Calcium lactate

The lactate ion is chiral, with two enantiomers, D (−,R) and L (+,S). The L isomer 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) salt. Both the L and the DL forms occur as crystals on the surface of aging Cheddar cheese.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. {{doi|10.3168/jds.2014-8277}}

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. {{doi|10.1021/jf402124n}} 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 {{chem|Ca|2+}} ions decreases by almost one half. This is explained as the lactate and calcium ions becoming less hydrated and forming a complex {{chem|C|3|H|5|O|3|Ca|+}}.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. {{doi|10.1021/jf501453c}}

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 form and losing its crystalline character. The process is reversed at 25 °C and 75% relative humidity.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. {{doi|10.1016/j.colsurfb.2005.10.004}}

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), 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.{{cite book|doi=10.1002/ddr.21085 |title=The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals, 15th Edition Edited by M.J.O'Neil, Royal Society of Chemistry, Cambridge, UK|isbn=9781849736701|page=2708|date=April 2013|last1=Williams |first1=Michael |series=Drug Development Research |volume=74 |issue=5 }}{{cite book|isbn=978-0857113757|date=1 October 2020 |title=Handbook of Pharmaceutical Excipients |last1=Sheskey |first1=Paul J. |last2=Hancock |first2=Bruno C. |last3=Moss |first3=Gary P. |last4=Goldfarb |first4=David J. |publisher=Pharmaceutical Press }}{{cite book|date=3 September 2012|isbn=978-0857110626 |title=Remington: The Science and Practice of Pharmacy |publisher=Pharmaceutical Press|page=3056}} 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).{{cite book|isbn=978-1032655628 |title=CRC Handbook of Chemistry and Physics |last1=Rumble |first1=John R. |date=4 June 2024 |publisher=CRC Press }}

Calcium lactate can be prepared by the reaction of lactic acid with calcium carbonate or calcium hydroxide.

Since the 19th century, the salt has been obtained industrially by fermentation of carbohydrates in the presence of calcium mineral sources such as calcium carbonate or calcium hydroxide.{{rp|p200}}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. ([http://www.dbpia.co.kr/Journal/ArticleDetail/NODE02243060 Abstract] {{Webarchive|url=https://web.archive.org/web/20170416044753/http://www.dbpia.co.kr/Journal/ArticleDetail/NODE02243060 |date=2017-04-16 }}) Fermentation may produce either D or L lactate, or a racemic mixture of both, depending on the type of organism used.Rojan P. John, K. Madhavan Nampoothiri, Ashok Pandey (2007): "Fermentative production of lactic acid from biomass: an overview on process developments and future perspectives" Applied Microbiology and Biotechnology, volume 74, issue 3, pages 524–534 {{doi|10.1007/s00253-006-0779-6}}

Calcium lactate has several uses in human and veterinary medicine.

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 lactate contains 13% elemental calcium.{{cite journal |vauthors=Straub DA |title=Calcium supplementation in clinical practice: a review of forms, doses, and indications |journal=Nutr Clin Pract |volume=22 |issue=3 |pages=286–96 |date=June 2007 |pmid=17507729 |doi=10.1177/0115426507022003286}}

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 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. {{doi|10.1001/archsurg.1938.01200030139008}}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. {{doi|10.1001/jama.1923.02640290009002}}

The compound is also found in some mouth washes and toothpaste as an anti-tartar agent.{{Cite web|title=Calcium Lactate Uses|url=https://www.tripurabiotech.com/details/calcium-sodium-lactate-products|access-date=2020-08-04|website=www.tripurabiotech.com|archive-date=2021-05-13|archive-url=https://web.archive.org/web/20210513144703/https://www.tripurabiotech.com/details/calcium-sodium-lactate-products|url-status=live}}

Calcium lactate (or other calcium salts) is an antidote for soluble fluoride ingestionCarolyn A. Tylenda (2011): "Toxicological Profile for Fluorides, Hydrogen Fluoride, and Fluorine (Update)". DIANE Publishing. {{ISBN|9781437930771}}{{rp|p165}} and hydrofluoric acid.

While aqueous solutions of calcium lactate exhibit a slightly basic (above 7) pH due to the slight hydrolysis of lactate ions, calcium lactate is not used in medicine as an antacid. The reasons lie in its chemical properties and physiological behavior in the gastrointestinal tract. Calcium lactate has insufficient acid-neutralizing capacity caused by its weak base formation. The lactate ion (C₃H₅O₃⁻) is the conjugate base of lactic acid, which is a weak acid. When calcium lactate dissolves in water, it releases lactate ions that can slightly increase the pH of the aqueous solution. The degree of hydroxide ion (OH⁻) generation through lactate ion hydrolysis 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.{{cite journal|doi=10.1016/j.ecl.2012.04.019 |title=Calcium Metabolism and Correcting Calcium Deficiencies |date=2012 |last1=Emkey |first1=Ronald D. |last2=Emkey |first2=Gregory R. |journal=Endocrinology and Metabolism Clinics of North America |volume=41 |issue=3 |pages=527–556 |pmid=22877428 }}{{cite book|date=7 November 2022|isbn=978-1265016982|page=1664 |title=Goodman Gilman's Pharmacological Basis T: Herapeutics 14e (Ie) |last1=Brunton |first1=Laurence L. |last2=Knollmann |first2=Björn C. |publisher=McGraw-Hill Education }}{{cite web | url=https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/ | title=Office of Dietary Supplements - Calcium | access-date=2024-11-17 | archive-date=2018-03-17 | archive-url=https://web.archive.org/web/20180317073525/https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/ | url-status=live }} 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 supplementation{{cite web | url=https://www.fda.gov/food/food-additives-petitions/food-additive-status-list | title=Food Additive Status List | work=FDA | date=10 October 2024 | last1=Program | first1=Human Foods | access-date=17 November 2024 | archive-date=12 November 2020 | archive-url=https://web.archive.org/web/20201112001714/http://www.fda.gov/food/food-additives-petitions/food-additive-status-list | url-status=live }} 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 enzymes 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.

The compound is a food additive classified by the United States FDA as generally recognized as safe (GRAS), for uses as a firming agent, a flavor enhancer or flavoring agent, a leavening agent, a nutritional supplement, and a stabilizer and thickener.U. S. Food and Drug Administration (2016): Code of Federal Regulations: Title 21 Volume 3, section [https://www.ecfr.gov/cgi-bin/text-idx?SID=4d839635685e075158bbffd9ed5b8785&mc=true&node=se21.3.184_11207&rgn=div8 21CFR184.1207 "Calcium lactate"] {{Webarchive|url=https://web.archive.org/web/20170415202630/https://www.ecfr.gov/cgi-bin/text-idx?SID=4d839635685e075158bbffd9ed5b8785&mc=true&node=se21.3.184_11207&rgn=div8 |date=2017-04-15 }}, revised April 1, 2016

Calcium lactate is also known as cheese lactate because it coagulates milk, making the chhena used in the production of paneer cheese. Chhena is also used to make various sweets and other milk proteins.

Calcium lactate is an ingredient in some baking powders containing sodium acid pyrophosphate. It provides calcium in order to delay leavening.E.J. Pyler (1988), Baking Science and Technology, Sosland Publishing{{rp|p933}}

Calcium lactate is added to sugar-free foods to prevent tooth decay. When added to chewing gum containing xylitol, it increases the remineralization of tooth enamel.{{cite journal | last = Sudaa | first = R. |author2=T. Suzukia |author3=R. Takiguchib |author4=K. Egawab |author5=T. Sanob |author6=K. Hasegawa | year = 2006 | title = The Effect of Adding Calcium Lactate to Xylitol Chewing Gum on remineralization of Enamel Lesions | journal = Caries Research | volume = 40 | issue = 1 | pages = 43–46 | doi = 10.1159/000088905 | pmid = 16352880 | s2cid = 45316316 }}

The compound is also added to fresh-cut fruits, such as cantaloupes, to keep them firm and extend their shelf life, without the bitter taste caused by calcium chloride, which can also be used for this purpose.{{cite journal | last = Luna-Guzman | first = Irene |author2=Diane M. Barrett | year = 2000 | title = Comparison of calcium chloride and calcium lactate effectiveness in maintaining shelf stability and quality of fresh-cut cantaloupes | journal = Postharvest Biology and Technology | volume = 19 | pages = 16–72 | doi = 10.1016/S0925-5214(00)00079-X }}

Calcium lactate is used in molecular gastronomy as a flavorless fat-soluble agent for plain and reverse spherification. It reacts with sodium alginate to form a skin around the food item.

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

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, which precipitated the calcium as calcium sulfate. 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, {{ISBN|9780792306252}}{{rp|p180}} 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.

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 {{chem|Al|Cl|3}}.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. {{doi|10.1007/s11270-011-0884-8}}

Addition of calcium lactate substantially increases the compressive strength and reduces water permeability of bioconcrete, by enabling bacteria such as Enterococcus faecalis, Bacillus cohnii, Bacillus pseudofirmus and Sporosarcina pasteurii to produce more calcite.{{cite journal|doi=10.4028/www.scientific.net/KEM.705.345 |title=Compressive Strength and Water Penetration of Concrete with Enterococcus faecalis and Calcium Lactate |date=2016 |last1=Irwan |first1=J.M. |last2=Anneza |first2=L.H. |last3=Othman |first3=Norzila |last4=Faisal Alshalif |first4=A. |journal=Key Engineering Materials |volume=705 |pages=345–349 }}{{cite web|last1=Moneo|first1=Shannon|title=Dutch scientist invents self-healing concrete with bacteria|url=https://canada.constructconnect.com/joc/news/Infrastructure/2015/9/Dutch-scientist-invents-self-healing-concrete-with-bacteria-1010047W|website=Journal Of Commerce|access-date=21 March 2018|date=11 September 2015|archive-date=22 March 2018|archive-url=https://web.archive.org/web/20180322142935/https://canada.constructconnect.com/joc/news/Infrastructure/2015/9/Dutch-scientist-invents-self-healing-concrete-with-bacteria-1010047W|url-status=live}}

• Calcium supplement
• Calcium lactate gluconate
• Calcium gluconate
• Calcium citrate

{{reflist}}

{{Mineral supplements}}

Category:Calcium compounds

Category:Lactates

Category:Food antioxidants

Category:E-number additives