David Wolfe has called these fruit, (not actually berries) Incan berries. So you can buy them at Whole Foods or whathaveyou, often as Incan Berries. You can even go to this site and go to products and buy them.
They are also known as:
golden berry (or goldenberry).
These superfoods should not be eaten green. They are in the same genus as tomatillo, which is what salsa verde is usually made from. Tomatillos are larger, and ripe when green.
Enjoy the video!