The Homo Scientificus blog looks at the ways Science and Culture intersect in everyday life.
Recently, the Ninth Circuit of Appeals issued a significant ruling in favor of the plant-based meat company Impossible Foods. At the heart of the lawsuit was one of the ingredients used in the company’s Impossible Burger, legume hemoglobin also known as leg hemoglobin.
On the heels of the U.S. Food and Drug Administration approving the Impossible Burger for consumption, food safety and anti-GMO groups cried foul. Last year, the Center for Food Safety (CFS) filed a lawsuit arguing that the FDA had not applied the correct standards when assessing Impossible Foods’ petition, and that longer-term animal studies were needed to reassure the public of leg hemoglobin’s safety. According to the CFS, there was no proof that consumption of leg hemoglobin was safe for humans.
Leg hemoglobin is a form of hemoglobin found in nitrogen fixing root nodules of leguminous plants such as green pea, lentil, and common beans. Specifically, the protein is produced by nitrogen-fixing bacteria also known as rhizobia. Just like its cousin found in animals, leg hemoglobin is red in color, thanks in part to the presence of iron. Because the protein contains iron, it imparts a “meaty” taste to the Impossible Burger. (Take it from someone who’s eaten meat-subsitites for over 20 years, it’s hard to underestimate the difference having “Fe” present makes. And even with leg hemoglobin, the Impossible Burger needs to be almost charred to actually taste like meat.)
When the FDA first approved the use of leg hemoglobin, it came after considerable back and forth with Impossible Foods. According to records, the company shared much of its clinical data with the FDA. When the agency was satisfied, it wrote that feeding studies “did not show any toxicologically relevant effects,” and that “the mutagenicity and genotoxicity studies provided in the petition showed no evidence of mutagenic activity or increased chromosomal aberrations in cells exposed” to soy leghemoglobin.
As for allergenicity, the FDA noted: “Soy leghemoglobin and P. pastoris proteins in the soy leghemoglobin preparation are readily digested at acidic pH conditions found in the stomach and denatured at normal cooking temperatures. We agree with the petitioner that the totality of evidence supports the conclusion that soy leghemoglobin protein and P. pastoris proteins present in soy leghemoglobin preparation do not pose risks of allergenicity when consumed, even for people who are allergic to foods containing soybean protein.”
To make a long story short, the FDA deemed leg hemoglobin as generally recognized as safe (GRAS). Since this is the first instance of consumption of the protein as part of a food, the notion of substantial equivalence undoubtedly played a role in analyzing its safety. (Read an in-depth look at the controversial notion of substantial equivalence: The Good, the Bad, and the Ugly of GMO Testing.)
Critics such as the Center for Food Safety counter that long-term safety studies have not been conducted with regards to leg hemoglobin consumption and that leg hemoglobin represents a completely new food ingredient that has no track record of safe consumption.
Meanwhile, other groups also point to the fact that the burger consists of fourteen separate patents. In their words The Impossible Burger is not food but “software.” We’ve listed them here:
- Patent No. 10287568 — Methods for extracting and purifying nondenatured proteins
- Patent No. 10273492 — Expression constructs and methods of genetically engineering methylotrophic yeast
- Patent No. 10172380 — Ground meat replicas
- Patent No. 10172381 — Methods and compositions for consumables
- Patent No. 10093913 — Methods for extracting and purifying nondenatured proteins
- Patent No. 10039306 — Methods and compositions for consumables
- Patent No. 10087434 — Methods for extracting and purifying nondenatured proteins
- Patent No. 9943096 — Methods and compositions for affecting the flavor and aroma profile of consumables
- Patent No. 9938327 — Expression constructs and methods of genetically engineering methylotrophic yeast
- Patent No. 9833768 — Affinity reagents for protein purification
- Patent No. 9826772 — Methods and compositions for affecting the flavor and aroma profile of consumables
- Patent No. 9808029 — Methods and compositions for affecting the flavor and aroma profile of consumables
- Patent No. 9737875 — Affinity reagents for protein purification
- Patent No. 9700067 — Methods and compositions for affecting the flavor and aroma profile of consumables
- Patent No. 9011949 — Methods and compositions for consumables
Lastly, anti-GMO groups point to the fact that the leg hemoglobin produced for use in the Impossible Burger comes from using a genetically modified yeast, Pichia pastoris. Undoubtedly, the GMO argument revolves around the long-term safety of consuming GM hemoglobin.
SCINQ Basics: Pichia pastoris is a species of methylotrophic yeast. It was found in the 1960s, with its feature of using methanol, as a source of carbon and energy. After years of study, P. pastoris was widely used in Biochemical research and Biotech industries. (Wikipedia)
With the Ninth Circuit of Appeals’ ruling, Impossible Foods got a very big win. It’s hard to imagine how they’d move past not being allowed to rely on leg hemoglobin. Without it, their burger would be just another wanna-be-meat alternative like Quorn (Mind you, Quorn also went through lots of challenges that eating a completely new type of food was dangerous long-term). And to be fair, if consumers are worried about the Impossible Burger and its GMO-never-before-eaten component, they can just not eat it. Simple as that. It’s what I do since it’s too damn expensive in the first place.
WORDS: Marc Landas.