SciELO - Scientific Electronic Library Online

 
vol.55Access and use of medicines by elderly individuals with dementiaAntifungal effect of sesame medicinal herb on Candida Species: original study and mini-review author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Brazilian Journal of Pharmaceutical Sciences

On-line version ISSN 2175-9790

Abstract

ALMEIDA, Tânia Santos de et al. Influence of preparation procedures on the phenolic content, antioxidant and antidiabetic activities of green and black teas. Braz. J. Pharm. Sci. [online]. 2019, vol.55, e17695.  Epub Sep 23, 2019. ISSN 2175-9790.  http://dx.doi.org/10.1590/s2175-97902019000117695.

The influence of common tea preparation procedures (temperature, infusion time, consumption time interval and tea bag/loose-leaf) and the type of water used, on the total phenolic content (TPC), the radical scavenging activity and the α-glucosidase inhibitory activity were assessed. Higher TPC and antioxidant activity were obtained when using lower mineralized waters. Tea bags also evidenced higher antioxidant activity than loose-leaf samples. Under the same conditions (90 ºC and five minutes of infusion time) green tea contains almost twice the quantity of polyphenols and the free radical scavenging ability of black tea. In the α-glucosidase assay all infusions were active (97-100 %). Furthermore, HPLC allowed to identify some of the polyphenols present in both teas and to monitor their composition change with time. After twenty-four hours, the antioxidant activity was maintained without significant changes, but a small decrease in enzyme inhibition was observed, although this activity was still very high.

Keywords : Black tea; Green tea; Antioxidant activity; α-Glucosidase activity; Water mineralization.

        · text in English     · English ( pdf )