Flavouring extracts, essential oils

The examples discussed above clearly demonstrate that C02-extraction is a more gentle procedure than steam distillation. The smaller processing stress widely avoids the formation of artefacts. Therefore C02-extracts often have a better efficacy or a richer aroma profile reflecting the complete flavour or fragrance spectrum of the herbal raw material. This is also confirmed in the literature where professional fla-vourists have compared the aroma profiles of C02-extracts, essential oils and oleores-ins for a range of different spices [7]. Moreover C02-extraction is carried out under precisely standardised and controlled conditions which allow reproducible results. Since C02-extracts have their own character different from the usual distillates, they are new and powerful means for flavourists and food technologists to modify, improve or boost existing products or to create new premium flavour qualities. 

Chapter 3 deals with the raw materials which are of interest for the flavour sector. The topics range from chemically defined flavouring substances, both of natural and synthetic origin, to flavouring preparations and source materials, such as complex natural extracts, essential oils and juices. Eurthermore, process flavourings and nonflavouring compounds which are important for food technology are also presented. 

In the context of flavour and fragrance ingredients, C02-extracted essential oils have found applications in many product areas. In fragrances their retained top notes and the character of the original (derived from the molecular weight components 200-400, not found in steam-distilled oils) impart both life and substantivity. Although most readily appreciated in fine perfumery and colognes, these features have also been demonstrated in toiletries and soaps. 

Supercritical fluid extraction (SFE) has been extensively used for the extraction of volatile components such as essential oils, flavours and aromas from plant materials on an industrial as well as an analytical scale (61). The extract thus obtained is usually analysed by GC. Off-line SFE-GC is frequently employed, but on-line SEE-GC has also been used. The direct coupling of SEE with supercritical fluid chromatography (SEC) has also been successfully caried out. Coupling SEE with SEC provides several advantages for the separation and detection of organic substances low temperatures can be used for both SEE and SEC, so they are well suited for the analysis of natural materials that contain compounds which are temperature-sensitive, such as flavours and fragrances. 

Joulain, D. and Laurent, R. (1989). The catty odour in blackcurrant extracts versus the blackcurrant odour in the cat s urine In (S.C. Bhattacharyya, N. Sen and K.L. Sethi (Eds.), 11th International Congress of Essential Oils, Fragrances, and Flavours, Oxford IBH Publishing. New Delhi, India, pp. 89. 

DC146 Cu, ]. Q., F. Perineau, M. Dealmas, and A. Gaset. Gomparison of the chemical composition of carrot seed essential oil DG157 extracted by different solvents. Flavour Fragrance J 1989 4(4) 225-231. 

Kreck, M., Scharrer, A., Bilke, S., Mosandl, A. (2002) Enantioselective analysis of monoter-pene compounds in essential oils by stir bar sorptive extraction (SBSE)-enantio-MDGC-MS. Flavour Fragrance ]. 17 32-40. 

There are a number of published applications in which spices are extracted with liquid carbon dioxide to isolate a flavour- or aroma concentrate [22,48,54], Liquid CO2 dissolves the essential oils and lighter fractions of the oleoresins. Supercritical CO2 is generally a better extracting-solvent than liquid CO2, because higher densities, equivalent to higher solubility, can be achieved by raising the pressure. 

H. -G. 1990. Enantiomeric distribution of a-pinene, P-pinene and limonene in essential oils and extracts Part 1. Rutaceae and Gramineae. Flavour Fragrance J. 5 193-199. 

A flavouring essence is a traditional flavouring product prepared by washing a selected oil blend (predominately citrus oils) with an aqueous alcoholic solvent mixture (e.g. 60% ethanol/40% water). It is an extraction process in which the aqueous extract phase becomes the flavouring. The process is earned out under cool temperatures, for example, 5-10°C, either batch-wise or by counter-current extraction. The soluble oxygenated flavouring constituents present in the essential oil blend (e.g. citral in lemon oil) are effectively partitioned between the two phases of the mixture. The low temperatures employed ensure that the transfer of any oil into the hydro-alcoholic phase is minimised as a poorly processed essence will tend to cloud when used in the drink formulation. 

Volatile or essential oils are usually obtained from the appropriate plant material by steam distillation, though if certain components are unstable at these temperatures, other less harsh techniques such as expression or solvent extraction may be employed. These oils, which typically contain a complex mixture of low boiling components, are widely used in flavouring, perfumery, and aromatherapy. Only a small number of oils have useful therapeutic properties, e.g. clove and dill, though a wide range of oils is now exploited for aromatherapy. Most of those employed in medicines are simply added for flavouring purposes. Some of the materials are commercially important as sources of chemicals used industrially, e.g. turpentine. 

Salzer, U.J. (1 975) Analytical evaluation of seasoning extracts (oleoresins) and essential oils from seasonings. I. International Flavours and Food Additives 6(3), 151-157. 

Bernard, T., Perineau, F., Delmas, M. and Caset, A. (1989) Extraction of essential oils by refining of plant materials. II. Processing of products in the dry state lllicium verum Hooker (fruit) and Cinnamomum zeylanicum (bark). Flavour and Fragrance Journal 4, 85-90. 

It has been used as a flavouring agent in food products, perfumes and cosmetics. Coriander has been credited with many medicinal properties. Powdered seeds or dry extract, tea, tincture, decoction or infusion have been recommended for dyspeptic complaints, loss of appetite, convulsions, insomnia and anxiety (Msaada et al., 2007). The essential oils and other extracts from coriander have been shown to possess anti-... 

High-pressure C02 extracts are, in many cases, superior to solvent oleoresins and essential oils when used as food flavourings and have significantly lower spice... 

In summary, Foeniculum is stated to have three species, F. vulgare (fennel), F. azoricum Mill. (Florence fennel) and F. dulce (sweet fennel). Fennel is widely cultivated, both in its native habitat and elsewhere, for its edible, strongly flavoured leaves and seeds. The flavour is similar to, but milder than, that of anise and star anise. Anethole and fenchone are the major constituents of the solvent extract of seed phenols, free fatty acids, carbohydrates, proteins, vitamins and minerals have been reported in varying proportions. In the mature fruit, up to 95% of the essential oil is located in the fruit, greater amounts being found in the fully ripe fruit. Approximately 45 constituents have been determined from fennel seed oil, the main constituents being frans-anethole, fenchone, estragol (methyl chavicol), limonene, camphene, a-pinene and other monoterpenes, fenchyl alcohol and... 

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