Orange oil
Encyclopedia
Orange oil is an essential oil
produced by cells inside the rind
of an orange fruit
. In contrast to most essential oils, it is extracted as a by-product
of orange juice production by centrifugation, producing a cold-pressed oil. It is composed of mostly (greater than 90%) d-limonene, and is therefore often used in place of pure d-limonene, which can be further extracted from the oil by distillation
.
is what gives citrus
fruit their familiar aroma, and is therefore used in perfume and household cleaners for its fragrance. It is also an effective, environmentally friendly, and relatively safe solvent
, which makes it an active ingredient of choice in many applications, such as, but not limited to, adhesive
and stain removers, cleaners of various sorts, and strippers.
. Most of the substances are part of the terpene
group with limonene
being the dominant one. Long chain aliphatic
hydrocarbon alcohols and aldehyde
s like octanol
and octanal
are second important group of substances.
Limonene and its oxidation products are skin irritants, and limonene-1,2-oxide (formed by aerial oxidation) is a known skin sensitizer. Most reported cases of irritation have involved long-term industrial exposure to the pure compound, e.g. during degreasing or the preparation of paints. However a study of patients presenting dermatitis showed that 3% were sensitized to limonene.
Limonene has been observed to cause cancer in male rat
s, by reacting with α2u-globulin, which is not produced by female rats. There is no evidence for carcinogenicity or genotoxicity in humans. The IARC
classifies d-limonene under Class 3: not classifiable as to its carcinogenicity to humans.
Limonene is also flammable.
green pesticides, and can kill individual and colonies of ant
s and eradicate their "scent-pheromone
trail" indicators to disrupt re-infestation. It is safe in areas such as kitchens.
Essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove...
produced by cells inside the rind
Peel (fruit)
Peel, also known as rind or skin, is the outer protective layer of a fruit or vegetable which could be peeled off. The rind is usually the botanical exocarp, but the term exocarp does also include the hard cases of nuts, which are not named peels since they are not peeled off by hand or peeler, but...
of an orange fruit
Orange (fruit)
An orange—specifically, the sweet orange—is the citrus Citrus × sinensis and its fruit. It is the most commonly grown tree fruit in the world....
. In contrast to most essential oils, it is extracted as a by-product
By-product
A by-product is a secondary product derived from a manufacturing process or chemical reaction. It is not the primary product or service being produced.A by-product can be useful and marketable or it can be considered waste....
of orange juice production by centrifugation, producing a cold-pressed oil. It is composed of mostly (greater than 90%) d-limonene, and is therefore often used in place of pure d-limonene, which can be further extracted from the oil by distillation
Distillation
Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction....
.
Limonene
LimoneneLimonene
Limonene is a colourless liquid hydrocarbon classified as a cyclic terpene. The more common D isomer possesses a strong smell of oranges. It is used in chemical synthesis as a precursor to carvone and as a renewably-based solvent in cleaning products....
is what gives citrus
Citrus
Citrus is a common term and genus of flowering plants in the rue family, Rutaceae. Citrus is believed to have originated in the part of Southeast Asia bordered by Northeastern India, Myanmar and the Yunnan province of China...
fruit their familiar aroma, and is therefore used in perfume and household cleaners for its fragrance. It is also an effective, environmentally friendly, and relatively safe solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
, which makes it an active ingredient of choice in many applications, such as, but not limited to, adhesive
Adhesive
An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...
and stain removers, cleaners of various sorts, and strippers.
Composition
The composition of orange oil varies for several reasons. Region and seasonal changes as well as the method used for extraction lead to these variations. Several hundred compounds have been identified with gas chromatograph-mass spectrometryMass spectrometry
Mass spectrometry is an analytical technique that measures the mass-to-charge ratio of charged particles.It is used for determining masses of particles, for determining the elemental composition of a sample or molecule, and for elucidating the chemical structures of molecules, such as peptides and...
. Most of the substances are part of the terpene
Terpene
Terpenes are a large and diverse class of organic compounds, produced by a variety of plants, particularly conifers, though also by some insects such as termites or swallowtail butterflies, which emit terpenes from their osmeterium. They are often strong smelling and thus may have had a protective...
group with limonene
Limonene
Limonene is a colourless liquid hydrocarbon classified as a cyclic terpene. The more common D isomer possesses a strong smell of oranges. It is used in chemical synthesis as a precursor to carvone and as a renewably-based solvent in cleaning products....
being the dominant one. Long chain aliphatic
Aliphatic compound
In organic chemistry, aliphatic compounds are acyclic or cyclic, non-aromatic carbon compounds.Thus, aliphatic compounds are opposite to aromatic compounds.- Structure :...
hydrocarbon alcohols and aldehyde
Aldehyde
An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....
s like octanol
Octanol
Octanol is a straight chain fatty alcohol with eight carbon atoms and the molecular formula CH37OH. Although the term octanol usually refers exclusively to the primary alcohol 1-octanol, there are other less common isomers of octanol such as the secondary alcohols 2-octanol, 3-octanol and...
and octanal
Octanal
Octanal is an aldehyde with the chemical formula C8H16O. It occurs naturally as a colorless or lightly yellow tinged liquid with a fruit-like odor. It is a fairly combustible liquid. It is used commercially as a component in perfumes and in flavor production for the food industry.Octanal can also...
are second important group of substances.
| Compound | Italian Orange Oil Concentration [%] | Valencia orange oil Concentration [%] | Valencia orange oil Concentration [%] | Valencia orange oil Concentration [%] |
|---|---|---|---|---|
| Limonene Limonene Limonene is a colourless liquid hydrocarbon classified as a cyclic terpene. The more common D isomer possesses a strong smell of oranges. It is used in chemical synthesis as a precursor to carvone and as a renewably-based solvent in cleaning products.... |
93.67 | 91.4 | 95.17 | 97.0 |
| α-Pinene | 0.65 | 1.4 | 0.42 | – |
| Sabinene Sabinene Sabinene is a natural bicyclic monoterpene with the molecular formula C10H16. It is isolated from the essential oils of a variety of plants including holm oak and Norway spruce... and β-Pinene |
1.00 | 0.4 | 0.24 | – |
| Myrcene | 2.09 | 4.3 | 1.86 | 0.03 |
| Octanal Octanal Octanal is an aldehyde with the chemical formula C8H16O. It occurs naturally as a colorless or lightly yellow tinged liquid with a fruit-like odor. It is a fairly combustible liquid. It is used commercially as a component in perfumes and in flavor production for the food industry.Octanal can also... |
0.41 | – | - | – |
| Linalool | 0.31 | 0.8 | 0.25 | 0.3 |
| δ-3-Carene Carene Carene, or delta-3-carene, is a bicyclic monoterpene which occurs naturally as a constituent of turpentine, with a content as high as 42% depending on the source. Carene has a sweet and pungent odor. It is not soluble in water, but miscible with fats and oils.... |
0.31 | – | – | – |
| Decanal Decanal Decanal is an organic compound with the chemical formula C9H19CHO. It is the simplest ten-carbon aldehyde. Decanal occurs naturally and is used in fragrances and flavoring. Decanal occurs in nature and is an important component in citrus along with octanal, citral, and sinensal... |
0.27 | 0.4 | 0.28 | – |
Safety
The limonene which is the main component of the oil is a mild irritant, as it dissolves protective skin oils.Limonene and its oxidation products are skin irritants, and limonene-1,2-oxide (formed by aerial oxidation) is a known skin sensitizer. Most reported cases of irritation have involved long-term industrial exposure to the pure compound, e.g. during degreasing or the preparation of paints. However a study of patients presenting dermatitis showed that 3% were sensitized to limonene.
Limonene has been observed to cause cancer in male rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s, by reacting with α2u-globulin, which is not produced by female rats. There is no evidence for carcinogenicity or genotoxicity in humans. The IARC
International Agency for Research on Cancer
The International Agency for Research on Cancer is an intergovernmental agency forming part of the World Health Organisation of the United Nations....
classifies d-limonene under Class 3: not classifiable as to its carcinogenicity to humans.
Limonene is also flammable.
Biological pest control
Orange oil can be used in biological pest controlBiological pest control
Biological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...
green pesticides, and can kill individual and colonies of ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s and eradicate their "scent-pheromone
Pheromone
A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual...
trail" indicators to disrupt re-infestation. It is safe in areas such as kitchens.