WHERE DOES THE AROMA OF TEA COME FROM?

Part 4: Understanding Aroma.

The aroma of tea primarily comes from the olfactory sense due to volatile compounds, including both physical and mental stimulation caused by these aromatic compounds. Therefore, a healthy body and a joyful, contented spirit will enhance the perception of aroma when drinking tea.

Aroma is the result of the combination of various aromatic compounds at specific concentrations and ratios, along with their comprehensive impact on the olfactory nerves. These aromatic compounds constitute only about 0.01% of the dry tea mass, but they significantly determine the quality of the tea and the customers’ preferences for it.

Approximately 600 aromatic compounds have been identified in tea, including more than 280 compounds in green tea and over 300 compounds in black and oolong teas.

Since 1990, it has been proposed to use the Terpenoid Index (TI) to evaluate the quality of tea aroma. However, it has not been widely used because the intensity and characteristics of the aroma cannot be assessed solely based on the quantity and content of aromatic compounds. In fact, compounds with high concentrations do not necessarily produce strong aromas.

Therefore, the concept of odor activity value (OAV) was proposed by Patton and Josephson, defined as the ratio of the content of an aromatic compound to the threshold of that compound.

For example, benzyl acetate has a 70% jasmine scent, a 20% fruity scent, and a 10% chemical scent.

Standardized quantitative terms, instead of vague phrases like “rich floral and fruity aroma” and “this tea has more fruity and woody aroma than that one,” should be used to objectively and quantitatively compare the aromatic characteristics and intensity of different products.

Quantification with standardization using the OVA method is widely employed in adjusting the aroma of various products, such as beverages, champagne, tobacco, cosmetics, and especially in today’s flavor and fragrance industry.