FLAVOUR IN FOOD INDUSTRIES

Presented By:Supta SarkarHHM-2013-10

M.Sc Foods & Nutrition, PJTSAU

SEE INSIDE…• Introduction• History• Classification• Flavour manufacturing techniques: -Production of natural flavouring substance -Production of artificial flavouring substance• Flavour retention methods• Conclusion

INTRODUCTION• 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.

HISTORY• Historically there is little literature in the public domain on food

flavours until the mid-1900s.• 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 growth.

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.

CLASSIFICATION:• There are three principal types of flavorings used in foods,

under definitions agreed in the E.U. and Australia.

TYPES DESCRIPTION

1. Natural flavoring

substances

Substances which are extracted from vegetable or animal materials and are not further chemically modified or changed. An example is vanilla extract.

2. Nature-identical flavoring

substances

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.

3. Artificial flavoring

substances

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 sugars.

• 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 source materials.

• 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 flavoring agents:

CHEMICAL ODORDiacetyl ButteryIsoamyl acetate BananaBenzaldehyde Bitter almondCinnamic aldehyde CinnamonEthyl propionate FruityMethyl anthranilate GrapeLimonene OrangeEthyl decadienoate PearAllyl hexanoate PineappleEthyl maltol Sugar, Cotton candyEthylvanillin VanillaMethyl 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 taste flavorants.

• 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 salts.

• 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. 

Acid DescriptionAcetic 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 tartness.

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 characteristic flavour.

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 MANUFACTURING:

Fig. The Flavour Industry: Flow of manufacturing processes for flavour

PetrochemicalRaw materials

PlantsAnimals

Essential oilsExtrudatesSecretions

SeparationDistillationModification

Natural raw materials

Aroma Chemicals

Customers & Manufacturers

Flavour compositions

Syntheticchemistry

Steam distillationExtractionExpression

ProcessingConcentratingDissolvingCompounding

MixingBlending

Flav

our &

frag

nanc

e in

dust

ry

Chem

ical

indu

stry

Agriculture

• Depending on the manufacturing process flavourings are divided into two major groups:

1. Natural flavouring substances

2. Synthetically produced flavouring substances

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.

1.EXTRACTION• 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 powder.

• The same principle of extraction is applied when deriving vanilla extract from vanilla beans. Alcohol or supercritical carbon dioxide (CO2) are used as solvents.

Extraction Techniques: i. Liquid Carbon Dioxide Extraction

• Raw material is packed into stainless steel extraction columns.

• 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 sophisticated heat

exchanger. This leaves a pure extract of the

product which is tapped from the process under

pressure, still below ambient temperature.

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 obtained.

• 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 by heating.

• The distillation process sees the plant or animal source material being brought to a certain, pre-determined boiling point.

• The steam is collected by cooling.• In flavouring production generally in

industries it is used to produce natural citral from lemon grass oil.

DISTILLATION TECHNIQUE:i. Vacuum Distillation

• This is one of the simple techniques for concentration of essential oils before molecular distillation.

• 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 flavour generation.

• 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 coffee flavour.

Steam distillation for coffee flavour in industries:

• 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 extract.

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 processing.

• Steam Cone Column (SCC) is largely used in the flavour industries.

• 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 during processing:

• Aroma Recovery from Waste Streams

• Superior fruit concentrates

• Aseptic packing

3. ENFLEURAGE • 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 methods.

4. BIOTECHNOLOGICAL PRODUCTION PROCESSES:

• 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 microorganisms.

• After the biotechnological production of a flavouring substance, the isolation of the substance by either extraction or distillation takes place.

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 aerobic conditions.

• 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 days.

• 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 product.

• 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 January 2011.

• 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 prepared:

• 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.

INGREDIENT PERCENT

Geraniol 1.00Ethyl methyl phenyl glycidate 3.332-Methyl-2-pentenoic acid 4.77Vanilin 5.66Ethyl pelargonate 13.06Isoamyl acetate 14.00Ethyl butyrate 57.181-(Prop-1’-enyl)-3,4,5-trimethoxybenzene 1.00

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.

Solvent assisted flavour evaporation (SAFE)

***

FLAVOUR RETENTION methods:ENCAPSULATION:

• 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 problems.• 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 eating.

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 emulsions.

A schematic illustration of different process of encapsulation of flavour compounds:

A. CHEMICAL ENCAPSULATION METHODS:1. COACERVATION: Coacervation consists of the separation from solution of colloid particles which then agglomerate into separate, liquid phase called coacervate (Korus, 2001).

2. CO-CRYSTALLIZATION: 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 entrapment.

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 compounds.

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 (Risch, 1995).

• 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, 1988).

5. Extrusion• 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 (Gouin, 2004).

• Extrusion methods can be: 1. Simple extrusion2. 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 & Barbosa-Canovas, 1995).

1. Release of flavour by diffusion:• 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 matrix.

• 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, 1989).

4. Release of flavour by melting

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

STUDY (Gray, 2011)

• 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.

CONCLUSION

REFERENCE• Augustin,M.A., Sanguansri,L., Margetts, C. & Young, B. 2001.

Microencapsulation of food ingredients. Food Australia. 53:220–223.• Engel,W., Bahr,W and Schieberle,P. 1999. Solvent Assisted Flavour

Evaporation- a new and versatile technique for the careful and direct isolation of aroma compounds from complex food matrices. Eur Food Research Technology. 209:239-241

• Fan,L.T & Singh,S.K. 1989.Controlled Release: a Quantitative Treatment. Berlin: Springer-Verlag.

• Gouin,S. 2004. Microencapsulation: industrial appraisal of existing technologies and trends. Trends in Food Science and Technology. 15: 330–347.

• Gray,N. 2011. Starch Encapsulation May Improve Flavor Stability And Release Profile: A Study. doi: 10.1016/j.lwt.2011.08.008

• Jayatilaka,A., Poole,S.K., Poole,C.F & Chichila,T.M.P. 1995. Analytica Chimica Acta. 302(2–3): 147–162.

• Karel,M & Langer,R. 1988. Controlled release of food additives. In:Flavour Encapsulation(edited by S.J. Risch & G.A. Reineccius). Pp. 177–191. ACS Symposium Series 370. Washington, DC: American Chemical Society.

• Korus,J. 2001. Microencapsulation of flavours in starch matrix by coacervation method. Polish Journal of Food and Nutrition Sciences. 10(51): 17–23.

• Madene,A., Jacquot,M., Scher,J.I. & Desobry,S. 2006. Flavour encapsulation and controlled release – a review, International Journal of Food Science and Technology. 41: 1–21.

• National Agricultural Biotechnology Council Report, 2001.

• Pothakamury,U.R & Barbosa-Canovas,G.V. 1995. Fundamental aspects of controlled release in foods. Trends in Food Science and Technology. 6: 397–406.

• Risch, S.J. 1995. Encapsulation: overview of uses and techniques. In: Encapsulation and Controlled Release of Food Ingredient(edited by S.J. Rish & G.A. Reineccius).Pp. 2–7. Washington, DC: American Chemical Society.

• Sparks,R.E., Jacobs, J.C & Mason,N.S. 1995. Centrifugal suspension-separation for coating food ingredients. In: Encapsulation and Controlled Release of Food Ingredient(edited by S.J. Rish & G.A. Reineccius). Pp. 87–89. Washington, DC: American Chemical Society.

• Taylor, A.H. 1983. Encapsulation systems and their applications in the flavor industry., Food Flavor Ingredient and Process Packaging. 4: 48–52.

• Zellner,D.A.2013. Color–Odor Interactions: A Review and Model, Chemosensory Perception. 6(4): 155-169.