What are the function of sodium bicarbonate in biscuits?

Leavening agent: When sodium bicarbonate reacts with an acidic ingredient, such as baking powder, buttermilk, or yogurt, it releases carbon dioxide gas. This gas causes the biscuits to rise and become fluffy.

Tenderizer: Sodium bicarbonate also helps to tenderize the biscuits by breaking down the gluten in the flour. This makes the biscuits less tough and more crumbly.

Flavor enhancer: Sodium bicarbonate can also enhance the flavor of biscuits by adding a slightly salty and alkaline taste.

Color enhancer: Sodium bicarbonate can help to give biscuits a golden brown color by promoting the Maillard reaction, which is a chemical reaction between amino acids and reducing sugars that occurs when foods are heated.