Lecithin (/ˈlɛsɪθɪn/LESS-ith-in; from theAncient Greekλέκιθοςlékithos "yolk") is a generic term to designate any group of yellow-brownishfatty substances occurring in animal and plant tissues which areamphiphilic – they attract both water and fatty substances (and so are bothhydrophilic andlipophilic), and are used for smoothing food textures,emulsifying,homogenizing liquid mixtures, and repelling sticking materials.[1][2]
Lecithin was first isolated in 1845 by the French chemist and pharmacistThéodore Gobley.[4] In 1850, he named the phosphatidylcholinelécithine.[5] Gobley originally isolated lecithin fromegg yolk and established the complete chemical formula of phosphatidylcholine in 1874;[6] in between, he demonstrated the presence of lecithin in a variety of biological materials, includingvenous blood, human lungs,bile,roe, andbrains of humans, sheep and chicken.
Commercial lecithin, as used by food manufacturers, is a mixture ofphospholipids inoil. The lecithin can be obtained by water degumming the extracted oil of seeds. It is a mixture of various phospholipids, and the composition depends on the origin of the lecithin. A major source of lecithin issoybean oil. Because of theEU requirement to declare additions of allergens in foods, in addition to regulations regardinggenetically modified crops, a gradual shift to other sources of lecithin (such as sunflower lecithin) is taking place.[8] The main phospholipids in lecithin from soy and sunflower arephosphatidylcholine,phosphatidylinositol,phosphatidylethanolamine,phosphatidylserine, andphosphatidic acid. They are often abbreviated to PC, PI, PE, PS and PA, respectively. Purified phospholipids are produced by companies commercially.[citation needed]
To modify the performance of lecithin to make it suitable for the product to which it is added, it may be hydrolysed enzymatically. In hydrolysed lecithins, a portion of the phospholipids have one fatty acid removed byphospholipase. Such phospholipids are called lysophospholipids. The most commonly used phospholipase is phospholipase A2, which removes thefatty acid at the C2 position of glycerol. Lecithins may also be modified by a process calledfractionation. During this process, lecithin is mixed with an alcohol, usuallyethanol. Some phospholipids, such as phosphatidylcholine, have good solubility in ethanol, whereas most other phospholipids do not dissolve well in ethanol. The ethanol is separated from the lecithin sludge, after which the ethanol is removed by evaporation to obtain a phosphatidylcholine-enriched lecithin fraction.[citation needed]
Genetically modified crops as a source of lecithin
As described above, lecithin is highly processed. Therefore, genetically modified (GM)protein orDNA from the originalGM crop from which it is derived often is undetectable – in other words, it is not substantially different from lecithin derived from non-GM crops.[9] Nonetheless, consumer concerns aboutgenetically modified food have extended to highly purified derivatives from GM food, such as lecithin.[10] This concern led to policy and regulatory changes in theEU in 2000, when Commission Regulation (EC) 50/2000 was passed[11] which requiredlabelling of food containing additives derived from GMOs, including lecithin. Because it is nearly impossible to detect the origin of derivatives such as lecithin, the European regulations require those who wish to sell lecithin inEurope to use a meticulous, but essential system ofidentity preservation (IP).[9][12]
Lecithin is used for applications in human food, animal feed, pharmaceuticals, paints, and other industrial applications.
Applications include:
In thepharmaceutical industry, it acts as a wetting agent, stabilizing agent and a choline enrichment carrier, helps in emulsification and encapsulation, and is a good dispersing agent. It can be used in manufacture of intravenous fat infusions and for therapeutic use.
Inanimal feed, it enriches fat and protein and improves pelletization.
In thepaint industry, it forms protective coatings for surfaces with painting andprinting ink, helps as arust inhibitor, is a colour intensifying agent,catalyst, conditioning aid modifier, and dispersing aid; it is a good stabilizing and suspending agent, emulsifier, andwetting agent, helps in maintaining uniform mixture of severalpigments, helps in grinding ofmetal oxide pigments, is a spreading and mixing aid, prevents hard settling of pigments, eliminatesfoam in water-based paints, and helps in fast dispersion oflatex-based paints.
Lecithin also may be used as arelease agent forplastics, an anti-sludge additive in motor lubricants, an anti-gumming agent in gasoline, and an emulsifier, spreading agent, and antioxidant in textile, rubber, and other industries.
The nontoxicity of lecithin leads to its use with food, as afood additive or in food preparation. It is used commercially in foods requiring a natural emulsifier or lubricant.
In confectionery, it reduces viscosity, replaces more expensive ingredients, controls sugar crystallization and the flow properties ofchocolate, helps in the homogeneous mixing of ingredients, improves shelf life for some products, and can be used as a coating. In emulsions andfat spreads, such asmargarines with a highfat content of more than 75%, it stabilizes emulsions, reduces spattering (splashing and scattering of oil droplets) duringfrying, improves texture of spreads and flavor release.[14] Indoughs andbaking, it reduces fat and egg requirements, helps even out distribution of ingredients in dough, stabilizesfermentation, increases volume, protectsyeast cells in dough when frozen, and acts as a releasing agent to prevent sticking and simplify cleaning. It improves wetting properties ofhydrophilic powders (such as low-fat proteins) andlipophilic powders (such ascocoa powder), controls dust, and helps complete dispersion in water.[15] Lecithin keepscocoa andcocoa butter in acandy bar from separating. It can be used as a component ofcooking sprays to prevent sticking and as a releasing agent.
Lecithin contains dietary precursors tocholine, an essential nutrient, which was formerly classified as a B vitamin (vitamin B4).[17][18] Lecithin is a mixture of fats that contains phospholipids, including phosphatidylcholine, and the human body can convert phosphatidylcholine into choline.[19][20][21] The choline content in lecithin can vary, but it's found that phosphatidylcholine makes up about 25 to 35 percent of lecithin. Furthermore, only about 12 percent of phosphatidylcholine is actually choline. This adds up to a choline content of approximately 4 percent for lecithin. For example, 10 grams of lecithin has 2,500mg of phosphatidylcholine.[21][19]
Phosphatidylcholine is approximately 13.7% choline; as such, about 342mg of choline is present per 10 grams of lecithin. Therefore, 10 grams of lecithin can be a source for the body to produce about the same amount of choline (342mg) as can be produced by the body from 2 egg yolks.[21][22][19] The recommended intake of choline varies depending on age, sex, and physiological conditions, and is roughly 500 mg per day for adults.[23][24]
There is no robust, scientifically validated clinical research investigating the safety and effectiveness of high-dose lecithin supplementation in lactating women and their infants. A meta-analysis found no evidence that high doses of lecithin improved milk flow inbreast-feeding mothers or infants, though concluded that "higher maternal choline intake was likely to be associated with better child neurocognition and neurodevelopment."[25][20]
Soy lecithin does not contain enough allergenic proteins for most people allergic to soy, although the US FDA only exempts a few soy lecithin products from its mandatory requirements for allergenic source labeling.[26] An alternative source of lecithin, derived from sunflowers, is available as a dietary supplement for those with concerns about soy-based foods.[27]
A 2003 review of randomized trials found no benefit of lecithin in people withdementia.[28]
Soy-derived lecithin is considered by some to bekitniyot and prohibited onPassover forAshkenazi Jews when many grain-based foods are forbidden, but not at other times. This does not necessarily affectSephardi Jews, who do not have the same restrictions on rice andkitniyot during Passover.[29]
Muslims are not forbidden to eat lecithin per se; however, since it may be derived from animal as well as plant sources, care must be taken to ensure the source ishalal. Lecithin derived from plants and egg yolks is permissible, as is that derived from animals slaughtered according to the rules ofdhabihah.[30]
Sunflower lecithin, sourced from the seeds of sunflowers, is entirely plant-based and may be an option for those with religious or cultural concerns regarding food intake.
^"Lecithin".Merriam Webster Dictionary Online.Archived from the original on 2018-06-12. Retrieved2015-11-18.
^Szuha BF (1989)."Chapter 7".Lecithins: Sources, Manufacture & Uses. The American Oil Chemist's Society. p. 109.ISBN0-935315-27-6.
^Smith J, Hong-Shum L, eds. (2011).Food Additives Data Book (2nd ed.). Chichester, West Sussex: Wiley-Blackwell. p. 334.ISBN978-1-4443-9773-4.Complex mixture of phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidic acid, glycolipids, etc.
^Gobley T (1850)."Recherches chimiques sur les œufs de carpe" [Chemical researches on carp eggs].Journal de Pharmacie et de Chemie. 3rd series (in French).17:401–430.Je propose de donner au premier le nom deLécithine (de λεκιθος, jaune d'œuf), parce qu'on le rencontre en grande quantité dans le jaune d'œuf ... (I propose to give to the former the name oflecithin (from λεκιθος, egg yolk), because it is encountered in great quantity in egg yolk ... )
^Gobley T (1874)."Sur la lécithine et la cérébrine" [On lecithin and cerebrin].Journal de Pharmacie et de Chimie. 4th series (in French).19:346–353.
^Efting M (August 3, 2021)."Emulsifier alternative: sunflower lecithin".Food & Beverage Insider.Archived from the original on July 24, 2023. RetrievedJuly 24, 2023.Sunflower lecithin is a promising alternative to the more common soybean lecithin, and could face increased demand from suppliers as a non-GMO product.
^"Choline". 11 August 2020.Archived from the original on 6 April 2024. Retrieved6 April 2024.
^ab"Lecithin". Drugs and Lactation Database, National Library of Medicine, US National Institutes of Health. 20 September 2021.PMID30000831.Archived from the original on 19 May 2022. Retrieved19 May 2022.
^"Soybeans and soy lecithin".Food Allergy Research and Resource Program. University of Nebraska–Lincoln. 7 August 2018.Archived from the original on 6 April 2024. Retrieved14 December 2018.
^Higgins JP, Flicker L (2003). "Lecithin for dementia and cognitive impairment".Cochrane Database of Systematic Reviews.3 (3): CD001015.doi:10.1002/14651858.CD001015.PMID12917896.
^(Reb Yehonatan Levy, Shomer Kashrut Mashgiach - based upon halachic rulings of CRC - Chicago Rabbinic Council, and from shiurim/lessons by Rabbi D. Raccah on "Pesach Preparations" following commentary from former Rishon-LeTzion Rav Ovadia Yosef). OK Kosher Certification,Keeping Kosher for Pesach.Archived 2012-03-15 at theWayback Machine Retrieved on September 10, 2008.
^Islamic Food and Nutrition Council of America FAQ,IFANCA: Consumer FAQ.Archived 2011-11-23 at theWayback Machine. Retrieved on July 7, 2010. The practice of consuming Halal products is not widespread among Muslims, the practice is common with Muslims who follow Sharia laws.
