Preparation Technique of Green Tea (Camellia sinensis) in Grins in Mali: Phytochemical Profiles and Antioxidant Activity

Abstract

The tea consumption has become an important part of the Malian’s habits. As a result, an image of tea preparation and consumption among Malians has become widely diffused; tea is offered in three successive glasses: the first drink (FD), the second drink (SD) and the third drink (TD). However, no study has been carried out on the antioxidant potential of this type of green tea preparation. The objective of this work was to evaluate the quality of the preparation methods of green tea (Camellia sinensis) as performed in grins. Thus, a phytochemical screening was carried out, the quantitative estimation of total polyphenols was performed by the method of Folin-Ciocalteu and that of flavonoids by using the aluminum trichloride. The in vitro antioxidant activity of the different tea extracts (macerated and decocted) was determined by the DPPH method. Thus, the presence of several metabolites was revealed in these tea extracts and the cumulative contents of phenolic compounds in the green tea extracts found in the glasses were 150.67 ±7.87 mg EAG/g, while 140.67 ±2.37 mg EAG/g were collected in the macerated extract (WM). Both types of extracts showed similar levels of flavonoids. The antioxidant activity of FD in all tea samples was statistically identical to that of the extracts (WM) from tea samples A and D (p-values > 0.05). It appears from this preliminary study that neither the total phenolic compound contents nor the antioxidant activity would be impacted by the way Malian green tea is prepared.