Baking soda is a fine, white powder used as a raising agent. It is pure sodium bicarbonate and is often used when fruit is added to a dough as it neutralizes its acidity. 

Use it for all sorts of pastries. It also accelerates the softening of legumes during cooking.

A refrigerator becomes odorless if all parts, especially the water collection tray, are cleaned with water-dissolved sodium bicarbonate and a small bowl with this solution is left in it.