Step 1: Understanding the Problem:
The question asks for the compound or combination of compounds responsible for the characteristic flavor, color, and mouthfeel of tea.
Step 2: Key Formula or Approach:
The overall sensory profile of tea (specifically fermented black tea) is determined by a complex mix of monomeric catechins and their enzymatic oxidation products (theaflavins and thearubigins) formed during the "fermentation" step of processing.
Step 3: Detailed Explanation:
• Catechins: Unoxidized monomeric polyphenols that contribute to the basic bitterness and astringency of green tea.
• Theaflavins: Yellow-orange pigments formed through enzymatic oxidation of catechins. They contribute to the briskness, brightness, and fresh-taste properties of brewed black tea.
• Thearubigins: Polymeric, brown-red compounds derived from further oxidation of theaflavins. They provide body, thickness, and depth of color to the tea infusion.
• Since commercial tea flavor and color characteristics are built upon the balanced composition of monomeric polyphenols and their various oxidation stages, the holistic sensory profile is attributed to all three classes.
Step 4: Final Answer:
Consequently, the characteristic flavor of tea is due to the combined presence of Catechins, Theaflavins, and Thearubigins.