Coriander powder loses flavor quickly due to the volatile oils within the ground spice oxidizing and dissipating when exposed to air, light, and heat. Proper storage is crucial to preserve its aroma and taste.
Coriander seeds contain aromatic compounds, primarily volatile oils, that give coriander powder its characteristic citrusy and slightly sweet flavor. When the seeds are ground into a powder, the surface area exposed to the environment dramatically increases. This increased exposure accelerates the degradation process.
Here's a breakdown of why this happens:
Oxidation: Oxygen in the air reacts with the volatile oils, causing them to break down and lose their flavor.
Light Exposure: Light, especially sunlight, can also degrade the volatile oils, leading to flavor loss.
Heat: Heat accelerates the oxidation process and can cause the volatile oils to evaporate more quickly.
Moisture: While not as direct, moisture can clump the powder and potentially lead to mold growth, indirectly affecting the flavor.
Therefore, the combination of increased surface area and exposure to these environmental factors causes coriander powder to lose its flavor much faster than whole coriander seeds.
To maximize the shelf life of your coriander powder, store it in an airtight container in a cool, dark, and dry place, away from direct sunlight and heat sources like the stove. Consider buying whole coriander seeds and grinding them yourself just before use for the freshest flavor.