Discover the world of flavours
Why do we add flavourings to foods?
There are two main reasons:Firstly, to add an intrinsic flavour - an example being flavoured mineral water with citrus extracts. The second reason is to add a flavour which has been lost or modified during processing. This can be seen in yogurt which contains fruit flavour.
Users of food flavourings include industrial food manufacturers, artisan food manufacturers and home cooks.
The use of flavourings is only authorised under specific regulatory conditions fixed by the respective manufacturing branch.
Food flavourings are also used in various oral pharmaceutical drugs to facilitate their ingestion.
Work of the flavourist
The flavourist's role is to combine different flavouring agents to obtain the final intended flavour. The flavourist's work involves several steps.Firstly, he or she identifies the dominant substances which determine the characteristic flavour. 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. Depending on the food matrix, flavours perform differently. As regards the flavour release, there is, for example, a significant difference between a 1.5% custard and a 3,5% fat custard.
If the flavourist and food manufacturer are satisfied with the taste, focus groups are set up to taste the product. It is only after this step is successfully completed, that the product has a chance to be launched.
General explanations on flavour categories / products
Flavourings may contain flavouring substances, flavouring preparations, process flavourings, smoke flavourings and other flavourings. The different flavour categories are detailed below:Flavouring substances - natural or synthetic
Flavouring substances are chemically defined substances with flavouring properties. To-date, some 10,000 flavouring substances have been identified in nature. The flavouring industry uses about 2,500 of these substances. Among these substances there are so-called “major” substances, such as citral which tastes of lemon or menthol which gives a peppermint taste, which are used in a myriad of food types.Depending on the manufacturing process flavourings are divided into two major groups:
1. Natural flavouring substances;
2. Synthetically produced flavouring substances.
1. 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.
Extraction process
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.
Distillation process
Human beings have in fact been distilling alcohol for thousands of years. During distillation, liquid mixtures are separated by heating. The technique is based on the fact that many substances have different boiling points.
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 distillation is, for instance used, to produce natural citral from lemon grass oil.
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.
Biotechnology has been used for generations in the production of foods such as cheese or sauerkraut. During the fermentation of white cabbage or maturation of cheese, lactic acid bacteria are busy at work. In addition, the presence of diverse yeasts is essential for bread, beer and wine production. In a maturing banana, for example, carbohydrates and proteins are produced biochemically and at the same time other biochemical processes occur that lead to the development of the flavouring substances typical in a banana. As soon as a banana turns golden yellow, its standard flavour that we all know, becomes apparent.
Today, it's hard to imagine food production without biotechnological processes. These enable vitamins and acids, as well as many flavouring substances to be produced. Such flavouring substances match the original flavouring substances contained in the foodstuffs. 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.
2. Synthetic 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.
Nature-identical flavouring substances are isolated from raw materials by chemical methods or are produced synthetically. For example, vanillin, the main component of vanilla beans, can be produced as a natural or a nature-identical flavouring substance. Nature-identical means that nature-identical flavouring substances are “born” in a laboratory but that their chemical structures are identical to the substances present in natural products. A substance can only be named as nature-identical if it naturally occurs in plant or animal raw materials. For example, the molecular structure and the smell or flavour of natural citral which can be distilled from lemon grass oil, and of nature-identical citral which is chemically synthesized, do not differ. Only the production methods are different, and the substances are obtained from different source materials.
By contrast artificial flavouring substances have no equivalent in nature. A well-known artificial flavouring substance is ethyl vanillin which smells and tastes like vanillin yet is roughly three times more taste-intensive. As flavouring, ethyl vanillin is normally added to products such as ice cream, confectionery and bakery wares.
Other flavouring categories
Flavouring preparationsFlavouring preparations are not chemically defined substances but complex mixtures whose composition is defined by natural raw materials. Well known examples are vegetable and fruit extracts, spice and herb extracts and yeast extract. As is the case with natural flavouring substances, flavouring preparations are obtained from plant, animal or microbiological source materials by means of physical or biotechnological production processes. Flavouring preparations are often the main component of citrus, spice and mint flavourings, reflecting their characteristic smell and taste.
This category also includes essential oils, such as clove and eucalyptus oil. The oils are obtained from plants, such as spices, herbs, fruit or blossoms, and represent the odoriferous and/or tasty “essence” of the plant. All plant parts which contain essential oils can serve as source material.
Thermal Process Flavourings
Thermal process flavourings are industrially produced by the controlled heating of several components (eg. by a Maillard reaction). During the process, intense flavours develop, as is the case when roasting meat or baking bread. The flavouring itself only develops as a result of the thermal process and the essential basic materials for their development include amino acids and also reducing sugars, such as dextrose (glucose). Thermal process flavourings develop in connection with heat.
These production processes are very similar to food preparation at home. A raw steak, for example, has hardly any taste. However, as soon as it is roasted or grilled, parts of the main components are transformed into flavourings under the influence of heat. These transformation processes also explain the large taste difference between a medium and a well-done steak.
Smoke flavourings
Smoking is one of the most ancient procedures to season and preserve foods. Smoke flavourings are not only used to preserve but to confer a special smoke flavour in foods such as fish and meat products, steak, sauces and chips.
Freshly produced smoke is obtained by means of controlled burning of hardwood at temperatures of up to 600°C. This happens mostly in the absence of air, and in many cases charcoal develops as a by-product. The smoke generated is condensed and for practical reasons, such smoke primary products can be mixed with solvents such as cooking oil or carriers such as table salt.