Natural citric acid is widely distributed in nature. Natural citric acid is found in the bones, muscles and blood of fruits such as lemons, citrus, pineapples and animals. Synthetic citric acid is produced by fermentation of sugary substances such as sugar, molasses, starch, grapes, etc., and can be divided into anhydrous and hydrated. Pure citric acid is a colorless transparent crystal or white powder, odorless, and has an attractive acidity.
Citric acid is an edible acid that enhances normal metabolism in the body, and the proper dose is harmless to the human body. The addition of citric acid to certain foods has a good mouthfeel and promotes appetite, allowing citric acid to be used in jams, beverages, cans and candies in China. Although citric acid is not directly harmful to the human body, it can promote calcium excretion and deposition in the body. For example, long-term consumption of citric acid-containing foods may lead to hypocalcemia and increase the risk of duodenal cancer. Children show nervous system instability, excitability, autonomic disorders; adults are convulsions of the hands and feet, muscle spasms, paresthesia, itching and gastrointestinal symptoms.
Based on the effect of citric acid on the metabolism of calcium, people who regularly consume canned food, beverages, jams, sour candy, especially children, should pay attention to calcium supplementation, drink raw milk, fish head and fish bone soup, eat small shrimp skin, etc. In order to avoid blood calcium deficiency and affect health, gastric ulcer, hyperacidity, dental caries and diabetes patients should not eat citric acid regularly. Citric acid cannot be added to pure milk, otherwise it will cause pure milk to solidify. In the dairy industry, a solution containing about 10% citric acid is often added to a low concentration milk solution, which should be stirred quickly.