Simulation of Trough Withering of Tea using One Dimensional Heat and Mass Transfer Finite Difference Model

Botheju, W.S.; Amarathunge, K. S. P.; Abeysinghe, I. Sarath B.

doi:10.4038/tar.v22i3.3701

Cited by 11 publications

(5 citation statements)

References 5 publications

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“…Botheju et al (2011a) presented a relationship between withering process and rate of moisture decrease of fresh leaves. Later, the moisture content in withering process was predicted using process simulation by Botheju et al (2011b) and a model using fuzzy logic in Gupta et al (2012). Both articles have the objective of providing models to help in the decision making of withering tea leaves.…”

Section: Introductionmentioning

confidence: 99%

Influence of raw material moisture on the synthesis of black tea production process

Vargas

Vecchietti

2016

Journal of Food Engineering

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Section: Introductionmentioning

confidence: 99%

Influence of raw material moisture on the synthesis of black tea production process

Vargas

Vecchietti

2016

Journal of Food Engineering

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“…Leaf quality is largely a reflection of plucking standards. Coarse plucking standards reduce black tea quality, [20][21][22][23][24][25] due to a decline in catechin levels 26 and changes in polyphenol oxidase iso-enzymes composition and activities. 27 These reduce the levels of total theaflavins 15,[22][23][24][25] in black tea.…”

Section: Discussionmentioning

confidence: 99%

Catechins and Plain Black Tea Parameters Variations in Selected Tea Growing Agro-Ecological Zones in Kenya

Mose

Ochanda²,

Moseti³

et al. 2018

IJTS

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Over 60% of tea in Kenya is produced by smallholder tea farmers distributed in the East and West of the Rift Valley. With all smallholder tea farmers using the same production technologies including planting materials, the quality of tea from different agro-ecological zones should be the same. However, black teas attract different prices. This study compared levels of leaf quality, catechins, and polyphenols in green leaf and quality parameters of black tea from twelve factories in three different agro-ecological zones in Kenya and assessed the relationships between the green leaf quality parameters and black tea quality parameters. The catechins contents, the black tea quality parameters, and sensory evaluations changed (p less than or equal to0.05) between the factories and with an agro-ecological zone of production. All black teas had high antioxidant activities, which differed (p less than or equal to0.05) across the factories and zones. Despite the use of same agronomic inputs in the smallholder tea growing zones in Kenya, the quality of resultant black teas was largely influenced by the environmental factors in the different regions. It is therefore not possible to produce black teas of the same quality across the country. Despite the variations, all regions exhibited high levels of black tea quality parameters and sensory evaluation, re-affirming the Kenyan smallholder black teas are of high quality. The high antioxidant activities suggest possible beneficial pharmacological activities from consumption the teas. The green leaf quality (leaf count) were significantly (p less than or equal to0.05) correlated with black tea brightness and all sensory evaluation parameters, demonstrating high benefits from good plucking standards. Green leaf gallic acid, epigallocatechin, epicatechin, epigallocatechin gallate, and total catechins levels were related (p less than or equal to0.05) to black tea total polyphenols and all sensory evaluation parameters. In addition, the green leaf caffeine, epicatechin, epigallocatechin gallate, and total catechins influenced (p less than or equal to0.05) theaflavins in black tea. These green leaf parameters are therefore key drivers of Kenyan plain black tea quality.

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“…The complexity of the previous models may vary based on the assumptions made regarding the mechanisms of simultaneous mass and heat transport in the product's interior and the external conditions applied on the domain boundaries of product and drying air. These models are reported to be successfully implemented on various herbs such as tea, yerba mate and tobacco leaves [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of a Moisture Diffusion Model for Analyzing the Convective Drying Kinetics of Lavandula x allardii Leaves

2021

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In the present case study, a moisture diffusion model is developed to simulate the drying kinetics of Lavandula x allardii leaves for non-stationary convective drying regimes. Increasing temperature profiles are applied over the drying duration and the influence of temperature advancing rates on the moisture removal and the drying rate is investigated. The model assumes a one-dimensional moisture transfer under transient conditions, which occurs from the leaf center to the surface by liquid diffusion due to the concentration gradient developed by the surface water evaporation caused by the difference of water vapor partial pressure between the drying medium and the leaf surface. A numerical solution of Fick’s 2nd law is obtained by an in-house code using the finite volume method, including shrinkage and a variable temperature-dependent effective moisture diffusion coefficient. The numerical results have been validated against experimental data for selected cases using statistical indices and the predicted dehydration curves presented a good agreement for the higher temperature advancing rates. The examined modeling approach was found stable and can output, in a computationally efficient way, the temporal changes of moisture and drying rate. Thus, the present model could be used for engineering applications involving the design, optimization and development of drying equipment and drying schedules for the examined type of non-stationary drying patterns.

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Simulation of Trough Withering of Tea using One Dimensional Heat and Mass Transfer Finite Difference Model

Cited by 11 publications

References 5 publications

Influence of raw material moisture on the synthesis of black tea production process

Influence of raw material moisture on the synthesis of black tea production process

Catechins and Plain Black Tea Parameters Variations in Selected Tea Growing Agro-Ecological Zones in Kenya

Evaluation of a Moisture Diffusion Model for Analyzing the Convective Drying Kinetics of Lavandula x allardii Leaves

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