Food is passed through the esophagus before it reaches the stomach. Mainly, the stomach simply acts as storage. The average stomach can expand to hold approx. 1/2 gallon of fo … od. The stomach contains acids that are strong enough to dissolve most metals, to aid in cleaning bacteria.igesting food is to break down the complex molecules of the food to simpler ones so the bo … dy can use it in the way it wants to. The function of each organ in the digestive system is to help convert food into simpler molecules so it can absorbed by your body and can then be used by the cells.