I saw the bright color of the dragon fruit skin, so I squeezed the juice and mixed it with flour to steam the steamed buns. However, after the steamed buns were steamed, the red color was gone at all. I want to ask for the reason.

High temperature will decompose the red pigment inside, so there will be no color. At the same time, since the steamed buns will become larger after steaming, the remaining red pigment will be more dispersed, so even if there is color, the color will be very light.

Finally, I would like to ask weakly, is that juice edible?