What red dragon fruit is
Red dragon fruit is Hylocereus costaricensis, sometimes sold as Costa Rican pitaya or red pitaya. The important distinction is that "red" here refers to the flesh, not the skin. This causes constant confusion, because the far more common white-fleshed variety also has pink or red skin. You cannot tell the two apart from the outside, which is why so many people cut open what they believed was a red dragon fruit and find white flesh inside.
The flesh of a true red dragon fruit is a deep, saturated magenta — closer to beetroot than to strawberry — right through to the centre, and dotted with the same small black seeds found in every variety.
Red compared with white
- Sweetness. Red is noticeably sweeter, typically 13 to 15 on the Brix scale against 11 to 13 for white.
- Flavour. Red has more depth and a faint earthy note underneath the sweetness, a little like beetroot. White is cleaner and more watery, closer to melon.
- Colour. Red is the reason dragon fruit drinks and bowls look the way they do. White produces a pale grey-pink that no amount of blending improves.
- Price and availability. White is the commodity crop, widely available and cheap. Red is a specialty item, usually costing significantly more.
- Staining. Red stains boards, worktops, clothing and hands. White does not.
The pigment, and why it matters
The colour comes from betacyanins, the same family of pigments that colours beetroot and prickly pear. This is unusual: most red and purple fruits get their colour from anthocyanins instead. Betalains and anthocyanins essentially never occur in the same plant, so this is a genuine point of difference rather than trivia.
Betacyanins are studied for antioxidant activity, and red dragon fruit accordingly tests higher for total antioxidant capacity than white. That is a real difference, though it is easy to overstate — this is a fruit, not a supplement, and the sensible framing is that red dragon fruit is a slightly better version of an already reasonable fruit.
The pigment has two practical consequences. First, it is fragile: heat, light and time all degrade it, which is why cooked dragon fruit turns brown and why bottled dragon fruit juice is usually coloured with something else. Second, it passes through the body largely intact, so eating a good quantity can turn urine or stool pink for a day. This is called beeturia when beetroot does it, it is completely harmless, and it alarms a great many people who have not been warned.
Nutrition
Per 100 g, red dragon fruit is roughly 60 calories, about 13 g of carbohydrate, 3 g of fibre, and 1 to 2 g of protein, with useful vitamin C, some iron and magnesium, and around 85 percent water. The figures are close to white-fleshed fruit; the meaningful differences are the higher sugar and the betacyanin content. Values vary with variety, growing conditions and ripeness, so treat these as typical rather than exact.
Buying and ripening
Since you cannot judge flesh colour from the outside, the only reliable ways to get red flesh are to buy from a seller who labels the variety, to buy a named cultivar, or to buy frozen red pitaya packs, which are labelled accurately and are often better quality than fresh imported fruit.
For ripeness, press gently — it should give slightly. The wings on the skin should be drying and browning at the tips. Remember that dragon fruit does not gain much sweetness after picking, so a hard fruit will soften but not improve much in flavour.
Using it
Red dragon fruit is the variety to choose whenever appearance matters: smoothie bowls, refreshers, sorbets, fruit platters and anything you intend to photograph. It is also the better one to simply eat cold with a squeeze of lime.
Avoid heating it. Cooking destroys the colour, and since the flavour is delicate to begin with, there is very little a cooked application gains. If you want the colour in a dessert, add the raw purée at the end, off the heat.