Citral

Citral is a lemon-scented mixture of the aldehyde isomers geranial and neral, found in citrus oils and used in flavorings and fragrances.

Geranial: Geranial is the E isomer of citral, a monoterpenoid aldehyde with a strong lemon odor. It is citral’s more abundant isomer in many natural sources and contributes its sharp lemon character.
Citral oxidation: Citral oxidation is the conversion of citral into oxidized products through reactions with oxygen or other oxidants. Oxidation during storage can alter citral’s odor and create sensitizing products.
Lemon oil: Lemon oil is a volatile essential oil obtained chiefly from the peel of lemons. It is a natural source of citral, though limonene is usually its dominant constituent.
Allergic contact dermatitis: Allergic contact dermatitis is an immune-mediated skin inflammation triggered by contact with a sensitizing substance. Oxidized citral can contribute to fragrance-related allergic reactions in susceptible people.
Neral: Neral is the Z isomer of citral, a monoterpenoid aldehyde with a lemon odor. It is the second aldehyde isomer that combines with geranial to make citral.
Citral cyclization: Citral cyclization is an acid-catalyzed rearrangement that forms cyclic terpenoid compounds, including p-cymene-related products. This reaction converts the open-chain aldehyde into compounds with different odors and structures.
Lemongrass oil: Lemongrass oil is an essential oil distilled from Cymbopogon grasses and rich in citral. It is one of the major commercial natural sources of citral.
Fragrance allergy: Fragrance allergy is allergic sensitization to one or more substances used in scented products. Citral is a recognized fragrance allergen that must be declared under some labeling rules.
Geometric isomerism: Geometric isomerism occurs when restricted rotation produces distinct spatial arrangements around a double bond. The different arrangements around citral’s double bond distinguish geranial from neral.
Citral hydrogenation: Citral hydrogenation adds hydrogen across its carbon–carbon double bonds or aldehyde group. Selective hydrogenation can turn citral into fragrance ingredients such as citronellal or geraniol.

Linked from 4 pages