What’s the difference in aroma from sliced vs. diced onions?

Question

Discover how onion cut shapes affect cooking speed, texture, and aroma release.

Answer 1

Sliced onions release fewer aroma compounds initially compared to diced onions because dicing ruptures more cells, releasing more volatile compounds. However, sliced onions, when cooked, can develop a sweeter, caramelized aroma due to more even browning.

Detailed Explanation:

The difference in aroma between sliced and diced onions stems from the degree of cellular damage inflicted during the cutting process. Onions contain enzymes and sulfur-containing compounds that, when combined upon cell rupture, produce volatile aroma compounds. Dicing involves more cuts, leading to a greater number of cells being broken open. This results in a more immediate and intense release of these compounds, producing a stronger, often sharper, raw onion smell.

Slicing, on the other hand, causes less cellular damage initially. Therefore, the immediate release of aroma compounds is less pronounced. However, the larger surface area of sliced onions, when exposed to heat during cooking, allows for more even browning and caramelization. This Maillard reaction creates a different set of aroma compounds, often described as sweeter and more mellow compared to the sharper, sulfurous notes of raw or quickly cooked diced onions. The cooking process also allows for a more gradual release of aroma compounds from the sliced onions.

Pro Tip:

If you want a milder onion flavor in a raw application like salsa, use sliced onions and soak them in cold water for 10-15 minutes before dicing. This helps to leach out some of the pungent sulfur compounds.