Shekwasha

Shekwasha is a citrus fruits which is distributed mainly in Okinawa in Japan.

Ogimi village in Okinawa Prefecture provides about 60% of Okinawa Prefecture's production and, when speaking of Ogimi village, shekwasha is known as Ogimi’s specialty.

Ogimi village

Ogimi village is famous as the "village of longevity" in the Okinawa prefecture which is already known in Japan for its longevity.

At the sports festival of the village, relays are known to be carried by five generations of the same family. Also, the elderly are known for doing field work even after 70 years old.

When the elderly people of Ogimi village are asked their secret of longevity, they answered "our traditional eating habits are good", "our community activities are thriving and our social ties are strong", and "we regularly work the body with field work and exercise". It is understood that their longevity is rooted in healthy lifestyle habits.

Among their healthy habits, we are focused on their eating habits.

In addition to reasonable eating habits in terms of contemporary nutrition science such as "seasoning with less salt", "recipes using minerals from vegetables and seaweed", and "eating high quality protein such as pig and tofu", we also found that "there are many shekwashas from long ago, so we had a habit of eating well instead of snacks".

Recent studies have found flavonoids called nobiletin in shekwasha which is also abundant in the pericarp.

In addition, we found elderly couples drink the dried powdered peel skin of shekwasha like dried citrus peel of traditional Chinese medicine.  We came to conclude that nobiletin is one of the key ingredients to their health.

Nobiletin

Nobiletin is a type of flavonoid. It is one of the ingredients that protect fruits from strong UV rays in Okinawa as well as pests.

The concentration of nobiletin increases in the summer to early autumn when sunlight is strong, there are many pests, and the fruit is unripe.

As Ogimi village became famous as a long-lived village, the physiological impact of nobiletin has been extensively studied and it is found that there are various beneficial effects mainly on lifestyle, diseases, and beauty.

Ogimi village's peel of green shekwasha

Nobiletin contained in the peel of the green shekwasha is about 170 times more than its pulp. Also, Ogimi’s green shekwasha contains twice the nobiletin of the peel of a typical shikwasha.

Analysis of the peel of the Ogimi village's green shekwasha found 620 mg of nobiletin per 100 g of the peel.

The concentration of nobiletin in juice extracted from pulp with peel is 3.6 mg / 100  g, which indicates that the peel has approximately 170 times more nobiletin.

In addition, the peel of the Ogimi village 's green shekwasha contains about twice the nobiletin of the peel of a typical shikwasha.