The Hero's Journey
“Heroism is endurance for one moment more.”
– George F. Kennan
Taste, texture, and nutrition – for the alternative protein industry, the holy grail is as alluring as it is elusive. Time and again, irrespective of technology, product, and region, this trifecta is seen as essential to a food product’s success. The industry has responded with a panoply of innovative ingredients and raw materials to meet the challenge. Whether it’s additive flavours and colourants for taste, binders and emulsifiers for texture, or nutraceuticals and plant proteins for nutrition, products are laced with additional ingredients to garner consumer interest. Unfortunately, this is a double-edged sword. These additives may inch the product closer to satisfying consumer expectations, but the elongated, indecipherable ingredient deck sends consumers running in the other direction. Ideally, an ingredient would offer these characteristics in an integrated package to enable favourable product attributes in a concise ingredient deck. Soy leghemoglobin, or heme, does exactly this.
The Hero Ingredient
For a moment, consider what computers looked like early in their existence – a monitor, a CPU, external storage, a keyboard, a mouse, and other supplemental accessories. Laptops today integrate all these components into a single product. This integration and consolidation significantly increases productivity and satisfaction. This is the case for heme as well. While there are high-performing ingredients to deliver taste, colour and nutrition, it is heme’s ability to provide these in an integrated offering that makes it a hero ingredient. In addition, regulatory ease and scalability couple to make this hero ingredient accessible.
Globins are a class of small heme proteins found in almost all living organisms1. Hemoglobin is a protein in the red blood cells of animals that carries oxygen. Myoglobin is a protein found in the heart and skeletal muscles. Both of these proteins consist of a ring-shaped molecule called heme2. Given its unique structure, the heme molecule can carry an iron atom within it and also bind with oxygen. This is the case in all animals. Heme plays several essential roles in animals such as lending the bright red colour to blood, carrying oxygen to specific tissues, and increasing the rate of chemical reactions (catalysis)3. Leghemoglobin (short for legume hemoglobin) is found in the nitrogen-fixing root nodules of leguminous plants and is structurally similar to myoglobin. Soy leghemoglobin is the hemoglobin found in soy, a leguminous plant.
Image credit: Impossible Foods
Essential Attributes, Exceptional Access
Soy is the fifth most-grown crop in the world (behind sugarcane, rice, wheat, and corn)4. Soybean seeds are already used for a plethora of products such as tofu and soymilk as a source of protein, and as a source of edible oils being an oilseed. In the plant-based meat sector, soy protein remains the ingredient of choice, followed by wheat and pea protein. As such, the scale at which soy is grown makes it convenient to utilise the roots to harvest the leghemoglobin, since the roots are a byproduct after soybeans are harvested. The issue with soy leghemoglobin is not the access to soy but rather the tedious process through which the leghemoglobin nodules need to be separated from the root and the soil. This led to the use of yeast to produce heme via precision fermentation. The Pichia pastoris yeast strain, which has been used in food preparation since the 1980s, was employed to grow heme. Pichia pastoris’ long lineage of use made scale-up easier5.
Heme has the advantage of offering benefits across the trifecta of essential characteristics for food products:
Taste: Since it is an iron-carrying molecule, heme creates a ‘meaty’ and metallic taste. Its role in chemical catalysis makes it an important addition during the cooking process. The ‘meaty’ aroma during cooking is a result of its interactions with cellular proteins and biomolecules6.
Colour: The red colour of meat can be attributed to heme and results from the interaction of the iron molecule that it carries with oxygen.
Nutrition: Heme iron is more bioavailable than non-heme iron. That is, heme iron is more easily absorbed by the body due to its higher solubility levels when compared with non-heme iron.
Innovation using algal extracts, precision fermentation and plant molecular farming for heme is steadily picking up pace. Impossible Foods and Motif FoodWorks are early entrants in the field, but there are several others.
Paleo is creating GMO-free heme proteins via precision fermentation.
IngredientWerks uses plant molecular farming to produce genetically engineered corn crops that express bovine myoglobin.
Kyomei uses plant molecular farming to produce meat proteins starting with bovine myoglobin.
South Korean company HN Novatech uses seaweed to extract heme-like molecules.
Back of Yards Algae Sciences debuted an algae-based heme.
Triton Algae Innovations has developed a scalable precision fermentation platform to grow heme using red microalgae.
tHEMEat uses food waste to create a vegan heme alternative.
Soy leghemoglobin-derived heme has been approved for human consumption in several regions including the United States (U.S.), Canada, Australia, New Zealand, Singapore, Hong Kong, Kuwait, and the United Arab Emirates (U.A.E). Key markets where approval is pending include the United Kingdom and China. As more markets approve the use of heme in food products, its production will continue to expand although only a small quantity of soy leghemoglobin is needed in meat analogues. The U.S., Australia, and New Zealand allow up to 0.8% of it on a weight-on-weight (w/w) basis. This is because 0.8% is the lower end of the concentration of myoglobin content in red meat (0.8%-1.8%). Singapore allowed Impossible Foods to incorporate up to 0.45% w/w. Interestingly, Impossible Foods’ alternative beef contains 0.45% soy leghaemoglobin while the pork alternative contains only 0.25%7. The sheer power packed in tiny quantities of the ingredient is a testament to its unparalleled performance.
Given the potential of heme, it is no wonder that it has been a fierce battleground for intellectual property. A case in point is the ongoing lawsuit between Impossible Foods and Motif FoodWorks. Impossible Foods’ heme is a replica of plant-sourced leghemoglobin while Motif FoodWorks’ HEMAMI is a yeast-derived bovine myoglobin. Impossible Foods filed a lawsuit against Motif FoodWorks in the U.S. for infringing upon its heme patent and Motif countersued Impossible Foods’ patents in the U.S. and the European Union (EU). As a result, Impossible Foods’ EU patent referring to the use of heme as an ingredient was revoked by the European Patent Office8. One thing is clear – heme is such a potent and valuable ingredient that it is worth two companies (three including Gingko Bioworks, which was added to the lawsuit by Impossible Foods), spending millions of dollars for its exclusivity.
Integration is Irreplaceable
The integration of functionality, availability, and customizability makes it difficult to find an alternative that rivals heme. Heme is unique in its ability to provide numerous benefits that span taste, colour, and nutrition, making it an essential component to an array of plant-based products vying to reach mainstream consumers. While we don’t know what the future of the food system will look like, it appears that heme is poised to play a meaningful role alongside other innovations in designing the next generation of alternative protein products.
Makalowski et al., 2014
Shelton et al., The Molecular Magic of “Meatless” Meats, 2020
Fraser et al., Safety Evaluations of Soy Leghemoglobin Protein Preparation Derived From Pichia pastoris, 2018
American Society for Microbiology
Food Standards Australia New Zealand (FSANZ)
Food Dive, Motif FoodWorks Continues to Challenge Impossible Foods’ Patents