Nutrition Guide

Damascones are a series of closely related chemical compounds that are components of a variety of essential oils. The damascones belong to a family of chemicals known as rose ketones, which also includes damascenones and ionones. beta-Damascone is a contributor to the aroma of roses, despite its relatively low concentration, and is an important fragrance chemical used in perfumery.[2]

Biochemically, the damascones are derived from the degradation of carotenoids.

Food orange 7, the ethyl ester of beta-apo-8′-carotenic acid, is a carotenoid with an orange-red color. It is found in small quantities in some plants, but is often produced commercially from apocarotenal (E160e).[1] It is used as a food coloring under the E number E160f.

Apocarotenal, or trans-beta-apo-8′-carotenal, is a carotenoid found in spinach and citrus fruits. Like other carotenoids, apocarotenal plays a role as a precursor of vitamin A, even though it has 50% less pro-vitamin A activity than beta-carotene. The empirical chemical formula for apocarotenal is C30H40O.

Apocarotenal has an orange to orange-red colour and is used in foods, pharmaceuticals and cosmetic products. Depending on the product forms, apocarotenal is used in fat based food (margarine, sauces, salad dressing), beverages, dairy products and sweets. Its E number is 160E.

Zeaxanthin is one of the most common carotenoid alcohols found in nature. It is the pigment that gives corn, saffron, and many other plants their characteristic color. Zeaxanthin breaks down to form picrocrocin and safranal, which are responsible for the taste and aroma of saffron.

There is epidemiological evidence of a relationship between low plasma concentrations of lutein and zeaxanthin on the one hand, and the risk of developing age-related macular degeneration (AMD) on the other. Some studies support the view that supplemental lutein and/or zeaxanthin help protect against AMD.

There is also epidemiological evidence that increasing lutein and zeaxanthin intake lowers the risk of cataract development.[citation needed]

On September 10, 2007, in a 6-year study, researchers, led by John Paul SanGiovanni of the National Eye Institute, Maryland found that Lutein and zeaxanthin (nutrients in eggs, spinach and other green vegetables) protect against blindness (macular degeneration), affecting 1.2 million Americans, mostly after age 65. Lutein and zeaxanthin reduce the risk of AMD (journal Archives of Ophthalmology). Foods considered good sources of the nutrients also include kale, turnip greens, collard greens, romaine lettuce, broccoli, zucchini, corn, garden peas and Brussels sprouts.[1]

Because of symmetry, the (3R,3′S) and (3S,3′R) stereoisomers of zeaxanthin are identical. Therefore, zeaxanthin has only three stereoisomeric forms. The (3R,3′S) stereoisomer is called meso-zeaxanthin.

The principal natural form of zeaxanthin is (3R,3′R)-zeaxanthin.

The macula mainly contains the (3R,3′R)- and meso-zeaxanthin forms, but it also contains much smaller amounts of the third (3S,3′S) form.

Zeaxanthin is one of the two carotenoids contained within the retina of the eye.

Within the central macula, zeaxanthin is the dominant component, whereas in the peripheral retina, lutein predominates.

Lutein and zeaxanthin have identical chemical formulas and are isomers, but they are not stereoisomers. The main difference between them is in the location of a double bond in one of the end rings. This difference gives lutein three chiral centers whereas zeaxanthin has two.

As a food additive, zeaxanthin is a food dye with E number E161h.

The xanthophyll cycle involves the enzymatic removal of epoxy groups from xanthophylls (e.g. violaxanthin, antheraxanthin, diadinoxanthin) to create so-called de-epoxidised xanthophylls (e.g. diatoxanthin, zeaxanthin). These enzymatic cycles were found to play a key role in stimulating energy dissipation within light harvesting antenna proteins by non-photochemical quenching- a mechanism to reduce the amount of energy that reaches the photosynthetic reaction centers. Non-photochemical quenching is one of the main ways of protecting against photoinhibition.[1] In higher plants there are three carotenoid pigments that are active in the xanthophyll cycle: violaxanthin, antheraxanthin and zeaxanthin. During light stress violaxanthin is converted to zeaxanthin via the intermediate antheraxanthin, which plays a direct photoprotective role acting as a lipid-protective anti-oxidant and by stimulating non-photochemical quenching within light harvesting proteins. This conversion of violaxanthin to zeaxanthin is done by the enzyme violaxanthin de-epoxidase, while the reverse reaction is performed by zeaxanthin epoxidase[2]

In diatoms and dinoflagellates the xanthophyll cycle consists of the pigment diadinoxanthin, which is transformed into diatoxanthin (diatoms) or dinoxanthin (dinoflagellates), at high light. [3]

Xanthophylls (originally phylloxanthins) are yellow pigments from the carotenoid group. Their molecular structure is based on carotenes; contrary to the carotenes, some hydrogen atoms are substituted by hydroxyl groups and/or some pairs of hydrogen atoms are substituted by oxygen atoms. They are found in the leaves of most plants and are synthesized within the plastids. They are involved in photosynthesis along with green chlorophyll, which typically covers up the yellow except in autumn, when the chlorophyll is denatured by the cold.

In plants, xanthophylls are considered accessory pigments, along with anthocyanins, carotenes, and sometimes phycobiliproteins. Xanthophylls, along with carotenic pigments are seen when leaves turn orange in the autumn season.

Animals cannot produce xanthophylls, and thus xanthophylls found in animals (e.g. in the eye) come from their food intake. The yellow color of chicken egg yolks also comes from ingested xanthophylls.

Xanthophylls are oxidized derivatives of carotenes. They contain hydroxyl groups and are more polar than carotenes; therefore, carotenes travel further than xanthophylls in paper chromatography.

The group of xanthophylls includes lutein, zeaxanthin, neoxanthin, violaxanthin, and ?- and ?-cryptoxanthin.

Xanthophyll has a chemical formula of C40H56O2.

Violaxanthin is a natural xanthophyll pigment with an orange color found in a variety of plants including pansies. It is biosynthesized from zeaxanthin by epoxidation.[1] As a food additive it used under the E number E161e as a food coloring.