Learn why some dals can still discolor over time, even in airtight containers. Discover how light and age can naturally affect their pigment.
1 Answer
Some dals discolor in airtight containers due to oxidation and enzymatic reactions, even in the absence of air, as residual moisture and enzymes within the dal continue to react over time. This is more common in dals with higher oil content.
Detailed Explanation:
While airtight containers prevent external air and moisture from entering, they don't eliminate the moisture and enzymes already present within the dal itself. Dals, especially those with a higher oil content like toor dal or urad dal, contain natural oils that can undergo oxidation. This process, although slowed down in an airtight environment, can still occur due to trace amounts of oxygen and the presence of enzymes. Enzymatic browning, similar to what happens when you cut an apple and leave it exposed, can also contribute to discoloration. The enzymes within the dal react with phenolic compounds, leading to the formation of brown pigments. The rate of these reactions is influenced by temperature and moisture levels, even within a sealed container. Furthermore, some discoloration can be attributed to Maillard reaction, a chemical reaction between amino acids and reducing sugars that is accelerated by heat and can occur slowly over time, even in stored products.
Pro Tip:
To minimize discoloration, store dals in a cool, dark place. Adding a bay leaf or a few dried red chilies to the container can help absorb excess moisture and inhibit enzymatic activity, potentially slowing down the discoloration process.