What gives onions their distinctive smell? Explained
As onions develop, they take in sulfur from the soil as one of their nutrients. When an onion is cut or crushed, it releases a volatile sulfur compound into the air. These sulfur-based compounds act as the building blocks for the distinct aroma and flavor associated with onions. Despite the pungent smell of various sulfur compounds, sulfur in its pure form is actually odorless. These sulfur compounds are responsible for the tear-inducing properties of onions, the unusual scent in urine after consuming asparagus, the recognizable aroma of garlic, and the unpleasant odor of rotten eggs.