(2) composition - destructive distillation

hydrocarbons and oxygenated compounds

• volatile oils are generally mixtures of ____ derived from these hydrocarbons

• the odor and taste of volatile oils is mainly determined by these oxygenated constituents, which are to some extent soluble in water but more soluble in alcohol

distillation

volatile oils are usually obtained by ___ of the plant parts containing the oil

water
water and steam
direct steam

3 types of distillation

water distillation

• applied to dried plant material and not subject to injury by boiling

• plant is introduced in distilling chamber → heated → oil and water condensed in condensing chamber

turpentine oil

• example of water distillation

• consists of terpenes, and is not affected by this amount of heat

water and steam distillation

• for dried or fresh substances that may be injured by boiling (with maceration)

• dried plant is ground and covered with water → steam is passed through macerated mixture → oily layer is separated from aqueous layer

cinnamon
clove

example of water and steam distillation

direct steam distillation

• applicable to fresh plant drugs

• plant is cut and placed on metal distilling flask → steam is forced thru the fresh herb → oil droplets are carried thru a vapor pipe to the condensing chamber

peppermint
spearmint

example of direct steam distillation

enzymatic hydrolysis

• glycosidic volatile oils are obtained thru this process

• black mustard seeds

sinigrin

in black mustard seed, the glycoside, ___ is hydrolyzed by myrosin with the production of volatile mustard oil

mustard oil

example of enzymatic hydrolysis

expression or ecuelle method

used to obtain citrus oil that cannot be distilled without decomposition

lemon oil
orange oil

example of expression or ecuelle method

enfleurage

• for volatile oils obtained from flowers

• triple extract

• formerly used in the production of perfumes and pomades

• fat is spread on glass plates → flower petals are placed on the fat → after saturation of fatty layer, remove oil by extraction with alcohol

modern essential oil

(extraction) production in the perfume industry

petroleum ether
benzene

by using solvent systems based on such volatile solvents as ____

50°C

uniform temperature of extraction

natural odor

extracted oils have a more ___ that is unmatched by distilled oils

distillation method

low-cost operation compared to the cost of the extraction process

destructive distillation

• obtaining empyreumatic oils

• wood or resin from the family of pinaceae or cupressaceae is heated without acces to air, decomposition takes place, and the resultant mass is charcoal.

charcoal

resultant mass of destructive distillation

wood naptha (methyl alcohol)
pyroligneous acid (crude)

aqueous layer of destructive distillation

Pine tar
Juniper tar

tarry liquid in the form of __
(destructive distillation)