Citric Acid Monohydrate

Brief Overview 

Citric acid is a weak organic acid with formula C₆H₈O₇, which occurs naturally in citrus fruits. It is part of the citric acid cycle which occurs in the metabolism of all aerobic organisms. Globally, more than a million tons of citric acid are produced annually, and more than 70% of the total production is used in the food and beverage industry as an acidifier or antioxidant to preserve or enhance the flavors and aromas of fruit juice, ice cream, and marmalades. Citric acid exists in the form of anhydrous, which is crystallized in hot water, or monohydrate, which is crystallized in cold water. The anhydrous form of citric acid can be produced by heating citric acid monohydrate.

Manufacturing Process

Citric acid is produced by submerged fermentation using fungus from different sources of carbohydrates, such as molasses and starch-based media. As precipitation, calcium oxide is added to form the slightly soluble tri-calcium citrate tetrahydrate. The precipitate is removed by filtration and washed to remove impurities. It is treated with sulphuric acid to form calcium sulfate and filtered off. The citric acid liquid is then treated with active carbon and passed through a cation and anion exchanger. Finally, the liquid is concentrated in vacuum crystallizers at 20 - 25℃, forming citric acid monohydrate.

Food Industry

Citric acid is widely used in the food and beverage industry for different purposes. Some food that contains citric acid includes jellies, jams, candies, dairy product, frozen fruit, oils, and animal feed. Beverages such as wine, ciders, soft drinks, and syrups also contain citric acid. Citric acid can be used for pH adjustment and preservation and can be used as an antioxidant agent, sequestering agent, acidulate, and flavor enhancer.

Pharmaceutical Industry    

Citric acid is also used in pharmaceuticals. It is combined with bicarbonates to use as an effervescent and anticoagulant. It is also used to adjust pH and as an antioxidant agent. Citric acid is used to increase the solubility of brown heroin. It is also used as feed in the production of antiviral tissues.

Agriculture Industry                                     

Citric acid is used as an agricultural repellent against frogs, especially in Hawaiian plants. As a corrosive and acidic compound, the amount of citric acid for plants must be specified. Adding too much citric acid can cause acidic soil, which can burn the plant root and cause the plant’s death.

Other Applications

Citric acid is used to remove metal oxides for the operational cleaning of iron and copper oxides. In industrial applications, citric acid is used as a buffering and neutralizing agent. It is also used in non-corrosive, non-toxic, and biodegradable processes and safety standards. Other uses include ceramic manufacture, ion complexion, leather tanning, copper plating, floor cement, adhesive, waste treatment, electroplating, textile, bottle washing compound, etc.