Camellia Sinensis Leaf Compounds. What´s the Tea Leaf Made of?

What is the Tea Leaf Made of? Camellia Sinensis Leaf Compounds.

Have you ever thought about what's our dear and magic tea leaf actually made of? Let's take a closer look at what the compounds/substances that make up Camellia Sinensis leaves (there are many of them, and still each of them is unique and indispensable its own way):
  • Moisture (or Water) Content (75% - 78% of the total composition of the tea leaf).
Of  course, not every leaf will have the exact amount of water, which will depend on factors like how old or young/fresh is the leaf, tea varietal, season of the year etc... However, it will be most of times falling in the above mentioned range. 
Water content, as it could not be otherwise, is the main reason giving origin to at least all the few first-stage tea processes such as withering (actually withering simply starts after plucking the leaf), “yao qing” (摇青 or shaking the green), “sha qing” (杀青 or killing  the green) etc... All these processes actually have a common target: reducing the moisture (or water) content in order to avoiding the decaying or rotting process as well as preparing for further processing.
  • Enzymes (several):
Enzymes are a of active protein body that act as a biological catalyst, which accelerate chemical reactions. Enzymes are crucial in the overall transformation and development of the Camellia Sinensis leaves’ ultimate tastes. Actually, water-soluble pigments formed in enzymatic and non-enzymatic oxidizations are principal flavour elements.
  • Fragrant Substances (0.02% of total fresh leaves):
Or aromatic substances refer to a type of volatile substances in tea.
The dry matter of the tea leaf, that represents around 22% to 25% of the total, is made up of the following compounds:
  • Tea polyphenols (20~30% of the total dry matter):
The catechins are the major polyphenolic compound (about 70% of tea polyphenols) that can be found in the green (fresh) tea leave, and they are actually responsible to a large extent for the tea leaf colour, fragrance and aroma. Tea polyphenols, it has been shown to have very positive effects on antioxidant, anti-inflammatory, cancer prevention as well as in the regulation of lipid metabolism
  • Protein (20%~30% of the total dry matter):
A big proportion of the protein content gets actually dissolved in water and in the end the directly used/consumed portion of protein accounts for just about 1% to 2%.
  • Sugars (20% - 25% of the total dry matter):
Polysaccharose is insoluble in water and is an important component to measure the aged/tenderness of tea.
  • Lipids (8% of total dry matter):
It is known that lipids can change by heating, oxidation, fermentation etc…, alterations occurring during common tea processing or tea storing, and that can result in loss of amino acids, formation of bitter taste etc… So that lipids play an important role also in the taste of tea.
Some lipids we can find in tea are: phospholipids, glycerides, sugar esters and thioesters.
  • Inorganic Compounds (3.5% ~ 7.0%of the total dry matter):
It is also known as ash, and yes! It is the ash you are thinking about! Products, foodstuff, plants etc… also contain ash (as an inorganic compound), and when they got incinerated (burnt at 550 C or more) the remaining residues will be the ashes (this time in the way all of us know). In genuine tea, 50% or more of the ash is water soluble and the rest is water insoluble. Ash content is actually rich in calcium, and we should not be mislead by the name and associate it to bad or good qualities or contents.
  • Alkaloids (2% - 5% of the total dry matter):
Caffeine is the most well-known alkaloid found in tea. Alkaloids (and caffeine), same as it occurs with coffee, it also determine the bitter taste of the magic leaf.
There is more caffeine content in leaves  than in stems, the amount decreases with the ageing of leaves, and the content is higher in summer than in spring.
  • Pectin (4% of the total dry matter):
Pectin and other substances in tea are metabolites of sugar.
  • Amino acids (1%~4% of the total dry matter):
Amino acid is the basic substance of protein.
  • Organic Acids(3% of the total dry matter):
Organic acids are an important component in the tea leaf determining tea’s aroma. Citric, isocitric, malic, succinic and oxalic, along with five unknown acids were found at appreciable levels in tea shoot tips.
  • Vitamins (0.6% - 1% of total dry matter):
Fat soluble vitamins include vitamins A, D, E, K, etc., being vitamin A content the highest among all. However different types of tea (green, white, yellow, oolong, black and dark) will contain more on such vitamins than others, and same way, different researches throw different results.
  • pigment (1% of the total dry matter):
Tea pigments are nothing but oxidized products of polyphenols derived from the Camellia Sinensis leave. Theaflavins are constituents of tea pigments that possesses antiinflammatory, antioxidant and antineoplastic properties.