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Citric Acid Monohydrate Sigma CAS 5949-29-1

Molecular Formula: C6H10O8

Formula Weight: 210.1388

ZSpharmac: Citric Acid Monohydrate Sigma Supplement

Product Name: Citric Acid Monohydrate Sigma
CAS No: 5949-29-1
Purity: 99%

Basic Info

Product Name:Citric Acid Monohydrate Sigma
Other Names:Citric Acid Monohydrate
Place of Origin:Shandong, China
Brand Name:ZSpharmac
Type:Food Additives
Appearance:White Solid
EINECS No.:200-662-2
Storage:No Restrictions.
Provide:Citric Acid Monohydrate Sigma MSDS;
Citric Acid Monohydrate Sigma COA

What is Citric Acid Monohydrate Sigma?

Citric Acid Monohydrate Sigma, also known as citric acid, citric acid, scientific name 3-hydrocarbyl-3-carboxyglutaric acid, citric acid monohydrate exists in nature in lemons, oranges, plums, plums, pears, peaches, figs, etc. Among the fruits, the acid content is higher in the immature ones. Citric acid monohydrate is a colorless translucent crystal or white crystalline powder, odorless, with a strong and pleasant sour taste, which gradually weathers in warm air and deliquescence in humid air. Depending on the crystallization conditions, the crystal forms include anhydrous citric acid and citric acid containing crystal water. Commercial citric acid is mainly anhydrous citric acid and citric acid monohydrate. Citric acid monohydrate is crystallized from an aqueous solution at a low temperature (below 36.6°C). The product after separation and drying has a molecular weight of 210.14, a melting point of 70 to 75°C and a density of 1.542. Placed in dry air, the crystal water in citric acid monohydrate will escape and weather. Anhydrous citric acid is crystallized in an aqueous solution above 36.6 °C, with a molecular weight of 192.12 and a density of 1.665. The critical temperature for the conversion of Citric Acid Monohydrate Sigma to citric acid anhydrous is 36.6 °C.

Citric Acid Monohydrate Sigma is widely used in the food industry, and can also be used as a feed additive, non-toxic detergent, mordant, etc. At the same time, Citric Acid Monohydrate Sigma can also be used in pharmaceuticals, chemicals, light industry, atomic energy, environmental protection and other industrial fields, and is also an indispensable raw material for cosmetics, metal cleaning agents, resins, cardboard, tobacco, electroplating, etc. The discovery of citric acid monohydrate has a history of more than 200 years. As early as 1784, someone first isolated citric acid crystals from lemon juice. In 1917, Citric Acid Monohydrate Sigma was produced by fermentation of Aspergillus niger, and industrial production of citric acid monohydrate began. The industrial production of citric acid monohydrate in my country began in 1963. At that time, there were not many manufacturers, and the scale and output were very small, which could not meet the domestic demand. The domestic market was in short supply and the demand depended on imports. Citric acid monohydrate is a necessity in the food industry and involves many industrial fields related to people’s lives.

With the development of my country’s Citric Acid Monohydrate Sigma industry, the products are constantly increasing, and the quality of citric acid monohydrate is also improving. Since citric acid monohydrate is mainly used in the food industry and medicine, it is related to people’s health and life safety, so there are strict regulations on the quality requirements of citric acid monohydrate. my country has also formulated relevant standards for Citric Acid Monohydrate Sigma, and gradually brought it into line with international standards.

Citric Acid Monohydrate Sigma Properties:

Melting point -94 °C(lit.)
Boiling point 56 °C760 mm Hg(lit.)
density 0.791 g/mL at 25 °C(lit.)
vapor density 2 (vs air)
vapor pressure 184 mm Hg ( 20 °C)
refractive index n20/D 1.359(lit.)
Fp 1 °F
storage temp. no restrictions.
solubility Citric Acid Monohydrate is very soluble in water, freely soluble in ethanol and sparingly soluble in ether.
pka3.138, 4.76, 6.401
form Solid
color White
Specific Gravity0.810 (20/4℃)
PH1.85 (50g/l, H2O, 25℃)
Water Solubility 1630 g/L (20 oC) ;H2O: soluble 54% (w/w) at 10°C (Citric acid in water)


Citric Acid Monohydrate Sigma Uses

  1. Citric Acid Monohydrate Sigma is mostly utilized in food as well as beverage industry as acidulant, seasoning agent, chemical as well as chemical. It is also made use of as antioxidant, plasticizer, cleaning agent in chemical market, cosmetic industry and also washing sector.
  2. Citric Acid Monohydrate Sigma is primarily utilized as a sour representative for food, and is additionally used in the prep work of pharmaceutical cooling agents, ingredients for detergents, etc.
  3. Citric Acid Monohydrate Sigma assays bismuth, nitrite, oxygen and also water, establishes aluminum, copper, mercury, nickel, oxygen as well as thorium, is utilized as a withdrawing representative, removes trace steels, prepares barrier options, as well as establishes serum potassium.

Production Method of Citric Acid Mono Hydrate Sigma

1. Using starch or sugar (such as sugarcane waste molasses) as raw materials, it is prepared by fermentation method. Sterilization and fermentation of potato flour ↓ Aspergillus niger 26 ℃ filtration mycelium washing filtrate heating → lime milk precipitation → sulfuric acid neutralization → decolorization → resin exchange → crystallization → citric acid

2. First sterilize 12%-16% potato flour, then inoculate the pre-cultured Aspergillus niger hyphae for fermentation. Ammonia water is added in the fermentation process, and after fermentation at 26° C. for 2 to 3 days, the mycelium is separated from the fermentation broth, and the water after washing the mycelium is added to the fermentation broth. Then heated to 90°C, citric acid was precipitated with lime milk, the obtained calcium citrate was decomposed with a slight excess of sulfuric acid to decompose citric acid, filtered, and the filtrate was decolorized with activated carbon, and then the impurities were removed through ion exchange resin, and the pressure was reduced at 60-70°C. Concentrating, cooling to a transformation temperature of not lower than 366℃, adding seed crystals, crystallizing, and drying with cold air, the finished citric acid can be obtained.

3. Using sugar solution as raw material, fermentation with Aspergillus niger, separation and purification. Or directly extracted from fruits containing citric acid, such as lemon juice (5% to 8% of citric acid can be obtained) and pineapple leftovers.

4. It is obtained by fermentation of Aspergillus niger from starchy raw materials such as dried potato and corn, and then the pure product can be obtained by separation and purification.

5.The raw materials can be carbohydrates such as molasses, sucrose, sweet potato and petroleum hydrocarbons. Generally, fungi are used for fermentation production. According to the fermentation method, it can be divided into two categories: surface fermentation and submerged fermentation. Surface fermentation is an early production method, and some Penicillium or Aspergillus niger are used as strains; submerged fermentation method also uses Aspergillus niger as strains, and the fermentation process The small spherical filamentous fungi aggregates are formed in the medium, and the formation of long and thin filamentous fungi should be avoided. The fermentation conditions are ph value of 1.5 to 2.8. At the same time, sterile air should be introduced and accompanied by stirring. Remaining solid residue, the filtrate is neutralized with calcium carbonate to obtain calcium citrate, then neutralized with concentrated sulfuric acid to obtain crude citric acid, which is purified, concentrated and crystallized by ion exchange resin to obtain the finished product.

Preparation of Citric Acid Monohydrate Sigma

The method is to squeeze the juice from the fruits containing citric acid such as immature lemons and citrus, and then mix the juice with lime milk to generate calcium citrate, and then treat it with sulfuric acid to obtain a purer citric acid solution, then The product is obtained by concentration and crystallization. Since 1784, when the Swedish chemical Scheele first extracted citric acid from lemon juice and crystallized solid citric acid, the natural juice extraction citric acid method became the main method of early citric acid production, which lasted about 50 years. The yield of citric acid produced by this method is low, and the method of extracting citric acid from natural fruit juice was gradually eliminated until the large-scale application of the microbial fermentation method in the middle of the 20th century.

Since 1880, citric acid was first synthesized in the laboratory, and now there are many different technical routes and methods. Among them, the synthesis of citric acid using acetone as a raw material is a relatively common synthesis method. After acetone is hydrated, reacted with hydrocyanic acid, and then hydrolyzed, citric acid can be obtained. In addition, there are also methods such as synthesis using methyl quinate aqueous solution and reaction synthesis between formaldehyde and isobutylene. However, the above-mentioned synthetic methods are relatively complicated, and most of the chemicals used are toxic, so far they have not been able to achieve industrialized production.

1. Culture of bacteria

The microbial fermentation method is used in the industrial production of citric acid, and only several kinds of Aspergillus and yeast are valuable. Among them, Aspergillus niger is the most competitive strain in the industry, and the most competitive yeasts are lipolytic pseudosaccharides. Silk yeast and saccharomyces cerevisiae, etc. Aspergillus niger is cultured on agar and forms limited colonies on the agar. After 10 to 14 days at room temperature, it becomes a rich and dense sporozoite, and the colonies are black and sometimes dark brown. Considering that the citric acid-producing bacteria should have the characteristics of strong acid-producing ability and high citric acid concentration, the acid filter paper method, the discoloration circle method and the single spore transplantation method can be used to isolate Aspergillus niger to avoid the interference of other miscellaneous bacteria. Become Aspergillus niger for the production of citric acid. Cultivation of yeast The yeasts that can be used for the production of citric acid include Candida lipolytica and Candida quaternaria. The former has a strong ability to decompose fat, and the better carbon source is n-alkane. The latter can be fermented from alkanes to produce citric acid, and can also be fermented from sugars to produce citric acid. The pH of yeast fermentation is 3.5~4.0.

2. Fermentation

The fermentation process is divided into surface fermentation and solid fermentation, and the culture medium of different raw materials is prepared according to different processes, and then the material is steamed. The purpose of steaming is to gelatinize starch and sterilize it. When steaming the material, the material should be heated evenly, the steam should be smooth, and the material should be added while steaming. The steamed materials should be spread out and cooled down. When the temperature drops below 37°C, water can be replenished and inoculated, and the fermentation is done. The end point of fermentation is determined by the acidity. Bacteria break down.

3. Extraction

Fermentation acid – filtration (removal of bacteria and residues) – neutralization, filtration – calcium citrate – acid hydrolysis, filtration – crude acid solution – purification – concentration – crystallization – centrifugation – drying – packaging – finished product. After the fermentation, the fermented aldehyde is processed. For surface fermentation, immediately separate the cap and the fermentation broth, then wash the cap and the shallow dish with a small amount of water, and combine the fermentation broth with the washing water; the citric acid in the solid fermentation solution should be leached with water at a temperature of 80°C for 2 to 3 times. , immersed in water to combine. The fermented acid is filtered with a filter press, and the filtrate and washing water are combined and put into the filtrate tank. Citric acid reacts with calcium salts and calcium bases to form calcium citrate which is precipitated from the liquid phase and separated from soluble impurities. If the acid solution contains a lot of oxalic acid, it can be precipitated in the hot neutralization solution below the pH value of 3, so that the oxalate can be separated first. The neutralization end point is tested with precision test paper, and the pH value is maintained at 6.0~6.8. Stir at about 85°C for 30 minutes to fully separate out calcium sulfate and filter. Calcium citrate is hydrolyzed with sulfuric acid, and the amount of sulfuric acid is determined according to the content of citric acid in the solution. Generally, the excess of sulfuric acid does not exceed 0.2%. After acid hydrolysis, the acid solution is filtered to purify the citric acid solution by adsorption decolorization and ion exchange to remove pigments, colloids and metal cations such as iron ions, calcium ions, copper ions, magnesium ions and anionic impurities such as sulfate ions in the solution. The purification is mostly carried out on the column, the decolorizing carbon is GH-15 granular carbon, and the ion resin is anion and cation resin. The concentration of citric acid purification solution is only 20%~25%, and crystallization can only be carried out when it is concentrated to more than 70%. When concentrating, the temperature should not be too high to avoid the decomposition of citric acid. The concentration of the purified liquid can be carried out under negative pressure. In order to save energy, a double-effect or triple-effect evaporator can be used. The concentration is carried out in 2 stages. After the first concentration, it is put into a settling tank for thermal insulation and sedimentation, and then most of the gypsum is removed; the second concentrated solution contains about 80% of citric acid, and the material is discharged and crystallized in time. For the second concentration, lift-type or bracket-type evaporators can be used to reduce the contact time between feed liquid and heat medium and improve product quality. Different crystallization methods can be used to obtain different products. For the crystallization of citric acid monohydrate, 80% solution, when the temperature is 55 °C, is stirred and cooled in a crystallizer. When the temperature drops to 0 °C, seed crystals are added to start crystallization. Control the temperature not to exceed 36°C, at this time the product is citric acid monohydrate; if the solution is concentrated to 83% at 60°C, cool to 46°C, add seed crystals, maintain the temperature at 40~60°C and slowly crystallize, and finally drop to 38℃, the product is anhydrous citric acid. The crystal paste is centrifuged to obtain crystalline commercial citric acid.

About Us

The production base is located in Zhangqiu chemical industry park and Tai’an high-tech chemical industry park. laboratory and workshop in strict accordance with the GMP standard and the product fit national ISO9001 and ISO2000 standards.

“Zhishang” products are exported to Europe, North and South America, the Middle East, Asia Pacific and Africa area, so as to establish a long-term and stable cooperation relationship with customer in the world.

Company Info
  • Business Type: Manufacturer
  • Product Range: Additive , Chemical Auxiliary & Catalyst , Organic Chemicals
  • Products/Service: Organic Intermediate,Inorganic Chemistry, APIs, Dyestuffs And Pigments, Fragrance And Spices, Food Additives
  • Total Employees: 51~100
  • Capital (Million US $): 10000000RMB
  • Year Established: 2016
Production Capacity
  • No. of Production Lines : 8
  • No. of QC Staff : 5 -10 People
  • OEM Services Provided : yes
  • Factory Size (Sq.meters) : 3,000-5,000 square meters
  • Certificate: ISO9001 , CE , GMP , API , MSDS
  • Factory Location : Diao Town Industry Park, Zhangqiu City, Jinan City, Shandong Province, China.


Pre-Sales Service

* Prompt reply and 24 hours online, professional team to provide best price and high quality product.

* Sample testing support.

* Every batch of products will be tested to ensureits quality.

*The packing also can be according the customers` requirment.

*Any inquiries will be replied within 24 hours.

*we provide Commerical Invoice, Packing List, Bill of loading, COA , Health certificate and Origin certificate. If your markets have any special requirements, let us know.


After-Sales Service

*The fact of logistics information monitoring.

* Any questions about the product can be consulted at any time.

*Product has any problem can return.


Do you accept sample order?

We will make samples before mass production, and after sample approved, we’ll begin mass production. Doing 100% inspection during production, then do random inspection before packing.



You can get free samples for some products,you only need to pay the shipping cost or arrange a courier to us and take the samples. You can send us your product specifications and requests,we will manufacture the products according to your requests.

What’s your MOQ?

Our MOQ is 1kg. But usually we accept less quantity such as 100g on the condition that sample charge is 100% paid.

Do you supply product report?

Yes. We’ll give you product analysis report before shipping.

  Is there a discount?

Different quantity has different discount.


1. ≤50kg, Express delivery recommended, usually called as DDU service;

2. ≤500kg, Air shipping recommended, usually called as FOB, CFR, or CIF service;

3. >500kg, sea shipping recommended, usually called as FOB, CFR, or CIF service;

4. For high value products, please select air shipping and express delivery for safe.

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