Golden Glow or Brown Blight? The Science of Mooncake Coloring

Golden Glow or Brown Blight? The Science of Mooncake Coloring

Mooncakes often have a beautiful golden-brown crust, but sometimes, fruits and vegetables can turn an unappetizing brown when cut and exposed to air. This unwanted browning, common in things like apples or avocados, is called enzymatic browning, and it can happen in some food preparations. Luckily, science helps us prevent it!

Enzymatic browning is a chemical reaction that occurs when certain enzymes (special proteins that speed up reactions) in food come into contact with oxygen in the air. These enzymes act on natural compounds in the food, creating new, brownish-colored ones. While a golden crust on a mooncake is good, if a fruit-based filling was to turn brown, it might look less appealing.

This is where ingredients like citric acid come in handy. Citric acid, found naturally in lemons and limes, works by lowering the pH (making things more acidic). Most browning enzymes are very sensitive to pH. When the environment becomes too acidic, the enzymes slow down or stop working altogether, preventing the browning reaction. So, adding a tiny bit of citric acid to certain mooncake fillings or fruit preparations is a clever scientific trick to keep them looking fresh and vibrant, ensuring every bite is as visually appealing as it is delicious!