I couldn’t decide between which oils to cover and initially had chosen two (YUZU and petitgrains) but have now back tracked as there is so much I have gathered on Yuzu and there is also so much to share on the diversity of the petitgrains that I will hold those ones over to the next newsletter. YUZU is an oil, which when you meet it, shows an intriguing persona. Parts of it seem familiar, much like when you bump into someone in the street and you recognise the face or voice, but can’t quite place them in context. The rest of it is evocative and exciting like meeting a stranger and you want to get to know them more! I first came across YUZU a few years ago while visiting New York for the very time. My good friend and host took me to ‘The Village’ where all the wonderful quirky shops are- and I saw some incense cones (I am not a fan of incense normally) but these were made of YUZU oil and I was hooked! I then spent a long time trying to track some down and as chance had it a group of Korean aromatherapists came to NZ and attended a workshop with me and I was gifted a precious bottle of Yuzu oil which I sniffed and shared but never used. Over time I was able to get some on an adhoc basis and now it feels like a ‘regular’ oil I use and love- but one which still excites me!
|Botanical name||Citrus junos Sieb. ex Tanaka|
|Extraction method||Cold expression of the rinds- this oil has been quite rare to Western aromatherapists until relatively recent times and is one of the most expensive of citrus oils in commercial production. The yield is between 0.18-0.2%. Research has been conducted on stem distilled oil, however i have not seen commercial steam distilled oil available for sale,|
|Main oil countries||Japan-some production in Korea. Originated in China and cultivated in Japan from the 10th C. It also appears that there is production from China, however I have not seen this oil available commercially. Yuzu is widely produced in various parts of Japan, with an estimated 20,000 tonnes produced annually, primarily for flavouring. The juice is used to make Japanese salad dressing called ‘Ponzu’ and the peel is used to make marmalade. A teaspoon of marmalade in a glass of champagen is reported to be a nice drink! The zest is also used in a spicy sauce made with chillies. In Korea the rind is made into a health tea taken for its antioxidant properties. In the last ten years there has been an increase in the demand for the essential oil, both for aromatherapeutic as well as fragrancing purposes.(Ref: Kasiwagi et al. 2009)|
|Description||The yuzu is a small tree (up to 4 m high), with yellow fruit similar to small oranges, large lemons. The rind can be quite knobbly or pitted. The lovely white flowers bloom in autumn. It is very cold resistant.The essential oil is pale yellow|
|Aroma||A tangy, crisp citrus oil-floral yet citrus like-similar to grapefruit but not as sweet. Similar to a cold pressed lime or very good quality bergamot. Descriptive aromatic notes present in decreasing order are : grassy, floral, herbal, sweet, citrus, green and bitter. Other minor aromatic notes include spicy, minty and astringent amongst others (Ref: Thi Lan Phi & Sawamura, 2008)|
|Key constituents %
174 differnt compounds have been detected, and of these around 74 have been postively identified
|Cold Pressed Oil
Between 94-98% of the total volume of constitutions are made up of a mix of monoterpene hydrocarbons (82%) and sesquiterpenes (6-7%). The most prominent constituent is d-limonene at 56-60%, the next most prominent is gamma terpinene at 11-13%. The remaining 60+ ingredients are mostly present in munite amounts of 0.1-3%
(Ref: Thi Lan Phi & Sawamura, 2008)
Steam Distilled Oi lFresh steam distilled yuzu oil has around 44 identified constituents, with monoterpen hydrocarbons accounting for >95%. Sesquiterpene hydrocarbons at <3%. Limonene was the most prominent at >72%. Gamma terpinene was the second most prominent at >11%. the SDO contains less alcohol and sesquiterpene hydrosols compared to the CPO as well as trace aldehyde's and esters.
When stored at 250C the SDO degraded more rapidly compared to the CPO, possibly due to the higher percentage of non volatiles in the CPO. One of the most significant changes was that p- cymene increased as it is converted from gamma terpinene. this can give an ‘off’ note to the oil. Spathulenol forms in the oil after 9 months so this can used to detect the age of the oil (Ref: Kasiwagi et al. 2010)
|Safety||Does not seem to have any safety concerns, not photo toxic as no furocourmarins present in oil|
|Therapeutic uses||Uplifting, anti septic, circulatory tonic, aches and pains|
|History||Widely used in Japan and Asia as a fragrance and flavouring agent-drinks, dressings, marmalade and ice cream. Used during the winter solstice to ward off winter ills- e.g. the whole fruit or rind is added to a hot bath.|
|Blends with||basil, benzoin, clary sage, chamomile Roman, cypress, frankincense, geranium, ginger, jasmine, juniper berry, lavender, neroli, patchouli, petitgrain, rose (absolute & otto), sandalwood, vetiver and ylang.|
|Aromatherapy details||It is a very effective oil for use with stress; burn-out, nervous tension or anxiety, where it helps to bring a soothing and calming effect to the emotions. Likewise it gives an uplift to depressive states, frustration, regret and also helps to build confidence. I have the oil to be very effective in small doses.If you are buying oil it would be important to know whether it is produced via cold pressing or steam distilled, given the variations in the constituents as described. Also the SDO oil will degrade faster, so it is best to store at below 250C and in dark glass bottles as all oils should be. Experimental studies (rat based :( ) suggest that Yuzu oil calms the sympathetic nervous system (kumagai et al, (2009).|
|Notes and research||The oil has been widely researched for use with agricultural areas to inhibit weeds and seed propagation. Experimental work has alos been untaken which shows that the oil has some chemoprotective effects against certain carcinogens and their assocaited cancers (Sawamura, 2000).
Kashiwagi, T., Thi Lan Phi, N. & Sawamura, M. (2010). Compositional Cahnges in Yuzu (Citrus Junos) Steam Distilled Oil and Effects of Antioxidants on Oil Quality During Storage. Food Science Technology Research, 16(1), 51-58
Kumagai et. al (2009).TitleEffects of olfactory stimulation with Yuzu (Citrus junos) peel oil on autonomic nerves, lipolysis and body temperature. Aroma Research Vol. 10 No. 2 pp. 156-161
Thi Lan Phi, N. & Sawamura, M. (2008). Characterisitc Aroma Composition profile of mature Stage Citrus junos (Yuzu) Peel Oil from Different Origins, Food Science Technology Research, 14(4), 359-366.
Journal of Agricultural Food Chemistry, 2009, 57 (5), pp 1990–1996Njoroge, S. et al (1996). Changes in the Volatile Composition of Yuzu (Citrus junos Tanaka) Cold-Pressed Oil during Storage Journal of Agricultural. Food Chemistry 1996, 44 (2), pp 550–556
Sawamura, M. (2000). Aroma Research Journal 2000 Vol. 1 No. 1 pp. 14-19 Aroma and functional properties of Japanese yuzu (Citrus junos Tanaka) essential oil.
For some wonderful images and ideas please see www.yuzupassion.com
One of the factors to consider with citrus essential oils is that many of them can cause photo toxic reactions when applied to the skin. What this means is that when the skin is exposed to sunlight or sun beds or other UV the rays of the sun will intensify on the skin and will cause burning, sensitisation or other such reactions. In effect it is the opposite action to sun blocks this effect is due to the presence of furocoumarins in the oils. Therapeutically these have been exploited in some ways in the past such as in the treatment of psoriasis (which responds positively to UV light). Also previously some tanning products may have used them to help the skin tan. We now know this is actually damaging to the skin. It is usually only cold pressed oils which are photo toxic and not all the citrus oils are. Furanocoumarins are not volatile so are never in the distilled citrus oils. They can however be present in CO2 extracted oils. Other constituents are also phototoxic including psoralens. The risk for phototoxic reactions occurs when the substance is applied to the skin, which is then exposed to UV light. The sensitivity peaks at 1-2 hours after application but will last up to 8 hours, so it is best to avoid any UV exposure for at least 12 hours. There is conflicting evidence as to whether this would increase the risk of skin cancer, however it is best to be prudent in any areas of potential or actual risk. If UV exposure can’t be avoided then wear suitable clothing or apply a sunscreen (at least factor 15).
The following table has the % of bergapten and the maximum allowable concentration for use on the skin. Please take note of this when you are making your blends. If you are making products to sell you will need to follow international standards for the incorporation of citrus oils into creams and lotions. These vary from country to country, however as a general guide they range from 0.4% and never exceed 5% as per the table below.
|Essential oil||Bergapten %||Max. Conc. %|
|Bitter orange (expressed)||0.07||1.4|
Posted: Tuesday 4 January 2022