Name: Citral
Chemical Name: 3, 7-DIMETHYL-6-OCTEN-1-OL
Chemical Formula: C15H26O
Appearance: Yellow liquid
Molecular Weight: 222.37
Odour: Powerful lemon alike odour
Specific gravity: 0.882 to 0.891 at 250oC
GLC Purity: 30% to 50% Neral, 45% to 65% Geranial, Min 95% Sum, Nerol & Geranial
Refractive Index: 1.486 to 1.490 at 20oC
Colour: Yellow

Citral is widely used in F&F industries because it is the best known aldehydic tandem. The aroma of citral is its characteristic among the other citrus fruits. Citral (C10H16O), is a pale-yellow liquid with strong lemon odour which occurs in essential oils of plants. Citral is insoluble in water but soluble in ethyl alcohol, diethyl ether and mineral oil. It is widely being used in perfumes and flavourings and in manufacture of other chemicals. It is a mixture of two aldehydes and has same molecular formula but with different structures. The essential oil which contains citral is lemongrass oil (70% to 80%), and it is isolated by distillation.

The other natural sources include oils of verbena and citronella.

Present in many essential oils

Citral can be synthesized from mycrene, ionone and methylionone. The ionone can be converted into synthetic Vitamin A. The other essential oils where citral is present are lemon, orange, limetta and pimento. Citral is one of the main characteristic flavours in the citrus family along with limonene. Citral is used in lemon and citrus flavour confectionery, soft drinks, cosmetics, after shave lotions and body lotions. In citral, the flavour of geranial is stronger than the flavour of neral even though both have the lemon flavour. It is used in the chemical synthesis of Vitamin A but do not have any vitamin activity. Citral is stable but easily isomerizes. It is not compatible with alkalies, oxidizing agents and strong acids.

Two forms of Isomers

Citral is combustible, light and air-sensitive and has two natural form of isomers called citral A or geranial and citral B or neral. Citral's strong and fresh odour of lemon peels makes it an important ingredient in many of the fragrance materials. The plant where high citral content is present is Litsea cubeba which is originally from China. It has both the forms of citral, neral and geranial, and historically it has been used as a source for natural citral. It overall gives the lemon odour to perfumes and after shave lotions and other lotions. It is widely used in soap industries to develop the rose note of the soap. Citral has sedative, antiviral, and antibacterial effects. It is widely used in the manufacture of laundry and dishwashing products and air care products