Query: black tea Manufacturing process

Candidate papers:

abstract: "Tea" is a beverage which has a unique taste and aroma. The conventional method of tea manufacturing involves several stages. These are plucking, withering, rolling, fermentation, and finally firing. The quality parameters of tea (color, taste, and aroma) are developed during the fermentation stage where polyphenolic compounds are oxidized when exposed to air. Thus, controlling the fermentation stage will result in more consistent production of quality tea. The level of fermentation is often detected by humans as "first" and "second" noses as two distinct smell peaks appear during fermentation. The detection of the "second" aroma peak at the optimum fermentation is less consistent when decided by humans. Thus, an electronic nose is introduced to find the optimum level of fermentation detecting the variation in the aroma level. In this review, it is found that the systems developed are capable of detecting variation of the aroma level using an array of metal oxide semiconductor (MOS) gas sensors using different statistical and neural network techniques (SVD, 2 NM, MDM, PCA, SVM, RBF, SOM, PNN, and Recurrent Elman) successfully.
author_names: Tharaga Sharmilan

Iresha Premarathne

Indika Lasantha Wanniarachchi

Sandya Kumari

Dakshika Wanniarachchi
title: Electronic Nose Technologies in Monitoring Black Tea Manufacturing Process
venue: J. Sensors
year: 2020

abstract: Amino acids contribute to the nutritional value and quality of black tea. Fermentation is the most important stage of the black tea manufacturing process. In this study, we investigated protein degradation and proteinaceous amino acid metabolism associated with enzymatic reactions during fermentation in the black tea manufacturing process. The results showed that the concentrations of both protein and free amino acids decreased during fermentation. We also confirmed that proteins were broken down into free amino acids by artificially synthesized dipeptide benzyloxycarbonyl glutamyl tyrosine (Z Glu Tyr) Metabolites of the amino acid metabolic pathway increased significantly during fermentation. Furthermore, we confirmed that free amino acids were degraded to volatile compounds in a tracer experiment with the isotope precursor. These results provide information that will help black tea manufacturers improve the quality of black tea.
author_names: Yiyong Chen

Lanting Zeng

Yinyin Liao

Jianlong Li

Bo Zhou

Ziyin Yang

Jinchi Tang
title: Enzymatic Reaction Related Protein Degradation and Proteinaceous Amino Acid Metabolism during the Black Tea (Camellia sinensis) Manufacturing Process
venue: Foods
year: 2020

abstract: This study is focused on how the variation of physical parameters (temperature and humidity) in the factory will affect the fermentation stage of the black tea manufacturing process. Data for this paper was collected using an automated temperature and humidity monitoring device. Here, physical parameters for fermentation of dhool 1 tea particles were analyzed for 33 batches of samples (672 data) to find the best fit model for the bed tea leaves temperature. This temperature is directly related to the oxidation of polyphenolic compounds in tea. Monitoring device placed on the fermentation bed records ambient temperature, exhaust temperature, bed tea leaves temperature, ambient humidity, exhaust humidity with 3 minutes and 20 second intervals. Then these data were analyzed by correlation and regression analysis to find the best model for the bed tea leaves' temperature. According to the results obtained in the present investigation, bed tea leaves' temperature depends on actual time, exhaust temperature, exhaust humidity and ambient temperature. These can be considered as significant quality factors for determining the optimum bed tea leaves' temperature. The optimized best fit model explains about 75.34 percent of the variation in the response. For these data, the R2 value indicates the model provides an adequate fit to the data. Finally, these results highlight the importance of measuring tea bed exhaust temperature and humidity parameters rather an ambient condition for the black tea fermentation process.
author_names: S Tharaga

B J Watawana

W K I L Wanniarachchi

K Sita Kumari

Dakshika Wanniarachchi
title: Significance of Physical Parameters to Optimize the Bed Tea Leaves' Temperature During Fermentation Stage of Black Tea Manufacturing Process
venue: 2018 IEEE International Conference on Information and Automation for Sustainability (ICIAfS)
year: 2018

abstract: 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.
author_names: Chandana Vindika Kumara Lokunarangodage

Indira Wickramasinghe

K K Ranaweera
title: Constraints and Compliances of Traceability in Low Grown Orthodox Black Tea Manufacturing Process
year: 2015

abstract: Abstract CTC (Crush, Tear and Curl) black tea, as one of the most representative black tea, is a very popular beverage in the world owing to its potential health benefits. However, the presence of toxic elements has gained more and more public health concerns. The contents of elements in tea were affected not only by growth environment but also by the technology of manufacturing process. Unfortunately, the studies of the influence of manufacturing process on the levels of elements in final tea products were very limited. In this study, the influence of manufacturing process on the levels of iron (Fe) copper (Cu) chromium (Cr) nickel (Ni) and manganese (Mn) in CTC black tea were determined by inductively coupled plasma mass spectrometry (ICP MS) It was found that the concentrations of Fe and Cu in tea leaves could greatly increase after rolling by rotorvane, which was proved to be the key stage affecting the Fe and Cu levels in final made tea. However, Cr and Ni contents in tea leaves increased greatly after cutting by CTC rollers. There was no significant difference among Mn concentrations in tea samples obtained from different stages according to the one way ANOVA analysis (p 0.05) The effect of brewing time and brewing times on the transfer rates were investigated. Ni displayed the highest transfer rate with the value of 75.74% while the transfer rates of Cu, Cr and Mn were 30.08% 26.62% and 34.98% respectively. With respect to the recommended daily allowance, the Fe, Cu, Cr and Ni in CTC black tea do not pose significant risk to human health while concerns should be paid to Mn since its HQ was still large than 1% even considering the bioavailability.
author_names: Lin Zhang

Jianyang Zhang

Liyan Chen

Ting Liu

Guicen Ma

Xin Liu
title: Influence of manufacturing process on the contents of iron, copper, chromium, nickel and manganese elements in Crush, Tear and Curl black tea, their transfer rates and health risk assessment
year: 2018

abstract: Abstract Instant tea powder is the fully soluble solid of tea that has emerged as a new and fast growing product in every country. The various processes involved in the commercial production of instant tea includeblending of tea leaves, hot water extraction, aroma recovery, soluble solids concentration, aroma restoration and dehydration. An envisaged process has been developed for the production of instant/soluble tea from the expressed juice of fermented tea leaves. Green tea leaves are subjected to withering, maceration, and fermentation process, which are similar to that of existing black tea production process. The fermented leaf is pressed to expel a part of juice containing soluble solids. The juice is then heated, centrifuged and vacuum dried to get soluble/instant tea powder. The pressed leaf residue is subjected to vacuum/hot air drying to obtain low grade conventional tea granules. About 20 2 g of soluble tea and 220 20 g of pressed cake tea are obtained from 1 kg of green tea leaves. The TF:TR ratio for soluble tea is 0.084 and that for pressed cake tea is 0.140. Industrial relevance The technology can be easily adopted by existing black tea manufacturers for simultaneous production of instant tea and black tea. The process is economical as both extracted juice and pressed cake are converted into value added products.
author_names: Chinta Someswararao

Prem Prakash Srivastav
title: A novel technology for production of instant tea powder from the existing black tea manufacturing process
year: 2012

abstract: Gasification of uprooted tea shrub (Camellia sinensis (L. O. Kuntze) is an attractive option for partial substitution of thermal energy in tea manufacturing industries. Chopped and dried uprooted tea branches with moisture content (X 20% have high energy contents suitable to generate process heat. Good number of tea processing units in Assam use old design and inefficient coal fired furnace and air heater with a low overall efficiency. Gasification of uprooted tea shrubs may be beneficial partially to substitute these old design coal fired furnaces. The calorific values of uprooted tea branches and generated producer gas were found 18.50 MJ kg 1 and 4.2 MJ m 3, yielded products at 65% cold gasification efficiency. Fermented tea samples with an average moisture content of 60% could be dried to 3% moisture using biomass gasifier and tea dryer setup. Simple economic analysis shows gasifier cum tea dryer technology may be economically favorable option with an annual saving of 21,067 in a medium scale tea factory (990 t per year made tea) if 28% of total thermal energy requirement is substituted by biomass gasification.
author_names: Partha Pratim Dutta

Debendra Chandra Baruah
title: Gasification of tea (Camellia sinensis (L. O. Kuntze) shrubs for black tea manufacturing process heat generation in Assam, India
year: 2014

abstract: As important biomolecules in Camellia sinensis L. lipids undergo substantial changes during black tea manufacture, which is considered to contribute to tea sensory quality. However, limited by analytical capacity, detailed lipid composition and its dynamic changes during black tea manufacture remain unclear. Herein, we performed tea lipidome profiling using high resolution liquid chromatography coupled to mass spectrometry (LC MS) which allows simultaneous and robust analysis of 192 individual lipid species in black tea, covering 17 (sub)classes. Furthermore, dynamic changes of tea lipids during black tea manufacture were investigated. Significant alterations of lipid pattern were revealed, involved with chlorophyll degradation, metabolic pathways of glycoglycerolipids, and other extraplastidial membrane lipids. To our knowledge, this report presented most comprehensive coverage of lipid species in black tea. This study provides a global and in depth metabolic map of tea lipidome during black tea manufacture.
author_names: Jia Li

Jinjie Hua

Qinghu Zhou

Chun-wang Dong

Jinjin Wang

Yuliang Deng

Haibo Yuan

Yongwen Jiang
title: Comprehensive Lipidome Wide Profiling Reveals Dynamic Changes of Tea Lipids during Manufacturing Process of Black Tea.
venue: Journal of agricultural and food chemistry
year: 2017

abstract: Glycosides are known to be precursors of the alcoholic aroma compounds of black tea. They are hydrolyzed by endogenous glycosidases during the manufacturing process. Changes in the amounts of these glycosides during the manufacturing process were investigated by using a capillary gas chromatographic mass spectrometric analysis after trifluoroacetyl derivatization of the tea glycosidic fractions. Primeverosides were 3 fold more abundant than glucosides in fresh leaves, but they decreased greatly during the manufacturing process, especially during the stage of rolling. After the final stage of fermentation, primeverosides had almost disappeared, whereas glucosides were substantially unchanged. These results show that hydrolysis of the glycosides mainly occurred during the stage of rolling and confirm that primeverosides are the main black tea aroma precursors. This was also supported by the changes in the glycosidase activities in tea leaves. The glycosidase activities remained at a high level during withering but decreased drastically after rolling.
author_names: Dongmei Wang

E Kurasawa

Yuichi Yamaguchi

Kikue Kubota

Akio Kobayashi
title: Analysis of glycosidically bound aroma precursors in tea leaves. 2. Changes in glycoside contents and glycosidase activities in tea leaves during the black tea manufacturing process.
year: 2001

abstract: Glycosides are known to be precursors of the alcoholic aroma compounds of black tea. They are hydrolyzed by endogenous glycosidases during the manufacturing process. Changes in the amounts of these glycosides during the manufacturing process were investigated by using a capillary gas chromatographic mass spectrometric analysis after trifluoroacetyl derivatization of the tea glycosidic fractions. Primeverosides were 3 fold more abundant than glucosides in fresh leaves, but they decreased greatly during the manufacturing process, especially during the stage of rolling. After the final stage of fermentation, primeverosides had almost disappeared, whereas glucosides were substantially unchanged. These results show that hydrolysis of the glycosides mainly occurred during the stage of rolling and confirm that primeverosides are the main black tea aroma precursors. This was also supported by the changes in the glycosidase activities in tea leaves. The glycosidase activities remained at a high level during withering but decreased drastically after rolling.
author_names: Donghai H Wang

E Kurasawa

Yuichi Yamaguchi

Ken-ichi Kubota

A Kobayashi
title: Analysis of glycosidically bound aroma precursors in tea leaves. 2. Changes in glycoside contents and glycosidase activities in tea leaves during the black tea manufacturing process.
venue: Journal of agricultural and food chemistry
year: 2001