Learn what causes fresh turmeric root to darken or blacken after you peel it. Discover if this is a normal reaction or a sign of spoilage.
1 Answer
Turmeric root blackens after peeling due to oxidation, a chemical reaction between compounds in the turmeric and oxygen in the air, often accelerated by enzymes. This is similar to what happens when you cut an apple and it turns brown.
Detailed Explanation:
When you peel turmeric, you expose the inner flesh to the air. Turmeric contains phenolic compounds, which are naturally present in many plants. When these compounds come into contact with oxygen, an enzyme called polyphenol oxidase (PPO) catalyzes a reaction. This reaction leads to the formation of melanins, which are pigments that cause the darkening or blackening you observe. The process is similar to enzymatic browning in fruits like apples and bananas. The rate of blackening can be influenced by factors such as the freshness of the turmeric, the temperature, and the presence of other compounds that might inhibit or accelerate the enzymatic reaction. While the blackening might be visually unappealing, it doesn't necessarily mean the turmeric is spoiled or unsafe to use.
Pro Tip:
To minimize blackening, submerge peeled turmeric in water with a little lemon juice or vinegar. The acidity helps to inhibit the enzyme activity and slow down the oxidation process.