Like other citrus fruits, the aroma of grapefruit can be incredibly uplifting.
What is the history of Grapefruit Essential Oil?
Grapefruit is a recently discovered citrus fruit belonging to the Rutaceae family. It was originally recorded in 1750 on the island of Barbados. Reverend Griffith Hughes, a Welsh naturalist, traveled to Barbados and published The Natural History of Barbados, in which he wrote the first description of the grapefruit. Hughes was in Barbados in search of the tree that was in the Garden of Eden, and he nicknamed grapefruit the “forbidden fruit”. Grapefruit is still referred to as one of the “Seven Wonders of Barbados.” [1, 2, 3]
By 1789, grapefruit’s moniker of the “forbidden fruit” had spread to Jamaica, where it was also called the “smaller shaddock.” Shaddock was a term for a pomelo (Citrus grandis), a fellow citrus fruit. In 1814, accounts of grapefruit under the name of “shaddock” were described by Jamaican planter and magistrate, John Lunan. John Lunan first used the English name grape-fruit in his writings, the Hortus Jamaicanensis, because it grows on the tree in clusters, similar to grapes. [1, 4, 5]
The origin of the shaddock (pomelo) is mysterious. A legend of a “Captain Shaddock,” who is believed to have brought the seeds to Barbados, has been a popular explanation. The discovery of a Captain Chaddock from the seventeenth century who traveled the West Indies has given some credence to the myth. [6]
Grapefruit is believed to be a hybrid between the sweet orange (Citrus sinensis) and the pomelo. The Jamaican sweet orange is believed to have originated in Asia, and the pomelo may have originated in Indonesia. Before 1837, the grapefruit was botanically classified with the pomelo. Grapefruit was not classified as its own species until 1837 when botanist James MacFayden separated the two fruits. At this time, it was still believed that the grapefruit was a type of pomelo. It was named Citrus paradisi until the 1940s, and then renamed Citrus x paradisi after the species was scientifically differentiated from the pomelo as a cross hybrid between the pomelo and sweet orange. [1, 7, 8]
The grapefruit was introduced to Florida in 1823 by one of the first permanent settlers to Pinellas County, French immigrant (and self-announced Count) Odet Phillipe. In 1870, Florida settler John MacDonald planted the first grapefruit nursery in Orange County. Later, an American entrepreneur, Kimball Atwood, began the Atwood Grapefruit Company which grew into the largest global source of grapefruit from Florida. Seedless pink grapefruit was discovered at the Atwood Company Groves in 1906. [7, 8, 9]
Common types of Grapefruit
Grapefruit (Citrus x paradisi) Varieties:
- Duncan
- Large oil glands
- Medium to large seeds
- Historically was the leading variety in Florida and Texas but now is commercially grown in India
- Highly aromatic
- Propagated by A.L. Duncan in 1892
- Marsh
- Propagated in 1862 by William Hancock
- Seedless
- Medium-sized oil glands
- Mildly aromatic
- Grown in Florida, Texas, California, Arizona, Australia, South America, South Africa, India, and Israel
- Foster
- Propagated in 1906
- Large oil glands
- Medium-sized seeds
- Grown in Florida, Arizona, Texas, and India
- Not extremely popular
- Oroblanco
- Hybrid made in 1958 by geneticists and patented in 1981
- Seedless
- Well adapted to California inland conditions
- Redblush (includes Ruby, Ruby Red, Curry Red, Shary Red, Facett Red, Webb, and Red Radiance)
- Seedless
- Very red pigment
- 75% of Florida’s grapefruit was red seedless by 1950
- Paradise Navel
- Propagated and patented by W.H. Nicholson in Winter Garden, Florida
- Distributed in 1976
- Smaller than other grapefruit
- Contained many seeds, but over time, it became seedless
- Star Ruby
- Discovered in the mid-1930s
- Introduced for distribution by 1971 after the seeds were irradiated out in 1959
- Due to the tree being susceptible to a type of root rot, and ringspot virus in Texas, Florida State ordered all trees to be destroyed.
- In 1977, disease-free budwood was made available
- The tree is more sensitive to sunburn, excessive water and not enough drainage, pesticides and herbicides, and bad weather
- Contains more sugar and acid than other varieties
- Sweetie
- Sweet flavor, rather than bitter
- Grapefruit crossed with pomelo in 1984 in Israel
- Triumph
- Propagated in 1884
- Medium-sized oil glands
- Has a slight flavor of an orange
- Contains seeds
- Thompson
- Also known as “Pink Marsh”
- Descendent of a “Marsh” grapefruit cultivar that was pink and seedless in 1913
- Small oil glands
- Faint aroma [8]
- Navel
- White flesh
- Seedless
- Navel on the blossom end
- Very sweet
- Rio Red
- Cross between Ruby Red and Star Ruby
- Rounder in shape than the Ruby Red and Star Ruby
- More juice than other varieties
- Stronger flavor
- Developed in Texas [3]
What is an essential oil?
Though essential oils do not contain any oils or fats (lipids), they are the distilled portion of the essence of the aromatic fruit or plant from which they are derived. Aromas are secondary defense mechanisms against threats from pests or animals. Essential oils are distilled essences of these defense mechanisms or secondary metabolites. Essential oils contain volatile compounds, with twenty to sixty constituents, and contain aromatic compounds and terpenes. [10]
How is Grapefruit Essential Oil Made?
The essential oil of citrus fruit is extracted in two ways: cold-pressed expression or distillation. The most popular method is through cold pressing, where the skin is pressed, and the essential oil that seeps out is collected. A method called “Écuelle à piquer” involves piercing the fruit and spinning the fruit so that the juice and oil that is released is caught and separated during the processing. Cold pressing with sponges is the traditional way that citrus essential oil was collected. Cold pressing citrus fruits yields more oil than distillation. [11][12]
Distillation of citrus fruits to yield essential oil is not common because it does not retain the same aroma as oils that have been extracted through cold-pressing. However, the distillation of citrus fruits for essential oils results in a purer oil that not contain the residues that are left behind by cold pressing methods. The residues left behind are waxes and some residues that may stain clothes and fabric, as well as clog aromatherapy diffusers over time. Additionally, distilled citrus oils do not contain photosensitizing furocoumarins. [11]
Why is Grapefruit Essential Oil a photosensitive essential oil?
Furocoumarins are nonvolatile compounds that function as a defense mechanism against insects and animals present in many citrus fruits. They are left behind after cold pressing extraction and can increase photosensitivity (a skin irritation caused by exposure to sunlight or UV light after applying them topically).
Some essential oils have been further distilled and heated to destroy the furocoumarins, and they are labeled “FCF” for furocoumarin-free. Steam distilled citrus essential oils do not contain furocoumarins.
Precautions to take when using cold-pressed citrus fruit essential oil is to avoid sunlight and UV lights (such as tanning beds) for 12-18 hours after you apply the essential oil. A common solution to working with these photosensitizing essential oils is to apply them at night.
Not all citrus fruits are equally as photosensitizing, and there are some members of the citrus family which are not photosensitizing. The photosensitizing members of the citrus family include grapefruit, lemon, and lime. The non-photosensitizing members of the citrus family are blood and sweet orange, red mandarin, and tangerine. [12]
What is Grapefruit Essential Oil made of?
Grapefruit essential oil contains antioxidants, polyphenols (caffeic acid, ferulic acid, p-coumaric acid, and sinapinic acid) [13], and the following constituents:
Limonene (95.00%)
α-Thujene (0.54%)
β-Pinene (0.25%)
Myrcene (1.90%)
Octanal (0.45%)
Octanol (trace)
β-Ocimene (0.08%)
γ-Terpinene (0.15%)
Linalol (0.13%)
Citronellal (trace)
Nonanal (0.06%)
Decanal (0.27%)
Geranial (0.09%)
Neral (trace)
Geranyl acetate (0.09%)
Valencene (0.06%)
β-Caryophyllene (0.24%)
Nootkatone (0.10%) [14]
It is important to note that grapefruit juice can interact with certain medications because of a constituent found in grapefruit juice: 6,7-dihydroxybergamottin (or DHB). DHB inhibits an enzyme, CYP3A4, that affects the bioavailability of certain medications and can cause blood levels of medications to stay too high without being metabolized correctly.
DHB is not found in the essential oil of grapefruit. It is theorized that DHB results from a hydrolyzation of epoxy-bergamottin (which is found in the peel and essential oil) during the extraction of juice from the grapefruit. Another cause of grapefruit juice/medication interactions is due to the flavonoids that contribute to the enzyme inhibitory effects of grapefruit juice. These flavonoids are not present in grapefruit essential oil. [15]
However, even though grapefruit essential oil is not likely to cause medication interactions, use caution if you are taking medications, or seek the advice of an aromatherapist or essential oil practitioner if you have questions. [15]
Safety and Side Effects of Grapefruit Essential Oil
Always be sure to dilute grapefruit essential oil with a carrier oil because undiluted grapefruit oil may cause skin irritation.
Avoid sunlight and UV lights for at least 12 hours after topical applications because of grapefruit’s photosensitizing properties.
Grapefruit oil is toxic to cats. [16]
Grapefruit essential oil has a reported oral toxicity in rats at greater than 5g/kg. Topical (dermal) toxicity in rabbits is greater than 5g/kg. [15]
References
- “Grapefruit.” New World Encyclopedia, www.newworldencyclopedia.org/entry/Grapefruit.
- “Griffith Hughes.” Wikipedia, en.wikipedia.org/wiki/Griffith_Hughes.
- “Florida Grapefruit.” All about Florida Oranges, sites.google.com/site/allaboutfloridaoranges/grapefruit.
- “John Lunan.” Wikipedia, en.wikipedia.org/wiki/John_Lunan.
- “Pomelo.” Wikipedia, en.wikipedia.org/wiki/Pomelo.
- Kumamoto, J., et al. “Mystery of the Forbidden Fruit: Historical Epilogue on the Origin of the Grapefruit,Citrus Paradisi (Rutaceae).” Economic Botany, vol. 41, no. 1, Jan. 1987, pp. 97–107., link.springer.com/article/10.1007/BF02859356.
- “Grapefruit.” Wikipedia, en.wikipedia.org/wiki/Grapefruit.
- Morton, J. “Grapefruit.” Fruits of Warm Climates, 1987, pp. 152–158., hort.purdue.edu/newcrop/morton/grapefruit.html.
- “Odet Philippe.” Wikipedia, en.wikipedia.org/wiki/Odet_Philippe.
- Yap, Polly Soo Xi et al. “Essential oils, a new horizon in combating bacterial antibiotic resistance.” The open microbiology journalvol. 8 6-14. 7 Feb. 2014, doi:10.2174/1874285801408010006. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3950955/.
- Schutes, Jade. “How Are Essential Oils Extracted?” naha.org/explore-aromatherapy/about-aromatherapy/how-are-essential-oils-extracted.
- Ming-Chiu Ou, Yi-Hsin Liu, Yung-Wei Sun, and Chin-Feng Chan, “The Composition, Antioxidant and Antibacterial Activities of Cold-Pressed and Distilled Essential Oils of Citrus paradisi and Citrus grandis (L.) Osbeck,” Evidence-Based Complementary and Alternative Medicine, vol. 2015, Article ID 804091, 9 pages, 2015. https://doi.org/10.1155/2015/804091.
- “All About Photosensitive Essential Oils.” Rocky Mountain Essential Oils, www.rockymountainoils.com/learn/all-about-photosensitive-essential-oils/.
- Okunowo, Wahab O., et al. “Essential Oil of Grape Fruit (Citrus Paradisi) Peels and Its Antimicrobial Activities .” American Journal of Plant Sciences, vol. 4, 2013, pp. 1–9., doi:http://dx.doi.org/10.4236/ajps.2013.47A2001 .
- Clarke, Sue. “Essential Chemistry for Aromatherapy (Second Edition).” 2008, www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/grapefruit.
- Tisserand, Robert, and Rodney Young, PhD. “Essential Oil Safety (Second Edition).” 2014, www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/grapefruit
- “Grapefruit.” Toxic and Non-Toxic Plants, www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/grapefruit.
