Nature Identical Flavourings

A. Artho and K. Grob, Determination of y-lactones added to foods as flavours. How far-must nature-identical flavours be identical with the nature , Mitt. Gebiete Lebensm. Hyg. 81 544-558 (1990). 

Flavours are complex substances that can conveniently be divided into three groups natural, nature identical and synthetic. 

These are materials that are synthetic but are the same compound as is present in a natural flavouring material. From time to time it emerges that one substance produces a given flavour. Most chemists know that benzaldehyde has a smell of almonds. Some chemists know that hydrogen cyanide smells of bitter almonds. If a natural flavouring can be represented by a single substance and that substance can be synthesised then the flavour is likely to be available as a nature identical flavour. Vanilla flavour is a good example. Vanilla flavour can be all natural and derived from vanilla pods or nature identical or artificial. The nature identical product would be based on vanillin, which is in vanilla pods and has a flavour of vanilla. An artificial vanilla flavour would be ethyl vanillin, which is not present in vanilla pods but has a flavour two and a... 

Practical flavours often contain a mixture of substances, some natural, some nature identical some synthetic. UK law classifies a flavour that contains any nature identical components as nature identical even though the rest of the flavour is natural. Similarly, the presence of any artificial components renders the flavour artificial. 

Whether the flavour used is natural, nature identical, synthetic, or a mixture it has to be dosed into the product. Although some flavourings are very intense the volume added to the product has to be large enough for the equipment or the people to add it with sufficient accuracy. The flavour of course has to be uniformly distributed in the product. This normally means producing the flavour as a solution. Flavours are prepared for a particular use. As an example, citrus oil based flavours can be dissolved in various alcohols. 

The application of ever improving analytical methods will continue to reveal new flavouring compounds, be they natural, nature identical or synthetic. Not only are ever more sophisticated analytical techniques available but also improved methods of data analysis. The new science of chemometrics has developed to cope with the situation where chromatograms with hundreds of compounds are obtained. 

It remains an interesting speculation what would happen if a mutation of vanilla was produced that produced ethyl vanillin rather than vanillin. The new variety would be much more potent as a flavour. However, ethyl vanillin might then have to be classified as nature identical. 

Emberger R, Hopp R, Synthesis and sensory characterization of menthol enantiomers and their derivatives for the use in nature identical peppermint oils, in Berger RG, Nitz N, Schreier P, (eds.). Topics in Flavour Research, H. Eichhorn, Marzling-Hangenham, Germany, pp. 201-218, 1985. 

In the meantime the existing national regulations of EU member states regarding flavouring substances are still in force. These existing national regulations show an unlimited permission of use for natural and nature-identical fla-... 

The US Regulations only distinguish between natural and artificial flavourings. The European category nature-identical is unknown in the legal definitions. If such substances are synthetically produced, they are classified as artificial flavouring substances in the USA. 

The reasons to use raw materials from renewable resources can be various. When a natural flavour ingredient has to be prepared, a natural raw material is essential, and natural raw materials are renewable, because they come from plants, animals or fermentation. For nature-identical flavour ingredients, a renewable raw material can be a good choice from a chemical point of view and quite often also from a cost point of view if turpentine is readily available in a country with limited or no petrochemical resources, -pinene from the renewable source is cheaper than chemically synthesised -pinene. A manufacturer chooses only for sustainable production if it is remunerative and at least as attractive as other options. 

Of course, during processing of fruit juices hydrolysis effects may occur, leading to decreased amounts of ethyl 2-methylbutanoate. However, its enantiomeric purity remains unchanged, whilst the corresponding 2-methylbutanoic acid is found as the (S)-enantiomer (99.5% or more) [33-37]. Consequently, the detection of racemic 2-methybutanoic acid (or the corresponding esters) definitely proves the addition of a synthetic (so called nature-identical) flavour compound. 

Natural raw materials are of high importance in flavour development. Natural isolates (Table 21.2) serve as a basis for most natural flavourings which can be blended with single natural aroma chemicals. The performance of nature-identical flavourings will be supported by using extracts and oils as they significantly enhance the complexity of flavourings and increase their authenticity. 

Aroma chemicals which are found in natural sources or food preparations but are synthesised by normal chemical procedures are defined by the status nature-identical . Most of them were discovered and developed during the nineteenth and twentieth centuries. The most important single aroma chemicals produced in very large amounts are vanillin, menthol, citral and anethol. They are used not only by flavour producers but also in large amounts in fragrance... 

Phenylethanol has a rose-like odour and makes the chemically produced compound the most used fragrance chemical in perfume and cosmetics, with a world market of about 7,000 t year [107, 108]. 2-Phenylethanol is also found in many foods as a characteristic flavour compound rounding off the overall aroma, especially in foods obtained by fermentation, such as wine, beer, cheese, tea leaves, cocoa, coffee, bread, cider and soy sauce [109]. In food applications, natural 2-phenylethanol is preferred rather than its nature-identical counterpart from chemical synthesis and it has a market volume of 0.5-11 year . This product is sold at market prices of up to US 1,000 per kiklogram and is mainly produced by yeast-based bioprocesses since its isolation from natural sources, e.g. rose oil, would be too costly [109]. 

Nature-identical flavouring substances. These are substances chemically isolated from aromatic raw materials or obtained synthetically. They are chemically identical to substances present in natural products intended for human consumption, whether processed or not. 

Flavourings. Flavourings are widely used in dilutable soft drinks to boost or substitute those occurring naturally. There are other publications that deal with this topic in more detail, but, in brief, it is necessary to ensure that appropriate beverage flavours are selected to produce adequate solubility. Most manufacturers of dilutables will use either natural or nature-identical flavours. 

Nature-identical claims are not much appreciated in English speaking countries, but in German speaking countries the claim is more popular. Initially, it is difficult to see why a synthetic substance that happens to be present in Nature should be preferred over a synthetic substance that is not found as a naturally-occurring substance. Presumably the advantage of a nature-identical substance is assumed because it is assumed to be inherently safe. This is a paradox since synthetic substances are normally tested for safety much more exhaustively than natural ones. However, nature-identical flavours do have the advantage over natural products in that the price or quality are not affected by adverse harvests. 

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