This fruit is a blind spot for northerners, but it is quite nutritious! It’s the perfect time to eat it now

In the hot summer, a special fruit is appearing on the promotional flyers of major milk tea shops. It is: kumquat!

The picture comes from a screenshot of a food delivery platform

Kumquat is a niche fruit in the south. Many northern friends may find it unfamiliar, but in fact it has become popular in the past two years. Not only does it frequently appear in various beverages, it even once ranked among the top three on the list of some major milk tea brands.

So what’s so special about yellow skin and why is it so popular?

What kind of fruit is kumquat?

Wampee, the peel is yellow or dark yellow, and the size is close to cherry tomatoes. In the south, wampee has many other names, such as yellow marbles, golden marbles, etc., but they are inseparable from its color and shape.

Kumquats, tangerines, oranges, grapefruits and kumquats all belong to the Rutaceae family. The difference is that the peel of kumquats cannot be peeled as easily as that of citrus, and there are not several pulpy lobes inside. Instead, the pulp tissue is a bit like that of grapes, with one or more granular seeds in the pulp.

Around July and August every year is the season when yellow peel is put on the market in large quantities. It tastes sour and astringent. Because of this unique taste, it is just right to use it to relieve the heat in summer or to relieve greasiness after eating greasy food. Because the strong sour taste can stimulate the continuous secretion of saliva in the human mouth, the astringent taste at the entrance will also produce sweetness over time. This progressive taste experience will make people quite "addicted" after gradually adapting to it, and even have an urge to "not stop".

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Yellow skin is very nutritious

Kumquat not only has a unique taste, but its nutritional value is also commendable.

1. Organic acids

Wongpi contains a lot of organic acid, which is also the source of its sour taste. Organic acid can stimulate saliva secretion, improve digestion, and boost appetite. If you often have no appetite, fatigue, and drowsiness in the hot summer, chewing a few yam peels is very helpful.

2. Phytochemicals

Yellow peel is also rich in phytochemicals, such as alkaloids, coumarins, volatile oils, flavonoids and polyphenols. Flavonoids and polyphenols usually have strong antioxidant effects, which can not only help the human body to resist inflammation and bacteria, but also help prevent cancer and protect the cardiovascular system.

3. Vitamin C

The vitamin C content in kumquat is not low, containing 35 mg of vitamin C per 100 grams. This value is comparable to its citrus relatives and more than 4 times that of bananas.

4. Potassium

The potassium content of kumquat is very high, reaching 226 mg/100 g, which is basically the same as bananas, which are known as potassium supplement experts, but the energy of kumquat is less than half of that of bananas. Friends who like to eat bananas to supplement potassium can try kumquats this summer, which can not only replenish potassium lost with sweat and help lower blood pressure, but also relieve greasiness and quench thirst.

5. Selenium

Selenium is a mineral with a strong antioxidant effect. It can improve the body's antioxidant and anti-aging abilities, and also has a certain protective effect on myocardial cells. There are not many foods with high selenium content in daily life, but the selenium content in yellow peel can reach 0.64 micrograms/100 grams, which is very good.

Comparison of nutritional components of yellow peel and other common fruits Data source: Yang Yuexin. Standard Edition of Chinese Food Composition Table (6th Edition/Volume 1) [M]. Peking University Medical Press, 2018.

Why isn’t yellow skin popular across the country?

Although kumquat is rich in nutrients, its goodness also has a "threshold".

In addition to the sour, slightly sweet, astringent, and slightly spicy tastes of kumquat, it also smells like turpentine. "The green trees are full of golden bullets, and the jelly is like sweet dew. The autumn colors of the wood are so precious, and the fragrance is like the branches in the summer." Dong Chuanze, a poet in the Ming Dynasty, expressed his admiration for the fragrance and taste of kumquat in "Eating Kumquat Fruit".

A large amount of volatile lipids in the yellow peel are the source of its "strange smell". For example, the smell of turpentine comes from its terpenes, which are the main components of pine and cypress oils. Friends who don't like the smell of pine oil may fail at the first hurdle of "smelling" the yellow peel; for another example, some friends will smell a mixed smell of coriander, tangerine peel, and camphor balls in the yellow peel, which also comes from its terpenes and terpenoids. These substances that emit "strange fragrances" make "those who love it salivate, and those who don't love it avoid it."

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Various ways to open yellow skin

There are many ways to eat kumquat. Here are some common ways to eat it. Maybe one of them will suit you.

1. Wash and eat directly, but remove the skin and spit out the core

If you are not so sensitive to the taste of turpentine, you can be "trained" to eat fresh kumquats. As long as the skin is removed, the sour and astringent taste of kumquats will be greatly reduced. Moreover, there are now sweeter varieties on the market, such as the large and dark chicken heart kumquats, which have significantly improved sour and astringent tastes and are mainly fresh, sour and sweet.

2. Mix with other fruits to make drinks

It is a good way to mix drinks with other sweet fruits and kumquats. People with normal blood sugar can add a small amount of sugar, honey or sweet drinks for flavoring. Some tea brands on the market have launched lychee kumquat drink, kumquat lemon tea... Just looking at the names can make people drool!

3. Sea salt yellow peel drink

This method is popular among the old Guangdong people. Add a little sea salt (or table salt) to the mashed yellow peel for seasoning. The presence of saltiness will reduce the sour taste and make the sweetness slightly more prominent. After refrigerating, take a sip of the sea salt yellow peel and the hot summer heat will be swept away. If you are worried that you can't get used to it, you can add some honey for seasoning.

4. Stewed Soup

Stewing soup with yellow peel is also a classic way to eat it. For example, the yellow peel pork ribs soup is popular among southerners. The greasiness of the ribs is completely suppressed by the yellow peel. It is fresh and delicious and is worth a try.

Precautions for eating yellow peel

Although kumquat is good, you need to pay attention to two points when eating it.

1. Don’t eat too much at one time. It is recommended to eat 5-6 pieces a day (about 100 grams). On the one hand, you need to consider the diversity of fruit intake and leave a margin for other fruits every day; on the other hand, kumquats are rich in organic acids, and excessive intake at one time may cause gastrointestinal discomfort.

2. People with gastrointestinal discomfort are advised to eat with caution. For people with excessive gastric acid secretion or gastric ulcers, eating yellow peel may cause acid reflux or other stomach discomfort. It is recommended to reduce the amount of consumption or wait until the symptoms disappear before eating.

In addition, the peel of kumquat is very thin and not easy to preserve. If you buy kumquat, it is recommended to eat it as soon as possible.

References

[1] Lin Chunyao, Liu Gongliang, Li Nanwei, et al. Research progress on functional components and processing of yellow peel[J]. China Brewing, 2020, 39(11): 25-29.

[2] Zou Bo, Zhong Siyan, Lin Jinbo, et al. Research progress on the structure and biological activity of flavonoids in yellow peel[J]. Chinese Fruit and Vegetable Journal 2024(002):47-53.

Author: Wang Lu, registered dietitian

Review丨Zhang Yu, researcher/PhD, Chinese Center for Disease Control and Prevention, national health science expert