The reason why the flesh of dragon fruit is red is because it contains a large amount of betalains.

Dragon fruit contains natural pigments such as anthocyanins and betalains. Betalains and anthocyanins are two different pigments. They have similar colors, but their chemical structures are different. They are two different pigment components. Betalains and anthocyanins generally cannot coexist in the same angiosperm.

Anthocyanins appear purple in an acidic environment and blue in an alkaline environment; betalains appear red in an acidic environment and yellow in an alkaline environment. The ph value of dragon fruit pulp is less than 7, which is acidic, so the pulp looks purple-red. And there are anthocyanins and betalains in many foods, such as grapes, blueberries, eggplants, etc.

Dragon fruit is a tropical fruit. When planting dragon fruit, you need to pay attention to the following points:

1. Soil selection: Dragon fruit likes well-drained soil rich in organic matter, with a pH value of Between 6.0-7.0. When selecting a site, you should choose a sunny and well-ventilated place.

2. Temperature requirements: Dragon fruit has high temperature requirements, and the optimal temperature range for growth is 25-35 degrees Celsius. The effect will be better when planted in spring and summer.

3. Watering management: Dragon fruit likes a humid environment, but it cannot be overwatered. The soil should be kept moist but not too wet to avoid standing water.

4. Fertilizer application: Dragon fruit needs sufficient nutrient supply during the growth period, and fertilizer can be applied every spring and summer. It is recommended to use organic fertilizers such as well-rotted compost or chicken manure.

5. Scaffold construction: Dragon fruit is a vine, and a scaffold needs to be built to support the growth of the plant during the planting process. It can be built using bamboo poles or metal supports.

Reference for the above content: Baidu Encyclopedia-Dragon Fruit