The Yuzu (Citrus junos Sieb. ex Tanaka) has been a popular citrus fruit in Japan for at least a thousand years. It may be the most important of all the citrus fruits in that country. It has a characteristic flavour not seen with other citrus fruit and has been used in Japanese cuisine, sauces, salads and condiments as a result as well as cosmetics. It has not yet found favour outside its native country. The aroma of Yuzu is also known to sooth and improve mood, and reduce stress. It is quite popular in spirits and commonly infused into chocolate.
Cultivation
The fruit grows in north-east Asia, Korea, China and Japan. It is not really grown outside these regions although there is interest in its hardiness. The fruit is often pressed to a juice that is used in various types of Japanese cuisine.
Appearance
The fruit has a yellow-golden peel.
Sensory Aspects
The yuzu produces a distinctive, pleasing aroma of citrus and floral notes. It tastes like a mix of citrus fruits from lemon to grapefruit but is being tried in a number of cross-over recipes.
Compounds
Most peel oils are analysed using a form of gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS). The cold-pressed peel oils have also been examined using similar techniques (Njoroge et al., 1994).
The key compounds of yuzu aroma were determined by gas chromatography-olfactometry (GC-O). Seventeen compounds from yuzu essential oil were screened for their relative flavour activity. The most flavour active were methyltrisulphide, 6-methyl-5-hepten-2-ol, n-octanol, neral, trans-2-undecanal and cedrol (Sawamura, 2000).
The active aroma compounds besides those mentioned previously were identified including borneol, trans-undec-2-enal, (+)-p-mentha-1-en-9-ol, eugenol and carvacrol. These too were found to be strongly involved in the characteristic flavour of yuzu (Song et al., 2000).
The fruit contains a range of valuable flavonoids including Yuzu also contains various flavonoids, such as hesperidin, naringin, rutin, rutin hydrate, narirutin, apigen-7-glucoside, quercetin, and tangeretin (Yang et al., 2013).
Health Benefits
It is known that yuzu oil and its components, which are mainly terpene hydrocarbons have a number of functional and chemopreventive properties such as inhibiting the formation of carcinogens and the proliferation of breast, pancreatic, lung and skin cancers. It has three times the vitamin C content of a lemon.
One study showed the formation of N-nitrosodimethylamine, which is a carcinogen causing liver and bladder cancers, was inhibited by as much as 80% by yuzu essential oil and its constituents such as myrcene, α-terpinene and terpinolene.
Mood Improvement And Enhancement
We know from Yuzu’s use in aromatherapy that its fragrant citrus notes have both mood enhancing and stress reducing benefits. A number of studies on women have shown that the fragrance helps promote psychosomatic health in Japanese women. The action centres on the autonomic nervous system which has a key role to play in mid and body connectedness.
In recent years, Japanese researchers have established that the fragrance of the fruit alleviate negative emotions and stress, especially in women with menstrual stress (Matsumoto et al., 2014; 2016). That study showed just 10 minutes worth of breathing in the yuzu fragrance could relax and reduce both emotional distress and mood disturbances.
The effect of Yuzu scent was measured on 17 women with premenstrual tension. It was found to improve their mood with a significant reduction in anxiety, levels of anger and tiredness (Matsumoto et al., 2017). The benefit was similar to the impact found with lavender oil.
Whilst we can identify natural remedies that have a clinical psychobiochemical route with little evidence to support their efficacy, the studies on Yuzu are proving to demonstrate some interesting findings on elevating mood. The presence of such fragrance in the rooms for yoga, exercise, mindfulness and meditation might prove a highly beneficial adjunct.
Inhibition Of Blood Clotting
Blood clotting is essential for proper wound healing and preventing excess bleeding. There are a number of conditions where harmful blood clots can lead to complications such as heart attack, stroke and pulmonary embolism because blood flow is severely restricted.
Some research on yuzu extracts in rats and animal cell models indicates that it can stop blood clots forming. The fruit contains anticoagulants which are compounds that act like warfarin in thinning the blood (Yu et al., 2011).
A 2015 study found that a yuzu extract inhibited platelet aggregation in human cells. Platelets are vital structures in blood that clump and aggregate to form the clot. In a separate but similar study, it was thought that hesperidin and naringin which are commonly found in many citrus fruit were the probable activators of this process (Kim et al., 2015). .
Contra-Indications And Warnings
If you are already taking blood thinners and anticoagulants, please consult your physician before consuming too much yuzu as it may enhance any medication and produce unwanted side effects.
References
Kim, T.-H., Kim, H.-M., Park, S.W., Jung, Y.-S. (2015) Inhibitory Effects of Yuzu and Its Components on Human Platelet Aggregation. Biomol Ther (Seoul). 2015 Mar; 23(2): pp. 149–155. doi: 10.4062/biomolther.2015.011
Matsumoto, T., Asakura, H., Hayashi, T. (2014) Effects of olfactory stimulation from the fragrance of the Japanese citrus fruit yuzu (Citrus junos Sieb. ex Tanaka) on mood states and salivary chromogranin A as an endocrinologic stress marker. J. Altern. Complement. Med. 2014 Jun;20(6):500-6. doi: 10.1089/acm.2013.0425. Epub 2014 Apr 17. PMID: 24742226 PMCID: PMC4048973
Matsumoto, T., Kimura, T., Hayashi, T. (2016) Aromatic effects of a Japanese citrus fruit-yuzu (Citrus junos Sieb. ex Tanaka)-on psychoemotional states and autonomic nervous system activity during the menstrual cycle: a single-blind randomized controlled crossover study. Biopsychosoc Med. Apr 21;10:11 (Article). eCollection 2016.
__________________________(2017) Does Japanese Citrus Fruit Yuzu (Citrus junos Sieb. ex Tanaka) Fragrance Have Lavender-Like Therapeutic Effects That Alleviate Premenstrual Emotional Symptoms? A Single-Blind Randomized Crossover Study. J Altern Complement Med. 2017 Jun;23(6) pp. 461-470. doi: 10.1089/acm.2016.0328. Epub 2017 May 8. PMID: 28481623
Njoroge, S.M., Ukeda, H., Kusunose, H., Sawamura, M. (1994) Volatile components of japanese yuzu and lemon oils. Flavour & Fragrance J. (Article).
Sawamura, M. (2000) Aroma and functional properties of Japanese yuzu (Citrus junos Tanaka) essential oil. Aroma Res. 1(1) pp. 14-19
Excellent product especially the juice. I use it for a sauce with chilli, garlic and ginger and its great with salmon and other high-end fish.
Anyday for me. I commented on the wasabi
paste in another item which I thought was great. For me you have to try the Tolushima Yuzusu Yuzu juice. It’s got a great taste and I use it make a fantastic ponzu sauce. It can also be added to sake and shochu which many of us have never really tried before. Try it on ice cream too as it makes for a great and distinct flavor combination with other. Don’t miss out on it.