2019). These chemically defined substances which act on the senses of smell and
taste are termed as ‘flavour compounds’ or ‘aromatic (aroma) compounds’ (Triumph
Venture Capital (Pty) Limited et al. 2004). These aromatic compounds vary widely
in their structures and may contribute to the overall flavour of a food. On the basis of
chemical structure, these compounds can be classified into hydrocarbons, alcohols,
aldehydes, ketones, acids, esters or lactones (Gatfield 1988; Bicas et al. 2010). These
compounds may be present in low concentrations which can be as low as 1 part in
10
12 (Rodríguez and Fernandes 2017). Both flavourings and fragrances are either
present naturally or added artificially to the food items. The compounds used for
flavourings and fragrances can be categorized into: (1) natural compounds,
(2) nature-identical compound and (3) artificial compounds (Zviely 2002; Joint
FAO/WHO food standards programme 2005; Fisk 2015). The natural compounds
are directly obtained from natural resources by physical methods such as pressing,
sublimation, distillation, chromatography and filtration (Zhang et al. 2018). Essential
oils, a class of such natural compounds, are the volatile substances which are
naturally derived from different parts of the aromatic plants (Cowan 1999; Dhifi
et al. 2016). These aromatic oils represent a cocktail of multiple chemical
components in variable amounts (Patrignani et al. 2015). These substances have
been known since ancient times and have been utilized enormously in different
sectors for their pleasing aromas. Most essential oils are directly used as flavours in
the edible as well as other products (Surburg and Panten 2006). Their wide application in the food items, cosmetics, pharmaceuticals and toiletries can be attributed to
their aromatic, anti-oxidant, immuno-modulatory and physiological properties
(Singh and Malik 2008; Malik and Singh 2010; Maen and Cock 2015). Further, a
variety of essential oils have also been found to show antimicrobial activities against
different microorganisms (Vandamme 2003; Malik et al. 2011, 2015; Hyldgard et al.
2012; Silva et al. 2013; Sirohi et al. 2016). In addition, food technologists and
scientists are now also formulating edible packaging for functional foods and
pharmaceutical products containing a defined concentration of these fragrant essential oils and their components (Antosik et al. 2017; Malik and Singh 2015; Malik
2017; Sarkic and Stappen 2018).
Nature-identical compounds are chemically isolated from aromatic raw materials
or are produced synthetically but are chemically identical to their natural
counterparts. These are produced by chemical transformation methods as they give
satisfactory yields and good production rates (Astray et al. 2007; Poornima and
Preetha 2017). Large-scale synthesis of aroma chemicals was started in the late
nineteenth century, with the methyl salicylate (1859), benzaldehyde (1870), vanillin
(1874) and coumarin (1878). Presently, there are about 5000 different aroma
chemicals that include both natural and synthetic product.
At present, approximately 5000 different aroma chemicals are available in the
market which include both synthetic and natural product (Personal Care Magazine
2009). These synthetic ingredients are nowadays playing a major role in the fragrance and flavour industry due to their convenient availability and the relatively
lower cost as compared to natural molecules, as the natural sources are relatively
limited. Health agencies and administrations have often not assessed the safety
7 Biotechnological Interventions for Production of Flavour and Fragrance. . .
133
taste are termed as ‘flavour compounds’ or ‘aromatic (aroma) compounds’ (Triumph
Venture Capital (Pty) Limited et al. 2004). These aromatic compounds vary widely
in their structures and may contribute to the overall flavour of a food. On the basis of
chemical structure, these compounds can be classified into hydrocarbons, alcohols,
aldehydes, ketones, acids, esters or lactones (Gatfield 1988; Bicas et al. 2010). These
compounds may be present in low concentrations which can be as low as 1 part in
10
12 (Rodríguez and Fernandes 2017). Both flavourings and fragrances are either
present naturally or added artificially to the food items. The compounds used for
flavourings and fragrances can be categorized into: (1) natural compounds,
(2) nature-identical compound and (3) artificial compounds (Zviely 2002; Joint
FAO/WHO food standards programme 2005; Fisk 2015). The natural compounds
are directly obtained from natural resources by physical methods such as pressing,
sublimation, distillation, chromatography and filtration (Zhang et al. 2018). Essential
oils, a class of such natural compounds, are the volatile substances which are
naturally derived from different parts of the aromatic plants (Cowan 1999; Dhifi
et al. 2016). These aromatic oils represent a cocktail of multiple chemical
components in variable amounts (Patrignani et al. 2015). These substances have
been known since ancient times and have been utilized enormously in different
sectors for their pleasing aromas. Most essential oils are directly used as flavours in
the edible as well as other products (Surburg and Panten 2006). Their wide application in the food items, cosmetics, pharmaceuticals and toiletries can be attributed to
their aromatic, anti-oxidant, immuno-modulatory and physiological properties
(Singh and Malik 2008; Malik and Singh 2010; Maen and Cock 2015). Further, a
variety of essential oils have also been found to show antimicrobial activities against
different microorganisms (Vandamme 2003; Malik et al. 2011, 2015; Hyldgard et al.
2012; Silva et al. 2013; Sirohi et al. 2016). In addition, food technologists and
scientists are now also formulating edible packaging for functional foods and
pharmaceutical products containing a defined concentration of these fragrant essential oils and their components (Antosik et al. 2017; Malik and Singh 2015; Malik
2017; Sarkic and Stappen 2018).
Nature-identical compounds are chemically isolated from aromatic raw materials
or are produced synthetically but are chemically identical to their natural
counterparts. These are produced by chemical transformation methods as they give
satisfactory yields and good production rates (Astray et al. 2007; Poornima and
Preetha 2017). Large-scale synthesis of aroma chemicals was started in the late
nineteenth century, with the methyl salicylate (1859), benzaldehyde (1870), vanillin
(1874) and coumarin (1878). Presently, there are about 5000 different aroma
chemicals that include both natural and synthetic product.
At present, approximately 5000 different aroma chemicals are available in the
market which include both synthetic and natural product (Personal Care Magazine
2009). These synthetic ingredients are nowadays playing a major role in the fragrance and flavour industry due to their convenient availability and the relatively
lower cost as compared to natural molecules, as the natural sources are relatively
limited. Health agencies and administrations have often not assessed the safety
7 Biotechnological Interventions for Production of Flavour and Fragrance. . .
133