carotenoid


Also found in: Dictionary, Thesaurus, Medical, Wikipedia.

Carotenoid

Any of a class of yellow, orange, red, and purple pigments that are widely distributed in nature. Carotenoids are generally fat-soluble unless they are complexed with proteins. In plants, carotenoids are usually located in quantity in the grana of chloroplasts in the form of carotenoprotein complexes. Carotenoprotein complexes give blue, green, purple, red, or other colors to crustaceans, echinoderms, nudibranch mollusks, and other invertebrate animals. Some coral coelenterates exhibit purple, pink, orange, or other colors due to carotenoids in the calcareous skeletal material. Cooked or denatured lobster, crab, and shrimp show the modified colors of their carotenoproteins.

The general structure of carotenoids is that of aliphatic and aliphatic-alicyclic polyenes, with a few aromatic-type polyenes. Most carotenoid pigments are tetraterpenes with a 40-carbon (C40) skeleton. More than 300 carotenoids of known structure are recognized, and the number is still on the rise.

There are several biochemical functions in which the role of carotenoids is well understood. These include carotenoids in the photosynthetic apparatus of green plants, algae, and photosynthetic bacteria, where carotenoids function as a blue light-harvesting pigment (antenna or accessory pigment) for photosynthesis. Thus carotenoids make it possible for photosynthetic organisms more fully to utilize the solar energy in the visible spectral region. See Chlorophyll, Photosynthesis

Another function of carotenoids is to protect biological systems such as the photosynthetic apparatus from photodynamic damage. This is done by quenching the powerful photodynamic oxidizing agent, singlet oxygen, produced as an undesirable by-product of the exposure of pigmented organisms to light.

Perhaps the most important industrial application of carotenoids is in safe coloration of foods, as exemplified in the coloring and fortification of margarine and poultry feedstuff.

carotenoid

[kə′rät·ən‚ȯid]
(biochemistry)
A class of labile, easily oxidizable, yellow, orange, red, or purple pigments that are widely distributed in plants and animals and are preferentially soluble in fats and fat solvents.
References in periodicals archive ?
M2 PRESSWIRE-August 26, 2019-: Carotenoids Market - Global Insights, Growth, Size, Comparative Analysis, Trends, Technology Status, Demands, Segmentation and Forecast to 2023
Carotenoids are molecules that give peaches their bright yellow and orange colors.
Total carotenoid contents (ug/g) were estimated spectrophotometrically whereas, total pro-vitamin A contents (ug/g) comprising of mainly [beta]-carotene and [beta]-cryptoxanthin were estimated using the high performance liquid chromatography (HPLC) protocol recommended and devised by Howe and Tanumihardjo, (2006).
Ongoing research will include (1) adding varying quantities (10% to 20%) of BSLM to diets of commercial layers and determining the corresponding concentration of specific carotenoids in the egg yolks, (2) examining the upper limit of carotenoid deposition and the medical effects of glucosinolates, and (3) determining the quantity of carotenoids in eggs before and after heating by various methods.
MPOD measurements have been found to correlate with serum and skin carotenoid measurements and carotenoid consumption.
Hoffmann et al., "Contribution of violaxanthin, neoxanthin, phytoene and phytofluene to total carotenoid intake: Assessment in Luxembourg," Journal of Food Composition and Analysis, vol.
An aliquot (200 [micro]L) of the carotenoid samples was mixed with 2 mL of the ABTS reagent and incubated for 10 min in dark.
Carotenoids, present in certain food items, circulate through the bloodstream and to the feather follicles when birds consume such food items.
'If you eat a lot of carrots, or other orange fruits, your skin colour can actually change in hue, the carotenoid in the actual pigmentation that changes the skin colour when you are eating these fruits and vegetables,' Pezdirc said.
The coloration of the fish skin is dependent on absorption and deposition of carotenoid pigments from the diet, since fish, like other vertebrates, are unable to synthesize carotenoids de novo (Goodwin, 1984).
C: Carotenoid content of food ([micro]g.g-1) at time t (e.g.