The essential oil of sweet orange what it is and what it is used for
Sweet orange is a cross between mandarin and pomelo and grows in numerous varieties throughout the world in warm, semi-tropical and tropical temperate zones.
The orange tree appears to have originated in the Far East in the area between the Himalayas and south-western China, and was brought to the Arab countries in the 9th century, and from there probably through the Mediterranean islands to Spain and to Italy around the 11th century. It is known that the trees were cultivated in Seville and Palermo in the 13th century.
Varieties: there are hundreds of different cultivars and grafts, which can however be divided into 4 groups (Saunt, 1990): Navel (type var. Washington), common orange (type Valencia), red oranges (type Sanguinello) and sweets (type Succhari).
Sweet orange essential oil: extraction method
There are different methods to extract the aromatic substances from the vegetable matrix: distillation, cold pressing, solvent extraction. In the case of citrus fruits, the preferred extraction method is cold pressing. The essential oil thus produced is then often distilled. The part used: the thin epicarp.
With the cold pressing method a product is obtained with characteristics closer to
those of the essence present in the plant matrix, because chemical or thermal treatments are not involved. It is used only for essences contained in surface cells in large quantities, as in the case of the epicarp of the fruits of the genus Citrus (Rutaceae). It is almost always a method associated with the citrus industry, in particular the juice industry, and the apparatuses are almost invariably
inserted in the main line for the separation of fruit juice and pulp.
Pratically, the method consists in the compression breakage of pockets full of essence present on the surface of the rind, and then in the collection of the essence thus released.
The method is very different from steam distillation, and therefore the product obtained will be different from the essential oils obtained by distillation. The product will have characteristics closer to those of the essence present in the plant matrix, because in the extraction there are no physical filters and the temperatures are much lower. In general, the essential oil from squeezing is always richer and more complex than the distillation oil, because in addition to all the volatile molecules it also contains non-volatile molecules (this also applies to extraction with solvents!) Because they are too heavy, but still fragrant. Among these non-volatile compounds there are also non-perfumed and uninteresting compounds, such as waxes and paraffins, and perfumed compounds that present risks, such as furocumarine, molecules that cause phototoxicity problems. They can also pass xenobiotic residues: it is therefore essential to use only organic fruits.
Waxes and paraffins can be eliminated with the method of dewaxing, which consists in keeping the essential oils in conical-shaped steel containers with stirrers, at temperatures from –4 ° C to –24 ° C for at least a week, to allow solidification and depositing the waxes, then centrifuging them and eliminating the inert elements. In recent years some companies have started using an ultra-rapid cooling technique to speed up the solidification of the waxes. The furanocumarine and the possible xenobiotics can instead be eliminated only by fractional distillation. A residual part of essence remains in the juice by squeezing, and is recovered by distillation of the juice itself.
The main modern methods for cold pressing are:
- peeler: the fruits pass through a rasping auger that breaks the oil pockets while a spray of water washes away the emulsion. The fruits then pass to rotors with needles that break the last pockets. A watery spray washes away the essence, which is then collected, filtered and separated from the water with a mechanism
- Brown oil extractor: application of the Eucelle method similar to the peeler, it is part of a more general citrus juice extraction apparatus, and is composed of rotating rollers equipped with penetrating tips that break the cells containing essence; a watery spray washes away the essence, which is then collected, filtered and separated from the water with a centrifugal mechanism;
- shading: the fruits cut in half are emptied of juice and pulp. The rinds remain 24 hours to macerate in a calcium carbonate solution and then pass through a steam roller which causes the bags to burst. A spray of water washes away the emulsion;
- brown Peel Shaver: similar to the nuance, it is part of a more general citrus juice extraction apparatus. The already emptied rinds are cut into four and passed through a system of compressed rollers and blades that eliminate the white part (albedo) from the rich part in essences (flavedo) and squeeze the essences from the latter. A watery spray washes away the essence, which is then collected, filtered and separated from the water with a centrifugal mechanism;
- FMC extractor: part of a more general citrus juice extraction apparatus, a pressure mechanism is composed at the same time peels and squeezes the peel, sucks pulp and juice and separates them. As for the other apparatuses, a spray of water washes away the essence that is then collected, filtered
and separated by centrifugation.
How to recognize the sweet orange essential oil
The color of the sweet orange essential oil varies from straw yellow to a moderate orange-brown.
As for its olfactory profile, with a characteristic aroma of orange peel, fruity, sweet, green-orange with a slightly orange and aldehyde finish note. The distinctive aroma is given by the presence of C8 (n-octanal) aldehydes, C10 (n-decanal) aldehydes, C15 aldehydes, α- and β-sinesal, citral aldehydes, and the various aliphatic esters present. The profile depends very much on the area of origin, from the moment of harvesting, from the variety used and also from the method of cold pressing used to obtain it. The blood oranges give a red oil and a sweeter aroma ("red orange").
Here are the various types of sweet orange on the market:
Sweet orange Brazil: perfume with a full character, citric with aldehyde notes from C10, more raw
Florida and less floral than California. Strong aldehyde final note.
California sweet orange: sweet fruity aroma reminiscent of orange juice, with a strong note of esters
and thin very light note of ethyl butyrate; not as fresh as Brazil. The final note after 24 hours is strongly aldehyde with a slight woodiness.
Sweet orange Florida: fruity and orangey scent, more externally fragrant than Brazil, but with
more harsh and rough, and aldehyde, although it is normally considered the softest and best on the market given the high percentage of aldehydes (1.6-1.8%). Strong final note, aldehyde and woody.
Sweet orange Greece: green, aldehyde, orange and a little fruity perfume. Final note moderately
strong orange, not very fat.
Sweet orange Guinea: full-bodied but still sour perfume. Final note softly aldehyde.
Sweet orange Seville: softer and thinner fragrance than Brazil, but less aldehyde. The note
final is one of the most rough and rough (very high percentage of aldehydes).
Sweet orange from Sicily: green-orange and fruity aroma with a slightly orange and aldehyde finish note.
The essential oil of organic red orange Gadoi (Citrus sinensis L. Osbeck, family of Rutaceae), which you can find in our aromatherapy department, comes from the pressing of the skins (of oranges from organic cultivation, harvested at 300m above sea level, in Sicily) with an innovative machine that gently pricks the skins without scratching them. In this way the essential oil is particularly pure. The scent is delicate and sweet.
The sweet orange essential oil: properties
- olfactory activity: Rovesti (1973) has experimented with the use of essential oil sprayed in the environment, nebulisation which has exerted a stimulating action on the CNS and is slightly antidepressant.
It can have a tranquilizing effect in case of anxiety, and can contribute to decreasing minor depressive states.
- antifungal activity: Low activity (Lis-Balchin, Deans, Hart, 1994; Maruzzella, 1960; Maruzzella, Liguori, 1958).
The sweet orange essential oil: possible uses
1) on the nervous system can have a tranquilizing effect in case of anxiety, and can contribute to decreasing minor depressive states. The best way to use the orange essential oil in the massage is to combine it with other essential oils, to give the mix fresh and fruity notes.
2) the orange essential oil is an effective environmental deodorant, it mixes very well with spicy essential oils such as clove, black pepper, ginger etc. Ideal for pot pourri.
Here is also, for environmental cleansing and perfuming, an easy recipe for cleaning and perfuming surfaces: mix 150 ml distilled water, 8 ml vinegar, 15 drops of essential pine oil, 6 drops of essential orange oil (Citrus sinensis). Put in a glass bottle with nebulizer and remember to shake well before use.
In our aromatherapy department you can find the relaxation mix, already prepared, for diffuser, formulated by Prof. Marco Valussi, composed of these essential oils of the production Gadoi: intermediate organic lavender, organic red orange and organic feminiello lemon and organic jojoba wax. Also acts as an air freshener.
The sweet orange essential oil: pay attention about possible adulterations
Adulteration takes place in many ways:
- mixing the essential oil with citric terpenes, distilled orange essential oil or other citric essential oils, synthetic limonene;
- the essential oil of sweet orange and bitter deterpenates, desesquiterpenates or concentrates are mixed with essential oil of sweet distilled orange;
- very often synthetic antioxidants are added to increase shelf life. The essential oil of sweet orange is sometimes used to replace bergamot.
The sweet orange essential oil: caution
The essential oil has a low risk of phototoxicity. Do not use if beyond the expiration date or more than two years after bottling because the oxidized oil could cause irritation. Store in sealed containers, away from light and heat, if possible in the refrigerator.
Individuals suffering from allergic reactions to cosmetics, perfumes or products based on citric fruits should avoid this essential oil
Average dose allowed in cosmetic creams = 0.1%; average dose allowed in perfumes = 0.8%.
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