Extraction citrus essences

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. 

Juice Cloud. Mechanical extraction of citrus fruits yields a turbid suspension of wall fragments and cellular organelles in a serum composed primarily of cell vacuolar fluids. In most citrus juice products, such a suspension of fragments and organelles is a desirable component, since it provides most of the characteristic color and flavor (28). Essence and peel oils suspended in juice contribute desirable citrus notes to flavor, and these oils are rapidly adsorbed by juice particulate material shortly after extraction (29). 

There are many applications where the organic compounds are extracted from natural materials. Extraction is used for preparation of pure flavor essences from expressed oils of various citrus fruit. Pyrethrum is recovered from pyrethrum flowers by solvent extraction. A continuous saponification, glycol extraction, and splitting process for converting fat into finished soap base has been used in soap production. 

Juice extraction represents 55% (w/w) of the initial weight of oranges, whereas the essential oils and essences extracted constitute only 0.2-0.22% (Sinclair, 1984). The citrus juice industry can recover essential oils from different intermediate process steps to obtain limonene or crude essences. In Figure 5.2, the different possibilities for obtaining essential oils with different properties are summarized (Girard and Mazza, 1998 Braddock, 1999). 

A simple way to obtain a clear soft drink is adding clear, water-soluble flavours, so-called essence flavours. The most popular products, usually derived from ethanol-extracted and distilled citrus peel oils, provide a subtle taste of lemon or lime. The dosage of these flavours is around 1 g per litre of final drink. Together with sweetener, acidifier and carbonation, one gets a fizzy clear and colourless drink with citrus taste. 

Conifer wood, balm trees, citrus fruits, coriander, eucalyptus, lavender, lemon grass, lilies, carnation, caraway, peppermint species, roses, rosemary, sage, thyme, violet and many other plants or parts of those (roots, rhizomes, stems, leaves, blossoms, fruits, seed) are well known to smell pleasantly, to taste spicy, or to exhibit specific pharmacological activities. Terpenes predominantly shape these properties. In order to enrich terpenes, the plants are carved, e.g. for the production of incense or myrrh from balm trees usually, however, terpenes are extracted or steam distilled, e.g. for the recovery of the precious oil of the blossoms of specific fragrant roses. These extracts and steam distillates, known as ethereal or essential oils ("essence absolue") are used to create fine perfumes, to refine the flavor and the aroma of food and drinks and to produce medicines of plant origin (phytopharmaca). 

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