Chemical profiling for the quality assurance of green tea commercialized in Colombia

Herbal medicine is permanently applied around of the world, being traditional Chinese medicine one of the most important practices. Particularly, high phenolic content and a great diversity of biological activities have been described for tea plants (Camelia sinensis) indicating that tea plays a significant role in folk medicine. Green tea is one of those teas which has been submitted at minimum oxidation treatment, and it has been popularized in recent years due to its health benefits. In Colombia, green tea has been increasingly commercialized but quality assurance protocols have not been established. Therefore, several commercial available trademarks of green tea were purchased at Bogotá. Samples were analyzed regarding total phenolic content, total flavonoid content, total catechin content, antioxidant capacity and LC profiles. Obtained results demonstrated a marked difference between trademarks through the variation of the major and minor constituents. This tendency was maintained by addition of ethanol as co-solvent in the extraction process, although extraction selectivity was highly modified. Unsupervised pattern recognition methods were also demonstrated as key tools in the treatment of chromatographic data set. Our findings reveal the need to establish adequate quality assurance protocols for plant material and plant extracts commercialized in Colombia. The present work is a product derived by the Project IMP-CIAS-1567 financed by Vicerrectoría de Investigaciones at UMNG – Validity 2014.