Unit 2-Fragrances Flashcards
What are essential oils?
Essential oils are concentrated extracts of the volatile, non-water soluble aroma compounds from plants.
Is isoprene saturated or unsaturated?
Unsaturated
What are the two procedures that can be used to extract the oils from the plant material?
Steam distillation
Solvent extraction
If these essential oils are ‘volatile’, why not just heat the plant and drive off the volatile oil?
The oils have quite high boiling points.
Heating to the temperature required to distil these could result in some break down of the oils, and possibly the plant materials.
Steam distillation does not allow the temperature to rise above 100°C.
Which solvent would be best to use to extract essential oils such as limonene?
Water, methanol, ethyl ethanoate or dilute hydrochloric acid.
Why?
Ethyl ethanoate which is non-polar will best most suitable.
The oils are hydrophobic, water-insoluble so the solvent must the same.
What are essential oils used in?
Perfumes, cosmetics, cleaning products and as flavouring in foods.
What type of chemical is one of the primary constituents of essential oils?
Terpenes
What is the name of the 5 carbon unit in terpenes?
Isoprene
What is the full name of isoprene?
2-methylbuta-1,3-diene
How many isoprene units are in this essential oil?
15 Carbons
3 x isoprene units
How many isoprene units are in this essential oil?
10 Carbons
2 x Isoprene units
Which functional groups will be present in these terpenes?
α-Phellandrene
Citral
Terpineol
α-Phellandrene has Carbon to carbon double bond
Citral is an aldehyde with C=O group
Terpineol is an alcohol with -OH group
