Rubi Protein: Harnessing Nature’s Most Abundant Resource (Image Credits: Unsplash)
San Diego – Plantible Foods achieved a key regulatory victory when the U.S. Food and Drug Administration issued a “No Questions” letter affirming the safety of its Rubi Protein ingredient.[1][2]
Rubi Protein: Harnessing Nature’s Most Abundant Resource
The ingredient stands out as the first isolated RuBisCO protein cleared for food applications, extracted from Lemna minor, a fast-growing aquatic plant known as duckweed.[3][1] This protein, which powers photosynthesis in all green plants, makes up about 74% of Rubi Protein’s composition and accounts for roughly 85% protein content by weight.[2]
Rubi Protein delivers a complete amino acid profile with all nine essentials, plus vitamin B12. Manufacturers value its neutral taste, off-white color, odorless profile, and superior functionality, including high solubility, emulsification, foaming, and gelling.[3][4] Free from common allergens, it supports clean-label products while enhancing texture and nutrition.
Production occurs in controlled greenhouses where Lemna doubles its biomass every 48 hours, using minimal resources and no arable land. The water footprint remains 10 times lower than soy’s, promoting sustainability.[3]
Historic FDA Milestone Unlocks Broader Use
The FDA completed review of GRAS Notice GRN 001256 on February 5, 2026, stating it had no questions about Plantible’s conclusion that Rubi Protein – also called Lemna Leaf Protein – is safe under intended conditions.[2] Submitted in March 2025 and filed in June, the notice detailed manufacturing, specs, exposure estimates, and safety data from similar duckweeds.[2]
“This is more than a regulatory milestone. It’s an industry-defining moment,” said Tony Martens, Plantible’s founder and CEO. “We are proud to be the first company to receive a ‘No Questions’ letter for RuBisCO protein.”[1] The letter excludes infant foods and USDA products but covers a wide range of categories.FDA response letter
Texas Facility Powers Expansion
Plantible opened its first commercial plant in Eldorado, Texas, last year, shifting from R&D to full-scale output.[5][1] Green Lemna grows in enclosed systems, undergoes milling, filtration, and drying to yield the final powder.
With clearance secured, the company accelerates capacity to meet demand from partners in baked goods, beverages, and more. Plans call for further expansion this year.[4]
Targeted Food Categories and Use Levels
Rubi Protein functions as an ingredient, emulsifier, thickener, gelling agent, or protein source at precise levels across foods.
| Food Category | Examples | Max Level (%) |
|---|---|---|
| Baked Goods | Cakes, Cookies, Bread | 2.5-5 |
| Beverages | Enhanced Water, Concentrates | 4.1 |
| Grain Products | Pasta, Protein Bars | 2.5-5 |
| Plant Protein Products | Meat/Dairy Substitutes | 5 |
| Snacks | Crackers, Chips | 2.5 |
- Supports egg alternatives amid bird flu disruptions.
- Improves sustainability without taste or texture trade-offs.
- Enables allergen-free, nutritious reformulations.
Key Takeaways:
- First FDA-cleared isolated RuBisCO protein opens new sustainable options.
- 85% protein concentration with full amino profile and no allergens.
- Texas facility expansion targets global food manufacturers.
Plantible’s progress signals a shift toward efficient, planet-friendly proteins. Food innovators now have a versatile tool to meet rising demand for clean, functional ingredients. What do you think about duckweed’s role in future foods? Tell us in the comments.
