Flavour extracts

CH3 CH0H CH20H, a colourless, almost odourless liquid. It has a sweet taste, but is more acrid than ethylene glycol b.p. 187. Manufactured by heating propylene chlorohydrin with a solution of NaHCO under pressure. It closely resembles dihydroxyethane in its properties, but is less toxic. Forms mono-and di-esters and ethers. Used as an anti-freeze and in the preparation of perfumes and flavouring extracts, as a solvent and in... 

Determination of chiral-y-lactones from raw flavour extract of strawberries and other-fruit-containing foods and beverages... 

K. MacNamara and A. Hoffmann, Simultaneous nitr Ogen, sulphur and mass spectr omet-rtc analysis after multi-column switching of complex whiskey flavour extracts , in... 

In the flavour extract of apricots, racemic dihydroactinidiolide (DHA) was found as the first natural racemate detected by enantio-MDGC analysis [16]. The absolute configurations and the optical activities have been reported to be (R)-(-) and (S)- +) enantiomers, respectively [17, 18]. 

It is very common to combine methods in obtaining aroma isolates. The simultaneous distillation/extraction method previously described is an example. Another popular combination method initially involves the solvent extraction of volatiles from a food and then high-vacuum distillation of the solvent/aroma extract to provide a fat-free aroma isolate. This technique is broadly used today to provide high-quality aroma extracts for numerous purposes. The apparatus used in solvent removal has been improved upon to reduce analysis time and efficiency the modified method is termed solvent-assisted flavour extraction (SAFE) [16]. 

While the first two examples of using adsorption methods to produce aroma isolates were from gas streams. Tan et al. [28] applied adsorption methods to the isolation of flavouring extracts from mushroom blanching water. Unfortunately, only an abstract was available of this work so it lacks detail. It appears that they evaluated the use of two different resins (not described) and ethanol, pentane, hexane, and other solvents for desorption. They claim to have had good success in obtaining a useful aroma isolate. 

Alcohol-free Masking flavours Extracts Flavoured pads... 

Determination of chiral-y-lactones from raw flavour extract of strawberries and other-fruit-containing foods and beverages Fused silica retention gap (10 m X 0.25 mm i.d.) coupled to a DB-1701 column (15 m X 0.25 mm i.d 1 pun film thickness) Glass capillary column (38 m X 0.2 mm i.d.) coated with heptakis (3-0-accly 1-2,6-di-O-pentyl)-/ -cyclodextrin 4... 

Food and flavours Extracts for brewing (hops) Cocoa defatting Spices... 

The previously described manufacturing processes for flavour chemicals and flavour extracts primarily regard the physical and physico-chemical isolation and purification of naturally occurring flavour chemicals derived from plant and animal tissue. The huge area of organic chemical synthesis of nature-identical and synthetical flavour chemicals is not within the scope of this book. 

Besides that, fermentation can only be industrially attractive if the process provides highest yields and exhibits an efficient isolation and purification process (downstream processing) with only minimal product losses. Additionally, suitable substrates must be commercially available at low cost. Finally, the generation of flavours by fermentation in bioreactors will only be profitable if the desired product, be it a pure substance or a complex flavour extract, is not obtainable with comparable quality by inexpensive classical techniques. 

This definition does not apply to flavouring extracts, processed natural food substances or mixtures of flavouring substances... 

Updating the monographs of 60 herbs and spices of major importance for the flavour industry (Karl, 1998) special emphasis was placed on the essential oils which are obtained from these raw materials as natural flavouring extracts . 

Regardless of this problem biotechnically produced flavour extracts are very attractive. Under properly defined conditions biotechnical reactions allow a significant increase of yield or strength of the flavours compared to purely natural flavours. It is also practised to run biotechnical reactions in such a way that the purity of the produced flavours is increased and undesired side products are suppressed. In comparison to the complicated chemical syntheses of pure isomers of flavours chemicals, the biotechnically manufactured substances are generally homogeneously composed by nature . 

These advantages have a positive influence on the economy of biotechnical manufacturing processes. In many cases expensive starting materials can be replaced by cheaper and simpler substrates of the biochemical reaction which results in a favourable cost price for the flavour extract. Compared to commodities which meanwhile include numerous biotechnical products (e.g. technical enzymes), the relatively high prices obtainable for flavour chemicals justify the relatively complicated techniques necessary for biotechnical processes. Production of flavour chemicals is, therefore, an interesting further application of biotechnology in line with e. g. the generation of pharmaceutical products. 

With most biotechnologically produced flavour extracts the taste quality of natural fermentation processes can be reached and even surpassed. Normally the taste intensity is significantly higher compared to the usual fermentation process in the raw food material. Even completely new taste types may be accessible biotechnologically. The time necessary for the development of the desired taste in most cases may be signifi-... 

Enzymes are catalysts, i.e. they will not get worn out. It is therefore possible to operate with very low amounts of the enzyme. All these facts point to a very cost-effective possibility for the manufacturing of flavour extracts. 

Contrary to microbial flavour generation directly in the food by starter cultures, the technical bioreactions for flavour production with micro-organisms do not use the complete food raw material as substrate. Isolated and purified single components of food are used as substrates for the micro-organisms. Examples are butterfat from butter, proteins from meat, carbohydrates from plant food materials. Microbial material syntheses may lead to chemically defined pure substances (cf. chapter 3.2.1.1.2). It is also possible to obtain complex mixtures of different compounds. Polysaccharides, natural colours and also complex flavour extracts belong to this category. Figure 3.17 outlines the principle of such processes. 

In most cases the same micro-organisms are used for the fermentative production of flavour extracts in bioreactors which may also be applied during the natural in-sim food fermentation. In this way a very authentical taste of the concentrated flavour extract may be obtained. 

Most technical experiences are based on plant cells. This may be explained by the fact that the majority of all commercial flavour extracts is of plant origin. Compared to intact freely grovm plants the in-vitro plant cell culture has advantages because... 

Plant cells show an extensive repertoire of chemical reaction mechanisms epoxi-dation, reduction, oxidation, hydroxylation, isomerisation. It is self-evident that plant cell cultures synthesize as enantioselectively as their mother organisms. Besides the well-known flavour extracts and single substances, also presently unknown naturally flavour chemicals and mixtures of these are in principle obtainable. Therefore the rapid progress in investigating this area is not surprising [26],... 

Although the main objective of present publications is the synthesis of pure flavour chemicals by plant cells there is a number of experiments with plant cell cultures for the manufacturing of complex flavour extracts. In these cases it is intended to produce flavour extracts using cell cultures of taste-delivering plants similar to the extracts rendered by extraction from the natural mother plant. 

Flavouring products, as they are presently prepared in the flavour industry, are mainly very complex mixtures of chemically derived flavouring materials and flavour extracts of varying compositions as well as various carriers and other components (e.g. additives). 

A product or a mixture prepared for its flavouring properties and produced from ingredients or mixtures of ingredients which are themselves permitted for use in foodstuffs, or are present naturally in foodstuffs, or are permitted for use in process flavourings, by a process for the preparation of foods for human consumption. Flavour adjuncts may be added. This definition does not apply to flavouring extracts, processed natural food substances or mixtures of flavouring substances. 

Extract or Essence (B 10.003) shall be a solution in ethyl alcohol, glycerol, propylene glycol or any combination of these, of sapid or odorous principles, or both, derived from the plant after which the flavouring extract or essence is named, and may contain water, a sweetening agent, food colour and a Class II preservative or Class IV preservative. 

Artificial or Imitation Extract/Essence (B 10.004) shall be a flavouring extract or essence except that the flavour principles shall be derived in whole, or in part, from sources other than the aromatic plant after which it is named, and if such extract or essence is defined in these Regulations, the flavour strength of the artificial or imitation extract or essence shall be not less than that of the extract of essence. 

In the food regulations [45] the articles 250-252 deal with flavourings. According to Art. 250 the denominations esencia (essence) or aceites esenciales (essential oils) and extractos aromaticos (flavouring extracts) can be used for inoffensive natural or artificial preparations. 

The next chapter describes the basic physical and biotechnological processes which are today available for the production of flavourings and flavour extracts. These range from more traditional methods such as extraction and distillation to more recent developments, e.g. supercritical fluid extraction, spray and freeze drying as well as microencapsulation, and include the rapidly increasing field of biotechnology. 

Quinine, an antimalarial drug and flavouring extracted from cinchona bark. 

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