In vitro analysis of the properties of Beiqishen tea

Chinese Beiqishen tea was studied in an in vitro test system. Phytochemical screening, trace element analysis, and the analysis of antioxidant properties were carried out. Characteristic constituents were determined by chromatographic (capillary gas chromatography and GCQ Ion Trap mass spectrometry) and spectrometric (ultraviolet and UV-VIS) methods. Element concentrations were determined by inductively coupled plasma optical emission spectrometry. Antioxidant capacity was studied by spectrophotometric and luminometric techniques using a Berthold Lumat 9501 luminometer. Hydrogen-donating activity, reducing power, and total scavenger capacity were measured. Total polyphenol content was 20.77 ± 0.52 g/100 g of drug; total flavonoid content was 0.485 ± 0.036 g/100 g of drug; and tannin content was 9.063 ± 0.782 g/100 g of drug. Caffeine content was 1.08 mg/100 g of drug. Essential oils were identified by gas chromatography: (+)-limonene (21%), p-cymene (1.7%), estragol (3.2%), β-ocimene (1.4%), and thymol (2.6%). Metallic ion analysis showed significantly high concentrations of Al, As, Ba, Cr, Cu, Fe, Mn, Ni, and Ti in the drug. Antioxidant and scavenger properties were identified as a function of concentration. The tea infusion contained some non-desirable trace elements and caffeine in addition to polyphenols and tannins in high concentrations. Therefore, the consumption of this tea may involve risks.