Are they all cactus fruits? Why do dragon fruits come in so many colors?

Audit expert: Shen Tingting

PhD in Botany

Dragon fruit is a very lovable fruit, with soft and tender flesh that can be sucked into the mouth like jelly. We usually eat dragon fruit with red skin and red flesh or red skin and white flesh. Have you ever seen dragon fruit with yellow skin? Why do dragon fruits of different colors have different prices? Today, let's learn about the story of dragon fruit.

Source: Sohu

Types of pitaya Pitaya belongs to the genus Hylocereus of the Cactaceae family and is native to tropical and subtropical regions of Mexico, Central America, and South America. Taiwan, my country, began to introduce pitaya cultivation in the early 1990s and is currently planted in Yunnan, Hainan, Guangdong and other places.

The skin of young dragon fruit is green, and turns red or yellow when ripe. Based on the color of the skin and flesh, dragon fruit is mainly divided into three categories: red skin and red flesh, red skin and white flesh, and yellow skin and white flesh. Red skin and red flesh dragon fruit are widely planted and are very common in supermarkets, while the golden dragon fruit with yellow skin and white flesh is a rare variety, so it is more expensive, and the market price can be as high as 100 yuan per piece.

Source: pixabay

Source: pixabay

Based on the shape of the peel, golden pitaya is divided into two categories. The one with many small thorns on the peel is the bird's nest fruit (Hylocereus megalanthus), also known as qilin fruit, which is native to Ecuador, Colombia and other countries in South America; the smooth-skinned thornless yellow dragon fruit originates from Israel, and its appearance, fruit shape and flesh color are similar to those of the white-heart pitaya.

Bird's Nest Fruit

Source of Thornless Yellow Dragon｜Fangchenggang News Network

Golden pitaya is suitable for growing in acidic soil and has high heat requirements. It is suitable for planting in areas where the lowest temperature throughout the year is above 8°C. It has a long growth cycle, and it takes 3 to 6 months from flowering to fruit ripening, which is conducive to the accumulation of sugar and organic matter, so the taste is better than the other two types of pitaya. However, the yield of golden pitaya is small, and large-scale commercial cultivation has not yet been achieved.

The sweet tropical dragon fruit is not only sweet, delicate and juicy, but also has high nutritional value and is rich in vitamins, dietary fiber, protein and minerals.

1. Anthocyanins and betacyanins

The peel and flesh of pitaya are rich in anthocyanins. The red color of pitaya comes from the large amount of betacyanin it contains. After eating red pitaya, your lips will look like you are wearing lipstick in the color of pitaya. In the body, the sugar group of betacyanin will be digested and decomposed first, while betaine (the main chromophore) is relatively stable and not easily degraded, and will be excreted from the body, resulting in the phenomenon of "hematuria".

Schematic diagram of the molecular structure of betalain Source: Baidu Encyclopedia

2. Sugar

The sugar content of pitaya is high, but the acid content is low, with a sugar-acid ratio of 16:0 to 26:1. Golden pitaya is the sweetest, with a soluble sugar content of up to 24%. The total sugar content of red-skinned and red-fleshed pitaya is about 18.70% ± 4.14%, which is significantly higher than that of red-skinned and white-fleshed pitaya.

3. Dietary fiber

Dietary fiber is a carbohydrate found in plants, which is divided into water-soluble dietary fiber and insoluble dietary fiber. The average dietary fiber content of red dragon fruit is 2.3%, which is significantly higher than the dietary fiber content of apples (1.2%), oranges (0.6%), and peaches (1.3%). In addition, the amount of water-soluble dietary fiber in dragon fruit is higher, accounting for about 69% of the total dietary fiber, so the texture of the flesh is very soft.

4. Protein and amino acids

The protein content of pitaya is high, about 1.2%, which is 2 to 3 times the protein content of mango, pineapple and other fruits. The albumin in its flowers, fruits and stems is very rich and very stable. Pitaya contains a wide variety of amino acids, including 17 kinds of amino acids, among which glutamic acid, glycine and proline are relatively high.

Dragon fruit flowers can be used to cook, delicious and nutritious source | Baidu Encyclopedia

5. Vitamins and minerals

Dragon fruit is rich in vitamins, including vitamin A, vitamin C, vitamin E, vitamin B2, vitamin B3, vitamin B5, vitamin B9, etc. Dragon fruit contains a large amount of phosphorus, potassium, calcium, magnesium, iron, selenium and other mineral elements. Among them, the iron and magnesium content in the pulp is the highest, the calcium element is mainly concentrated in the peel, and the zinc content in the fruit seeds is the richest.

6. Fatty acids

Fatty acids are the smallest unit molecules of oil and fat, which can provide energy for the body. The fatty acids in pitaya are concentrated in the seeds, and most of them are unsaturated fatty acids, such as linoleic acid and oleic acid, with contents of 44.29% and 31.75% respectively.

7. Polyphenols

The polyphenol compounds in pitaya include tannins, ellagic acid and flavonoids, etc. The polyphenol content in the peel of red-skinned and red-fleshed pitaya is higher than that in the flesh, and there are also many polyphenols in pitaya flowers.

How much do you know about its medicinal effects? Because pitaya contains a variety of nutrients, it also has high nutritional and health functions and medicinal value.

1. Reduce fat, lose weight, and prevent colon cancer

The water-soluble dietary fiber rich in pitaya has the health benefits of weight loss, lowering blood sugar, moisturizing the intestines, and preventing colorectal cancer. In addition, the dietary fiber in pitaya can enhance people's sense of fullness and reduce energy intake, thus having the effect of weight loss.

2. Anti-oxidation and anti-tumor

The anthocyanins contained in pitaya have antioxidant, anti-aging and anti-free radical effects. They can remove free radicals that induce cancer and cause aging in the human body and inhibit the occurrence of tumors. At the same time, anthocyanins can effectively prevent vascular sclerosis. In addition, the flavonoids, vitamin C and vitamin E contained in pitaya also have certain antioxidant functions.

Source: unsplash

3. Reduce Cardiovascular Disease

The linoleic acid in pitaya seeds is an unsaturated fatty acid that can lower the cholesterol content in human blood and has the effect of preventing atherosclerosis and hypertension.

4. Detoxification and stomach protection

The plant albumin in pitaya can combine with heavy metal ions in the human body and excrete them through the excretory system, thus preventing the intestinal absorption of heavy metals and thus having a detoxifying effect. At the same time, albumin can also form a protective film to protect the stomach wall.

With its thin skin, thick flesh, sweet and refreshing taste, and rich nutrition, dragon fruit is really a fruit with both good looks and good qualities. This summer, I hope everyone can fully enjoy this sweet taste.