Abstract
The widely known leaves of Camellia sinensis (L.) derive the most consumed beverage globally. All over the world, like in the Democratic Republic of the Congo (DR Congo), they are marketed in the form of packaged and in bulk black tea. The aim of this study was to report the microscopic botanical features, the chromatographic fingerprints, the antioxidant activities, and the peroxidase inhibition of bulk-marketed black teas consumed in DR Congo. The microscopic analysis of powders from unpackaged black tea marketed in DR Congo allowed the identification of specific microscopical features, which are characteristic to C. sinensis (L.) such as numerous asterosclerites, numerous fragments of unicellular trichomes; fragments of abaxial epidermis consisting of cells with slightly wavy walls, numerous anomocytic stomata, and the detection of biological contaminants, e.g. the dust mites. TLC and HPLC analysis indicated that flavonoids (hyperoside, rutin) and phenolic acids (chlorogenic acid, gallic acid) were major phenolic compounds, along with other secondary metabolites. Aqueous extracts from all bulk-marketed black teas exhibited good antioxidant activities at the concentrations range of 1 - 20 μg·mL-1 using in vitro ABTS and DPPH assays. These extracts showed equally inhibitory effects on myeloperoxidase (MPO) and horseradish peroxidase (HRP) activities at the concentration ranges of 1 - 20 μg·mL-1 and 20 - 100 μg·mL-1 respectively. Bulk-marketed black teas consumed in DR Congo possess antioxidant and anti-inflammatory properties comparable to packaged Ceylon tea largely marketed. The observed bioactivities support the health benefits of the consumed black tea by Congolese people, despite the storage conditions to be improved in order to preserve its nutritional and therapeutic assets.
Highlights
Camellia sinensis (L.) grows best in some tropical and subtropical country such as the Democratic Republic of the Congo (DR Congo) [1]
The microscopic analysis of powders from unpackaged black tea marketed in DR Congo allowed the identification of specific microscopical features, which are characteristic to C. sinensis (L.) such as numerous asterosclerites, numerous fragments of unicellular trichomes; fragments of abaxial epidermis consisting of cells with slightly wavy walls, numerous anomocytic stomata, and the detection of biological contaminants, e.g. the dust mites
Examined under a microscope using European Pharmacopeia reagent (Lactic acid reagent), the powders of different samples showed the following diagnostic characters: numerous asterosclerites (Figure 2), numerous fragments of unicellular trichomes; fragments of abaxial epidermis consisting of cells with slightly wavy walls, numerous anomocytic stomata, slightly thickened walls, accompanied by cells of the underlying palisade parenchyma; numerous isolated and grouped sclereids (Figure 3), palisade parenchyma usually arranged in 2 layers, spongy parenchyma including cells containing cluster crystals of calcium oxalate; fragments of spiral vessels accompanied by lignified fibers
Summary
Camellia sinensis (L.) grows best in some tropical and subtropical country such as the Democratic Republic of the Congo (DR Congo) [1]. Tea is generally consumed in the forms of green, Oolong, Puerh, and black tea, all of which originate from the leaves of the plant C. sinensis (L.) [3] [4]. Oolong tea is very common in many countries; green tea is preferred over the other types in China and Japan. In the Democratic Republic of the Congo (DR Congo), black tea is largely consumed during breakfast such as a popular drink by Congolese population. Packaged and bulk-marketed black teas are marketed under various trade names presented such as having high quality nutritional and therapeutic values. The Congolese population gives more preference to packaged teas at the expense of bulk-marketed black teas for quality reasons. To better characterize the different teas investigated, their microscopical characteristics and their chromatographic fingerprints were determined
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
