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Bio-inspired tea stain removal

GERD REINHARDT

Clariant Produkte (Deutschland) GmbH, Industriepark Hoechst, D 562, Frankfurt am Main, 65926, Germany

TEA STAIN REMOVAL
Besides water, black tea is the most widely consumed beverage on a global basis. Prepared as an infusion of fermented tealeaves in hot water it contains a number of polyphenolic compounds giving the characteristic astringent fl avour and the brown-red colour. On cooling down in cups and pots, components such as thearubigins and theafl avins in combination with water hardness ions form a brown scum. Further oxidation reactions take place at the water/air phase leaving brown stains on porcelain surfaces which are hard to remove. Supported by the universal cleaning power of phosphates, commonly used oxygen-based bleaches are able to break down the stain at high temperature. However, being a chemical reaction, teastain removal becomes more diffi cult at