Learn why chopped onions release water in the fridge. Discover the science behind it and how it affects their texture and flavor.
1 Answer
Chopped onions become watery after refrigeration because the cold temperature damages their cell structure, causing them to release moisture and enzymes that break down cell walls. This process results in a loss of crispness and a watery texture.
Detailed Explanation:
Onions are composed of cells containing water, sugars, and various compounds. When you chop an onion, you break these cells. Refrigeration further exacerbates this process. The cold temperature causes ice crystals to form within the cells. As these ice crystals grow, they rupture the cell walls.
When the onion thaws (even slightly within the refrigerator), the damaged cells release their contents, including water and enzymes. These enzymes then start to break down the remaining cell walls, further contributing to the watery texture. The released water dilutes the onion's flavor and makes it less appealing for use in cooking or salads. The sulfur compounds released also contribute to a stronger, sometimes unpleasant, odor.
Therefore, the combination of physical damage from chopping and cellular damage from refrigeration leads to the watery and less flavorful chopped onions you observe.
Pro Tip:
To minimize wateriness, chop onions right before you need them. If you must chop them in advance, store them in an airtight container in the refrigerator and use them as soon as possible, preferably within a day. Consider using them in cooked dishes where the texture change is less noticeable.