Oolong tea, also known as green tea, is a semi fermented tea. In terms of quality characteristics, oolong tea has a robust and tight appearance, with a predominantly dark brown and oily color. It has a natural floral and fruity aroma and the characteristic of "green leaves with red edges", as well as the fragrance of green tea and the rich taste of black tea, making oolong tea different from other types of tea.Oolong tea contains tea polyphenols, alkaloids, proteins, amino acids, vitamins, pectin, organic acids, lipopolysaccharides,sugars, enzymes, pigments, and other components. In addition, oolong tea also contains catechins, various amino acids, potassium, calcium, magnesium, cobalt, iron, manganese, aluminum, sodium, zinc, copper, nitrogen, phosphorus, fluorine and other components.