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Studies on the formation and composition of ‘cream’ in tea infusions
Author(s) -
Smith R. F.
Publication year - 1968
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740190910
Subject(s) - creaming , chemistry , theaflavin , caffeine , black tea , food science , composition (language) , fractionation , chromatography , polyphenol , organic chemistry , emulsion , medicine , linguistics , philosophy , antioxidant , endocrinology
Abstract Tea ‘cream’ is a finely‐divided suspension of insoluble particles that forms when a strong infusion of black tea cools. This study not only confirms that the principal constituents of ‘cream’ are theaflavins, thearubigins and caffeine, but shows that ‘cream’ also contains smaller amounts of other flavonoids, non‐caffeine nitrogen compounds, chlorophyll, and inorganic material; all of which are present in the original black tea. The effects of caffeine, theaflavin and thearubigin content, also the composition of the thearubigins (as indicated by the E 380 / E 460 value) of black tea, the strength of infusion, and the pH of the infusing water on the amount of cream formed in infusions were investigated. Evidence was obtained that creaming causes a partial fractionation of the thearubigins. A method for determining the ‘creaming power’ of tea is proposed.