What is the function of MACP when making cake?

It's more likely that you are thinking of MCP, which stands for Monocalcium Phosphate, a common baking powder ingredient.

Here's how MCP functions in cake baking:

* Acid component in baking powder: MCP is one of the acidic components in baking powder. When combined with baking soda (the alkaline component) and moisture, it creates carbon dioxide bubbles. These bubbles expand during baking, giving the cake its rise and light texture.

* Improves cake's structure: MCP helps to create a more stable cake structure by strengthening the gluten network in the flour. This results in a cake that is less likely to fall or become dense.

In summary, MCP is an important ingredient in baking powder, which plays a crucial role in the leavening and structure of cakes.