Lutein (pronounced|ˈlutiːn) (from
Latin"lutea" meaning "yellow") is one of over 600 known naturally occurring carotenoids. Found in green leafy vegetables such as spinachand kale, lutein is employed by organisms as an antioxidantand for blue light absorption. Lutein is present in the plant as fatty-acid ester, with one or two fatty acids bound to the two hydroxyl-groups. Saponificationof lutein estersyields lutein in approximately a 2:1 weight-to-weight conversion. Lutein is also found in egg yolks, animal fats and the corpus luteum. [ [http://www.m-w.com/dictionary/lutein Merriam-Webster Online Dictonary] ]
Lutein is a
lipophilicmolecule and is generally insoluble in water. The presence of the long chromophoreof conjugated double bonds ( polyenechain) provides the distinctive light-absorbing properties. The polyene chain is susceptible to oxidative degradation by light or heat and is chemically unstable in acids.
The principal natural
stereoisomerof lutein is (3R,3'R,6'R)-beta, epsilon-Carotene-3,3'-diol.
As a pigment
xanthophyll, like its sister compound zeaxanthin, has primarily been used as a natural colorant due to its orange-red color. Lutein absorbs bluelight and therefore appears yellowat low concentrations and orange-red at high concentrations.
Lutein was traditionally used in
chickenfeed to provide the yellow color of broilerchicken skin. Polled consumers viewed yellow chicken skin more favorably than white chicken skin. Such lutein fortification also results in a darker yellow egg yolk. Today the coloring of the egg yolk has become the primary reason for feed fortification. Lutein is not used as a colorantin other foods due to its limited stability, especially in the presence of other dyes.
Role in human eyes
Lutein was found to be present in a concentrated area of the
macula, a small area of the retina responsible for central vision. The hypothesis for the natural concentration is that lutein helps protect from oxidative stressand high-energy light. Various research studies have shown that a direct relationship exists between lutein intake and was a small study, in which the authors concluded that more study was needed.
Lutein may also play a role in
Haidinger's brush, an entoptic phenomenonthat allows humans to detect polarized light.
Lutein is a natural part of human diet when fruits and vegetables are consumed. For individuals lacking sufficient lutein intake, lutein-fortified foods are available, or in the case of elderly people with a poorly absorbing digestive system, a
sublingualspray is available. As early as 1996, lutein has been incorporated into dietary supplements. While no recommended daily allowancecurrently exists for lutein as for other nutrients, positive effects have been seen at dietary intake levels of 6 mg/day. [Seddon, J.M., "et al.", Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. Eye Disease Case-Control Study Group. "JAMA, 1994. 272(18): p. 1413-20. PMID|7933422"] The only definitive side effect of excess lutein consumption is bronzing of the skin ( carotenodermia).
The functional difference between lutein (free form) and lutein esters is not entirely known. It is suggested that the
bioavailabilityis lower for lutein esters, but much debate continues.
food additive, lutein has the E numberE161b and is extracted from the petals of marigold ( Tageteserecta). [ [http://www.codexalimentarius.net/gsfaonline/additives/details.html?id=384 WHO/FAO Codex Alimentarius General Standard for Food Additives] ]
Several [researchers] including a group led by John Paul SanGiovanni of the
National Eye Institute, Marylandfound that high intakes of Lutein and zeaxanthin( nutrientsin eggs, spinachand other green vegetables) are associated with a lower risk of blindness( macular degeneration), affecting 1.2 million Americans, mostly after age 65. ( journal Archives of Ophthalmology).
Whether this relation is causal and whether lutein and zeaxanthin actually reduce the risk of AMD is unknown. Hopefully the question will be answered by the AREDS2 trial which will report its results by 2015 (http://clinicaltrials.gov).
Foods considered good sources of the nutrients also include
kale, turnipgreens, collardgreens, romaine lettuce, broccoli, zucchini, corn, garden peasand Brussels sprouts. [ [http://news.yahoo.com/s/nm/20070910/hl_nm/eyesight_nutrients_dc;_ylt=AhJwo077jBEbQvMoRIMIxV2s0NUE Yahoo.com, Study finds spinach, eggs ward off cause of blindness] ]
The Lutein market is segmented into Pharmaceutical, Nutraceutical, Food, Pet Foods and Animal Feed and Fish Feed. The Pharmaceutical market is estimated to be about US $ 190 Million, Nutraceutical and Food is estimated to be about US $ 110 Million. Pet foods and other applications are estimated at US $ 175 Million annually. Apart from the customary Age related Macular Degeneration applications, newer applications are emerging in Cosmetics, Skin Care and as an Antioxidant. It is one of the fastest growing areas of the $2 Billion carotenoid market. [FOD025C The Global Market for Carotenoids,
BCC Research] There are several lutein ester suppliers, but few pure lutein (Free Form) suppliers due primarily to patent protections on obtaining purified Lutein from natural products, namely marigolds. Companies like Indus Biotech Pvt. Ltd, OmniActive Health Technologies and Kemin Industries have patents. The market size of lutein is anticipated to grow at an average annual growth rate of over 22%.
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Look at other dictionaries:
Lutein — Lu te*in, n. [From corpus luteum.] (Physiol. Chem.) A substance of a strongly marked yellow color, extracted from the yolk of eggs, and from the tissue of the corpus luteum. [1913 Webster] … The Collaborative International Dictionary of English
Luteïn — Luteïn, der gelbe Farbstoff des Eidotters, des Blutplasmas, Blutserums, der mit dem Farbstoff der Maiskörner, mancher Blüten und Staubfäden identisch sein soll … Meyers Großes Konversations-Lexikon
Lutein — ⇒ Xanthophylle … Deutsch wörterbuch der biologie
lutein — lutèīn m <G luteína> DEFINICIJA biol. žuta boja u lišću biljaka i u žumanjku ETIMOLOGIJA lat. luteum: žumanjak + in … Hrvatski jezični portal
lutein — [lo͞ot′ē in] n. [< (CORPUS) LUTE(UM) + IN1] 1. XANTHOPHYLL 2. a preparation of dried and powdered corpus luteum … English World dictionary
Lutein — Strukturformel Allgemeines Name Lutein Andere Namen … Deutsch Wikipedia
Lutein — Lu|te|in 〈n. 11; unz.; Biochem.〉 ein z. B. in grünen Blättern, Eidotter u. Kuhbutter vorkommender, gelber organ. Farbstoff [zu lat. luteus „goldgelb“; zu lutum „Wau“ (Färberpflanze)] * * * Lu|te|in [lat. luteus = gelb, goldgelb; ↑ in (3)], das;… … Universal-Lexikon
lutein — noun Date: 1869 an orange xanthophyll C40H56O2 occurring in plants, animal fat, egg yolk, and the corpus luteum … New Collegiate Dictionary
lutein — /looh tee in/, n. Biochem. 1. Also called xanthophyll. a yellow red, water insoluble, crystalline, carotenoid alcohol, C40H56O2, found in the petals of marigold and certain other flowers, egg yolk, algae, and corpora lutea: used chiefly in the… … Universalium
lutein — noun A yellow carotenoid pigment, widely distributed in both plants and animals. Syn: E161b, food colouring, xanthophyll … Wiktionary