About Botanical Oils
The use of botanical oils can be traced back thousands of years, with roots in cultures as diverse as the ancient Sumerians, Chinese and Roman Empire. Botanical oils are prepared from whole plant, preserving its scent, main active ingredients, and the essence of the plant. Botanical oils made from various plants have been used throughout history to honor gods, prepare bodies for funerals, preserve beauty, assist with hygiene and treat a wide variety of medical conditions. Instructions for the preparation and use of plants as medicine is catalogued in the works of Dioscorides, De materia medica, back in the first century.
Modern technology has allowed the active parts of plants to be identified and studied for their role in health and their usefulness against various medical conditions. The value of botanical oils has stood the test of time.
The Properties Of Oranges
The orange is believed to be a native of tropical areas in Asia, from which it spread to India, the east coast of Africa and the eastern Mediterranean. The development of Arab trade routes and the spread of Islam moved the orange around the globe. While the orange is a tropical fruit, the trees grow best where there is a light frost in the winter. The original name for the orange comes from the Sanskrit word “naranga,” which comes from the Tamil word “naru” meaning fragrant.
Type Of Oranges
Orange trees are the most commonly cultivated fruit tree in the world, and there are several varieties or cultivars of the orange, whose Latin name is Citrus sinensis. Different cultivars are grown based on how well they thrive at different times of the year and in different soil conditions. In the U.S., California primarily produces the “Washington Navel” and the “Valencia” cultivars and Florida produces the “Hamlin,” “Pineapple” and “Valencia.”
The popular cultivars listed above are sweet oranges valued for their juice. Around the world, bitter fruits are consumed to stimulate digestion. There are several sour orange varieties, including Citrus Aurantium grown in Vietnam, which is used in liquors including Triple Sec, Grand Marnier and Curacao. The Daidai, variety of C. Aurantium, is used therapeutically in Chinese and Japanese medicine and exchanged at the Japanese New Year to bring longevity. The sour Seville orange is used in marmalades due to its high pectin content, and the chinotto orange is a flavoring in liqueurs including Campari. Orange oil is taken from the peels of several varieties, including the sweet Valencia orange, Citrus aurantium, and the sour Bergamot variety of orange, whose oil is a well known flavor in Earl Grey tea.
The orange is a famously bright orange, vitamin C-rich fruit, and indeed each cup of orange slices provides almost 100mg of vitamin C. Its lesser known nutrients include potassium, phosphorus, magnesium, folate and vitamin A. The orange contains a range of fatty acids as well, mainly unsaturated fatty acids, including linoleic, palmitic, linolenic and vaccenic. The main alkaloid in bitter oranges is para-synephrine.
Pectin is a water-soluble fiber that is found in fruits and vegetables. It is rich in the orange, some coming from the pulp of the orange, but more present in the peel. In the plant itself, pectin help bind the plant cells together, which supports the fruit’s shape. Over time, enzymes from the plant will digest pectin, as you notice in a ripening fruit that is losing its rigidity. The range of pectin present in oranges ranges from 0.25 to 0.76 percent, a wide range dependent on the variety of orange and the ripeness of the fruit. Pectin, as a fiber source, lowers cholesterol and helps manage blood sugar.
Did You Know?
The fruit of the orange becomes ripe while the outside of the orange is still green. The practice of “degreening” the orange uses ethylene, the aging hormone of plants, to ripen oranges post-harvest, creating the bright orange color. Degreening needs to take place under carefully managed conditions, or it can lead to rotting and other problems for the fruit.
Orange Oil Preparation
The essential oils of the orange are taken from the bright orange peel. This outer peel of citrus fruits is called the “flavedo,” and it is covered with tiny glands. Each gland contains one drop of essential oil. To extract the organic oil, the peel must be physically broken open. The main components of orange oil are somewhat different between a sweet orange and a bitter orange oil.
Expression Or Cold Pressing
Expression refers to the process of slowly breaking down orange peel under mechanical pressure to release the oils from the glands of the peel. This is process uses ecuelle a piquer, or an apparatus designed to extract oils from fruit rinds. It began in France as a bowl lined with needles to prick the fruit’s peel, and a funnel to collect the released oils. It has been modernized to accommodate commercial practices, but uses the same principles of poking and agitating the rind.
Bitter orange oils are obtained via cold pressing. Cold pressed means that the oil was expressed at a low temperature. The low temperature preserves the volatile oil, which provides the rich scent of the plant. The best yield from orange rinds appears to come when the peel has been dried first.
The oil that is collected will range in composition, depending on the how mature the plant was and which variety of orange was used. All varieties of orange produce volatile oils that are very rich in the monoterpene hydrocarbon, limonene. The flavor of the oil comes from its sesquiterpene hydrocarbons. Hesperidin and other flavonoids are abundant in the peels, but they break down quickly during processing.
Distillation extraction means exposing a plant to water or steam to break down the plant material and release the essential oil. The oils are cooled and condensed for collection. Distillation is used for orange extraction, using either the whole fruit or the peel.
Steam distilled orange peel oil will not contain the waxy residue that a cold-pressed oil would contain. This makes them less likely to clog oil diffusers, stain fabric and, as they are less biologically active, extends the shelf life. Distillation also allows the fucouramins to be removed from orange oils. Furocoumarins have been found to be photocarcinogenic, which means that when these compounds are exposed to light, they can cause mutations in cells that lead to cancer. This helps with leave-on skin products that might be scented with orange oil. The toxicity is not observed in wash away products, but there is some evidence that drinking orange juice regularly causes the photosensitivity that can lead to skin cancer.
Medicinal Uses for Orange Oil
Uses In Traditional Chinese Medicine
The peels of both C. Aurantium and the sweeter mandarin orange (Citrus reticulate) are used in Chinese medicine. The orange is considered effective for clearing obstructions. The peels are primarily used to improve digestion, relieving gas and bloating. When symptoms of digestive disturbances, such as diarrhea or constipation, occur together with respiratory symptoms of phlegm and chest congestion, bitter orange rinds are used to treat them together.
As the problem of antimicrobial-resistant organisms spreads, the interest in plant sources of anti-fungals, antibiotics and anti-viral agents has increased. Bitter orange oil has been studied for it its success treating microbial infections, such as Athlete’s foot and ring worm. Orange oil has demonstrated promising efficacy against fungus, although used as a pure oil it can be somewhat irritating to the skin. Cold-pressed terpeneless Valencia orange oil and an extract of limonene both inhibit the growth of Campylobacter and Arcobater species of bacteria.
The fragrant essential oil of has been shown to reduce anxiety before operations, in patients awaiting dental procedures, and in kids having dental work done. These effects were not based on self-report, but were demonstrated in lowered pulse rates and salivary cortisol levels. In one study that compared self-reports of anxiety and the systolic blood pressure in patients exposed to neroli oil from C. Aurantium or placebo when undergoing a colonoscopy showed that the physiological change of lowered blood pressure happened even when the experience of anxiety was present.
The antioxidant-rich orange is useful for improving flow through blood vessels. Endothelial damage from obesity was found to improve in teenagers who were given capsules of dried C. aurantium over just one month. Longer trials are needed, but this supports a larger body of research into the flavonoids and antioxidants that are abundant in orange peels and ability to repair the walls of blood vessels.
The main alkaloid in bitter oranges is p-synephrine and it has been the center of some controversy. As a common ingredient in ephedrine-free weight loss supplements, there are recommendations against its safety. P-synephrine is a beta agonist, which means it increases the breakdown of fat and the production of energy. A similar agent, meta-synephrine, does not naturally occur in oranges, but is sometimes synthesized and added to weight loss supplements. While p-synephrine does not bind to the receptors in the body that raise blood pressure, m-syneprhine does. The concerns about p-synephrine don’t appear to be well-founded, but they do persist. The synephrine of bitter orange is a banned substance by the National Collegiate Athletic Association (NCAA).
Orange oil has been used to enhance “tired blood,” most likely anemia, as well as fatigue from viral infections, impurities of the skin, hair loss, bruising, pain and frost bite. It has been used for several conditions of the eye, including swollen lids and bleeding from the retina. Most likely due to its anti-microbial action, it has been used to treat bed sores.
Questions About Orange Oil
What should I look for in an orange oil?
Cold-pressed orange essential oils are generally pale in color, but may vary depending on the time of year and type of orange that was used. It should smell strongly like oranges, although neroli oil from bitter oranges may smell unlike the expected citrus aroma. If the oil has been distilled, it will be clear and may be thinner than a pressed oil, as all waxes and residues will have been removed in processing. If using it as a topical agent that will remain on the skin, look for a psoralen-free orange oil.
If I am allergic to citrus, can I use orange oil?
If you have an allergy to any kind of citrus, or if you are not sure if you have a citrus allergy, orange oil should be avoided, even as a topical agent. The IgE reaction that occurs when someone has an orange allergy seems to cause a cross-reaction with pollen, so if you know you have a strong pollen allergy, talk to your doctor before trying citrus oil.
Is it safe to use orange oil on kids?
Do not use orange oil on the skin of kids if they will be in the sun. It can raise their risk for sunburns and skin cancer. Orange, as a member of the citrus family, is a common allergen, so watch closely for signs of allergic reaction. Never use undiluted orange oil on the skin, and always watch for irritation when using any preparation with essential oils on the skin. Allergies can develop over time.
Never give a child any essential oil internally. A drop of essential oil diluted in a carrier oil applied to the feet is sufficient to get the benefits for a child.
How long is the shelf life of orange oil?
Kept under proper storage conditions, orange oil will only last about nine to 12 months. It should be stored in a dark bottle, and in a cool dark place since light and heat will oxidize it. Watch for clouding or an unpleasant smell as signs it has spoiled.
Can I use it on my skin?
Orange oil alone is very irritating to the skin. Even when used a topical anti-fungal, it should be diluted to represent only 25 percent or less of the solution. Orange oil on the skin in the sun is photosensitizing, possibly increasing your risk of a sunburn, and photocarcinogenic, potentially increasing the risk of skin cancer. This will not occur from use of products that wash off, such as shampoo or soaps, as these do not leave the furocoumarins on the skin. Use caution with orange oils in products used on sun-exposed skin, such as lotions.
Caution And Considerations
Use caution with orange or any citrus oil on the skin. They are photosensitizing and can increase the risk of a sunburn or increase the risk of skin cancer. If you are at high risk for skin cancer, there may be reason to be cautious with orange juice consumption, as the oils present in the juice and pulp may be photosensitizing as well.
While orange juice is safe to drink, never take essential oils internally.
Orange juice, like its fellow citrus member grapefruit, can have some effect on how you metabolize medications. If you are using medication, ask your doctor what a safe level of orange juice intake is for you.
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