Characterization of Black and Green Tea from Local Market

Abstract

The leaves from Camellia sinensis are used from ancient times for preparation of tea but also as raw material for different extracts which are used in food industry as well as in pharmaceutical or cosmetic products. Due to the increasing interest in tea health benefits, the aim of the present study was to characterize several brands of green and black tea found on local market, regarding their content in total phenolic compounds, flavonoids and antioxidant capacity. Total phenolics and flavonoids were determined spectrophotometrically using a modified Folin-Ciocalteu method, respectively a chromogenic system of NaNO2–Al(NO3)3–NaOH based method. The antioxidant capacity of each tea sample was assessed through the evaluation of free radical scavenging effect on 2,2-diphenyl-1-picrylhydrazyl. The results obtained for the green and black tea samples varied widely, depending on the tea variety. The antioxidant capacity of the analyzed teas ranged between 12.10 and 40.03%RSA, while the total phenolic content was within 2090 and 6080 mg GA/ 100g. The concentrantion in flavonoids was between 9.04 and 15.34 g/100g of tea.

Comparative Evaluation of Biofunctional Compounds Content from Different Herbal Infusions

“…The highest concentration in phenolic compounds was determined for green tea (45.90 mg GAE/100 ml), closely followed by black and mint tea (39.60 respectively 39.30 mg GAE/100 ml). These data corroborate with those obtained in a previous study by Socaci et al, 2013. Not the same order was observed for flavonoids; John's wort and mint had the highest content (17.15 respectively 13.24 mg QE/100 ml) followed by the linden sample (8.66 mg QE/100 ml).…”

“…The health effects associated with the consumption of green or black tea, suggested by recent human studies, are: the reduction of cardiovascular diseases risk and different forms of cancer, reduction of blood pressure, the presence of compounds with anti-Alzheimer's effect, antibacterial and antiviruses activity, solar ultraviolet protection, bone mineral increase density, source of bio-essential elements (Cabrera et al, 2006;Socaci et al, 2013).…”