Lettuce engineered to produce meat proteins

Perhaps you enjoy a burger in a lettuce wrap once in a while—but what if greens were also crucial to the patty? That’s the ultimate promise of new research showing lettuce can be engineered to produce myoglobin, a protein found in meat.

Myoglobin (and its better-known relative hemoglobin) contains the compound heme, the red pigment in blood. Adding heme can give plant-based meat alternatives a meaty flavor and the ability to “bleed.” For example, Impossible Foods uses a compound called leghemoglobin (a heme protein derived from soybeans) to flavor its meat alternatives. But using myoglobin…