1. Food industry

　　1) Because citric acid has a mild and refreshing sour taste, it is commonly used in the manufacture of various beverages, soft drinks, wine, candy, snacks, biscuits, canned fruit juice, dairy products and other foods, and can also be used as an antioxidant in edible oils. At the same time improve the sensory properties of food, enhance appetite and promote the digestion and absorption of calcium and phosphorus substances in the body.

　　2) Citric acid salts such as calcium citrate and ferric citrate are fortifiers that need to add calcium and iron ions in certain foods.

　　3) Citric acid esters such as triethyl citrate can be used as non-toxic plasticizers to manufacture plastic films for food packaging. They are sour agents and preservatives in the beverage and food industries.

　　2. Industrial application

　　1) Citric acid can be used as reagents for chemical analysis, experimental reagents, chromatographic analysis reagents and biochemical reagents; used as complexing agents, masking agents; used to prepare buffer solutions.

　　2) The use of citric acid or citrate as a builder can improve the performance of washing products, can quickly precipitate metal ions, prevent contaminants from re-attaching on the fabric, and maintain the necessary alkalinity for washing; disperse dirt and ash and Suspension; improve the performance of surfactant, is an excellent chelating agent;

　　3) It can be used as a reagent for testing the acid resistance of architectural ceramic tiles.

　　4) Citric acid and modified citric acid can be made into a formaldehyde-free anti-crease finishing agent, used for anti-crease finishing of pure cotton fabrics. Not only the anti-wrinkle effect is good, but also the cost is low.

　　5) It also has metal complexing ability, has good complexing ability to metal ions, and is used as complexing agent and buffering agent in electroplating industry.

　　3. Environmental protection

　　Citrate-sodium citrate buffer is used for flue gas desulfurization. Citric acid-sodium citrate buffer solution is a desulfurization absorbent with great development value because of its low vapor pressure, non-toxicity, stable chemical properties, and high SO2 absorption rate.

　　4. Livestock feed

　　Adding citric acid to the piglet feed can early wean, increase the feed utilization rate by 5% -10%, and increase the sow litter size. Adding 1% to 2% citric acid to the growing fattening pig diet can increase daily gain, reduce feed-to-meat ratio, increase protein digestibility, reduce back fat thickness, and improve meat quality and carcass characteristics. Rare earth citric acid is a new type of high-efficiency feed additive, suitable for various animals such as pigs, chickens, fish, shrimps, cattle, sheep, rabbits, silkworms, etc. It can promote animal growth, improve product quality, improve disease resistance and survival rate, Improve the feed conversion rate, shorten the feeding cycle and other characteristics.

　　5. Cosmetics

　　Citric acid is a kind of fruit acid. Its main role is to speed up the renewal of keratin. It is commonly used in lotions, creams, shampoos, whitening products, anti-aging products, acne products, etc. The renewal of keratin contributes to the exfoliation of melanin in the skin, the narrowing of pores, the dissolution of blackheads, etc.

　　6. Cleaning and descaling

　　Citric acid has the ability to disinfect, bleach and eliminate fat. It can remove scale, wipe the surface of kitchen stoves, clean sinks, sewer pipes, and clean glass surfaces.

　　7. Sterilization

　　The combined action of citric acid and 80 ℃ temperature has a good effect of killing bacterial spores, and can effectively kill contaminated bacterial spores in the hemodialysis machine pipeline.