The Impossible Burger is made through a combination of plant-based ingredients. A key ingredient is soy leghemoglobin. Soy leghemoglobin is a protein that carries heme, an iron-containing molecule that occurs naturally in every animal and plant. Heme is the “magic ingredient” that enables the Impossible Burger to satisfy meat lovers’ cravings.
Before issuing its no-questions letter, the FDA reviewed comprehensive test data about soy leghemoglobin to assess its status as “generally recognized as safe,” or GRAS. “We have no questions at this time regarding Impossible Foods’ conclusion that soy leghemoglobin preparation is GRAS under its intended conditions of use to optimize flavor in ground beef analogue products intended to be cooked,” the FDA said in a statement.