https://www.bakechem.com/products/ammonium-bicarbonate-powder-in-food-e503.html Ammonium Bicarbonate Powder E Number: E503 Food Additive Supplier Ammonium Bicarbonate Powder (Food Grade) E503 food additive is a commonly used food leavening agent that can be used to make foods such as bread, biscuits and cakes to make them fluffy and crispy. E503 ammonium bicarbonate food additive powder decomposes at high temperatures to produce gas, which causes the food to expand, thereby increasing its volume and taste.