Pitaya
this fruit of several cactus species indigenous to the Americas. Pitaya ( Dragon fruit ) has a quite mild taste, which is quite similar to melon in texture and is not too sweet.
It also features a quite pear-like flavor, which is great for creating stunning, brightly-colored smoothies.
image credit http://www.davaoorganics.com/general/davao-organics-fast-juicy-facts-about-organic-dragon-fruit