Evaluation of low temperature drying characteristics of fresh tea leaves (Camellia assamica) in an environmental chamber using mathematical models

Autor: Anindita Sharma, Partha Pratim Dutta
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Research in Agricultural Engineering, Vol 69, Iss 2, Pp 55-64 (2023)
Druh dokumentu: article
ISSN: 1212-9151
1805-9376
DOI: 10.17221/28/2021-RAE
Popis: Low-temperature drying (withering) is the first stage in black tea processing. Determination of appropriate end moisture content of green tea leaf as well as temperature and relative humidity (RH) maintained during withering eventually aid the final quality of the processed tea. Therefore, the tea leaf withering (partial drying) properties were evaluated in an environmental chamber using mathematical models. The temperatures and RH considered were 25, 30, 35 °C and 80, 85, 90%, respectively. A total of nine combinations of temperature and RH were considered by keeping one parameter constant. The conditions were taken adhering to that of the climatic conditions of Assam, India. The withering data from experiments were fitted into five drying models using the curve fitting method. The Page model gave better predictions with an R2 value of 0.9989 at 30 °C temperature and 90% RH. The total phenolic and flavonoid contents of the tea leaf samples were evaluated. The best results were 50.60 ± 0.02 mg GAE.g-1 (GAE - gallic acid equivalent) and 22.47 ± 0.01 mg QCE.g-1 (QCE - quercetin equivalent) at 30 °C withering temperature.
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