Essential Oil A volatile oil obtained from a wide variety of plant, scrub, and tree species and from various parts of the plant anatomy, such as the roots, rhizomes, wood bark, leaves, stems, fruit, flowers and seeds. Usually extracted by hydro or steam distillation, expression or effleurage - Hunter 1996
Concretes and Absolutes Volatiles and waxes extracted from plant material with hydrocarbon solvents (usually benzene and hexane) through washing and removal of the volatile solvent with distillation. A waxy aromatic substance remaining is called a concrete. The concrete is washed with alcohol to remove the volatile materials and ethanol removed through vacuum distillation to leave an absolute.
The Human Olfactory System Odour molecules pass through the olfactory organ
Olfactory epithelium Olfactory mucosa Mucus! High in nasal cavity Site of transduction Contains olfactory receptor neurons (ORN)
11 Nose hair: Olfactory cilia ORN have cilia Cilia contain olfactory receptor proteins Similar to visual pigment Transduction Odorants bind to ORs Change shape of protein Ion flow across OR Electricity
Transmission Olfactory Receptors Olfactory Cells line the Olfactory Epithelium which is responsible for olfaction Each cell has cilia where receptor sites are located Replaced every month Axons of the olfactory receptors carry information to the olfactory bulb Olfactory bulb sends axons to several specific parts of the cortex with precise connections From the cortex, information is sent to other areas that control feeding & reproduction Olfactory Disorder Anosmia: the general lack of olfaction Specific Anosmia: the inability to smell a specific chemical
13 How many receptor types are there? 1000 different kinds of olfactory receptors (OR) 10 million OR neurons 10,000 of each type of OR Each OR neuron has only one type of receptor 1000 neuronal chemical detectors Potential to differentiate between 5,000-10,000 different odours
Olfactory Bulbs An outcropping of the brain Its like a snail in your brain! Electrical responses in cilia passed through olfactory nerve to OB
The hedonic primacy of olfaction Sensory and emotional experience Not the same for vision/audition Seeing and feeling more distinct More intertwined in the chemical senses Why? Orbitofrontal cortex Plays multiple roles Critical for emotional experience Secondary sensory cortex for olfaction Also centre of creativity and imagination
The olfactory interpretation process from input to response
Discovered in 1937, the First Publication on Raspberry Ketone appears in 1961
1964 – Introduction of Furaneol® 1965 – First publications on isolation of Furaneol® from strawberry and pineapple
1965-66 – α- & β-Sinensal isolated from orange oil
1960’s – Nootkatone First isolated in 1962, it’s importance to citrus flavor was unknown until it’s isolation from grapefruit by Mcleod in 1964. In 1966, Coca-Cola introduced Fresca. By 1970, Nootkatone was GRAS and became a key ingredient in Fresca. Coca-Cola manufactured Nootkatone for many years and soon made it available to the flavor industry. (+)-Nootkatone strong grapefruit odor, bitter in taste (-)-Nootkatone weak woody (vetiver note); no grapefruit character; virtually no taste Threshold: 60,000 ppb 800 ppb
1970’s-80’s – Other Furanones Sotolon (caramel furanone) & Maple furanone identified in cane sugar – powerful caramel maple notes Maple Furanone (Abhexone) Sotolon Threshold: 0.003 ppb 0.00005 ppb Sotolon – key flavorant of fenugreek, sake, sherry wine
1968 – Pfizer patents Ethyl maltol Ethyl maltol (Veltol Plus®) was touted to be about 6X stronger than maltol and an important substitute for Coumarin. Well, at least it is stronger than maltol.
1975 - Introduction of α-Damascone and β-Damascone 1982 – Introduction of Damascenone 1970 – Discovery Damascenone & β-Damascone
1974 – Thiomenthones identified in Buchu oil Key component for black currant and the “fuzzy” peach skin note
1980 – Patent on Oxane® 1977 - Winter identifies 2-methyl-4-propyl-1,3-oxathiane as a character impact compound in Passionfruit 1984 – Pickenhagen determines that (-)- cis- 2-methyl-4-propyl-1,3-oxathiane is the important diastereomer (-)-(2R,4S)-2-methyl-4-propyl-1,3-oxathiane
1982 – 1-p-Menthene-8-thiol Demole identifies 1-p-Menthene-8-thiol as a character impact compound in Grapefruit Juice Very powerful with an odor threshold of 0.0001 ppb, it also requires stabilization as it tends to rapidly cyclize to the thio analog of dihydropinol.
Ylang Ylang (Cananga odorata) benzyl acetate (ca. 25 %), p-cresyl methyl ether (ca. 20 %), methyl benzoate (ca. 5 %), methyl salicylate, cinnamyl acetate, (-)-linalool (ca. 15 %), geranyl acetate (ca. 10 %), farnesyl acetate (ca. 3 %), as well as a number of other sesquiterpenes and their oxygenated derivatives, e.g. muurolol T (ca. 2 %) Extraction Method: Steam distillation of the flowers Origin: Indonesia, Madagascar
Patchouli Oil (Pogostemon cablin) There are no synthetic equivalents of the patchouli scent. Main Constituents: (-)-patchoulol (30-40 %). However, it is maintained that norpatchoulenol, present in only 0.3-0.4 %, is playing a principal part in the overall odour picture. (-)-patchoulol andnorpatchoulenol Obtained by steam distillation under pressure or CO2- extraction of the dried leaves Patchouli is mostly grown in Indonesia
Pandanus Oil (Pandanus odoratissimus) phenethyl methyl etherpandanol phenethyl methyl ether ( pandanol) (38 %), together with terpinen-4-ol (19 %), alpha-terpineol (8 %) and phenethyl alcohol (7 %) . Phenethyl alcohol and its derivatives are common odorants in flowers The flowers are hydro-distilled to yield a 'kewda attar Origin: native of South East Asia and is much cultivated on the Indian East Coast
Backhousia citriodora (Lemon Myrtle) High Investment to Expand Industry in Australia Strong Demand as an Ingredient for tea Good Crop to Grow in Most Parts of Thailand Citral (geranial 51.43 % and neral 42.12 % )
1959 – Roche Process for Linalool & Citral via Acetylene
Points to Remember The highest probability is not necessarily the correct one Check back to see if that chemical could physically be present You will have to add new materials to your database (Both NIST & Wiley databases) Is it an artifact? Confirm your analysis with other supportive data
No. 3: Nobel Prize in Chemistry 1910 – Otto Wallach
Helps elucidate many of the C10H16 group terpene structures present in essential oils utilizing common reagents such as hydrogen chloride and hydrogen bromide. In 1909 he published the results of his extensive studies in the book Terpene und Campher, a volume of 600 pages dedicated to his pupils.