Organic compounds are mainly classified as aliphatic and aromatic compounds. Aliphatic compounds are open chain or cyclic compounds such as alkane, alkene, alkyne and cycloalkane. Aromatic compounds are planer, cyclic compounds with conjugated pi-electron system. Aromatic compounds exhibit extra stability due to delocalized pi-electron system. Usually aromatic compounds have special aroma and high C- ratio compare to aliphatic compounds. That is the reason they burn with black sooty flame.
Benzene is simplest aromatic compound in which six carbon atoms are arranged in planer hexagonal form in which each carbon atom is sp2 hybridized and also bonded with one H atom. There are three pi-bonds in the ring which remain delocalize in hexagonal ring. The presence of different functional groups on benzene ring forms different derivatives of benzene like phenol, aniline, anisol, benzoic acid, benzaldehyde etc. These aromatic compounds are well known for their aroma and unique chemical and physical properties.
Aroma chemicals can be defined as the aromatic compounds which have aromatic synthetic aromas. They are mainly involved in the perfume industries. Aroma chemicals are derived from natural products. A little amount of these aroma chemicals makes up unique perfumes and flavors. Some of the aroma chemicals have wonderful odour in their raw state whereas other chemicals may have unpleasant odour but when use in small amounts, they may produce long lasting odour. Most of the perfumes have 6-60% of aroma chemicals. Many aroma chemicals are used to provide flavors in candy, baked goods, drinks etc. First synthetic aroma chemicals are used in perfumes in 20th century. Aroma chemicals have different strengths like some of them are very strong whereas others are very soft and mild. Usually aroma chemicals with soft and mild odour are more useful than aroma chemicals with strong odour.
6-Methyl Coumarin: It is also named as 6-Methyl 1,2 Benzopyrone, Toncarine, 6 Methyl Benopyrone. The structure of this aroma chemical is given below.
It is an aromatic compound with molecular formula C10H8O2 and molecular mass 160.17 g/mol. 6-Methyl Coumarin is usually found as white crystalline solid and has dry herbaceous coconut smell. Melting point is 74oC - 76oC and flash point is around 101oC. It is one of the most common constituent of coconut flavors. It is mainly used in fig, date, caramel, nut, butter, root beer etc. It is also used in different vanilla compositions. Because of its thermal stability it can be used to provide flavor in baked goods.
Other names of this aroma compound are 1-Ethoxy-2-hydroxy-4-propenyl benzene or vanitrope. The IUPAC name suggests that there is an ethoxy group, hydroxyl group and allyl group bonded on aromatic ring. It is a white color powder that provides vanilla like flavor and taste. It is used to provide flavor to chocolate, nut, butterscotch, rum, mapple, vanila, and caramel. Sometime it is also used in perfumes as sweetener and also acts as replacement of vanillin.
Resorcinol Dimethyl Ether
Resorcinol dimethyl ether is also called as meta-dimethoxybenzene or 1,3-diethoxybenzene. The molecular formula of compound is C8H10O2 with molar mass 138.12 g/mol. It is pale coloured liquid with sweet intense nut link odour and taste. It is used as a novel additive to moss-base and also as part of hazelnut imitation flavor and fruit complexes.
Veratraldehyde is an aromatic ketone and also known as 3,4-dimethoxybenzaldehyde or Vanillin methyl ether or veratruc aldehyde. It is white crystalline fused mass with sweet or woody vanilla odor. It is one of the excellent perfume materials and also a part of different fruit complexes.
Zinerone or zingerone is also called as 4-(3-Methoxy-4-Hydroxyphenyl)-2 â Butanone or Vanillyl acetone. It is a pale yellow coloured crystalline mass with pungent odor like vinegar. It is mainly used in perfume industries as a sweetener of warm, slightly spicy-tobacco like effect.
It is another aroma compound which is also named as 4- (para-methoxyphenyl)-2- Butanone or Raspberry ketone methyl ether. It is a colourless to pale yellow liquid with sweet, fruity flavor and taste. Some common uses of anisyl acetone are listed below.
- As a modifier for heliotropine
- As a sweetener for cyclamen aldehyde
- As blender in sweet florals, fougeres and oriental fragrances
It is mainly used in perfume industries but may cause skin sensitization on skin contact.
It is a white crystalline powder and also known as para-vinyl guaicol. 2-Methoxy-4-Vinyl Phenol is well known for powerful spicy clove like odour.
Aroma compounds are widely used in perfume industries. Some of the common aroma chemicals which are used in perfume industries are listed below.
| Aroma compounds
| Flavor and Fragrance
| 3-Phenyl Propanol FCC
|| Balsamic and oriental
| Amboryl Acetate
|| Woody and amber
| Amyl Cinnamic Aldehyde
| Jasmine and cocoa
| Benzyl Benzoate
| Bigarade Oxide
|| Woody and herbal
| Cinnamic Alcohol FCC
|| Spicy and oriental
| Citralis PQ
|| Fresh rosy and citrus
|| Warm, spicy and balsamic
|| Sweet, balsamic and oriental
|| cyclamen and lilac
| Florosol A
|| floral green
| Florosol S
|| rose, cyclamen and lilac
|| Floral and sweet
| Hexyl Cinnamic Aldehyde
|| Floral, jasmine
|| Fatty-green and aldehydic
|| Fresh and rosaceous
|| Fruity and earthy
| LilestralisÂ® Pure
|| Fresh and floral
| Methyl Benzoate
|| Wintergreen and camphoraceous
| Methyl Cinnamic Aldehyde
| Spicy and balsamic
| Nopyl Acetate
|| Mild, woody
| Ocimene PQ
|| Warm, Â¬floral and sweet
|| damp wood and vegetation
Decyl acetate, Lauryl acetate, Hexyl acetate, Adoxal, Haptanol, Allyl amyl glycolate and Allyl cyclohexyl propionate are common aroma chemicals that are used in food industries to provide unique aroma to different food stuff.
The scents of flowers are due to presence of different aroma compounds. For example; roses have cis-rose oxide, β-damascenone and β-ionone which are responsible for their special aroma. Similarly eugenol, β-caryophyllene and methyl salicylate are present in carnations. Scents of liles are due to linalool, β-ocimene and myrcene. Some other flowers with their aroma compounds are listed below.