Effects of chemical composition of wild bush tea (Athrixia phylicoides DC.) growing at locations differing in altitude, climate and edaphic factors

Abstract

This study was conducted to determine the chemical composition of wild bush tea growing at locations differing in altitude, climate and edaphic factors. Samples were collected from 8 locations selected for their abundance of wild bush tea and replicated 6 times in the laboratory using a completely randomized design (CRD). The areas where bush tea samples were collected comprised of Khalavha, Louis Trichardt, Mudzidzidzi, Muhuyu, Haenertsburg, Hazyview, Barberton and Levubu, respectively. Bush tea samples were collected from the bush, and the total polyphenol content, tannin and total antioxidant contents were determined. Polyphenol content reached a maximum of 7.7 mg/100 g in bush tea samples from Haenertsburg, whereas the lowest content of 3.6 mg/100 g was recorded in Levubu. The highest polyphenol content was reached when altitude was at 1 410 m in Haenertsburg. Tannin content was the lowest (0.05 mg/100 g) in Khalavha. The highest tannin content was observed in Levubu with a maximum of 9.8 mg/100 g. The amount of total antioxidant content remained the same in all the locations at 35 µmol/ g. A positive correlation (R2 = 0.55) was observed between total polyphenol content and altitude. However, rainfall, temperature, soil macro elements and soil pH did not have any influence on total polyphenol, total tannin and total antioxidant contents. Key words: Polyphenols, tannins, antioxidants, edaphic factors, climatic factors.