ВЛИЯНИЕ ФЕРМЕНТАЦИИ И ИЗМЕНЕНИЯ КИСЛОТНОСТИ СРЕДЫ НА СОСТАВ И АНТИОКСИДАНТНУЮ АКТИВНОСТЬ ВОДНЫХ ЭКСТРАКТОВ ЧАЯ
Рябинина, Елена Ивановна
Зотова, Елена Евгеньевна
Пономарева, Наталия Ивановна
Мезенцева, Ольга Александровна
Булгакова, Мария Александровна
- Publisher: Altai State University
Khimiia rastitel'nogo syr'ia (Chemistry of plant raw material)
(issn: 1029-5143, eissn: 1029-5151)
antioxidant activity, polyphenols, potentiometric and amperometric methods, tea. | антиоксидантная активность, полифенолы, потенциометрический и амперометрический методы, чай.
mesheuropmc: food and beverages | complex mixtures
The presense of hydrolysable tannins in green tea, as well as hydrolysable and condensed tannins in black tea has been prooved with the help of potentiometric method, and condensed compounds take 70% of the total content. Antioxidant activity of tea extracts with different type of fermentation has been measured using amperometric method and determined, that the samples of green tea have the highest value of activity. Correlation between the total amount of polyphenols in tea and antioxidant activity was found. There was established, that decrease of pH lowers the quantity of tannins, which take part in oxidation-reduction processes, what may have a connection with their transformation into non-ionized form.