At the Optimist Daily, we tend to write quite a bit about meat alternatives. After all, getting people to eat less meat (thus creating less emissions) by offering faux meat that looks and tastes just like the real thing seems to be working pretty well. Just look at Impossible Foods, which has impressed so much with its plant-based burger that Burger King has added it to its menu. But have you ever asked yourself what exactly is being added to this veggie burger to make it seem so real? Well, if you haven’t received an answer yet, look no further. The Impossible Burger includes an ingredient from soybeans called leghemoglobin, a protein that is chemically bound to a non-protein molecule called heme that gives leghemoglobin its blood-red color. In fact, a heme — an iron-containing molecule — is what gives blood and red meat their color. Leghemoglobin is evolutionarily related to animal myoglobin found in muscle and hemoglobin in the blood and serves to regulate oxygen supply to cells. In short, it’s heme that gives the Impossible Burger the appearance, cooking aroma and taste of beef. It should be added that the leghemoglobin used in the burgers comes from a genetically engineered yeast that harbors the DNA instructions from the soybean plant to manufacture the protein, which means its technically GMO. Some vegans might insist that a GMO product cannot be vegan for various reasons, including animal testing of products such as leghemoglobin. A counter-argument, as the author of this story points out, is that the moral certitude of that position can be challenged because it does not take into account the cattle that are spared. In any case, now you know a bit more about the faux meat from Impossible Foods.