Question

The bitter flavour of the tea is due to the presence of ________.

• A. Caffeine
• B. Theine
• C. Tannin
• D. Flavour compounds

Hint:

Adding milk to tea helps reduce its bitterness.
The proteins in milk (casein) bind to the free tannins, preventing them from interacting with salivary proteins in the mouth.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Tea (Camellia sinensis) contains several organic compounds that contribute to its aroma, stimulating effects, and taste.
These components include alkaloids, polyphenols, and essential oils.

Step 2: Detailed Explanation:
The taste of tea is a balance of bitterness, astringency, sweetness, and aroma.
- Alkaloids like caffeine and theine are responsible for the stimulating physiological effects of tea.
While they contribute a mild, clean bitterness, they do not provide the characteristic puckery astringency of tea.
- Tannins (specifically polyphenols like catechins, theaflavins, and thearubigins) are the primary compounds responsible for the bitter flavor and astringent mouthfeel of tea.
Tannins are water-soluble polyphenols that bind to and precipitate salivary proteins, causing the characteristic drying sensation in the mouth.
Over-steeping tea in hot water extracts high concentrations of these tannins, resulting in an overly bitter and astringent beverage.
Therefore, the dominant bitter and astringent profile of tea is attributed to tannins.

Step 3: Final Answer:
The characteristic bitter and astringent flavor of tea is primarily due to the presence of Tannins.