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What Is Rubisco? Everything You Need to Know & More

Right now, rubisco is emerging as a new, rich source of plant protein that’s readily available in nature, sustainable to grow at a large scale, and highly digestible compared to other proteins that leave you feeling bloated.

Nick Walker

Nick Walker

12 October 2023

4min read


What is rubisco?

In the world of health and wellness, there’s often a buzz around what the new ‘it’ thing might be. Followers are often early adopters, eager to get on board emerging trends to see how it benefits them.

Right now, rubisco is emerging as a new, rich source of plant protein that’s readily available in nature, sustainable to grow at a large scale, and highly digestible compared to other proteins that leave you feeling bloated.

What is rubisco?

Rubisco is the protein in green leaves that’s responsible for photosynthesis. It’s sustained herbivores and vegetarian animals for many years, but until recently has been difficult for humans to digest. 

Leaft Foods’ cutting edge food-safe technology is playing a key role in making the benefits of rubisco available, creating value for eaters with positive environmental outcomes at the same time. 

The Importance of Rubisco

Rubisco plays a critical role in helping plants to grow. In fact, this role is what makes it such a powerful source of protein for those that can digest it.

Rubisco is the enzyme that incorporates CO2 into plants during photosynthesis. It converts sunlight, water and CO2 into energy for plants, enabling their growth and development. It’s considered the most abundant plant protein in the world, which demonstrates just how much potential there is for rubisco as a food source for humans.

Rubisco has a different nutritional profile to other plant proteins such as wheat, soy and pea. It is a complete protein with a similar amino acid profile to beef. This may make it more effective at delivering certain health and performance benefits of protein like:

  • Building muscle
  • Recovering after exercise
  • Reducing inflammation
  • Building immunity

Not only is rubisco a great source of protein, but it may be easier than others to consume. Where users of whey protein can find it leaves them feeling bloated or lethargic, rubisco may be more digestible.

It has no known allergens, is neutral-tasting and it doesn’t have the grittiness others can have. Rubisco is also incredibly versatile; able to be used to supercharge smoothies, baking, salads and many other foods. 

Rubisco Extraction Technology

Leaft Foods’ food-safe technology is the key to rubisco’s digestibility. When we eat a leafy green like kale, we do get some rubisco, but our digestive systems can’t unlock all of it. 

The human body just isn’t built to digest naturally occurring rubisco in the same way cows, rhinos and other animals are. Someone would have to eat an unreasonable amount of leaves to sustain themselves on rubisco protein alone.

This is not unusual. Many other plant proteins are trapped inside plant cells. For example, they come in seeds that are designed to be eaten by animals and pooped out in more or less the same form. When this happens, much of their nutritional value remains untouched. 

Leaft Foods’ rubisco extraction technology unlocks the powerful nutritional value of rubisco so that when it's eaten, it’s absorbed into the body. Cleverly, it extracts the protein while preserving its nutritional properties. 

Initially, the protein is extracted from leaves which is then processed into a neutral tasting and smelling protein powder. 

Our founders, John Penno and Maury Leyland Penno spent years experimenting in their home kitchen and researching leaf protein to validate the concept, developing the cutting edge rubisco extraction technology in the process.

One of the things that encouraged them to keep pursuing rubisco extraction over this time is its potential as a highly sustainable food source. Because it exists in any leafy green, growers can utilize the most sustainable crops - in Leaft Foods’ case, we use nitrogen-fixing crops like lucerne (aka alfalfa). 

The ability to harvest rubisco from these types of sustainable crops offers the potential to reduce our reliance on traditional crop-based proteins and promote a more environmentally friendly food system. 

Rubisco and Sustainable Food Systems

The very reason Leaft Foods exists is to reduce the environmental impact of food production. With concerns over the sustainability of traditional food production methods, finding new ways of producing food is critical.

Traditional crop systems require high water usage and frequent cultivation can end up impacting the soil. Crop diversity is a proven way to boost soil health, but monocropping (i.e. mass producing one crop only) misses this opportunity. 

The most sustainable rubisco crops are considerably different. Alfalfa and other similar plants are easy to grow and require much less water and input than other crops. For farmers looking to diversify their production and income streams, it’s a user-friendly way to improve their sustainability profile.

Planting alfalfa and growing rubisco on as little as 20% of agricultural land can have big impacts on reducing emissions, benefiting soil health and creating feed self-sufficiency for farmers. Because it’s easy to grow, it can also improve crop rotation and further contribute to soil diversity. 

Diversification is a significant advantage because of the way horticulture and agriculture practices are beginning to value it more and more. Plainly, farmers and growers have their own lifestyle and financial needs, and there is a real benefit in being able to produce a high protein food source reliably, alongside existing farming methods.


The food production industry is under huge pressure to evolve. The environmental impact of producing food with conventional methods is under the microscope, while at the same time, the knowledge and importance of a healthy diet is increasingly being valued. This is all happening against a backdrop of a growing growing population that needs to be fed.  

As a rich, efficient plant-protein, rubisco has huge potential to respond to these key issues. It has the ability to be grown in a sustainable way, then harvested to provide a powerful source of protein for many.

By making such an abundant protein available for consumption, Leaft Foods is playing a key role in driving positive change in the food industry. 

It’s an ideal solution for those looking to optimize their own diets from a health or environmental perspective. Whether you’re a fitness fanatic, sustainability supporter or health conscious eater, rubisco has something for you.

We are doing exciting things. Learn more below.