair, not-satisfactory, etc.) on individual tea liquor's quality attributes and the perception of the evaluators (e.g., extremely important, highly important, important, somewhat important, not-at-all important, etc.) for relative importance of these quality attributes were obtained. Sensory score between 0 and 100 for (i) Judges' preference for different quality attributes of tea liquor in general, (ii) Quality attributes ranking of tea liquor and the (ii) Overall quality of tea liquor were estimated. The last one can be utilized for the ranking of the different tea liquors.

MODELING DESORPTION ISOTHERMS AND THERMODYNAMIC PROPERTIES OF ASSAM CTC MANUFACTURED FROM TEA CULTIVAR T3E3

ABSTRACT Moisture sorption isotherms of Assam CTC manufactured from tea cultivar T3E3 were determined at 30, 40 and 50C using the static gravimetric method over a range of relative humidity from 0.1 to 0.9. The equilibrium moisture content of the tea sample decreased with increase in temperature at constant relative humidity. Seven mathematical models (Brunauer–Emmett–Teller, Peleg, Oswin, Henderson, Halsey, modified Chung–Pfost and Guggenheim–Anderson–de Boer [GAB]) were used for fitting experimental data. The Oswin and GAB models were found to have better suitability for describing the sorption curves. The monolayer moisture content values for the sorption at different temperatures were calculated by using the GAB model. The net isosteric heat of sorption was estimated from equilibrium sorption data, using the Clausius–Clapeyron equation. The enthalpy–entropy compensation theory was applied to sorption isotherms, and plots of Δhd versus ΔSd provided the isokinetic temperatures, indicating an enthalpy-controlled sorption process. PRACTICAL APPLICATIONS Assam CTC tea is an important processed food commodity involving substantial commercial activities at national as well as international levels. Appropriate processing and perfect storage of this commercially important commodity are two critical issues to be addressed to fetch higher prices at competitive tea markets. The cultivars available today for tea production are T3E3, S3A1, S3A3, TV1 to TV31, etc. T3E3 is a very popular yield clone for CTC tea production in Assam. There is a considerable variation in the rate of loss of moisture among these cultivars. The knowledge of equilibrium moisture content (EMC) vis-à-vis water activity (Aw), which is the central theme of the present investigation, is one of the important factors to regulate overall manufacturing processes. Moreover, results of the present investigation will also be helpful to ascertain appropriate storage conditions for processed tea. Because biologic activities in tea during storage are highly sensitive to its moisture content due to the presence of several complex enzymes, such as polyphenol oxidase, peroxidase, etc., inactivation of these enzymes requires the knowledge of safe moisture content. Thus, the results of the present investigation would have important practical applications, particularly in tea processing and marketing sectors.

Radical Scavenging Capacity of Rwandan CTC Tea Polyphenols Extracted Using Microwave Assisted Extraction

Radical Scavenging Capacity of Rwandan CTC Tea Polyphenols Extracted Using Microwave Assisted Extraction

Imidacloprid in processed tea and tea liquor

Imidacloprid is a newly introduced broad-spectrum chloronicotinyl insecticide and will find its way in agricultural production, particularly in Asia. However, information on the fate of imidacloprid in crop plants is lacking. The degradation of imidacloprid in processed CTC tea and tea liquor was investigated in the present study in which imidacloprid was applied at recommended application rate (30.0 g a.i./ha) and twice the recommended application rate (60.0 g a.i./ha) for three consecutive seasons. Imidacloprid was rapidly dissipated in processed tea following first order reaction kinetics at all application rates and had half-lives of 0.91-1.16 d with the residue in tea liquor found to be below detectable limit on 3rd day samples. The study revealed that imidacloprid is safe for human consumption and will not pose any residual toxicity problem.