Lycopene

Aside from tomatoes or tomato products like ketchup, it is found in watermelons, grapefruits, red guavas, and baked beans. It has no vitamin A activity.{{cite web|url=https://lpi.oregonstate.edu/mic/dietary-factors/phytochemicals/carotenoids|title=Carotenoids: α-Carotene, β-Carotene, β-Cryptoxanthin, Lycopene, Lutein, and Zeaxanthin|publisher=Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis, OR|date=October 2023|access-date=3 December 2024}}

In plants, algae, and other photosynthetic organisms, lycopene is an intermediate in the biosynthesis of many carotenoids, including beta-carotene, which is responsible for yellow, orange, or red pigmentation, photosynthesis, and photoprotection.

Like all carotenoids, lycopene is a tetraterpene. It is soluble in fat, but insoluble in water. Eleven conjugated double bonds give lycopene its deep red color.

Owing to the strong color, lycopene is used as a food coloring (registered as E160d) and is approved for use in the US,{{cite web|title=21 CFR 73.585. Tomato lycopene extract|url=https://www.gpo.gov/fdsys/pkg/CFR-2012-title21-vol1/pdf/CFR-2012-title21-vol1-sec73-585.pdf|publisher=US Food and Drug Administration|date=26 July 2005}} Australia and New Zealand (registered as 160d),Australia New Zealand Food Standards Code{{cite web |url=http://www.comlaw.gov.au/Details/F2011C00827 |title=Standard 1.2.4 – Labelling of ingredients (search "lycopene")|date=8 September 2011 |access-date=2011-10-27}} and the European Union (E160d).{{cite web|publisher=UK Food Standards Agency|url=http://www.food.gov.uk/safereating/chemsafe/additivesbranch/enumberlist |title=Current EU approved additives and their E Numbers |access-date=2011-10-27}}

Lycopene is a symmetrical tetraterpene because it consists entirely of carbon and hydrogen and is derived from eight isoprene subunits. Isolation procedures for lycopene were first reported in 1910, and the structure of the molecule was determined by 1931. In its natural, all-trans form, the molecule is long and somewhat flat, constrained by its system of 11 conjugated double bonds. The extended conjugation is responsible for its deep red color.

Plants and photosynthetic bacteria produce all-trans lycopene. When exposed to light or heat, lycopene can undergo isomerization to any of a number of cis-isomers, which have a less linear shape. Isomers distinct stabilities, with highest stability: 5-cis ≥ all-trans ≥ 9-cis ≥ 13-cis > 15-cis > 7-cis > 11-cis: lowest.{{cite journal|doi=10.1016/S0166-1280(01)00424-9|title=An ab initio computational study on selected lycopene isomers|journal=Journal of Molecular Structure: Theochem|volume=571|issue=1–3|pages=27–37|year=2001|last1=Chasse|first1=Gregory A.|last2=Mak|first2=Melody L.|last3=Deretey|first3=Eugen|last4=Farkas|first4=Imre|last5=Torday|first5=Ladislaus L.|last6=Papp|first6=Julius G.|last7=Sarma|first7=Dittakavi S.R|last8=Agarwal|first8=Anita|last9=Chakravarthi|first9=Sujatha|last10=Agarwal|first10=Sanjiv|last11=Rao|first11=A.Venket|url=https://publicatio.bibl.u-szeged.hu/28647/1/Anabinitiocomputationalstudyonselectedlycopeneisomers1-s2.0-S0166128001004249-main.pdf }}{{cite journal|doi=10.1016/S0166-1280(01)00413-4|title=Conformational potential energy surfaces of a Lycopene model|journal=Journal of Molecular Structure: Theochem|volume=571|issue=1–3|pages=7–26|year=2001|last1=Chasse|first1=Gregory A.|last2=Chasse|first2=Kenneth P. |last3=Kucsman|first3=Arpad|last4=Torday|first4=Ladislaus L.|last5=Papp|first5=Julius G.|url=https://publicatio.bibl.u-szeged.hu/28646/1/ConformationalpotentialenergysurfacesofaLycopenemodel1-s2.0-S0166128001004134-main.pdf }} In human blood, various cis-isomers constitute more than 60% of the total lycopene concentration, but the biological effects of individual isomers have not been investigated.{{cite journal|pmid=16046737|year=2005|last1=Erdman Jr|first1=J. W.|title=How do nutritional and hormonal status modify the bioavailability, uptake, and distribution of various isomers of lycopene?|journal=The Journal of Nutrition|volume=135|issue=8|pages=2046S–7S|doi=10.1093/jn/135.8.2046s|doi-access=free}}

Image:Carotenoid synthetic pathway.svg

Carotenoids like lycopene are found in photosynthetic pigment-protein complexes in plants, photosynthetic bacteria, fungi, and algae. They are responsible for the bright orange–red colors of fruits and vegetables, perform various functions in photosynthesis, and protect photosynthetic organisms from excessive light damage. Lycopene is a key intermediate in the biosynthesis of carotenoids, such as beta-carotene, and xanthophylls.{{cite web| last=NDSU Agriculture | title=What Color is Your Food? |url=http://www.ag.ndsu.edu/pubs/yf/foods/fn595w.htm | access-date=10 May 2012}}

Dispersed lycopene molecules can be encapsulated into carbon nanotubes enhancing their optical properties.{{cite journal

|author = Yanagi, Kazuhiro

|title = Light-Harvesting Function of β-Carotene Inside Carbon Nanotubes

|journal = Phys. Rev. B

|volume = 74

|issue = 15

|page = 155420

|year = 2006

|url = http://pubman.nims.go.jp/pubman/item/escidoc:1587358:2/component/escidoc:1597178/Prb155420.pdf

|doi = 10.1103/PhysRevB.74.155420

|last2 = Iakoubovskii

|first2 = Konstantin

|last3 = Kazaoui

|first3 = Said

|last4 = Minami

|first4 = Nobutsugu

|last5 = Maniwa

|first5 = Yutaka

|last6 = Miyata

|first6 = Yasumitsu

|last7 = Kataura

|first7 = Hiromichi

|bibcode = 2006PhRvB..74o5420Y

|access-date = 2019-02-12

|archive-date = 2020-10-02

|archive-url = https://web.archive.org/web/20201002235524/http://pubman.nims.go.jp/pubman/item/escidoc:1587358:2/component/escidoc:1597178/Prb155420.pdf

|url-status = dead

}} Efficient energy transfer occurs between the encapsulated dye and nanotube—light is absorbed by the dye and without significant loss is transferred to the nanotube. Encapsulation increases chemical and thermal stability of lycopene molecules; it also allows their isolation and individual characterization.

{{cite journal

|author=Saito, Yuika

|title=Vibrational Analysis of Organic Molecules Encapsulated in Carbon Nanotubes by Tip-Enhanced Raman Spectroscopy

|journal=Jpn. J. Appl. Phys.

|volume=45 |pages=9286–9289

|year=2006

|doi=10.1143/JJAP.45.9286

|bibcode=2006JaJAP..45.9286S

|issue=12

|last2=Yanagi

|first2=Kazuhiro

|last3=Hayazawa

|first3=Norihiko

|last4=Ishitobi

|first4=Hidekazu

|last5=Ono

|first5=Atsushi

|last6=Kataura

|first6=Hiromichi

|last7=Kawata

|first7=Satoshi

|s2cid=122152101

}}

The unconditioned biosynthesis of lycopene in eukaryotic plants and in prokaryotic cyanobacteria is similar, as are the enzymes involved. Synthesis begins with mevalonic acid, which is converted into dimethylallyl pyrophosphate. This is then condensed with three molecules of isopentenyl pyrophosphate (an isomer of dimethylallyl pyrophosphate), to give the 20-carbon geranylgeranyl pyrophosphate. Two molecules of this product are then condensed in a tail-to-tail configuration to give the 40-carbon phytoene, the first committed step in carotenoid biosynthesis. Through several desaturation steps, phytoene is converted into lycopene. The two terminal isoprene groups of lycopene can be cyclized to produce beta-carotene, which can then be transformed into a wide variety of xanthophylls.

Lycopene is the pigment in tomato sauces that turns plastic cookware orange. It is insoluble in plain water, but it can be dissolved in organic solvents and oils. Because of its non-polarity, lycopene in food preparations will stain any sufficiently porous material, including most plastics. To remove this staining, the plastics may be soaked in a solution containing a small amount of chlorine bleach.{{cite news|url=http://www.huffingtonpost.com/chris-barnes/how-to-clean-tomato-sauce_b_1521201.html|title=How To Clean Tomato Sauce Stains From Plastic Storage Containers|author=Barnes, Chris|date=11 October 2011|work=The Huffington Post|access-date=29 May 2017}}

The bleach oxidizes the lycopene, thus rendering it colourless.

Absorption of lycopene requires that it be combined with bile salts and fat to form micelles. Intestinal absorption of lycopene is enhanced by the presence of fat and by cooking. Lycopene dietary supplements (in oil) may be more efficiently absorbed than lycopene from food.

Lycopene is not an essential nutrient for humans, but is commonly found in the diet mainly from dishes prepared from tomatoes. The median and 99th percentile of dietary lycopene intake have been estimated to be 5.2 and 123 mg/d, respectively.

Fruits and vegetables that are high in lycopene include autumn olive, gac, tomatoes, watermelon, pink grapefruit, pink guava, papaya, seabuckthorn, wolfberry (goji, a berry relative of tomato), and rosehip. Ketchup is a common dietary source of lycopene. Although gac (Momordica cochinchinensis Spreng) has the highest content of lycopene of any known fruit or vegetable (multiple times more than tomatoes),{{cite journal|pmc=4779482|year=2015|last1=Tran|first1=X. T.|title=Effects of maturity on physicochemical properties of Gac fruit (Momordica cochinchinensis Spreng.)|journal=Food Science & Nutrition|volume=4|issue=2|pages=305–314|last2=Parks|first2=S. E.|last3=Roach|first3=P. D.|last4=Golding|first4=J. B.|last5=Nguyen|first5=M. H.|doi=10.1002/fsn3.291|pmid=27004120}}{{Cite journal|vauthors=Ishida BK, Turner C, Chapman MH, McKeon TA |title=Fatty acid and carotenoid composition of gac (Momordica cochinchinensis Spreng) fruit |journal=Journal of Agricultural and Food Chemistry |volume=52 |issue=2 |pages=274–9 |date=January 2004 |pmid=14733508 |doi=10.1021/jf030616i |bibcode=2004JAFC...52..274I }} tomatoes and tomato-based sauces, juices, and ketchup account for more than 85% of the dietary intake of lycopene for most people. The lycopene content of tomatoes depends on variety and increases as the fruit ripens.{{cite journal|pmid=26462607|year=2016|last1=Ilahy|first1=R|title=Fractionate analysis of the phytochemical composition and antioxidant activities in advanced breeding lines of high-lycopene tomatoes|journal=Food Funct|volume=7|issue=1|pages=574–83|last2=Piro|first2=G|last3=Tlili|first3=I|last4=Riahi|first4=A|last5=Sihem|first5=R|last6=Ouerghi|first6=I|last7=Hdider|first7=C|last8=Lenucci|first8=M. S.|doi=10.1039/c5fo00553a}}

Unlike other fruits and vegetables, where nutritional content such as vitamin C is diminished upon cooking, processing of tomatoes increases the concentration of bioavailable lycopene.{{cite journal|url=http://scielo.isciii.es/scielo.php?script=sci_arttext&pid=S0212-16112012000500025&lng=en&nrm=iso&tlng=en|journal=Hospital Nutrition (Madrid)|volume=27|issue=5|year=2012|pages=1542–6|vauthors=Perdomo F, Cabrera Fránquiz F, Cabrera J, Serra-Majem L |title=Influence of cooking procedure on the bioavailability of lycopene in tomatoes|pmid=23478703|doi=10.3305/nh.2012.27.5.5908}} Lycopene in tomato paste is up to four times more bioavailable than in fresh tomatoes.{{Cite journal | doi = 10.1002/jsfa.6546| pmid = 24375495| title = Home processing of tomatoes (Solanum lycopersicum): Effects onin vitrobioaccessibility of total lycopene, phenolics, flavonoids, and antioxidant capacity| journal = Journal of the Science of Food and Agriculture| volume = 94| issue = 11| pages = 2225–33| year = 2014| last1 = Kamiloglu | first1 = S. | last2 = Demirci | first2 = M. | last3 = Selen | first3 = S. | last4 = Toydemir | first4 = G. | last5 = Boyacioglu | first5 = D. | last6 = Capanoglu | first6 = E. | bibcode = 2014JSFA...94.2225K}} Processed tomato products such as pasteurized tomato juice, soup, sauce, and ketchup contain a higher concentration of bioavailable lycopene compared to raw tomatoes.{{cite book|last1=Yamaguchi|first1=Masayoshi|title=Carotenoids : Properties, Effects and Diseases|date=2010|publisher=Nova Science Publishers|location=New York|isbn=9781612097138|page=125}}

Cooking and crushing tomatoes (as in the canning process) and serving in oil-rich dishes (such as spaghetti sauce or pizza) greatly increases assimilation from the digestive tract into the bloodstream. Lycopene is fat-soluble, so the oil is said to help absorption. Gac has high lycopene content derived mainly from its seed coats.{{Cite journal

| pmid = 12506992

| year = 2002

| last1 = Aoki

| first1 = H

| title = Carotenoid pigments in GAC fruit (Momordica cochinchinensis SPRENG)

| journal = Bioscience, Biotechnology, and Biochemistry

| volume = 66

| issue = 11

| pages = 2479–82

| last2 = Kieu

| first2 = N. T.

| last3 = Kuze

| first3 = N

| last4 = Tomisaka

| first4 = K

| last5 = Van Chuyen

| first5 = N

| doi = 10.1271/bbb.66.2479

| s2cid = 2118248

| doi-access = free

}} Cara Cara navel oranges, and other citrus fruit, such as pink grapefruits, also contain lycopene.{{Cite journal

| pmid = 18538806

| year = 2008

| last1 = Alquezar

| first1 = B

| title = Regulation of carotenoid biosynthesis during fruit maturation in the red-fleshed orange mutant Cara Cara

| journal = Phytochemistry

| volume = 69

| issue = 10

| pages = 1997–2007

| last2 = Rodrigo

| first2 = M. J.

| last3 = Zacarías

| first3 = L

| doi = 10.1016/j.phytochem.2008.04.020

| bibcode = 2008PChem..69.1997A

}} Some foods that do not appear red also contain lycopene, e.g., baked beans.

When lycopene is used as a food additive (E160d), it is usually obtained from tomatoes.{{cite journal |last1=Li |first1=Lei |last2=Liu |first2=Zhen |last3=Jiang |first3=Hong |last4=Mao |first4=Xiangzhao |title=Biotechnological production of lycopene by microorganisms |journal=Appl. Microbiol. Biotechnol. |date=2020 |volume=104 |issue=24 |pages=10307–10324 |doi=10.1007/s00253-020-10967-4 |pmid=33097966 |s2cid=225058089 |url=https://pubmed.ncbi.nlm.nih.gov/33097966/}}

File:Lycopene in DCM.jpg

Lycopene is non-toxic and commonly found in the diet, mainly from tomato products. There are cases of intolerance or allergic reaction to dietary lycopene, which may cause diarrhea, nausea, stomach pain or cramps, gas, and loss of appetite.{{cite web

| title = Lycopene

| url = http://www.mayoclinic.org/drugs-supplements/lycopene/background/hrb-20059666

| publisher = Mayo Clinic

| date = 2017

| access-date = 29 May 2017

| archive-date = 23 September 2017

| archive-url = https://web.archive.org/web/20170923043049/http://www.mayoclinic.org/drugs-supplements/lycopene/background/HRB-20059666

| url-status = dead

}} Lycopene may increase the risk of bleeding when taken with anticoagulant drugs. Because lycopene may cause low blood pressure, interactions with drugs that affect blood pressure may occur. Lycopene may affect the immune system, the nervous system, sensitivity to sunlight, or drugs used for stomach ailments.

Lycopenemia is an orange discoloration of the skin that is observed with high intakes of lycopene.{{cite journal | vauthors = Trumbo PR | title = Are there adverse effects of lycopene exposure? | journal = The Journal of Nutrition | volume = 135 | issue = 8 | pages = 2060S–1S | year = 2005 | pmid = 16046742 | doi = 10.1093/jn/135.8.2060s| quote = Lycopenemia, characterized by an orange discoloration of the skin, has been observed with high intakes of lycopene-containing foods. One case study reported the incidence of lycopenemia in a 61-y-old woman who had consumed ~2 L of tomato juice daily for several years (10). Although there was evidence of lycopene and fatty deposits in the liver, there was an absence of measurable hepatic dysfunction. After 3 wk of consuming a diet free of tomato juice, the orange discoloration faded.| doi-access = free }} The discoloration is expected to fade after discontinuing excessive lycopene intake.

A 2020 review of randomized controlled trials found conflicting evidence for lycopene having an effect on cardiovascular risk factors,{{cite journal |last1=Tierney |first1=Audrey |last2=Rumble |first2=Chloe |last3=Billings |first3=Lauren |last4=George |first4=Elena |date=2020 |title=Effect of Dietary and Supplemental Lycopene on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis |url= |journal=Advances in Nutrition |volume=11 |issue=6 |pages=1453–1488 |doi=10.1093/advances/nmaa069 |pmid=32652029|pmc=7666898 }} whereas a 2017 review concluded that tomato products and lycopene supplementation reduced blood lipids and blood pressure.{{cite journal|last1=Cheng|first1=Ho Ming|last2=Koutsidis|first2=Georgios|last3=Lodge|first3=John K.|last4=Ashor|first4=Ammar|last5=Siervo|first5=Mario|last6=Lara|first6=José|title=Tomato and lycopene supplementation and cardiovascular risk factors: A systematic review and meta-analysis|journal=Atherosclerosis|volume=257|year=2017|pages=100–108|issn=0021-9150|doi=10.1016/j.atherosclerosis.2017.01.009|pmid=28129549|s2cid=19287598 |url=http://nrl.northumbria.ac.uk/29320/1/Cheng_etal_Atherosclerosis_January_2017_NRL.pdf}}

A 2015 review found that dietary lycopene was associated with reduced risk of prostate cancer,{{cite journal|display-authors=3 | last1=Chen | first1=Ping | last2=Zhang | first2=Wenhao | last3=Wang | first3=Xiao | last4=Zhao | first4=Keke | last5=Negi | first5=Devendra Singh | last6=Zhuo | first6=Li | last7=Qi | first7=Mao | last8=Wang | first8=Xinghuan | last9=Zhang | first9=Xinhua | title=Lycopene and Risk of Prostate Cancer | journal=Medicine | volume=94 | issue=33 | date=2015-08-21 | issn=0025-7974 | pmid=26287411 | pmc=4616444 | doi=10.1097/md.0000000000001260 | page=e1260}} whereas a 2021 meta-analysis found that dietary lycopene did not affect prostate cancer risk.{{Cite journal |last1=Luo |first1=Jie |last2=Ke |first2=Dandan |last3=He |first3=Qingwei |date=2021 |title=Dietary Tomato Consumption and the Risk of Prostate Cancer: A Meta-Analysis |journal=Frontiers in Nutrition |volume=8 |pages=625185 |doi=10.3389/fnut.2021.625185 |issn=2296-861X |pmc=8129008 |pmid=34017849|doi-access=free }} Other reviews concluded that research has been insufficient to establish whether lycopene consumption affects human health.{{cite journal|pmc=3850026|year=2010|last1=Story|first1=EN|title=An Update on the Health Effects of Tomato Lycopene|journal=Annual Review of Food Science and Technology|volume=1|issue=1|pages=189–210|last2=Kopec|first2=R. E|last3=Schwartz|first3=S. J|last4=Harris|first4=G. K|doi=10.1146/annurev.food.102308.124120|pmid=22129335}}

In a review of literature on lycopene and its potential benefit in the diet, the European Food Safety Authority concluded there was insufficient evidence for lycopene having antioxidant effects in humans, particularly in skin, heart function, or vision protection from ultraviolet light.{{cite journal|journal=EFSA Journal|volume=9|issue=4|year=2011|title=Scientific Opinion on the substantiation of health claims related to lycopene and protection of DNA, proteins and lipids from oxidative damage (ID 1608, 1609, 1611, 1662, 1663, 1664, 1899, 1942, 2081, 2082, 2142, 2374), protection of the skin from UV-induced (including photo-oxidative) damage (ID 1259, 1607, 1665, 2143, 2262, 2373), contribution to normal cardiac function (ID 1610, 2372), and maintenance of normal vision (ID 1827) pursuant to Article 13(1) of Regulation (EC) No 1924/2006|doi=10.2903/j.efsa.2011.2031 |page=2031|doi-access=free}}

Although lycopene from tomatoes has been tested in humans for cardiovascular diseases and prostate cancer, no effect on any disease was found.{{cite web|title=Qualified Health Claims: Letter Regarding Tomatoes and Prostate Cancer (Lycopene Health Claim Coalition) (Docket No. 2004Q-0201) (Updated 9 July 2015)|publisher=US Food and Drug Administration|url=https://www.fda.gov/Food/IngredientsPackagingLabeling/LabelingNutrition/ucm072767.htm|date=8 November 2005|access-date=16 December 2019|archive-url=https://web.archive.org/web/20170722101944/https://www.fda.gov/Food/IngredientsPackagingLabeling/LabelingNutrition/ucm072767.htm|archive-date=22 July 2017|url-status=dead}} The US Food and Drug Administration, in rejecting manufacturers' requests in 2005 to allow "qualified labeling" for lycopene and the reduction of various cancer risks, provided a conclusion that remains in effect {{Asof|2015|lc=y}}:

{{blockquote |text=no studies provided information about whether lycopene intake may reduce the risk of any of the specific forms of cancer. Based on the above, FDA concludes that there is no credible evidence supporting a relationship between lycopene consumption, either as a food ingredient, a component of food, or as a dietary supplement, and any of these cancers.}}

In a review of research through 2024, the US National Cancer Institute concluded that the FDA has not approved the use of lycopene as effective for treating any medical condition, including various types of cancer.{{cite web |title=Lycopene |url=https://www.cancer.gov/about-cancer/treatment/cam/hp/prostate-supplements-pdq#_16 |publisher=US National Cancer Institute |access-date=14 September 2024 |date=5 April 2024}}

• Lycopene (data page)
• Lycopane
• Nutrition
• Tocopherol
• Tocotrienol
• Tomatine

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