Flavor

This article is about flavor as a sensory impression. For the particle property, see Flavour (particle physics). For other uses, see Flavor (disambiguation).

Flavor or flavour (see spelling differences) 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. The flavor of the food, as such, can be altered with natural or artificial flavorants, which affect these senses.

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.

Of the three chemical senses, smell is the main determinant of a food item's flavor. While the taste of food is limited to sweet, sour, bitter, salty, and savory (umami) – the basic tastes – the smells of a food are potentially limitless. A food's flavor, therefore, can be easily altered by changing its smell while keeping its taste similar. Nowhere is this better exemplified than in artificially flavored jellies, soft drinks and candies, which, while made of bases with a similar taste, have dramatically different flavors due to the use of different scents or fragrances. The flavorings of commercially produced food products are typically created by flavorists.

Although the terms "flavoring" or "flavorant" in common language denote the combined chemical sensations of taste and smell, the same terms are usually used in the fragrance and flavors industry to refer to edible chemicals and extracts that alter the flavor of food and food products through the sense of smell. 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. Identification of nature-identical flavorants are done using technology such as headspace techniques.

Flavorants or flavorings

Flavorings are focused on altering or enhancing the flavors of natural food product such as meats and vegetables, or creating flavor for food products that do not have the desired flavors such as candies and other snacks. Most types of flavorings are focused on scent and taste. Few commercial products exist to stimulate the trigeminal senses, since these are sharp, astringent, and typically unpleasant flavors.

There are three principal types of flavorings used in foods, under definitions agreed in the E.U. and Australia:^[1]

Type	Description
Natural flavoring substances	Flavoring substances obtained from plant or animal raw materials, by physical, microbiological or enzymatic processes. They can be either used in their natural state or processed for human consumption, but cannot contain any nature-identical or artificial flavoring substances.
Nature-identical flavoring substances	Flavoring substances that are obtained by synthesis or isolated through chemical processes, which are chemically and organoleptically identical to flavoring substances naturally present in products intended for human consumption. They cannot contain any artificial flavoring substances.
Artificial flavoring substances	Flavoring substances not identified in a natural product intended for human consumption, whether or not the product is processed. These are typically produced by fractional distillation and additional chemical manipulation of naturally sourced chemicals, crude oil or coal tar. Although they are chemically different, in sensory characteristics are the same as natural ones.

Regulations on natural flavoring

UK Food Law defines a natural flavor as:

a flavouring substance (or flavouring substances) which is (or are) obtained, by physical, enzymatic or microbiological processes, from material of vegetable or animal origin which material is either raw or has been subjected to a process normally used in preparing food for human consumption and to no process other than one normally so used.^[2]

The U.S. Code of Federal Regulations describes a "natural flavorant" as:

the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or any other edible portions of a plant, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose primary function in food is flavoring rather than nutritional.^[3]

The European Union's guidelines for natural flavorants are slightly different. Certain artificial flavorants are given an E number, which may be included on food labels.

Smell

Smell flavorants, or simply, flavorants, are engineered and composed in similar ways as with industrial fragrances and fine perfumes. To produce natural flavors, the flavorant must first be extracted from the source substance. The methods of extraction can involve solvent extraction. To begin producing artificial flavors, flavor manufacturers must either find out the individual naturally occurring aroma chemicals and mix them appropriately to produce a desired flavor or create a novel non-toxic artificial compound that gives a specific flavor.

Most artificial flavors are specific and often complex mixtures of singular naturally occurring flavor compounds combined together to either imitate or enhance a natural flavor. These mixtures are formulated by flavorists to give a food product a unique flavor and to maintain flavor consistency between different product batches or after recipe changes. The list of known flavoring agents includes thousands of molecular compounds, and the flavor chemist (flavorist) can often mix these together to produce many of the common flavors. Many flavorants consist of esters, which are often described as being "sweet" or "fruity".

Chemical	Odor
Diacetyl	Buttery
Isoamyl acetate	Banana
Benzaldehyde	Bitter almond
Cinnamic aldehyde	Cinnamon
Ethyl propionate	Fruity
Methyl anthranilate	Grape
Limonene	Orange
Ethyl- (''E'',''Z'')-2,4-decadienoate	Pear
Allyl hexanoate	Pineapple
Ethyl maltol	Sugar, Cotton candy
Ethylvanillin	Vanilla
Methyl salicylate	Wintergreen

The compounds used to produce artificial flavors are almost identical to those that occur naturally. 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.^[4] Natural flavors in contrast may contain impurities from their sources while artificial flavors are typically more pure and are required to undergo more testing before being sold for consumption.^[4]

Flavors from food products are usually the result of a combination of natural flavors, which set up the basic smell profile of a food product while artificial flavors modify the smell to accent it.

Unlike smelling, which occurs upon inhalation, the sensing of flavors in the mouth occurs in the exhalation phase of breathing and is perceived differently by an individual. In otherwords, the smell of food is different depending on when you are smelling it in front of you or whether it has already entered your mouth.^[5]

Taste

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. Artificial sweeteners are also technically flavorants.

Umami or "savory" flavorants, more commonly called taste or flavor enhancers are largely based on amino acids and nucleotides. These are typically used as sodium or calcium salts. Umami flavorants recognized and approved by the European Union include:

Acid	Description
Glutamic acid salts	This amino acid's sodium salt, monosodium glutamate (MSG), a notable example, is one of the most commonly used flavor enhancers in food processing. Mono and diglutamate salts are also commonly used.
Glycine salts	Simple amino acid salts typically combined with glutamic acid as flavor enhancers.
Guanylic acid salts	Nucleotide salts typically combined with glutamic acid as flavor enhancers.
Inosinic acid salts	Nucleotide salts created from the breakdown of AMP. Due to high costs of production, typically combined with glutamic acid as flavor enhancers.
5'-ribonucleotide salts	Nucleotide salts typically combined with other amino acids and nucleotide salts as flavor enhancers.

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. Each acid imparts a slightly different sour or tart taste that alters the flavor of a food.

Acid	Description
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 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

Color

The color of food can affect flavor. For example, adding more red color to a drink increases its sweetness with darker colored solutions being rated 2–10% higher than lighter ones even though it had 1% less sucrose concentration.^[6] The effect of color is believed to be due to cognitive expectations.^[7]

Dietary restrictions

Food manufacturers are sometimes reluctant about informing consumers about the source from where the flavor is obtained and whether it has been produced with the incorporation of substances such as animal by-products glycerin (note that glycerin is also available from vegetable sources), gelatin, and the like, and the use of alcohol in the flavors. Many Jews, Jains, Hindus, and Muslims adhere to religious dietary laws, and vegans to personal convictions, which restrict the use of animal by-products and/or alcohol in foods unless subject to oversight and inspection by their respective religious authority or less-strict or circumstantial moral belief. In many western countries, some consumers rely on a Jewish Kosher Pareve certification mark to indicate that natural flavorings used in a food product are free of meat and dairy (although they can still contain fish). The Vegan Society's Sunflower symbol (which is currently used by over 260 companies world wide) can also be used to see which products do not use any animal ingredients (including flavorings and colorings)

Flavor creation

Most food and beverage companies do not create their own flavors but instead employ the services of a flavor company. Food and beverage companies may require flavors for new products, product line extensions (e.g., low fat versions of existing products) or due to changes in formula or processing for existing products.

The flavor creation is done by a specially trained scientist called a "flavorist". The flavorist's job combines extensive scientific knowledge of the chemical palette with artistic creativity to develop new and distinctive flavors. The flavor creation begins when the flavorist receives a brief from the client. In the brief the client will attempt to communicate exactly what type of flavor they seek, in what application it will be used, and any special requirements (e.g., must be all natural). The communication barrier can be quite difficult to overcome since most people aren't experienced at describing flavors. The flavorist will use his or her knowledge of the available chemical ingredients to create a formula and compound it on an electronic balance. The flavor will then be submitted to the client for testing. Several iterations, with feedback from the client, may be needed before the right flavor is found.

Additional work may also be done by the flavor company. For example, the flavor company may conduct sensory taste tests to test consumer acceptance of a flavor before it is sent to the client or to further investigate the "sensory space." The flavor company may also employ application specialists who work to ensure the flavor will work in the application for which it is intended. This may require special flavor delivery technologies that are used to protect the flavor during processing or cooking so that the flavor is only released when eaten by the end consumer.

Determination

Few standards are available or being prepared for sensory analysis of flavors.^[8] In chemical analysis of flavors, solid phase extraction (SPE), solid phase microextraction (SPME), and headspace gas chromatography are applied to extract and separate the flavor compounds in the sample. The determination is typically done by various mass spectrometric techniques.^[9]

Scientific resources

• Flavour and Fragrance Journal

See also

Food portal

• Aroma compound
• Cooking
• E number
• Ester (for list of some artificial flavor chemical compounds)
• Flavor companies
• Flavor Spray
• Food additive
• Fragrance oil
• Monosodium glutamate, commonly known as MSG
• Palatability
• Preservative
• Seasoning

References

1. ^ From Australian Food Standards Guidelines
2. ^ The Flavourings in Food Regulations, Amended 1994
3. ^ Code of Federal Regulations
4. ^ ^{a b} R.L. Smitha, S.M. Cohenb, J. Doullc, V.J. Ferond, J.I. Goodmane, L.J. Marnettf, P.S. Portogheseg, W.J. Waddellh, B.M.Wagneri, R.L. Hallj, N.A. Higleyk, C. Lucas-Gavinl and T.B. Adamsm (2005). "A procedure for the safety evaluation of natural flavor complexes used as ingredients in food: essential oils". Food and Chemical Toxicology 43 (3): 345–363. doi:10.1016/j.fct.2004.11.007. PMID 15680674. 
5. ^ Masaoka Y, Satoh H, Akai L, Homma I. (2010). Expiration: The moment we experience retronasal olfaction in flavor. Neurosci Lett. 473:92–96. doi:10.1016/j.neulet.2010.02.024 PMID 20171264
6. ^ Johnson, J., & Clydesdale, F. (1982). Perceived sweetness and redness in colored sucrose solutions. Journal of Food Science, 47, 747–752. doi:10.1111/j.1365-2621.1982.tb12706.x
7. ^ Shankar MU, Levitan CA, Spence C. (2010). Grape expectations: the role of cognitive influences in color-flavor interactions. Conscious Cogn. Mar;19(1):380-90. doi:10.1016/j.concog.2009.08.008 PMID 19828330
8. ^ e.g. ISO 13301:2002 Sensory analysis -- Methodology -- General guidance for measuring odor, flavor and taste detection thresholds by a three-alternative forced-choice (3-AFC) procedure. or ISO 6564:1985 Sensory analysis -- Methodology -- Flavor profile methods.
9. ^ Use of Ozone Depleting Substances in Laboratories. TemaNord 2003:516. norden.org

External links

• How Stuff Works How do artificial flavors work?
• The Science in artificial flavor creation
• Monell Chemical Senses Center
• Flavourists view