• Flavour manufacturing techniques:
-Production of natural flavouring substance
-Production of artificial flavouring substance
• Flavour retention methods
• Flavor or flavour is the sensory impression of a food or other
substance, and is determined mainly by the chemical senses
of taste and smell.
• The "trigeminal senses", which detect chemical irritants in the
mouth and throat as well as temperature and texture, are also
very important to the overall gestalt of flavor perception.
• Flavorant is defined as a substance that gives another
substance flavor, altering the characteristics of the solute,
causing it to become sweet, sour, tangy, etc.
• The flavor of the food, as such, can be altered with natural or
artificial flavorants, which affect these senses.
• Historically there is little literature in the public domain on food flavours until
• At the beginning of the 1900s, a growing number of food and beverage
companies including Kellogg, Campbell Soup, Coca-Cola and Pepsi-Cola,
created even more demand for commercial flavors.
• Formalizing their association in the wake of the first Pure Food and Drugs
Act of 1906, these early pioneers created the Flavoring Extract
Manufacturers’ Association (FEMA), the forerunner of today’s Flavor and
Extract Manufacturers Association.
• Today Indian share is about 10 % of the globe, which is USD 2000 Millions
(Rs. 10,000 Crores).
• Indian population is however is 17.8% of the globe which indicates potential
WHY DO WE ADD FLAVOURING???
• There are two main reasons:
1. To add an intrinsic flavour - an example being flavoured
mineral water with citrus extracts.
2. To add a flavour which has been lost or modified during
processing. Example: Fruit flavour in yogurt.
• There are three principal types of flavorings used in foods,
under definitions agreed in the E.U. and Australia.
Substances which are extracted from vegetable or animal materials
and are not further chemically modified or changed. An example is
Substances that are chemically identical to natural substances, but
which are obtained by chemical processes or by chemical
modification of other natural substances. An example is vanillin, which
is identical to the vanillin in vanilla, but not obtained from vanilla pods.
Substances obtained by chemical synthesis or chemical modification
of natural substances, but which are not present in natural products.
3 more flavour categories:
• Flavouring preparation is a product from natural origin, but
which is not highly purified. For example concentrated
apple juice can be defined as a flavouring preparation.
• Process flavourings are substances that are formed from
natural substances upon processing, mainly heating. A
common example is caramel, which is produced by heating
• A smoke flavouring means a smoke extract used in
traditional foodstuffs smoking processes. These are
obtained by collecting the smoke into a fluid, which can be
applied in a different production process.
• Due to the high cost or unavailability of natural flavor
extracts, most commercial flavorants are nature-identical,
which means that they are the chemical
equivalent of natural flavors but chemically
synthesized rather than being extracted from the
• It has been suggested that artificial flavors may be
safer to consume than natural flavors due to the
standards of purity and mixture consistency that are
enforced either by the company or by law.
• The “natural” flavor extract contains traces of
hydrogen cyanide, a deadly poison evolved by plants
to protect their seeds from insects (National
Agricultural Biotechnology Council Report, 2001).
The list of known nature-identical
Isoamyl acetate Banana
Benzaldehyde Bitter almond
Cinnamic aldehyde Cinnamon
Ethyl propionate Fruity
Methyl anthranilate Grape
Ethyl decadienoate Pear
Allyl hexanoate Pineapple
Ethyl maltol Sugar, Cotton candy
Methyl salicylate Wintergreen
• 2 important components that contribute to
flavour: Taste & Colour.
• Certain colors are seen as corresponding to,
and thus appropriate to certain odors (e.g.,
red for cherry odor). There is influence of
color on odor identification, odor
discrimination, odor intensity, and odor
pleasantness (Zelnar, 2013).
• While salt and sugar can technically be
considered flavorants that enhance salty and
sweet tastes, usually only compounds that
enhance umami, as well as other secondary
flavors are considered and referred to as
• Umami or "savory" flavorants, more
commonly called taste or flavor
enhancers, are largely based on amino
acids and nucleotides.
• Umami flavorants recognized and
approved by the European Union include:
Glutamic acid, glycine salts, guanylic acid
salts, inosinic acid salts, 5’-ribonucleotide
• Certain organic and inorganic acids can be used to
enhance sour tastes, but like salt and sugar these
are usually not considered and regulated as
flavorants under law.
Acetic acid Gives vinegar its sour taste and distinctive smell.
Ascorbic acid Found in oranges and green peppers and gives a crisp, slightly sour
taste. Better known as vitamin C.
Citric acid Found in citrus fruits and gives them their sour taste.
Fumaric acid Not found in fruits, used as a substitute for citric and tartaric acid.
Lactic acid Found in various milk or fermented products and give them a rich
Malic acid Found in apples and gives them their sour/tart taste.
Phosphoric acid Used in all cola drinks to give an acid taste.
Tartaric acid Found in grapes and wines and gives them a tart taste.
WORK OF FLAVORIST IN INDUSTRIES:
1. Identifies the dominant substances which determine the
2. From these substances, the flavourist then creates a
flavouring, which tends to have a more simplistic structure
than the natural original but at the same time complies
with the natural flavouring profile.
3. If the flavourist and food manufacturer are satisfied with
the taste, focus groups are set-up to taste the product.
4. It is only after this step is successfully completed, that the
product has a chance to be launched.
Flavour & fragnance industry
Fig. The Flavour Industry: Flow of manufacturing processes for flavour
• Depending on the manufacturing process
flavourings are divided into two major
1. Natural flavouring substances
2. Synthetically produced flavouring
A. Producing natural flavouring substances
The flavouring substances, which are naturally
present in plant and animal source materials, must
be isolated for example via extraction or distillation
- processes where specific substances are
separated from a natural mixture.
• A simple process of obtaining flavouring substance
from the origin.
• A typical extraction process can be seen in coffee
preparation. This process involves hot water
separating the flavouring substances and flushing
them out of the coffee powder. The filter then
separates the soluble coffee components from the
• The same principle of extraction is applied when
deriving vanilla extract from vanilla beans. Alcohol or
supercritical carbon dioxide (CO2) are used as
i. Liquid Carbon Dioxide Extraction
• Raw material is packed into stainless steel extraction
• Dynamic flow of carbon dioxide in liquid form, at
pressures of 40-60 atmospheres.
• Low temperatures between 0-10°C.
• The liquefied CO2 dissolves the lower molecular weight
organoleptically active components of the raw material,
leaving behind the higher molecular weight unwanted
materials such as heavier fats, waxes, pigments, sugars,
starches and tannins.
• The solution of product
in CO2 emerging from
the extraction columns
is passed to a
exchanger. This leaves
a pure extract of the
product which is
tapped from the
pressure, still below
ii. Counter Current Extraction:
• Citrus oils in hydrocarbon
solvent are continuously fed
into a specially-designed
column containing many
compartments and this
complex mixer, in which a
counter-flow of ethanol
containing a small amount
of water, extracts the flavour
and aroma molecules
leaving the terpenes to
emerge from the opposite
end of the column.
iii. Solvent Extraction
• Organic solvent extraction is the most common and most
economically important technique.
• Raw materials are submerged and agitated in a solvent that can
dissolve the desired aromatic compounds.
• Commonly used solvents for maceration/solvent extraction include
hexane and dimethyl ether.
• In organic solvent extraction, aromatic compounds as well as other
hydrophobic soluble substances such as wax and pigments are also
• The extract is then subjected to vacuum processing, which removes
the solvent for re-use (or) The solvent is then removed by a lower
temperature distillation process and reclaimed for re-use.
2. DISTILLATION PROCESS
• The technique is based on the fact that many
substances have different boiling points.
• During distillation, liquid mixtures are separated
• The distillation process sees the plant or animal
source material being brought to a certain, pre-determined
• The steam is collected by cooling.
• In flavouring production generally in industries it
is used to produce natural citral from lemon
i. Vacuum Distillation
• This is one of the simple techniques for
concentration of essential oils before
• The raw material or crude oil is heated
under vacuum at precisely controlled
temperatures, turning the components into
vapour, which is then cooled and
condensed to a purified liquid product.
ii. Molecular distillation
• This distillation technique employs the
material to heat for the briefest possible time,
while at the same time allowing a very high
vacuum to be achieved, which lowers the
vaporizing temperature, contributing further to
the limited exposure to heat.
• It allows a continuous feed of liquid to enter
and pass down the inside of a heated jacket,
wiped into a thin film by the centrifugal force
of rotating rollers and falling by gravity.
iii. Alcohol Co-Distillation
• It involves the addition of pure alcohol to the
raw material which are first treated with
water, followed by atmospheric pressure or
low-vacuum distillation of the alcohol and
some water which co-distils the more volatile
components to yield a high aroma product
• Some of the advantages associated with
these type of natural products are clean label,
100% Natural, enhanced functionality,
product differentiation and true to nature.
iv. Steam distillation
• Steam distillation is used as a general term to
such products which requires roasting for
• The method includes are:
1.Wetting the material with moist gas,
2.Steaming at varying pressure &
3.Adding hot water.
• Generally used in industries for obtaining
Steam distillation for coffee flavour
• Wetting the coffee beans at 220° F (104°C)
causes some steam to lead the extract flow.
• The steams wet the coffee and drives off coffee
aroma and flavour volatiles.
• The vented gas pass through an ice water
condenser and leave at about 35°F (2°C) to
remove as much moisture as possible.
• This richly flavored condensate
is restored to the drawn off
V. Spinning Cone Column
• Spinning cone columns are used in a form of
low temperature vacuum steam distillation to
gently extract volatile chemicals from liquid
foodstuffs while minimising the effect on the
taste of the product.
• For instance, the columns can be used to
remove some of the alcohol from wine, 'off'
smells from cream, and to capture aroma
compounds that would otherwise be lost in
• Steam Cone Column (SCC) is largely used in the
• The product is poured in at the top under vacuum, and
steam is pumped into the column from below.
• The vanes provide a large surface area over which
volatile compounds can evaporate into the steam, and
the rotation ensures a thin layer of the product is
constantly moved over the moving cone.
• It typically takes 20 seconds for the liquid to move
through the column, and industrial columns might
process 16-160 litres per minute.
• The temperature and pressure can be adjusted
depending on the compounds targeted.
SCC has several advantage which not only helps
in manufacturing but also in flavour retention
• Aroma Recovery from Waste Streams
• Enfleurage is a two-step process during which the
odour of aromatic materials is absorbed into wax
or fat, then extracted with alcohol.
• Extraction by enfleurage was commonly used
when distillation was not possible because some
fragrant compounds denature through high heat.
• This technique is not commonly used in modern
industry, due to both its prohibitive cost and the
existence of more efficient and effective extraction
4. BIOTECHNOLOGICAL PRODUCTION
• In the case of source materials not being available in quantities
necessary to produce a flavouring substance or if the production
is too complex and expensive, natural flavourings can also be
produced by biotechnological techniques.
• These techniques see the flavouring substances being produced
by micro-organisms such as acetic acid bacteria or enzymes
acting as biocatalysts.
• In biotechnical production, flavouring manufacturers use specific
microorganisms and fungi suitable for food.
• Increasingly, isolated and purified enzymes are used instead of
• After the biotechnological production of a flavouring substance,
the isolation of the substance by either extraction or distillation
EXAMPLE OF BIOTECHNOLOGICAL PROCESS:
CHEESE FLAVOR BY FERMENTATION:
• Fermented flavor cream-cheese type is produced by growing a mixture
of Streptococcus lactis and Streptococcus diacetilactis on milk under
• Maximum flavour is produced at 20-45°C,
preferably at 32°C in 2-5days in the presence of citric acid.
• To ensure aerobic conditions the fermentation is carried out for 1-10
• The product then obtained can be used as such but preferably it is dried,
Eg: spray drying, roller-drying, freeze drying, thin-film drying to preserve
• The resulting powder has a strong flavour and can be used to impart a
cream cheese-type flavour to a dip, cream cheese, butter or margarine.
B. Producing ARTIFICIAL flavouring substances
• Experts distinguish nature-identical and artificial flavouring
substances both being produced by chemical methods.
• However, nature-identical flavouring substances have the
same chemical formula as their natural model. This is not the
case for artificial flavouring substances.
• The classification between nature-identical and artificial
flavouring substances will become obsolete with the
application of the new EC Flavouring Regulation on 20th
• Under the new Regulation both flavouring
substances groups will be subsumed under
the category of “flavouring substances” with
no further distinction being made between them.
EXAMPLE: STRAWBERRY FLAVOR
• For synthetic strawberry flavour the following concentrate is
Ethyl methyl phenyl glycidate 3.33
2-Methyl-2-pentenoic acid 4.77
Ethyl pelargonate 13.06
Isoamyl acetate 14.00
Ethyl butyrate 57.18
• The concentrate prepared is dissolved in four times its volume of
propylene glycol and the mixture is added to a hard candy melt at
the rate of 1.5oz of the concentrate solution per 100 pound of
melt. After the finished candy has been produced, it is found to
have an excellent strawberry flavor.
Solvent assisted flavour evaporation (SAFE)
Engel et al., 1999 developed a new and versatile technique
for the careful and direct isolation of aroma compounds
from complex food matrices.
In connection with a high vacuum pump (5×10–3 Pa), SAFE
allows the isolation of volatiles from either solvent extracts,
aqueous foods such as milk or beer, aqueous food
suspensions such as fruit pulps, or even matrices with a
high oil content.
Application of SAFE to model solutions of selected aroma
compounds resulted in higher yields from both solvent
extracts or fatty matrices (50% fat) as compared to
previously used techniques, such as high vacuum transfer.
FLAVOUR RETENTION methods:
• Encapsulation is the technique by which one
material or a mixture of materials is coated with or
entrapped within another material or system. The
coated material is called active or core material, and
the coating material is called shell, wall material,
carrier or encapsulant (Madene et al., 2005).
• Encapsulation of flavoring materials is one of the
most active areas currently under development.
• Encapsulation can protect flavors from ingredients
and conditions like heat, moisture and acidity that
cause them to degrade.
• Encapsulation work is focused in three different areas:
proteins, fats and carbohydrates.
• These address different needs, solve different
• It does not give protection from oxidation, but it
prevents the flavors from volatilization.
1. The most important technology in terms of protection
revolve around polymers, or proteins. The release
mechanism for these is physical rupture.
2. The carbohydrate encapsulation helps with shelf
stability, especially in dry applications. Moisture then
releases the flavor.
3. The third type, fat, helps to protect flavors against
moisture, and releases with heat. This works in things
like microwave products that are warmed before
Flavour encapsulation and controlled
release – a review
(Madene et al, 2006)
• The process for encapsulation of sensitive
compounds consists of two steps:
1. The first is often emulsification of a core
material, such as the lipid-aroma system,
with a dense solution of a wall material
such as a polysaccharide or protein.
2. The second is drying or cooling of the
A schematic illustration of different process
of encapsulation of flavour compounds:
A. CHEMICAL ENCAPSULATION METHODS:
Coacervation consists of the separation from solution of colloid particles
which then agglomerate into separate, liquid phase called coacervate (Korus,
Spontaneous crystallization of supersaturated syrup is achieved at high
temperature (above 120°C) and low moisture (95–97°Brix) and aroma
compounds can be added at the time of spontaneous crystallization. The
crystal structure of can be modified to form aggregates of very small crystals
that incorporate the flavours; either by inclusion within the crystals or by
3. MOLECULAR INCLUSION:
In the food industry, flavours have been encapsulated within cyclodextrins.
The inner hydrophobic cavity of β-cyclodextrin is torus shaped, and its
molecular dimensions allow total or partial inclusion of a wide range of aroma
B. MECHANICAL ENCAPSULATION METHODS:
1. Spray Drying:
• In spray drying, an aqueous infeed material (water,
carrier, and flavor) is atomized into a stream of hot air.
• The atomized particles dry very rapidly, trapping volatile
flavor constituents inside the droplets.
• The powder is recovered via cyclone collectors.
• Flavor retention is maximized by using a high infeed
solids level, high viscosity infeed, optimum inlet (160-
210°C) and high exit (>100°C) air temperatures and high
molecular weight flavor molecules.
2. Spray chilling
• In the spray chilling technique, the coating
material is melted and atomized through a
pneumatic nozzle into a vessel generally
containing a carbon dioxide ice bath
(temperature 50°C) as in a holt-melt fluidized
bed. Thus droplets adhere on particles and
solidify forming a coat film.
• The process is suitable for protecting many
water-soluble materials that may otherwise
be volatilized or damaged during thermal
processing (Augustin et al., 2001).
3. Spray cooling
• This method is similar to spray chilling, the
only difference is the temperature of the
reactor in which the coating material is
sprayed. A molten matrix material containing
minute droplets of the core materials may be
spray cooled. Also, vegetable oil can be used
and the normal melting point is 45–122°C
• The disadvantage of spray chilling and spray
cooling is that special handling and storage
conditions can be required (Taylor, 1983).
4. Freeze Drying:
The freeze-drying technique, which is
lyophilization, is one of the most useful processes
for drying thermosensitive substances that are
unstable in aqueous solutions. In this process,
upon water crystallization, the non-frozen solution
is viscous and the diffusion of flavours is retarded.
Upon starting freeze drying, the surface of the
solution becomes an amorphous solid in which
selective diffusion is possible (Karel & Langer,
• Encapsulation of flavours via extrusion has been used for
volatile and unstable flavours in carbohydrate products.
• The principal advantage of the extrusion method is the
stability of flavours against oxidation. Carbohydrate
matrices in the glassy state have very good barrier
properties and extrusion is a convenient process
enabling the encapsulation of flavours in such matrices
• Extrusion methods can be:
1. Simple extrusion
2. Double-capilarity extrusion (Coaxial double capillary
device & Centrifugal extrusion device)
3. Recycling centrifugal extrusion
C. CONTROLLED FLAVOUR RELEASE
• Controlled release may be defined as a method
by which one or more active agents or
ingredients are made available at a desired site
and time and at a specific rate (Pothakamury &
1. Release of flavour by
• Diffusion is controlled by the solubility of a
compound in the matrix (this establishes a
concentration in the matrix which drives division)
and the permeability of the compound through the
• The principal steps in the release of a flavour
compound from matrix system are: diffusion of the
active agent to the surface of the matrix; partition
of the volatile component between the matrix and
the surrounding food and transport away from the
matrix surface (Fan & Singh,1989).
2. Release of flavour by degradation:
The release of an active compound from a matrix-type
delivery system may be controlled by diffusion, erosion or a
combination of both.
3. Release of flavour by swelling:
When the matrix polymer is placed in a thermodynamically
compatible medium, the polymer swells because of
absorption of fluid from the medium. The aroma in the
swollen part of matrix then diffuses out (Fan & Singh,
4. Release of flavour by
This mechanism of release involves the melting of the
capsule wall to release the active material.
This is readily accomplished in the food industry as there
are numerous materials that can be melted and that are
approved for food use (lipids, modified lipids or waxes).
In such applications, the coated particles are stored at
temperatures well below the melting point of the coating,
then heated above this temperature during preparation
or cooking (Sparks et al, 1995).
STARCH ENCAPSULATION MAY IMPROVE
FLAVOR STABILITY AND RELEASE PROFILE: A
• The technique can provide a food grade complex of nanometric
size which could serve as an efficient platform for the control of
aroma in the oral cavity.
• The starch-aroma complexes prepared by starches of different
amylose content, menthone, menthol and limonene.
• Result from digestion shows that complexes are broken down by
alpha-amylase in the mouth, leading to controlled release of the
aroma in the oral cavity.
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direct isolation of aroma compounds from complex food matrices.
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