Citric acid monohydrate is a tricarboxylic acid compound found in citrus fruits such as oranges, lemons, grapes, etc. Citric acid monohydrate has a sour taste. This compound has the compound formula C6H8O7.H2O. Judging from the molecular formula, this compound is a modification of citric acid with the addition of one water molecule. Jabir Ibn Hayyan, an alchemist, discovered this compound in the 8th century. And in 1784, Carl Wilhelm Scheele successfully isolated citric acid in its pure form from lemon juice.

Monohydrate citric acid has advantages when compared to other citric acid derivative products such as anhydrous citric acid. The advantage lies in the presence of water bonds in the compound, making citric acid more suitable as a raw material that has moist characteristics. Ease of availability is another advantage of using citric acid monohydrate in industrial processes. In the food and beverages industry, citric acid monohydrate functions as an acidulant, preservative, and also an antistaling agent.

Citric acid monohydrate is a derivative of citric acid which is further processed using water to obtain crystals. Previously, citric acid was obtained by fermenting carbohydrates as a substrate, such as using starch or media based on sucrose. There are at least three types of fermentation that can be carried out, namely: submerged, surface, and solid.

Submerged fermentation (SmF) is a method of fermentation in a liquid substrate. This technique is very suitable when using bacteria that require high water levels. Surface fermentation is a fermentation technique that can be carried out with solid or liquid substrates. In this fermentation method, microorganisms will grow on the surface of the substrate. Solid fermentation, as the name suggests, is fermentation carried out on a solid substrate with very little water. After the citric acid solution is formed, citric acid monohydrate can be obtained by crystallization process from the citric acid solution at a temperature of 20.25 degrees Celsius.

The Uses of Citric Acid Monohydrate in Food and Beverages

1. As an Acidulant

As an acidulant, citric acid monohydrate works by releasing H+ ions which will react with the solution so that the pH will decrease. Basically, there are other compounds that have the ability to act as acidulants, such as lactic acid, malic acid, ascorbic acid, acetic acid, but citric acid has several advantages that strengthen its position as a good acidulant. This advantage lies in the characteristic sour taste produced which provides a fresher, lighter and more natural tone because citric acid is obtained from fruit. Its use is also more suitable for food or drinks that give a fruit sensation. Apart from that, citric acid also does not have side effects such as those that occur when using phosphat acid which has a swelling effect in carbonated drinks.

2. For Food Preservation

As an ingredient intended to preserve food, there are at least two functions carried out by citric acid monohydrate, antimicrobial and antioxidant. As an anti-microbial, citric acid monohydrate can utilize its acidic properties to lower the pH of food. This decrease in pH contributes to the creation of an environment that is less friendly for the growth of microorganisms. For its role as an antioxidant, citric acid monohydrate will work as an electron donor which will reduce free radicals so that it becomes a more stable molecule. More stable molecules will cancel the oxidative chain reaction. The use of citric acid as a preservative has been instrumental in increasing the shelf life of various snack products, candies, sauces, etc.

3. As an Antistaling Agent

citric acid monohydrate

An application that is no less important than the use of citric acid monohydrate in the food and beverages industry is its role as an antistaling agent in bread products and other flour products. Of course, when we want to eat bread, we expect a combination of delicious bread taste and soft bread texture. These two aspects are common properties to pay attention to in the bakery industry.

However, bread that is left out for too long tends to experience staling, which is a hardening process in the bread structure. Staling can occur by a process called starch retrogradation. Starch retrogradation occurs after the baking process when the gelatinized starch (amylose and amylopectin) cools and begins to conform to the previously baked structure. This process produces a hard crust as well as a crumb. In this case, citric acid monohydrate has a role in influencing the pH of the bread by providing an acidic atmosphere. An acidic atmosphere will affect the structure of flour by developing gluten. Apart from that, acidic conditions can affect the activity of the amylase enzyme which will prevent the structure from becoming too dense in bread.

Remember amylose and amylopectin? A strong bond between the two can result in a structure that is too strong. Therefore, citric acid monohydrate can form a complex with metal ions which in turn will inhibit the bond that occurs between amylose and amylopectin. Apart from that, the presence of water molecules in citric acid monohydrate is able to increase the water content in bread because it has hygroscopic properties. The water content in bread can increase the soft texture of the bread.

Side Effects of Citric Acid Monohydrate

With the many uses of citric acid monohydrate in food and drinks, there are several bad effects that can result. Therefore, it is recommended to weigh the required levels optimally. Too much citric acid monohydrate can affect the taste of the product. In addition, excess citric acid can cause gastrointestinal irritation, causing symptoms of nausea, vomiting and diarrhea. Levels of citric acid monohydrate can also have a bad impact on teeth. The acidic nature of citric acid monohydrate can erode tooth enamel and leave the tooth layer thinner. Thinning tooth enamel is often associated with symptoms of sore teeth.


In general, citric acid monohydrate is an acidic compound with one water bond which has many benefits in the food and beverages industry. The benefits obtained from using this compound include as an acidulant, preservative, and also antistaling agent. These benefits are obtained from its ability to release ions and react with products. Apart from that, the presence of water molecules in citric acid monohydrate crystals also influences the favorable hygroscopic properties. However, with the many positive sides of using this compound, there are also risks that must be aware of. The best solution is to use this compound in sufficient levels and ensure the quality of the citric acid monohydrate product to be used.