Learn why urad dal paste can turn grey. Discover how oxidation is the cause and how to minimize it to keep your batter looking fresh.
1 Answer
Urad dal paste turns grey in storage due to oxidation, a chemical reaction with oxygen in the air, and enzymatic browning, which is accelerated by enzymes present in the dal. Refrigeration and proper storage can slow down this process.
Detailed Explanation:
Urad dal, like many other foods, contains compounds that are susceptible to oxidation and enzymatic browning. When the dal is ground into a paste, more surface area is exposed to oxygen. This leads to a reaction where the compounds in the dal react with oxygen, causing a change in color. Additionally, enzymes present in the dal become more active when the dal is ground and exposed to air. These enzymes catalyze reactions that produce melanins, which are brown or grey pigments. The combination of oxidation and enzymatic browning results in the greyish discoloration you observe in stored urad dal paste. The rate of these reactions is influenced by factors like temperature and pH. Higher temperatures accelerate both oxidation and enzymatic activity.
Pro Tip:
To minimize the grey discoloration, store urad dal paste in an airtight container in the refrigerator. Adding a small amount of lemon juice (an acid) can also help inhibit enzymatic browning and preserve the paste's original color for a longer period.