Final answer:
The descriptor of bitterness in food is Astringent, which is a sensation perceived as sharp or disagreeable, often found in coffee, beer, and citrus peels.
Step-by-step explanation:
The descriptor of bitterness in food is D) Astringent. Bitterness is a taste sensation that we often perceive as unpleasant, sharp, or disagreeable. Foods and beverages that commonly exhibit bitter flavors include coffee, unsweetened cocoa, beer, olives, and citrus peel.
The presence of compounds such as alkaloids makes certain plants and their derivatives bitter, which can serve as a defense mechanism against consumption by microbes and herbivores. This taste may also trigger a gag reflex to prevent the ingestion of potentially poisonous substances. Overall, bitter taste receptors in our mouth play a crucial role in recognizing these flavors.