Calcium lactate is a white crystalline

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

with formula , consisting of two lactate

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

s (CHOH) for each

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

cation An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

. It forms several

hydrate In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...

s, the most common being the pentahydrate ·5. Calcium lactate is used in medicine, mainly to treat calcium deficiencies; and as a

food additive Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives, such as vinegar ( pickling), salt ( salting), smoke ( smoking) and sugar ( crystallization), have been used f ...

with

E number E numbers, short for Europe numbers, are codes for substances used as food additives, including those found naturally in many foods, such as vitamin C, for use within the European Union (EU) and European Free Trade Association (EFTA). Commonly ...

of E327. Some cheese crystals consist of calcium lactate.

Properties

The lactate ion is

chiral Chirality () is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek language, Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is dist ...

, with two

enantiomer In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities whi ...

s, D (−,''R'') and L (+,''S''). The L

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formula – that is, the same number of atoms of each element (chemistry), element – but distinct arrangements of atoms in space. ''Isomerism'' refers to the exi ...

is the one normally synthesized and metabolized by living organisms, but some bacteria can produce the D form or convert the L to D. Thus calcium lactate also has D and L isomers, where all anions are of the same type. Some synthesis processes yield a mixture of the two in equal parts, resulting in the DL (

racemic In chemistry, a racemic mixture or racemate () is a mixture that has equal amounts (50:50) of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as r ...

) salt. Both the L and the DL forms occur as crystals on the surface of aging

Cheddar cheese Cheddar cheese (or simply cheddar) is a natural cheese that is relatively hard, off-white (or orange if colourings such as annatto are added), and sometimes sharp-tasting. It originates from the English village of Cheddar, Somerset, Cheddar in ...

.G.F. Tansman, P.S. Kindstedt, J.M. Hughes (2014): "Powder X-ray diffraction can differentiate between enantiomeric variants of calcium lactate pentahydrate crystal in cheese". ''Journal of Dairy Science'', volume 97, issue 12, pages 7354–7362. The solubility of calcium L-lactate in water increases significantly in presence of d- gluconate ions, from 6.7 g/ dl) at 25 °C to 9.74 g/dl or more.Martina Vavrusova, Merete Bøgelund Munk, and Leif H. Skibsted (2013): "Aqueous Solubility of Calcium l-Lactate, Calcium d-Gluconate, and Calcium d-Lactobionate: Importance of Complex Formation for Solubility Increase by Hydroxycarboxylate Mixtures". ''Journal of Agriculture and Food Chemistry'', volume 61 issue 34, pages 8207–8214. Paradoxically, while the solubility of calcium L-lactate increases with temperature from 10 °C (4.8 g/dl) to 30 °C (8.5 g/dl), the concentration of free ions decreases by almost one half. This is explained as the lactate and calcium ions becoming less hydrated and forming a complex .Martina Vavrusova, Ran Liang, and Leif H. Skibsted (2014): "Thermodynamics of Dissolution of Calcium Hydroxycarboxylates in Water". ''Journal of Agriculture and Food Chemistry'', volume 62, issue 24, pages 5675–5681. The DL (racemic) form of the salt is much less soluble in water than the pure L or D isomers, so that a solution that contains as little as 25% of the D form will deposit racemic DL-lactate crystals instead of L-lactate.Gil Fils Tansman (2014): ''Exploring the nature of crystals in cheese through X-ray diffraction'' Masters Dissertation, University of Vermont The pentahydrate loses water in a dry atmosphere between 35 and 135 °C, being reduced to the

anhydrous A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achie ...

form and losing its crystalline character. The process is reversed at 25 °C and 75%

relative humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog t ...

.Yukoh Sakata, Sumihiro Shiraishi, Makoto Otsuka (2005): "Characterization of dehydration and hydration behavior of calcium lactate pentahydrate and its anhydrate". ''Colloids and Surfaces B: Biointerfaces'', volume 46, issue 3, pages 135–141. In aqueous solutions, calcium lactate partially dissociates into calcium ions (Ca²⁺) and lactate ions (C₃H₅O₃⁻). The lactate ion, being the conjugate base of lactic acid (a

weak acid Acid strength is the tendency of an acid, symbolised by the chemical formula , to dissociate into a proton, , and an anion, . The dissociation or ionization of a strong acid in solution is effectively complete, except in its most concentrated s ...

), can undergo slight hydrolysis, making the solution mildly alkaline. This reaction increases the concentration of hydroxide ions (OH⁻), resulting in a solution with a pH slightly above 7, that is,

basic Basic or BASIC may refer to: Science and technology * BASIC, a computer programming language * Basic (chemistry), having the properties of a base * Basic access authentication, in HTTP Entertainment * Basic (film), ''Basic'' (film), a 2003 film ...

. Here are approximate pH values for calcium lactate solutions at various concentrations: Calcium lactate pentahydrate has solubility in water of or 79 g/L at 25 °C. That property makes calcium lactate readily available for absorption when consumed. It is more soluble than some other calcium salts, such as citrate (which has solubility of 0.85 g/L at 25 °C).

Preparation

Calcium lactate can be prepared by the reaction of

lactic acid Lactic acid is an organic acid. It has the molecular formula C3H6O3. It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as wel ...

with

calcium carbonate Calcium carbonate is a chemical compound with the chemical formula . It is a common substance found in Rock (geology), rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skel ...

calcium hydroxide Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca( OH)2. It is a colorless crystal or white powder and is produced when quicklime ( calcium oxide) is mixed with water. Annually, approxim ...

. Since the 19th century, the salt has been obtained industrially by

fermentation Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic molecules, such as glucose or other sugars, are catabolized and reduce ...

carbohydrate A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ...

s in the presence of calcium mineral sources such as

.Kook Hwa Choi, Yong Keun Chang, and Jin-Hyun Kim (2011) "Optimization of Precipitation Process for the Recovery of Lactic Acid". ''KSBB Journal'', volume 26, pages 13-18.
Abstract
) Fermentation may produce either D or L lactate, or a racemic mixture of both, depending on the type of organism used.

Uses

Medicine

Calcium lactate has several uses in human and

veterinary medicine Veterinary medicine is the branch of medicine that deals with the prevention, management, medical diagnosis, diagnosis, and treatment of disease, disorder, and injury in non-human animals. The scope of veterinary medicine is wide, covering all a ...

. It is also used to treat hypocalcaemia (calcium deficiencies). It can be absorbed at various pHs, thus it does not need to be taken with food. However, in this use it has been found to be less convenient than

calcium citrate Calcium citrate is the calcium salt of citric acid. It is commonly used as a food additive ( E333), usually as a preservative, but sometimes for flavor. In this sense, it is similar to sodium citrate. Calcium citrate is also found in some ...

. Calcium lactate contains 13% elemental calcium. In the early 20th century, oral administration of calcium lactate dissolved in water (but not in milk or tablets) was found to be effective in prevention of tetany in humans and dogs with

parathyroid Parathyroid glands are small endocrine glands in the neck of humans and other tetrapods. Humans usually have four parathyroid glands, located on the back of the thyroid gland in variable locations. The parathyroid gland produces and secretes pa ...

insufficiency or who underwent parathyroidectomy.Sloan J. Wilson (1938): "Postoperative Parathyroid Insufficiency and Calcium Lactate". ''Archives of Surgery'', volume 37, issue 3, pages 490-497. A.B. Luckhardt and B. Goldberg (1923): "Preservation of the Life of Completely Parathyroidectomized Dogs by Means of the Oral Administration of Calcium Lactate." ''Journal of the American Medical Association'', volume 80, issue 2, pages 79-80. The compound is also found in some mouth washes and toothpaste as an anti-tartar agent. Calcium lactate (or other calcium salts) is an antidote for soluble

fluoride Fluoride (). According to this source, is a possible pronunciation in British English. is an Inorganic chemistry, inorganic, Monatomic ion, monatomic Ion#Anions and cations, anion of fluorine, with the chemical formula (also written ), whose ...

ingestionCarolyn A. Tylenda (2011): "Toxicological Profile for Fluorides, Hydrogen Fluoride, and Fluorine (Update)". DIANE Publishing. and

hydrofluoric acid Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colorless, acidic and highly corrosive. A common concentration is 49% (48–52%) but there are also stronger solutions (e.g. 70%) and pure HF has a boiling p ...

. While aqueous solutions of calcium lactate exhibit a slightly

(above 7) pH due to the slight hydrolysis of lactate ions, calcium lactate is not used in

medicine Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...

as an

antacid An antacid is a substance which neutralization (chemistry), neutralizes gastric acid, stomach acidity and is used to relieve heartburn, indigestion, or an upset stomach. Some antacids have been used in the treatment of constipation and diarrhe ...

. The reasons lie in its chemical properties and physiological behavior in the

gastrointestinal tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the Digestion, digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascula ...

. Calcium lactate has insufficient acid-neutralizing capacity caused by its weak base formation. The lactate

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

(C₃H₅O₃⁻) is the

conjugate base A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid gives a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as it loses a hydrogen ion in the reve ...

, which is a

. When calcium lactate dissolves in water, it releases lactate ions that can slightly increase the pH of the aqueous solution. The degree of

hydroxide Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It ...

ion (OH⁻) generation through lactate ion

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water ...

is minimal, making the solution only mildly basic. Calcium lactate is more soluble in water compared to other calcium salts such as calcium citrate or carbonate, leading to quicker absorption in the small intestine rather than reacting in the stomach. The slight increase in pH from calcium lactate is rapidly buffered by the stomach's acidic environment, as such, it does not provide the rapid pH shift needed to relieve symptoms of hyperacidity. As such, the role of calcium lactate is to supply calcium ions to the body—a source of bioavailable calcium. Calcium lactate is a well-absorbed and generally safe form of

calcium supplement Calcium supplements are salts of calcium used in a number of conditions. Supplementation is generally only required when there is not enough calcium in the diet. By mouth they are used to treat and prevent low blood calcium, osteoporosis, an ...

ation that does not interfere with digestion. Its properties allow it to be used effectively without disrupting normal gastrointestinal function, making it suitable for individuals seeking to increase their calcium intake without affecting their digestive processes. Calcium lactate does not interact significantly with

digestive enzyme Digestive enzymes take part in the chemical process of digestion, which follows the mechanical process of digestion. Food consists of macromolecules of proteins, carbohydrates, and fats that need to be broken down chemically by digestive enzymes ...

s or other components of the gastrointestinal tract. It dissolves and releases calcium ions that are absorbed in the small intestine without affecting the digestion of proteins, carbohydrates, or fats.

Food industry

The compound is a food additive classified by the United States

FDA The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

generally recognized as safe Generally recognized as safe (GRAS) is a United States Food and Drug Administration (FDA) designation that a chemical or substance added to food is considered safe by experts under the conditions of its intended use. An ingredient with a GRAS d ...

(GRAS), for uses as a firming agent, a

flavor enhancer A flavoring (or flavouring), also known as flavor (or flavour) or flavorant, is a food additive that is used to improve the taste or smell of food. It changes the perceptual impression of food as determined primarily by the chemoreceptors of t ...

flavoring agent A flavoring (or flavouring), also known as flavor (or flavour) or flavorant, is a food additive that is used to improve the taste or Sense of smell, smell of food. It changes the perceptual impression of food as determined primarily by the chem ...

, a

leavening agent In cooking, a leavening agent () or raising agent, also called a leaven () or leavener, is any one of a number of substances used in doughs and batters that cause a foaming action (gas bubbles) that lightens and softens the mixture. An altern ...

, a

nutritional supplement A dietary supplement is a manufactured product intended to supplement a person's diet by taking a pill, capsule, tablet, powder, or liquid. A supplement can provide nutrients either extracted from food sources, or that are synthetic ( ...

, and a stabilizer and thickener.U. S. Food and Drug Administration (2016): ''Code of Federal Regulations: Title 21'' Volume 3, sectio
21CFR184.1207 "Calcium lactate"
, revised April 1, 2016 Calcium lactate is also known as cheese lactate because it coagulates milk, making the

chhena Chhena () or chhana () is a kind of acid-set cheese originating in the Indian subcontinent that is made from water buffaloDalby, A 2009, ''Cheese: A Global History'', Reaktion Books, p. 73, Kapoor, S & Kapoor, A 2006, ''Sanjeev Kapoor's No-oil V ...

used in the production of

paneer Paneer (), is a fresh acid-set cheese, common in cuisine of South Asia, made from cow milk or buffalo milk. It is a non-aged, non-melting soft cheese made by curdling milk with a fruit- or vegetable-derived acid, such as lemon juice. Pa ...

cheese. Chhena is also used to make various sweets and other milk proteins. Calcium lactate is an ingredient in some

baking powder Baking powder is a dry chemical leavening agent, a mixture of a carbonate or bicarbonate and a weak acid. The base and acid are prevented from reacting prematurely by the inclusion of a buffer such as cornstarch. Baking powder is used to increas ...

s containing

sodium acid pyrophosphate Disodium pyrophosphate or sodium acid pyrophosphate (SAPP) is an inorganic compound with the chemical formula . It consists of sodium cations () and dihydrogen pyrophosphate anions (). It is a white, water-soluble solid that serves as a bufferin ...

. It provides calcium in order to delay leavening.E.J. Pyler (1988), Baking Science and Technology, Sosland Publishing Calcium lactate is added to sugar-free foods to prevent

tooth decay Tooth decay, also known as caries,The word 'caries' is a mass noun, and is not a plural of 'carie'.'' is the breakdown of teeth due to acids produced by bacteria. The resulting cavities may be a number of different colors, from yellow to black ...

. When added to

chewing gum Chewing gum is a soft, cohesive substance designed to be chewed without being swallowed. Modern chewing gum is composed of gum base, sweeteners, softeners/plasticizers, flavors, colors, and, typically, a hard or powdered polyol coating. Its tex ...

containing

xylitol Xylitol is a chemical compound with the formula , or HO(CH2)(CHOH)3(CH2)OH; specifically, one particular Stereoisomerism, stereoisomer with that structural formula. It is a colorless or white crystalline solid. It is classified as a polyalcoho ...

, it increases the

remineralization In biogeochemistry, remineralisation (or remineralization) refers to the breakdown or transformation of organic matter (those molecules derived from a biological source) into its simplest inorganic forms. These transformations form a crucial link ...

tooth enamel Tooth enamel is one of the four major Tissue (biology), tissues that make up the tooth in humans and many animals, including some species of fish. It makes up the normally visible part of the tooth, covering the Crown (tooth), crown. The other ...

. The compound is also added to fresh-cut fruits, such as

cantaloupe The cantaloupe ( ) is a type of true melon (''Cucumis melo'') with sweet, aromatic, and usually orange flesh. Originally, ''cantaloupe'' refers to the true cantaloupe or European cantaloupe with non- to slightly netted and often ribbed rind. ...

s, to keep them firm and extend their shelf life, without the bitter taste caused by

calcium chloride Calcium chloride is an inorganic compound, a Salt (chemistry), salt with the chemical formula . It is a white crystalline solid at room temperature, and it is highly soluble in water. It can be created by neutralising hydrochloric acid with cal ...

, which can also be used for this purpose. Calcium lactate is used in

molecular gastronomy Molecular gastronomy is the Science, scientific approach of cuisine from primarily the perspective of chemistry. The composition (Structural formula, molecular structure), properties (mass, viscosity, etc) and transformations (chemical reaction ...

as a flavorless

fat In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food. The term often refers specif ...

-soluble agent for plain and reverse spherification. It reacts with

sodium alginate Alginic acid, also called algin, is a naturally occurring, edible polysaccharide found in brown algae. It is hydrophilic and forms a viscous gum when hydrated. When the alginic acid binds with sodium and calcium ions, the resulting salts are kn ...

to form a skin around the food item.

Animal feeds

Calcium lactate may be added to animal rations as a source of calcium.B.N. Paul, S. Sarkar, S. S. Giri, S. N Mohanty, P. K. Mukhopadhyay (2006): "Dietary calcium and phosphorus requirements of rohu ''Labeo rohita'' fry". ''Animal Nutrition and Feed Technology'', volume 6, issue 2, pages 257-263

Chemistry

The compound was formerly an intermediate in the preparation of lactic acid for food and medical uses. The impure acid from various sources was converted to calcium lactate, purified by crystallization, and then converted back to acid by treatment with

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...

, which precipitated the calcium as

calcium sulfate Calcium sulfate (or calcium sulphate) is an inorganic salt with the chemical formula . It occurs in several hydrated forms; the anhydrous state (known as anhydrite) is a white crystalline solid often found in evaporite deposits. Its dihydrate ...

. This method yielded a purer product than would be obtained by distillation of the original acid.H. Benninga (1990): "A History of Lactic Acid Making: A Chapter in the History of Biotechnology". Volume 11 of ''Chemists and Chemistry''. Springer, Recently ammonium lactate has been used as an alternative to calcium in this process."A gypsum-free, energy-saving route to lactic acid" ''Chemical Engineering'', July 1, 2009.

Water treatment

Calcium lactate has been considered as a coagulant for removing suspended solids from water, as a renewable, non-toxic, and biodegradable alternative to

aluminum chloride Aluminium chloride, also known as aluminium trichloride, is an inorganic compound with the formula . It forms a hexahydrate with the formula , containing six water molecules of hydration. Both the anhydrous form and the hexahydrate are col ...

.R. Devesa-Rey, G. Bustos, J. M. Cruz, A. B. Moldes (2012): "Evaluation of Non-Conventional Coagulants to Remove Turbidity from Water". ''Water, Air, & Soil Pollution'', volume 223, issue 2, pages 591–598.

Bioconcrete

Addition of calcium lactate substantially increases the compressive strength and reduces water permeability of bioconcrete, by enabling bacteria such as ''

Enterococcus faecalis ''Enterococcus faecalis'' – formerly classified as part of the group D '' Streptococcus,'' is a Gram-positive, commensal bacterium naturally inhabiting the gastrointestinal tracts of humans. Like other species in the genus '' Enterococcus'', ' ...

'', '' Bacillus cohnii'', '' Bacillus pseudofirmus'' and ''

Sporosarcina pasteurii ''Sporosarcina pasteurii'' formerly known as ''Bacillus pasteurii'' from older taxonomies, is a gram positive bacterium with the ability to precipitate calcite and solidify sand given a calcium source and urea; through the process of microbiolo ...

'' to produce more

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

References

{{Mineral supplements Calcium compounds Lactates Food antioxidants E-number additives