The temperature dependence of the rate of extraction of soluble constituents of black tea

Autor:	John C. Spitzer, William E. Price
Rok vydání:	1993
Předmět:	Aqueous solution Chromatography medicine.diagnostic_test Kinetics Extraction (chemistry) food and beverages General Medicine Analytical Chemistry Matrix (chemical analysis) chemistry.chemical_compound chemistry Spectrophotometry medicine Caffeine Black tea Food Science Tea leaf
Zdroj:	Food Chemistry. 46:133-136
ISSN:	0308-8146
DOI:	10.1016/0308-8146(93)90025-b
Popis:	The temperature eVect on the infusion of solubles from black tea leaf was examined by analysing the infusion characteristics of UV active solubles present in the tea leaf by spectrophotometric means. The results represent the Wrst set of kinetic data for extraction of solubles from an Australian CTC tea (Nerada). From the experiments conducted, the activation energy for the infusion of solubles was determined to be 41 kJ mol−1. This value is higher than previous ones in the literature. The results are discussed by comparing them with the temperature dependence for diVusion of species in aqueous solutions. The Wndings are consistent with the likely rate-determining step being the hindered diVusion of a soluble constituent through the leaf matrix.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::010020dc3370e6c037f833b80b0df327 https://doi.org/10.1016/0308-8146(93)90025-b Zobrazit plný text záznamu