Just like durian the mango fruit is sweet and increase heat to the body due to the high sugar content. It will cause some burping too but the difference is mango doesn't produce bad burping smell. This is probably because of the present of citric acid that make up the sour taste of the mango. Surprisingly enough the mango fruit ripen flesh is full of stringy fiber and it can be as tough as nylon plastic.
The black area is formed by the latex when the fruit fall from its stem. In the wild there are mangoes where the latex can caused burnt to skin. I remember long years ago during my childhood living in the village - eating wild mangoes caused burnt to my lips after eating it and contact with the latex. It will turn my lips to almost black in color as shown below and it hurts. That is probably because of the higher concentration of citric acid in the latex.
See the actual fiber in the mango fruit flesh - very similar to nylon and it's as stuff. You can feel them when eating mango some of these fiber might stuck in between your teeth and try to pull it out - you will understand what i meant.
Extracted juice from the mango flesh - after sometimes the sugar will eventually formed soft jelly like below. I am wondering if that's how mango pudding are made?