How Mission Barns is Solving Alternative Protein’s Biggest Challenge

By Dr. Bianca Lê

Sustainable and ethical meat alternatives have gained popularity over the past decade, yet plant-based meat sales still only account for 1% of the total meat market in the US. The primary barrier preventing consumers from purchasing plant-based meat is simple: plants don’t taste like meat. Cultivated meat not only sidesteps the environmental and ethical issues associated with livestock farming, but it also ensures the experience of eating meat remains uncompromised with the craveable flavor and juicy bite diners are looking for.

But the success of cultivated meat—in the timelines necessary to address our climate crisis—is not inevitable, despite early optimism. Recent skepticism and questions about the scalability and commercial viability of cultivated meat need to be addressed. People are asking—will we be able to produce enough cultivated meat to make a meaningful dent in the conventional meat industry? Will we be able to produce it at costs that will be acceptable by shoppers?

These are good questions—and the reality is that picking up wholly cultivated structured meat products (e.g., pork chops, steaks etc.) at your local grocery store at $9.99 / pound may still require years of R&D and technological advancement. Although it’s worth noting conventional meat may not be so affordable if the U.S government didn’t spend $38 billion each year to subsidize animal agriculture.

So what do you do when you have an urgent climate crisis, a technology that is still evolving, and billions of hungry people who want to eat delicious food without harming the planet or animals? At Mission Barns, we produce the key component of meat that gives you the biggest flavor bang for your buck—animal fat. By combining a small amount of cultivated animal fat to provide flavor and juiciness, in a product made of largely cheap, readily available plant proteins (which are already good at recreating the muscle grain texture in many meat alternative products), Mission Barns is able to make delicious, sustainable alternative meat products at much lower costs and larger scale.

Although meat is made up of muscle, fat, and connective tissue, it is fat—not muscle—which is the major contributor to species-specific flavor in meat. Conveniently, fat cells are currently easier and cheaper to grow compared to myofibers (a type of mature muscle cell and the stringy “grain” you see in meat).

Fat is the Part of Meat People Crave

Think about the most expensive cuts of marbled beef at a steakhouse. Or the unmistakable aroma of someone frying bacon in the morning. Or the best sushi restaurants serving a simple slice of otoro (fatty tuna belly) on rice. What do they all have in common? High fat content.

The quantity of fat marbling, known as intramuscular fat, is pivotal for determining tenderness, juiciness and flavor—core indicators of meat quality. Many flavor precursors and volatile aroma compounds (e.g. Maillard reaction products, Strecker aldehydes, certain short-chain acids etc.) are lipophilic (i.e attracted to fat). This means that fat is a carrier for many of these compounds and the distinctly meaty taste and aroma of meat is created when fat is melted and these compounds are released. From a texture perspective, the specific melting point of animal fat (i.e. which is lower than muscle) also allows the intramuscular fat to melt during chewing, which creates a juicy and tender sensation. Even a slight increase in fat content significantly impacts overall liking. Research has shown that even at 3% inclusion of animal fat, there is a significant increase in palatability of meat and such cuts were considered more tender, juicier, and more flavorful than those with less fat.

Animal fats and plant oils have different fatty acid profiles and melting points, which makes replicating meat flavor with plant-based ingredients challenging. The variations in fatty acid profiles between animal species and breeds contribute to the uniquely nuanced and complex flavor found in meat, absent in plant-derived alternatives. Thus, the inclusion of fat cells (adipogenic cells or adipocytes) is crucial for cultivated meat to authentically emulate conventional meat’s sensory profile.?

If we want to realize the decarbonization potential of cultivated meat ASAP, we are going to need fat to make craveably delicious and affordable products that will increase the likelihood of mass consumer adoption.

While it may seem obvious to some that fat is flavor, a lesser talked about benefit of cultivated fat is that it is also easier and cheaper to grow than muscle.

Muscle is Hard and Expensive to Cultivate at Scale (right now)

In addition to the per unit mass sensory advantages of fat as a minimum viable product for cultivated meat, it is currently more technically feasible and cheaper to cultivate fat at scale compared to muscle tissue.

There are two key reasons why muscle tissue is more challenging to produce cheaply today: it has a complex structure and is protein-rich.

Muscle has a complex structure that is difficult to recreate at large scale While fat cells remain globular as they increase in volume during differentiation, muscle cells undergo major morphological changes. Transcription factors cause individual mononucleated myocytes to fuse together, forming multinucleated myotubes. These then undergo additional fusion and form parallel myofibers within a complex extracellular matrix. Current tissue engineered techniques can recreate these initial stages but struggle to achieve further mass accumulation due to the lack of supporting cell types (vasculature and motor innervation) and electro-mechanical stimulation. Even after many weeks in culture, cultured muscle cells remain small and relatively unstructured, falling short of the desired texture we expect in meat.?

All cell types require specific growth factors and nutrients for mass accumulation. In addition to these biological inputs, muscle cells also require mechanical stimulation. Just like in our bodies, muscle cells need weight bearing exercise to grow. Muscle growth is tightly regulated by contraction-induced mechanics, making it challenging to trigger differentiation, myotube formation, and hypertrophy (increasing cell volume) in a large-scale bioreactor. While major progress has been made (e.g. via 3D printing, or growing muscle in edible scaffolds with grooved topography), creating the intricate structure of muscle fiber grain found in meat will take significant time and resources.

Amino acids - the building blocks of protein - are expensive

In addition to exercise, muscle tissue's dry mass is predominantly composed of protein, necessitating a high supply of amino acids for growth and maintenance—a raw ingredient that is not yet cheap enough for mass production of cultivated muscle. To address the negative impacts of animal agriculture quickly, we need to focus on building a product that can be scaled in a few years, not decades.

In comparison, adipocytes are immobile, globular cells that don't require exercise to grow.? Feed the cells with cheap glucose and they’ll convert it into valuable fatty acids and flavor precursors, thanks to de novo lipogenesis. Additionally, structured fat tissue isn’t a necessity for most meat products, since rendered animal fat (lard, tallow, schmaltz, etc., commonly used in cooking to make food taste significantly better) is just fat cells without the tissue scaffolding matrix.

If fat is so easy to grow then why isn’t everyone doing it? The research field that serves as the scientific foundation of cellular agriculture, stem cell therapy, was never really interested in growing lots of fat cells for therapeutic purposes. When embarking on this cultivated fat journey, we knew very well all the fundamental questions that needed to be solved to make delicious animal fat cheaply. From developing a fat cell line from livestock species without genetic modification or editing (a concern for some consumers and food regulators), to perfecting the feed inputs to fatten the fat cells (the literature on fat cell differentiation is frustratingly sparse), Mission Barns has developed an end-to-end bioprocess platform to address these unknowns.

If you’re interested in learning about how we’re tackling these technical whitespaces, keep your eyes glued here. I might share Mission Barns’ super-secret technology plan in my next article…