https://www.cnbc.com/2018/07/24/key-ingredient-in-impossible-burger-approved-by-fda.html

The U.S. Food and Drug Administration has approved the key ingredient in the vegetarian-friendly Impossible Burger. It's a big win for Silicon Valley-based Impossible Foods as it expands its distribution.

The ingredient, soy leghemoglobin, releases a protein called heme that gives the meat substitute its distinctive blood-like color and taste. Just as the Impossible Burger was gaining in popularity and reach, The New York Times published a report last year revealing that the FDA was concerned that the soy-based ingredient had never been consumed by humans.