I. Taxonomy and Morphological Characteristics
Dragon fruit (scientific name: Hylocereus undatus) belongs to the genus Hylocereus or Hylocereus in the family of Cactaceae, which is native to the tropical desert areas of Central America and is now widely distributed in subtropical areas such as Hainan, Guangxi and Guangdong in China. The plant is a perennial climbing succulent, with a trigonous stem that can be up to 7 metres long and grows by climbing through aerial roots. The fruit is ellipsoid, 10-12 cm in diameter, with red or yellow skin, white, red and yellow flesh, containing black sesame seeds.
Nutritional value and bioactive components
The flesh of dragon fruit has a water content of more than 83%, and each 100 grams of edible portion contains 51-59 kcal, 1.1-2.0 grams of dietary fibre, 5-7 mg of vitamin C, and is rich in calcium, phosphorus, iron and other minerals. Its core functional ingredients include:
Vegetable Albumin: It can bind heavy metal ions and expel them from the body, with detoxification and protection of gastric mucosa;
Anthocyanin (higher content in red meat varieties): a powerful antioxidant that prevents hardening of blood vessels and inhibits degeneration of brain cells;
Soluble dietary fibre: promote intestinal peristalsis, assist in lowering blood sugar and cholesterol.
Third, medicinal efficacy and health effects
Metabolic regulation: dietary fibre and low-calorie properties contribute to weight management, and clinical studies have shown that it can improve constipation and reduce the risk of diabetes;
Antioxidant and anti-aging: anthocyanins work synergistically with vitamin C to reduce free radical damage and slow down skin aging;
Heavy metal detoxification: the chelating effect of albumin on heavy metals such as lead and mercury has been verified in children’s lead overload intervention.
IV. Cultivation technology and production status
Since 2010, China has been promoting the cultivation of red-fleshed dragon fruit on a large scale, and the main variety ‘Jindu 1’ has achieved high yield through self-pollination technology, and the national production in 2023 exceeded 1.6 million tonnes, ranking the first in the world. Key technologies include:
Photoperiod control: LED supplemental light at night (22:30-2:30) can extend the flowering period by 3-4 months and increase the yield by 50%;
Resistance management: drought and barren tolerance characteristics make it adaptable to saline soil, but it needs to maintain temperature ≥8℃ in winter to prevent frost damage;
Disease and pest control: the main disease is stem rot, which can be prevented by controlling humidity and applying organic fertiliser.
V. Consumption precautions and contraindications
Contraindications: diarrhoea patients, cold body and menstruating women need to control the intake, so as not to aggravate the symptoms of cold body;
Risk of diabetes: Although the sugar content is low (mainly glucose), excessive consumption may still cause blood sugar fluctuations;
Food pairing: avoid eating with milk, as vitamin C may trigger protein precipitation and affect digestion and absorption.
VI. Variety differentiation and market trends
Red-fleshed dragon fruit is gradually replacing traditional white-fleshed varieties as the mainstream market due to its high anthocyanin content and significant sweetness (16-18 Brix). Yellow skin and white flesh of the ‘bird’s nest fruit’ because of the difficulty of planting, unique flavour, the purchase price of up to 30 yuan / kg, is a high-end category. Consumers can select quality fruit by skin colour (bright red/bright yellow), weight (high density is juicy) and navel condition (no rot).
