The "sweet egg yolk" that grows on trees is high in antioxidants, nutritious and delicious

There is a kind of fruit that looks plump, juicy, golden and attractive, but it is actually deceiving you! If you take a bite, you will find that this guy should be expelled from the fruit family. It is so sweet and choking. There is no water at all. It is clearly a dry egg yolk.

Coincidentally, its name is really "egg yolk fruit", but people who like to eat it are really impressed by its sweet and soft taste. In this article, let's learn about this peculiar fruit.

Copyrighted stock images, reprinting and using may cause copyright disputes

"Egg yolk" growing on trees

If you usually like to eat egg yolks, then you must not miss the egg yolk fruit. When this fruit is ripe, the skin is generally yellow, thin and smooth, and the flesh is orange-yellow, rich in starch, with a texture similar to egg yolk, powdery, and sweet taste.

Picture: Ripe egg yolk fruit

It should be noted that the egg yolk fruit is not the egg fruit, they are two different fruits. The egg yolk fruit belongs to the perennial plant of the Sapotaceae family. It is native to Cuba and tropical North America. It has an irregular shape, including spherical, spindle-shaped, obovate, and peach-shaped, so it is also called the "fairy peach" in the mortal world in winter. In addition, the egg yolk fruit has many common names, such as lion head fruit, egg fruit, and peach olive.

The egg fruit is actually passion fruit, also known as passion flower. It is a vine plant of the genus Passiflora in the family Passifloraceae. It is native to South American countries such as Brazil, Argentina and Chile. It comes in two varieties: purple and yellow. Many people habitually call the purple variety passion fruit and the yellow variety egg fruit.

Figure: China iPlant Plant Intelligence

The taste of the two is completely different. The egg fruit tastes sweet and sour and juicy, and is known as the "king of juice"; while the egg yolk fruit tastes soft and glutinous, just like eating sweet egg yolk.

The reason why the egg yolk fruit has such a taste is mainly because it has a low water content and a high starch content. Its water content is only 64%, while the water content of egg yolk is generally 52%, which is still very close; the starch content of egg yolk fruit is mostly 5%~9%, and the starch content of some varieties can be as high as nearly 19%. The egg yolk fruit has a low water content and high starch content, so the flesh is "silky" and it will be a bit choking to eat.

Sweet and dense, nutritious

The ripe egg yolk fruit can be eaten directly with a spoon. The full and sweet taste fills the whole mouth. It not only tastes like egg yolk, but also a bit like cooled baby pumpkin, and it also feels like eating mousse.

Photo: A spoonful of egg yolk fruit

Egg yolk fruit not only looks good and tastes great, but is also nutritious.

1

Vitamin C is comparable to oranges

The vitamin C content of egg yolk fruit is quite good, ranging from 14 to 69 mg/100 g, with differences between different varieties. Some literature shows that the vitamin C content of the "papaya fairy peach" variety is 14.1 mg/100 g, and the vitamin C content of the "Yaotang fairy peach" variety is 29 mg/100 g; there is also literature that measures the vitamin C content of the mixed pulp of "Xiantao No. 1", "Xiantao No. 2" and "Yueyin No. 2" to be 50.7 mg/100 g, which is 1.5 times that of oranges.

2

More dietary fiber than bananas

Although the egg yolk fruit tastes a bit greasy, it is high in dietary fiber. The center is relatively soft and sticky, and the flesh close to the peel is slightly fibrous. A study found that the dietary fiber content of the mixed flesh of "Xiantao No. 1", "Xiantao No. 2" and "Yueyin No. 2" was as high as 9 grams per 100 grams, which is higher than that of bananas. It is a good source of daily dietary fiber.

3

The antioxidant activity is the best among tropical fruits

Like most fruits, lucuma also contains antioxidants. A study compared the antioxidant activity of eight tropical fruits, including sapodilla, wax apple, mangosteen, durian, lucuma, passion fruit, soursop and jackfruit. The results showed that the total phenol content (3.80%) and total flavonoids content (7.60%) of lucuma were the highest among the eight fruits, and the antioxidant activity was the strongest.

The antioxidant activity of these eight tropical fruits is ranked as follows: egg yolk fruit > mangosteen > wax apple > passion fruit > sugar apple > jackfruit > durian > sapodilla.

4

Rich in carotene

The flesh of egg yolk fruit is orange-yellow and rich in carotenoids, which can be converted into vitamin A in the body and are very helpful in maintaining the health of the eyes and skin.

In addition, the egg yolk fruit tastes sweet and has a high sugar content, with a total sugar content of 15-20 grams per 100 grams. The "Yaotang Xiantao" variety has a higher sugar content of 19 grams per 100 grams. The sugar content of the apples we usually eat is mostly around 10%, and the sugar content of the "Sugar Heart Apple" is relatively high, at about 16%. Its calories are naturally not low. Data shows that the calories of the egg yolk fruit are 129 kcal/100 grams, which is almost catching up with durian (150 kcal/100 grams).

Overall, the nutritional value of egg yolk fruit is quite high, but it is a high-sugar and high-calorie fruit. If you are controlling blood sugar and losing weight, don't eat too much! The edible part of egg yolk fruit is more than 70%, and a single fruit is 120-150 grams. The larger fruit can weigh more than 220 grams. The fruit has 1 to 4 seeds. If you don't want to gain weight by eating it, it is recommended to eat no more than 1 medium-sized one, and no more than half a large one.

Picture: A medium-sized egg yolk fruit weighs about 140 grams

Picture: The larger egg yolk fruit weighs about 220 grams

Picture: Egg yolk fruit seeds, shiny and textured brown, quite nice

Egg yolk fruit is delicious, but you should also pay attention to these

1

Don't eat unripe fruits or seeds.

Don’t eat unripe custard apples that are still hard to the touch. The difference in taste between unripe custard apples and ripe custard apples is greater than the difference between unripe persimmons and ripe persimmons.

As a fruit of the Sapotaceae family, the branches, leaves, flowers, and fruits of the egg yolk fruit can secrete white milky juice. The texture of this juice is like paint and very sticky. Rubber-like substances can be extracted from this latex. This kind of substance is an excellent insulating material and has great economic value. For example, the genus Bakelite can produce the famous gutta-percha; the bark of species such as the genus Bauhinia contains tannins, which can be used to extract tannin extract.

Ripe egg yolk fruit is not easy to store and transport, so most of what we buy are not fully ripe and need to be ripened before eating. You can put it in a bag with ripe bananas and apples and seal it, using the ethylene gas released by these fruits to ripen it, and it can usually be eaten in two or three days.

You can also place the unripe egg yolk fruit directly at room temperature. It will gradually soften over a period of time. Gently pinch the fruit with your hand and you can eat it when you feel the whole fruit turns yellow and softens.

In addition, the core of the lucuma fruit contains some natural toxic ingredients, so we should avoid eating the core of the lucuma fruit.

2

Tips for storage

The sugars contained in egg yolk fruit include fructose, glucose and sucrose. Some have the highest sucrose content, while others have the highest fructose content. The ones with high fructose content will taste sweeter after refrigeration, so the ripe egg yolk fruit can be refrigerated before eating, and it may be sweeter.

Egg yolk fruit is a late-ripening tropical fruit. It can only be stored for about 5 days at room temperature (≥25℃). The higher the temperature, the easier it is for the fruit to soften and spoil. It is recommended to store ripe egg yolk fruit at a low temperature below 10℃, which can generally be stored for nearly 30 days.

Summarize

Egg yolk fruit is a tropical fruit variety, and the price is not cheap. Although it tastes a bit like egg yolk, it is denser and sweeter than egg yolk. It is also nutritious, supplementing vitamin C, dietary fiber, carotenoids, and has high antioxidant activity. If you haven't eaten it, it is still worth buying to try it!

References

[1] Jiang Yan, Yan Wei, Ni Zhangguang, Chen Yufu, Zhang Yong, Wang Tieyun, Zhang Cuixian, Luo Xinping, Yang Linyuan, Wang Meicun. Performance and evaluation of four egg yolk fruit varieties introduced in Menglian area[J]. Chinese Agricultural Science Bulletin, 2024, 40(28): 37-41.

[2] Zhou Jing, Lan Qingjiang, Lu Yanchun, Tang Junhai, Wei You. Collection and evaluation of egg yolk fruit germplasm resources in southwestern Guangxi [J]. Guangxi Tropical Agriculture, 2009(6):21-25

[3] Fang Guihong, Dong Chunbo, Zhan Damou, Xu Li, Wang Xia. Analysis of nutritional components of egg yolk fruit[J]. Hubei Agricultural Sciences, 2018, 57(7): 111-113

[4] Lv Jinhui, Zheng Zhongbing, Wu Tao, Sun Yahui, Chen Ping. Comparative analysis of antioxidant activity of eight tropical fruits from Hainan[J]. Journal of Southern Agriculture, 2023, 54(8): 2388-2395

[5] Zhan Huiling, Lan Weigen, Liu Jun, Chen Yonghong, Liao Wenbo. Development and utilization of Sapotaceae plant resources in China[J]. Anhui Agricultural Sciences, 2012, 40(29): 14285-14287

[6] Chen Jiaying, Liu Shenghui, Wang Songbiao, Xie Jianghui. Determination of sugars in egg yolk fruit by HPLC[J]. Fujian Fruit Trees, 2005, 23(4): 11-12

[7] Li Wenyan, Zhou Caixia, Lu Meiying, Huang Lijun, Wei You, Zhuo Fuchang, Zhou Jing. Effects of four preservation treatments on storage quality of egg yolk fruit[J]. Preservation and Processing, 2021, 21(8): 28-34

[8] Liu Jiangping, Huang Xiaohua, Wan Nianqing, Zhong Ning, Zheng Liangyong. Biological characteristics and cultivation techniques of the rare tropical fruit tree egg yolk fruit[J]. Guangdong Agricultural Science, 2008, 35(3): 24-25

Planning and production

Author: Xue Qingxin, registered nutritionist

Review | Ruan Guangfeng, Deputy Director of Kexin Food and Health Information Exchange Center

Gu Lei, PhD in Botany, Chinese Academy of Sciences, Associate Professor, Capital Normal University