Chemical changes in food products

In the first step, creaming is done. The sugar is creamed with the fat until it becomes light and fluffy. Due to the incorporation of tiny air bubbles, it increases slightly in volume. After the addition of egg, foaming is done through beating. The physical impact of beating unfolds the protein molecules to unwind which is known as denaturation. Beating also incorporates air into the egg whites. These denatured proteins forms a network which holds water and air together due to it having both hydrophillic (likes water) and hydrophobic (dislikes water) parts. When the flour is mixed in with the liquid mixture, hydration of the starch granules occurs.

During baking, the protein from the eggs and flour denatures and coagulate, which leads to the solid structure. The air bubbles which was incorporated in earlier remains trapped in the batter and expands as the cake is baked, which leads to tiny air cells in the baked product. As they expand, the also cause the cake to rise in volume.

The browning of the surface of the cake is due to Mailard Reaction which is a non-enzymatic browning. It is a chemical process which happens when a amino acid is dry heated with a reducing sugar. The carbonyl group of the sugar reacts with the amino group of the amino acid. Brown polymers which are responsible for the browning are formed.