Calcium carbonate is added to food primarily to fortify nutrition, adjust texture and stability, and also serves as an acidity regulator and anti-caking agent. It is widely used due to its abundant sources, low cost, and compliance with food additive safety standards. Its specific functions are categorized as follows:
1. Nutritional fortifier (calcium supplement)
Calcium is a major component of human bones and teeth, and is involved in physiological activities such as nerve conduction and muscle contraction. Calcium carbonate is a commonly used calcium fortifier in food, with a calcium content of about 40%—much higher than that of organic calcium salts like calcium gluconate and calcium lactate.
It is often used in calcium-fortified foods including:
– Dairy products: Such as high-calcium milk, yogurt, and cheese, to compensate for the differences in natural calcium content of milk sources.
– Cereal products: Such as calcium-fortified biscuits, bread, and cereal, to meet the calcium intake needs of populations with insufficient daily dietary calcium.
– Infant food: Such as baby rice cereal and formula milk powder, to support the bone development of infants and young children.
2. Acidity regulator and buffering agent
Calcium carbonate is alkaline, which can neutralize acidic substances in food, adjust pH value, and maintain the stability of the food system.
– In flour products (e.g., steamed buns, bread), it can neutralize lactic acid produced by yeast fermentation, prevent dough from turning sour, and improve the fluffiness and taste of finished products.
– In beverages (e.g., plant protein drinks, fruit juices), it can buffer acidity and prevent beverage stratification and precipitation caused by pH fluctuations.
3. Anti-caking agent and dispersant
Calcium carbonate has good adsorption and dispersion properties, which can prevent powdered or granular food from caking and maintain its loose state.
– It is added to powdered foods such as milk powder, cocoa powder, and protein powder to avoid caking due to moisture absorption, making them easy to take and dissolve.
– It is added to condiments (e.g., table salt, monosodium glutamate) to improve the fluidity of powder.
4. Improving food texture and processing performance
– In flour products, calcium carbonate can interact with gluten protein to enhance the toughness and ductility of dough, improving the cooking resistance of noodles and the chewiness of steamed buns.
– In candies and chocolates, it can be used as a filler to adjust the hardness and taste of products and reduce production costs.
Safety Note
Food-grade calcium carbonate undergoes strict purification, with impurity contents such as heavy metals complying with national standards. Moderate intake is harmless to the human body. Calcium carbonate ingested by the human body will decompose into calcium ions under the action of gastric acid and be absorbed by the intestines. Excessive intake may increase the burden on the gastrointestinal tract. Therefore, food safety authorities around the world have clear limits on its addition amount.
