Shikuwasa (Citrus depressa) is a citrus fruit, native to Taiwan and the Okinawa island of Japan. Okinawa has been a part of Japan for around 150 years, but shikuwasa has been growing there for much longer.
The Okinawa people are famed for their longevity, which has been attributed in part to the consumption of shikuwasa, along with a healthy diet and social customs. It has been a part of their diet for thousands of years.
On the island, the fruits are cultivated in the forest areas in the north, about three hours from the capital of Naha.
Shikuwasa is also known as shikwasa, shiquasa, shiikuwasha, shequasar, Taiwan tangerine, flat lemon, hirami lemon, or thin-skinned flat lemon.
The fruit grows on a tree that typically reaches between nine and 15 feet tall. The white flowers that adorn the fruit before fruiting are fragrant and usually appear in April.
The fruit’s squat, round exterior is similar to that of a tangerine. Shikuwasa usually measures around three centimeters in diameter. That makes it quite a bit smaller than other citrus fruits.
The skin is very thin and most often green. The fruit holds many seeds, which is why it is often juiced by poking a hole or making a slit in the fruit rather than cutting it open and squeezing. Each fruit weighs between one and two ounces.
Legend has it that shikuwasa is one of the original mandarin oranges, of which there are only two in Japan. However, it packs loads more nutritional benefits than oranges, including 40 times the flavonoids.
That means you’d have to eat either 20 oranges or just half of a tiny shikuwasa to get the same benefits. That is pretty amazing. No wonder why it’s thought of being a great contributor to the longevity of local Okinawans.
How do you eat shikuwasa?
The shikuwasa are rarely eaten straight and are most prized for their juices. A great way to squeeze the fruit by hand is to make a single insertion along the outside of the fruit.
Then, squeeze away. This allows the juice to exit but keeps the seeds inside. You can also poke the fruit with a toothpick on the top or bottom and then squeeze in the middle to release the juice.
Shikuwasa is usually too sour to just drink straight, but many people mix it with water or use it as an ingredient in juices. Ripe shikuwasa can be drunk straight as juice, though.
Other uses include marinating fish, sprinkling in soy sauce to eat with sushi, and using it as a dressing on salads. It is also used to make jams or added to tea. Shikuwasa makes a nice drink garnish if you poke it through with a skewer and let it drip bit by bit into the drink.
What does shikuwasa taste like?
Shikuwasa has an orange citrusy taste, although it is quite a bit sourer than lemons and even limes. The flavor is very strong and the juice is quite bright…like a citrus x 10 times.
If you eat unripe shikuwasa, it is very sour. The strong acidity makes it unpalatable without dilution or adding sugar. However, when it’s ripe there is a bit of sweetness along with the sour.
When is shikuwasa in season?
Shikuwasa is in season from July to January. As it is a fruit that is enjoyed unripe as well as ripe, the season is extended. Unripe, green shikuwasa is available from July to October. Ripe, yellow shikuwasa is available from November to January.
Benefits of shikuwasa
The inhabitants of Okinawa are some of the longest-living in the world, and the shikuwasa is an important part of their diet. It stands to reason, then, that it is full of healthy components. Read on to find out what they are:
- It may have the potential to stop cancer. In studies, shikuwasa has been proven to suppress the growth of cancer cells and to even cause cancer cells to die off. The compound nobiletin was explicitly tested and shown to have an effect on gastric cancer cells.
- It may help to prevent the onset of obesity. The peel contains an extract that has been shown to suppress the key signals of weight gain in the body. This included the adipose tissue, the adipocytes, the stored fatty acids, and the leptin levels. This study could mean that it may prevent obesity and abnormal lipid activity in the blood.
- It may be good for the liver. The juice contains flavonoids that are shown to suppress liver injury in some studies. Keeping the liver healthy allows us to detoxify the body, achieve a healthy metabolism, regulate the production of hormones, and decompose red blood cells.
- It has loads of antioxidants. Thanks to its citrus profile, it contains plenty of vitamin C, an antioxidant. It can relieve the oxidative stress load in the body. Vitamin C has also been shown to have positive effects on muscles when taken before exercise.
5 x shikuwasa facts
- Taiwan plans to increase its production of the fruit with an aim to feed it to livestock, especially pigs, creating a Shikuwasa Pork.
- The amount of nobiletin in shikuwasa is anywhere from 6 to 12 times that in other citrus fruits, meaning it has extra special powers fighting carcinogens.
- The marketing of shikuwasa calls its juice “golden extract”, meant to convey the vitality and richness of the extract.
- The village of Ogimi is known as the capital of shikuwasa production. It produces more than 60% of the island’s total amount.
- The name comes from the Okinawan dialect. Shii means ‘sour’ and kwaasaa is Okinawan for ‘food’.