Prime Roots elevates plant-based cold cuts with koji—an ancient fungus

The plant-based food and beverage market is booming. From nondairy milks to animal-free meats, a range of innovations continue to permeate the industry.

Prime Roots, which utilizes koji (Aspergillus oryzae) to craft plant-based deli and charcuterie meats, is on a mission to “provide a better cut of meat for every type of eater.” Traditionally grown on rice, barley and soybeans, koji is a centuries-old filamentous fungus that originated in Asia. It is a key ingredient used in the production of a variety of fermented foods and beverages, such as miso, soy sauce, mirin and sake.

Koji, which has been deemed GRAS (generally recognized as safe) by FDA and safe for human consumption by World Health Organization (WHO), scientifically showed to have positive effects on gut health.

For Kimberlie Le, co-founder and CEO of Prime Roots, koji has been a staple in her family for decades. “My mom was a chef, so we’ve been using it in the kitchen since I was 4 years old,” she said. “It’s very versatile, clean, and has a meaty texture and umami flavor that adds that meaty flavor to our deli meats and charcuterie.”

When Le attended UC Berkeley, where she received a bachelor’s degree in society and environment, she also wrote, designed and taught a course on environmental sustainability, which ultimately sparked the idea to create Prime Roots. “I learned about the impacts of animal agriculture on the climate and really felt compelled to launch a sustainable food company that was good for people and the planet,” she said.

Less than five years after she graduated, Prime Roots was born. Launched by Le and Joshua Nixon, the company offers a range of flavored, plant-based meats, including turkey, ham, salami, pepperoni, bacon, foie gras and pâté, that are non-GMO and free of the nine major food allergens.

“The first ingredient in all our products is koji, and it enables us to eliminate common processed proteins that are in most plant-based products like gluten or soy,” Le explained of the products created by a talented team of R&D professionals and food scientists. “The koji is made using fermentation. It’s then harvested, and we use meat-making techniques to turn it into our deli meats. For example, our meats are roasted, smoked and handled the same way as conventional meats. They also slice identically in store so you can have the meat shaved or even thick cut.”

Contrary to animal-based deli meats, which can take weeks or months to create, Prime Roots’ products only take three to five days to make. The products are also encased like their animal-based counterparts using plant-based casings. “Making koji-deli meats is simple and requires little processing,” Le said.

Perfecting the koji-style deli meats, however, took about five years, since the team takes an epicurean approach to everything it makes. “We really study the flavors and ingredients for different deli classics like our Black Forest ham,” Le explained. “We studied every single ham we could taste to learn and understand the right amount of juniper berries to add for that special Black Forest taste that people recognize and love.”

It also took many years to achieve the desired textures for all of the meats the company offers. “For instance, salami is dried, and we do the same, versus the ham that needs to be netted and smoked,” Le said.

The R&D team at CuliNEX, a clean label and plant-based food product development company, can attest to the challenges koji presents when using it to create deli-style meats. “We tried using koji in one project to mimic fat, but it was unsuccessful,” Webb Girard, senior director of R&D at CuliNEX, said of the plant-based salami and pepperoni meat analogues his team has worked on. “We found that the texture provided too much of a bouncy/rubbery texture and found the use of different combos of gums, thermo reversible and irreversible, in combination with fat, provided a more similar texture to real fat that you would expect in a salami/pepperoni.”

For Girard and Le, finding the right balance of materials to attain the right textures and tastes, especially for plant-based meats, is key.

Prime Roots mixes koji with a few other plant- and fungi-derived ingredients—fats like coconut or rice bran oil and natural seasonings like garlic powder and sesame oil—to make meats that taste, feel and look like conventional animal products. Le noted, “We are really food- and culinary-forward in all that we do, given our roots and wanting to make a big impact making products that are loved by meat eaters and plant-based eaters alike.”