Nutritional and medicinal improvement of black tea by yeast fermentation

Black tea fermentation with Dabaryomyces hansenii for 10 days resulted in accumulation of major vitamins, such as A, B-1, B-2, B-12 and C in sufficient quantities to fulfil the recommended dietary allowances (RDA). Fermentation of tea by yeast resulted in reduction of caffeine and excess tannins in significant amounts. After fermentation, the amount of theophylline was increased to make fermented tea a potent bronchodilator. Tea fermentation with D. hansenii improved its nutritional and medicinal values. Our observations suggest that intake of fermented tea is advantageous over black tea in terms of its nutritive and therapeutic values. (C) 2004 Published by Elsevier Ltd.