Nepali tea teas like green tea, oolong tea, white tea and hand rolled tea fall under the category of orthodox tea. In Nepal, orthodox tea is produced and processed in the mountainous regions of Nepal at an altitude ranging from 3,000 – 7,000 feet above the sea level. There are six major districts, primarily in the eastern regions of Nepal that are known for producing quality orthodox tea, which are Ilam, Panchthar, Dhankuta, Terhathum, Sindhulpalchok and Kaski. Orthodox tea in Nepal is characterized by four flushes:- Crush, tear, curl (CTC) tea is a method of processing Assam variety "(Camellia sinensis" var. "assamica)",
Camellia sinensis there is no high-quality evidence that tea confers significant benefits. In clinical research over the early 21st century, tea has been studied extensively for its potential to lower the risk of human diseases, but none of this research is conclusive as of 2017. Caffeine is a molecule produced in "Camellia sinensis" and functions as a secondary metabolite. Caffeine is a purine alkaloid and its biosynthesis occurs in young tea leaves and is regulated by several enzymes. The biosynthetic pathway in "C. sinensis" differs from other caffeine producing plants such as coffee or guyausa. Analysis of the pathway was carried out