Citral

Citral, or 3,7-dimethyl-2,6-octadienal or lemonal is either a pair, or a mixture of terpenoids with the molecular formula C₁₀H₁₆O. The two compounds are double bond isomers. The E-isomer is known as geranial or citral A or transCitral. The Z-isomer is known as neral or citral B or cisCitral…. 

I assume, it is the most boring entrance ever… (Wiki style J )

Let me use my own words;

Citral consists of 2 BFF, ¡Best Friends Forever!, Geranial & Neral. Besides they are best friends, they are also monozygotic twins (identical formula, C10H16O) with different attitudes. Geranial is more aggressive than Neral. When Geranial gives strong fresh lemon odor, his twin brother Neral gives the same lemon odor but not that strong but also sweeter.

Citral is a pale yellow liquid. It is less dense than water (0.9 g/cm3) and not soluble in water neither but only in alcohol and some other solvents.  

Want some citrusy taste or odor? Citral is your buddy..

USAGE of CITRAL

Citral is used directly in Fragrance and Flavor (F&F) industry or as a starting material to produce Menthol, Aroma Chemicals and Vitamins (A&E).  

Direct usage;

Citral is often used to give a citrusy zing to fragrances and a citrus flavoring to sweets and soft drinks.

It’s also used when imitating grapefruit, orange, lime and even to give the fresh fruit tang to apple and strawberry products.

Similarly, the fragrances used in producing perfumes and soap will often include citral in everything from oil of bergamot to ginger and rose. If you use laundry, dishwashing products or cleaning products with a lemon scent, they probably have Citral.

All Fragrance and Flavor (F&F) houses use a lot of Citral in their formulas.

Starting Material;

Citral is used as a starting material to produce many important Aroma chemicals, Menthol and also Vitamin A and E.

Some aroma chemicals derived from Citral à Citronellol, Citronellal, Geraniol, Hydroxycitronellal, Beta ionone, Linalool, Linalyl Acetate, Rose Oxide, Citronellyl acetate, Geranyl Acetate, Pyranol ….

Also if you consider the derivatives of these aroma chemicals, it would be easier to understand how important Citral is for F&F world.

For those who likes graphs, come here! Here you see usage of Citral.

 

Right now, stop what you are doing, which is reading.. well okay, dont stop what you are doing, but stop what you are thinking and think about Citral and give her a "salud", because the taste of Mint that refreshes you right now with a gum in your mouth is from this magical ingredient. 

                                          << Salud >>

Menthol Synthetic. And this is not my hand! 

SOURCING CITRAL

There are two source of Citral. Naturally sourced Citral and synthetically sourced Citral.

Citral Natural

You see below Natural sources and citral contents of them

Source	Plant Origin	Citral Content %
Lemon Myrtle	Australia	90-98
Lemon Grass	India, Adrica, South East Asia	65-85
Litsea Cubea	China, Indonesia, South East Asia	70-85
Lemon Tea-Tree	Kenya, South Africa, Australia	70-80
Clove Basil	Africa, Southern Asia	65-70
Petitgrain	Paraguay, France	35-40
Lemon Verbena	South America	30-35

As you see in the graph, LEMON MYRTLE has the highest content of Citral where LEMON GRASS and LITSEA CUBEBA are the most common source for Citral Natural.

Citral from Lemon Grass 

Litsea Cubeba with 70-85 % Citral 

Citral Synthetic

Before talking about Citral synthetic, I believe I should dig the history of Citral a little to understand WHY on earth we needed synthetic Citral? Isnt Naturally sourced Citral enough or what?  

Vitamin A (I can see empty eyes when I started with Vitamin A suddenly but I promise there is a connection) is essential for human development, the support of immune system, gene transcription, skin and cellular health, effective vision (eyes, not mental vision! You should travel for thatJ) etc. etc.

Carrot is healthy!

Vitamin A was produced first in 1947 by two Dutch scientists by reacting Citral with Acetone to form Beta-ionone which is further processed to synthesize Vitamin compounds.

In this process, to produce Vitamin A;

Citral is an important intermediate and become much more important and needed.

ATTENTION!!! we are talking about 1950`s, right after 2^nd world war, half of the population was wounded, people need to be treated and developed physically. So the demand on these kind of supplementary increased a lot.

Plus naturally sourced Citral was being used for perfumery already.

On top of it, it was hard to get the consistency of quality required for medical use

So here is where we NEED more and Medical quality Citral!!!

As a result, the chemical company Roche found an alternative route to beta-ionone, while competitor BASF produced Citral instead, from readily available Isobutene and Formaldehyde (Petrochemicals). BASF remains one of the world’s biggest producers of Vitamin A and Citral right now!

How sad for Roche no? If they focus on producing Citral instead of Beta Ionone, they would be the one who says “we create chemistry” now JJ

At the end we can separate Citral History into 2 era, BVa (before Vitamin A) and AVa (after Vitamin A) J

BASF developed very complicated and sophisticated process to synthesize Citral from the reaction of ISOBUTYLENE and FORMALDEHYDE which can be shown as below;

Yes this is my finger..

Well ok, agreeJ, it does not seen that complicated in my hand-made drawing but believe me it is super-complicated!!

At the end, thanks to BASF, today we are able to produce Citral synthetic and leave alone a little bit these cute and beautiful Lemon Grass or Litsea Cubeba bushes.. 

INTERESTING FACTS

Like Citronela Oil, citral has an effect on some insects. It has a mild repellent action for some species, but for bees the effect is quite the opposite. J

Citral is a component of the Nasanov pheromone, produced by worker bees to help foragers (bees for finding food) find their way back to the hive. Citral, on its own, attracts foraging honey bees and can be used by beekeepers to bring them to a particular location. It is kinda catnip for cats J

Citral has a very special effects on another animal. It also appears to act as a sex pheromone for the green-veined white butterfly, released by males to attract mates. Its Channel Bleu of green-veined white butterfly when they hunt JJ

Also two studies have shown 1–1.7% of people to be allergic to Citral 

" himmm would you like some Citral honey-bee ?? "