Lactic acid

• CAS: 50-21-5
• Catalog Number: ACM50215-8
• Category: Main Products
• Molecular Weight: 90.08
• Molecular Formula: C3H6O3
• Description: A concentrated solution of lactic acid is typically a mixture of lactic acid lactate and lactic acid. The concentration of this solution is approximately 90% (w/w).; Lactic acid appears as a colorless to yellow odorless syrupy liquid. Corrosive to metals and tissue. Used to make cultured dairy products, as a food preservative, and to make chemicals.; 2-hydroxypropanoic acid is a 2-hydroxy monocarboxylic acid that is propanoic acid in which one of the alpha-hydrogens is replaced by a hydroxy group. It has a role as a Daphnia magna metabolite and an algal metabolite. It is functionally related to a propionic acid. It is a conjugate acid of a lactate.; A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. Sodium lactate is the sodium salt of lactic acid, and has a mild saline taste. It is produced by fermentation of a sugar source, such as corn or beets, and then, by neutralizing the resulting lactic acid to create a compound having the formula NaC3H5O3. Lactic acid was one of active ingredients in Phexxi, a non-hormonal contraceptive agent.
• Synonyms: α-Hydroxypropanoic acid; lactic acid; 2-hydroxypropanoic acid; DL-Lactic acid; 50-21-5; 2-hydroxypropionic acid
• IUPAC Name: 2-Hydroxypropanoic acid
• Canonical SMILES: CC(C(=O)O)O
• InChI: InChI=1S/C3H6O3/c1-2(4)3(5)6/h2,4H,1H3,(H,5,6)
• InChI Key: JVTAAEKCZFNVCJ-UHFFFAOYSA-N
• Boiling Point: 122 °C /15mmHg (lit.)
• Melting Point: 18 °C
• Flash Point: >230 °F
• Density: 1.209 g/ml
• Solubility: Water-soluble
• Appearance: Clear, water-white viscous liquid, characteristic odor
• Application: Lactic acid appears as a colorless to yellow odorless syrupy liquid. Corrosive to metals and tissue. Used to make cultured dairy products, as a food preservative, and to make chemicals.Used as a solvent and acidulant in the production of foods, drugs, and dyes; Also used as a mordant in woolen goods printing, a soldering flux, a dehairing agent, and a catalyst for phenolic resins; Also used in leather tanning, oil well acidizing, and as a plant growth regulator. Applied in Petroleum Production and Refining, Soldering, Farming (Pesticides) ,Leather Tanning and Processing, Fur Dressing and Dyeing, Textiles (Printing, Dyeing, or Finishing); The fastest growing use for lactic acid is its use as a monomer for the production of polylactic acid or polylactide (PLA). Applications for PLA include containers for the food and beverage industries, films and rigid containers for packaging, and serviceware (cups, plates, utensils). The PLA polymer can also be spun into fibers and used in apparel, fiberfill (pillows, comforters), carpet, and nonwoven applications such as wipes.; In dyeing baths, as mordant in printing woolen goods, solvent for water-insoluble dyes (alcohol-soluble induline, nigrosine, spirit-blue). Reducing chromates in mordanting wool. Manufacturing cheese, confectionery. Component of babies' milk formulas; acidulant in beverages; for acidulating worts in brewing. In preparation of sodium lactate injections. Ingredient of cosmetics. Component of spermatocidal jellies. For removing Clostridium butyricum in manufacturing of yeast; dehairing, plumping, and decalcifying hides. Solvent for cellulose formate. Flux for soft solder. Manufacturing lactates which are used in food products, in medicine, and as solvents. Plasticizer, catalyst in the casting of phenolaldehyde resins.
• Storage: Store light-protected at a cool and dry place
• Assay: 88.0-92.0%
• Composition: Lactic acid, water
• EC Number: 200-018-0
• Exact Mass: 90.031694049
• Features And Benefits: Very useful to rejuvenate the skin by encouraging the shedding of old surface skin cellsCan reduce the appearance of fine lines, irregular pigmentation, age spots & decreases enlarged poresGood choice for first-time peel users or for those with sensitive skinOften used in creams & lotions at a lower concentration for a more gentle acid-based peel.
• Form: Viscous liquid
• Hazard Statements: Xi,C
• HS Code: 1518004000
• Monoisotopic Mass: 90.031694049
• NACRES: NA.25
• Packaging: 100 mL or 500 mL in poly bottle
• Packing Group: III
• pH: 2
• Physical State: Liquid
• pKa: 3.08
• Quality Level: 200
• Refractive Index: n20/D 1.4262(lit.)
• Safety Description: 26-39-45-36/37/39
• Solubility In Water: Soluble
• Stability: Stable. Combustible. Incompatible with strong oxidizing agents.
• Storage Conditions: 2-8 °C
• Supplemental Hazard Statements: H290-H314-H303-H315-H318
• Symbol: GHS05
• Topological Polar Surface Area: 57.5 Ų
• UN Number: 3265
• WGK Germany: 2

Case Study

Production of lactic acid

Martinez, Fabio Andres Castillo, et al. Trends in food science & technology 30.1 (2013): 70-83.

The interest in lactic acid is related to many aspects, one of which is its relatively high added value. In addition, the market growth potential for this type of chemical is huge. Lactic acid can be produced alternatively by fermentation or chemical synthesis, and a wide range of different waste materials can be used as substrates. Lactic acid has many applications. It exists in two stereoisomers, which in fact makes the application of one of them or the racemic mixture of great interest in different fields. In particular, the food and pharmaceutical industries prefer the isomer, which is the only one that can be metabolized by the body; however, the chemical industry requires one pure isomer or a mixture of both, depending on the application.
Lactic acid bacteria are named according to their ability to produce lactic acid as the main product of sugar fermentation. Many lactic acid bacteria also encode the enzymes required for aerobic respiration, but do not synthesize heme. Therefore, the respiratory chain does not work unless heme (and heme and menaquinone for some bacteria) is added to the culture medium. Most lactic acid bacteria are catalase-negative, non-motile, non-spore-forming, and have an optimal growth temperature between 20 and 45°C. In addition, they are highly tolerant to acidic conditions (pH < 5), which gives them a competitive advantage over other bacteria. As shown in Table 1, the selection of appropriate microorganisms can ferment sugar solutions from different sources.

Industrial Uses of Lactic Acid

Vijayakumar, J., R. Aravindan, and T. Viruthagiri. Chemical and biochemical engineering quarterly 22.2 (2008): 245-264.

Lactic acid, a naturally occurring multifunctional organic acid, is a valuable industrial chemical used as an acidulant, preservative, and chemical raw material in the food industry, pharmaceutical, leather, and textile industries. One of the most promising applications of lactic acid is its use in biodegradable and biocompatible lactate polymers such as polylactic acid. Lactic acid can be produced by fermentation or chemical synthesis, but biotechnological fermentation processes have received great attention due to environmental concerns, use of renewable resources instead of petrochemicals, low production temperatures, low energy requirements, and high purity. A great deal of research has been conducted on the development of biotechnological methods for lactic acid production, with the ultimate goal of making the process more efficient and economical.
Lactic acid is widely used in almost every area of the food industry, playing a wide range of roles. The main use of lactic acid is in food and food-related applications, which account for about 85% of the demand in the United States. The remaining (about 15%) uses are for non-food industrial applications. Lactic acid occurs naturally in many foods. It has been used for quite some time as an acidulant, preservative, and pH adjuster. Many properties of lactic acid make it a versatile ingredient in the food industry. It has a significant preservative effect and can modulate microbial flora. It has been found to be very effective against certain types of microorganisms. Sometimes a combination of lactic acid and acetic acid is used because it has a stronger bactericidal activity. When turbidity caused by calcium salts is a problem, the use of lactic acid can result in a clear product. Lactic acid is a natural acid found in biological systems, so it can be used as an acidifier and does not introduce foreign elements into the body. In addition, lactic acid is used commercially in the processed meat and poultry industry to extend the shelf life of the product, enhance the flavor, and better control foodborne pathogens. Another potential application of lactic acid in the food industry is the mineral fortification of foods.

Biotechnological production of lactic acid and its recent applications

Wee, Young-Jung, Jin-Nam Kim, and Hwa-Won Ryu. Food Technology and Biotechnology 44.2 (2006): 163-172.

Lactic acid is widely used in food, cosmetics, pharmaceutical and chemical industries and has attracted increasing attention as a monomer for the production of biodegradable polylactic acid. It can be produced by biotechnological fermentation or chemical synthesis, but the former route has attracted considerable interest recently due to environmental issues and limited availability of petrochemical feedstocks. Various attempts have been made to efficiently produce lactic acid using inexpensive raw materials. Microorganisms capable of producing lactic acid can be divided into two categories: bacteria and fungi. Although most studies on lactic acid production have been conducted with lactic acid bacteria (LAB), filamentous fungi such as Rhizopus can aerobically utilize glucose to produce lactic acid. Rhizopus species such as R. oryzae and R. arrhizus possess amylolytic enzyme activity, which enables them to convert starch directly into (+)-lactic acid. Fungal fermentation has some advantages because R. oryzae requires only a simple culture medium and produces (+)-lactic acid, but it also requires vigorous aeration because R. oryzae is an obligate aerobic microorganism. In fungal fermentation, low productivity below 3 g/(L·h) may be due to low reaction rates caused by mass transfer limitations. The low yield of fungal fermentation products is partly due to the formation of byproducts such as fumaric acid and ethanol.
Lactic acid and its salts are increasingly used in various types of chemical products and processes. In such applications, lactic acid can be used as a descaling agent, pH adjuster, neutralizer, chiral intermediate, solvent, cleaning agent, slow-release acid agent, metal complexing agent, antimicrobial agent and humectant. Natural lactic acid has an emerging use as an excellent and safe solvent and alternative in many fine machinery cleaning applications. Due to its high solvency and solubility, lactic acid is an excellent remover of polymers and resins. Its isomeric purity is greater than 98%, making it suitable as a raw material for herbicide or pharmaceutical production.

Pharmaceutical applications of lactic acid

Krishna, Battula Savithra, et al. Int J Biotechnol Res 1.1 (2018): 42-54.

Lactic acid is one of the most commercially useful hydroxycarboxylic acids. Its applications range from mass production of products like polylactic acid (PLA) in industry to simple household applications like food containers. Many inexpensive materials like starch and cellulosic materials, as well as renewable materials like agricultural waste, can be used as feedstock for lactic acid production. Microorganisms belonging to the bacterial and fungal classes actively participate in the production of lactic acid from the provided feedstocks.
In the pharmaceutical industry, lactic acid is used as an electrolyte in various parenteral/intravenous solutions. These parenteral solutions are prepared to replenish body fluids. Apart from this, lactic acid also plays a role in pH regulation, chiral intermediates, and metal chelation. Lactic acid is also used in mineral preparations, tablets, prostheses, controlled drug delivery systems, surgical sutures, and in the preparation of dialysis solutions for dialysis processes like continuous flow peritoneal dialysis using an artificial kidney machine. Lactic acid and its salts act as intermediates in the manufacture of pharmaceuticals to adjust the pH of the preparations. Pharmaceutical products contain L (+) lactic acid as the D (-) isomer is not metabolized by the body. Lactate salts (e.g., calcium, iron, sodium, and other salts) are used in the pharmaceutical industry for their antitumor activity.

Custom Q&A

What is the molecular formula of lactic acid?

The molecular formula of lactic acid is C3H6O3.

What are some synonyms of lactic acid?

Some synonyms of lactic acid are 2-hydroxypropanoic acid and DL-Lactic acid.

What is the molecular weight of lactic acid?

The molecular weight of lactic acid is 90.08 g/mol.

Is lactic acid corrosive to metals and tissue?

Yes, lactic acid is corrosive to metals and tissue.

How is lactic acid used in the food industry?

Lactic acid is used to make cultured dairy products, as a food preservative, and to make chemicals.

What is the IUPAC name of lactic acid?

The IUPAC name of lactic acid is 2-hydroxypropanoic acid.

What is the InChIKey of lactic acid?

The InChIKey of lactic acid is JVTAAEKCZFNVCJ-UHFFFAOYSA-N.

What are some other identifiers of lactic acid?

Some other identifiers of lactic acid include CAS numbers (50-21-5, 26100-51-6, 598-82-3, 152-36-3), EC numbers (200-018-0, 209-954-4, 825-250-5), and ICSC number (0501).

How is sodium lactate related to lactic acid?

Sodium lactate is the sodium salt of lactic acid. It is produced by fermenting a sugar source and neutralizing the resulting lactic acid.

Was lactic acid one of the active ingredients in a contraceptive agent approved by the FDA?

Yes, lactic acid was one of the active ingredients in Phexxi, a non-hormonal contraceptive agent that was approved by the FDA in May 2020.