What it is
Soapbark or yucca extract, whipped into root beer and slushes for a stable foam — a real plant material concentrated for its natural surfactant.
Why your biology objects
The foam comes from triterpenoid saponins, genuine plant surfactants (the same Quillaja saponin family used as a vaccine adjuvant). Real botanical origin, but it's a concentrated-saponin extract dosed for foam, and saponins mildly irritate the gut at high intake — an industrial tell more than a hazard.