Withering timings affect the total free amino acids and mineral contents of tea leaves during black tea manufacturing
| Autor: | Sahib Alam, Hamid Ullah Shah, Saiqa Jabeen, F. S. Hamid, Rukhsana Bibi, Waqar Ahmad, Maria Saleem |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
Chemistry(all) Moisture General Chemical Engineering Withering Ash General Chemistry Free amino Amino acid lcsh:Chemistry Black tea lcsh:QD1-999 chemistry Biochemistry Mineral contents Fermentation Chemical Engineering(all) Amino acids Potential source Camellia sinensis Food science Water content |
| Zdroj: | Arabian Journal of Chemistry, Vol 12, Iss 8, Pp 2411-2417 (2019) |
| ISSN: | 1878-5352 |
| DOI: | 10.1016/j.arabjc.2015.03.011 |
| Popis: | The aim of the present study was to investigate the effect of withering timings (i.e. 0, 21, 22, 23 and 24 h) on the moisture, total free amino acids, ash, essential and toxic mineral element contents of tea (Camellia sinensis L.) leaves during black tea manufacturing. Moisture, ash, Na, P, Mg, Cu, Zn, Mn, Al, Ni and Pb contents were significantly (P 0.05) results were noted for total free amino acids, K, Fe and Cd contents. The highest moisture content (76.4%) was examined in fresh leaves that progressively decreased to 63.8% in 24 h withering. Total free amino acid contents gradually increased up to 23 h and then decreased. Ash, P, Cu, Zn and Mn contents showed an increasing trend with withering time. Conversely, significantly lowered amounts of Na (162.5 mg/kg) and Mg (803 mg/kg) were recorded in tea leaves after 24 h withering. Among the toxic elements, Al, Ni and Pb contents were progressively increased over withering time. It was concluded that tea is a potential source of essential chemical constituents and during processing proper care should be taken to produce high quality black tea. Keywords: Black tea, Withering, Amino acids, Mineral contents, Ash, Fermentation |
| Databáze: | OpenAIRE |
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