Can the way you cut an onion affect its flavor?
We took eight onions and cut each two different ways: pole to pole (with the grain) and parallel to the equator (against the grain). We then smelled and tasted pieces from each onion cut each way. The onions sliced pole to pole were clearly less pungent in taste and odor than those cut along the equator. Here’s why: The intense flavor and acrid odor of onions are caused by substances called thiosulfinates, created when enzymes known as alliinases contained in the onion’s cells interact with proteins that are also present in the vegetable. These reactions take place only when the onion’s cells are ruptured and release the strong-smelling enzymes. Cutting with the grain ruptures fewer cells than cutting against the grain, leading to the release of fewer alliinases and the creation of fewer thiosulfinates.