Calcium oxide, CaO, occurs as white or grayish-white lumps or granular powder. The presence of iron gives it a yellowish or brownish tint.
Calcium Oxide is a general food additive consisting of white granules or powder of poor water solubility. it is obtained by heating limestone (calcium carbonate) in a furnace. it is also termed lime or quicklime. it is used as an anticaking agent, firming agent, and nutritive supple- ment in applications such as grain products and soft candy.