**1.2. Natural versus artificial flavours**

In the United States, there is a legal definition of natural and artificial flavours.

The complete definitions are found in the Code of Federal Regulations (CFR) Title 21 101.22 (Code of Federal Regulations, 2008). Artificial flavours are defined in (a)(1) as follows:

The term artificial flavour or artificial flavouring means any substance, the function of which is to impart flavour, which is not derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, fish, poultry, eggs, dairy products, or fermentation products thereof. Artificial flavour includes the substances listed in Sec. 172.515(b) and 182.60 of this chapter except where these are derived from natural sources.

Natural flavours are defined in (a)(3) of Title 21 101.22, as follows:

The term natural flavour or natural flavouring means the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavouring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose significant function in food is flavouring rather than nutritional. Natural flavours include the natural essence or extractives obtained from plants listed in Sec. 182.10, 182.20, 182.40, and 182.50 and part 184 of this chapter, and the substances listed in Sec. 172.510 of this chapter.

The browning reaction will be discussed later and it is interesting to note that process flavours can be made using the browning reaction and are defined as natural since they are a product of roasting or heating.

Spices are also defined in (a)(2) of Title 21 101.22 as follows:

The term spice means any aromatic vegetable substance in the whole, broken, or ground form, except for those substances which have been traditionally regarded as foods, such as onions, garlic and celery; whose significant function in food is seasoning rather than nutritional; that is true to name; and from which no portion of any volatile oil or other flavouring principle has been removed.

The regulation goes on to list a number of individual spices. It should be noted that many materials that are considered artificial are identical to those in nature: it is simply how they were produced that determines whether they are natural or artificial. As an example, diacetyl is natural if it comes from milk or is produced by fermentation (as in wine and fermented dairy products) but is artificial if it is synthesized from other chemicals. All of the chemical properties are the same no matter where the individual chemical came from. The only time that a compound can never be natural is if it has never been found from any natural source. One compound, which gives a cotton candy type flavour, is ethyl maltol. This has never been found in nature so if a flavor contains this compound, it will be at least partially artificial.

In other countries, there are different definitions as to what is natural and artificial. In some countries, there is the concept of nature identical. It states that if a compound exists in nature, then it does not matter where it comes from, it would not be considered artificial. The flavour could not be called natural but has simply been referred to as flavour. It is important that the regulations for each country be checked to understand what is allowed and how flavours added to products should be labeled.

#### **2. Sources of flavours**

18 The Development and Application of Microwave Heating

Flavour is defined as the experience of the combined perception of compounds responsible for taste and aroma. The flavour of food is very important for its acceptability and a slight change in the odour of processed food may affect the overall quality of the product. Aromas come from low molecular weight organic compounds that can volatilize and be sensed in the nasal cavity. These compounds are not of one simple class of chemicals but rather are many different chemical types, including acids, esters, alcohols, ketones, pyrazines, thiazoles and terpenes as well as many others. The human body has a complex set of receptors that recognize both individual compounds as well as mixture of compounds to

Character impact compounds are individual chemicals with a specific, recognizable aroma. Some examples are methyl anthranilate (concord grape), citral (lemon), cinnamic aldehyde (cinnamon), methyl salicylate (wintergreen) and diacetyl (butter). While these individual compounds have a characteristic odour, they do not make up the complete flavour of a product, whether naturally occurring such as in a concord grape or in a flavour added to a product. Many other compounds are also present which build the overall flavour profile. Considerable work has been done to identify the flavour compounds in different foods. There are over 170 compounds that have been identified that contribute to the flavour of a strawberry, while coffee and chocolate are much more complex with over 800 compounds

In the United States, there is a legal definition of natural and artificial flavours.

Natural flavours are defined in (a)(3) of Title 21 101.22, as follows:

The complete definitions are found in the Code of Federal Regulations (CFR) Title 21 101.22 (Code of Federal Regulations, 2008). Artificial flavours are defined in (a)(1) as follows:

The term artificial flavour or artificial flavouring means any substance, the function of which is to impart flavour, which is not derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, fish, poultry, eggs, dairy products, or fermentation products thereof. Artificial flavour includes the substances listed in Sec. 172.515(b) and 182.60 of this chapter except where these are

The term natural flavour or natural flavouring means the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavouring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose significant function in food is flavouring rather than nutritional. Natural flavours include the natural essence or extractives obtained from plants listed in Sec. 182.10, 182.20,

**1.1. Flavour definition** 

identify different flavours.

**1.2. Natural versus artificial flavours** 

derived from natural sources.

identified.

Flavouring materials come from a variety of sources. One of the main sources is plants. The flavour materials can be present in any part of a plant including the flower, leaf, stem or bark. To be used in food products, the materials are generally extracted from the plant material to provide an isolate that is just the flavour. There are different techniques that can be used for isolation including solvent extraction (often ethanol), steam distillation and supercritical fluid extraction. Dairy products and meats and seafood can also be sources of flavouring materials. Dairy products provide a good source of base material that can be modified by enzymes to create much more concentrated flavors than are present in the natural dairy product. The enzymes break down the fats and proteins present to yield higher concentrations of the flavour compounds that represent the flavors of these dairy

products. Some of the components of dairy flavors are short chain fatty acids including butyric acid that are unpleasant at high concentrations but help to contribute to the characteristic flavour of dairy products.

Many flavours are produced by processing, primarily with the use of heat. The subject of browning will be covered in more detail later in this chapter but will be briefly addressed here. Flavours can be created by heating one or more reducing sugars with one or more amino acids for different times and at different temperatures. Very different flavours can be produced which can be added to foods as natural flavours.

Flavours can also be produced using biotechnology. This is an area that has been explored for years to determine ways to get plants or microorganisms to produce higher quantities of flavouring materials than they do naturally. While there has been limited success by some companies to produce individual flavour compounds through this process, it has not achieved wide commercial success.
