What plants are sources of albumin? Exploring vegan proteins and recombinant options

December 13, 2025 •

3 min read

Albumin is not exclusive to animal products like eggs and blood; it is a family of proteins found extensively in both animal and plant tissues. While human serum albumin is critical for blood function, many plants contain distinct albumin-like proteins that offer nutritional and functional benefits.

Quick Summary

Certain plants like quinoa and hemp seeds naturally contain albumin-like proteins valuable for nutrition and food science. Research also develops recombinant human serum albumin (rHSA) from transgenic rice for medical and cosmetic applications.

Key Points

Plant 2S Albumins: Seeds from quinoa, hemp, legumes, and oilseeds contain 2S albumins, which are important storage proteins with nutritional value.
Recombinant Albumin: Genetically engineered plants like transgenic rice are capable of producing recombinant human serum albumin (rHSA) for medical use, offering a safe, cost-effective alternative to blood-derived proteins.
Superior Foaming Properties: Plant albumins, especially from legumes and rapeseed, exhibit excellent foaming capabilities comparable to or better than egg white protein, making them valuable for food applications.
Enhanced Digestibility: The albumin and edestin found in hemp seeds are noted for their high digestibility, which aids in nutrient absorption and muscle repair.
Waste Stream Recovery: In conventional protein extraction, valuable albumins are often discarded. Newer methods using membrane filtration and enzymes allow for the recovery of these techno-functional proteins from industrial side streams.
Allergen Potential: While some plant albumins are major food allergens (e.g., in peanuts and Brazil nuts), others like hemp protein are less likely to cause allergic reactions.

What is Albumin?

Albumin is a type of globular, water-soluble protein with various functions across living organisms. In humans, serum albumin, produced by the liver, transports hormones and fatty acids through the bloodstream. In plants, however, albumins, primarily known as "2S albumins," serve as important storage proteins in seeds. These plant-derived albumins differ structurally and functionally from human serum albumin, yet they hold significant value in nutrition and food processing. The increasing demand for plant-based alternatives and ethical considerations surrounding animal products have propelled research into unlocking the potential of these botanical protein sources. The following sections explore key plant sources of natural and engineered albumin-like proteins.

Natural Plant Sources of 2S Albumins

Many common grains, seeds, and legumes contain substantial amounts of water-soluble albumin proteins, which are a valuable part of a balanced diet, particularly for vegans and vegetarians. These plant-based albumins contribute to the overall protein content and provide unique functional properties in food products.

Quinoa: As a complete protein source, quinoa contains a robust protein profile with both 11S globulins and 2S albumins, comprising about 35% of its total protein content. This makes quinoa an excellent plant-based option for delivering a full spectrum of essential amino acids.
Hemp Seeds: Known for their exceptional nutritional value, hemp seeds are a source of two key proteins: edestin and albumin. The albumin in hemp seeds is easily digestible, providing a quick and accessible protein source, though it is more sensitive to heat than its counterpart, edestin.
Legumes: A cornerstone of many plant-based diets, legumes like peas, chickpeas, lentils, and soybeans are rich in protein, including both albumins and globulins. Pea protein isolate, for example, is composed of 10-20% 2S albumin proteins. Mung beans also contain a significant albumin fraction.
Oilseeds: Seeds from plants such as rapeseed, sunflower, and mustard are notable for containing 2S albumins as their primary storage protein. These have been studied for their structural and functional properties, including their stability and allergenic potential.

Functional Properties of Plant Albumins

Plant albumins possess desirable functional characteristics that make them attractive for the food industry. Unlike globulins, they are often heat-stable and highly soluble, even under heating and spray-drying conditions. Plant albumins, such as those from legumes and rapeseed, exhibit superior foaming properties, comparable to or exceeding those of egg white and dairy proteins. This makes them valuable for stabilizing emulsions and foams in products like meringues, whipped toppings, and plant-based dairy alternatives. Mild extraction methods, such as enzymatic or ultrasonic assistance, can be used to recover these functional proteins, which are often discarded in conventional protein extraction processes.

Recombinant Albumin from Genetically Engineered Plants

Beyond natural plant proteins, advanced bioengineering allows for the production of recombinant human serum albumin (rHSA) in transgenic plants.

Transgenic Rice: Rice is a major candidate for rHSA production due to its low-cost scalability and inherent safety, as it eliminates the risk of viral contamination associated with blood-derived albumin. The rHSA produced in rice has been shown to have identical molecular mass and secondary structure to natural human plasma albumin, with applications in cell culture media, drug delivery, and vaccine formulation.

A Comparison of Albumin Protein Sources


Source	Albumin Type	Natural / Engineered	Foaming Ability	Digestibility	Allergen Potential
Quinoa Seeds	2S Albumin	Natural	Variable	High	Can be an allergen
Hemp Seeds	Albumin	Natural	Good	High	Low
Pea Seeds	2S Albumin	Natural	Superior	Good	Can be an allergen
Transgenic Rice	Recombinant HSA	Engineered	High	N/A (pharmaceutical)	Very Low (High Purity)
Egg White	Ovalbumin	Animal	Superior	High	Common allergen

Conclusion

The plant kingdom offers diverse and valuable sources of albumin-like proteins. From naturally occurring 2S albumins in seeds and legumes to cutting-edge recombinant human albumin grown in transgenic rice, these botanical options provide ethical, functional, and safe alternatives to animal-derived sources. As research advances, particularly into functional properties and extraction methods, plant-based albumins will play an increasingly vital role in sustainable nutrition, food processing, and medical applications. For further information on the expression and purification of rHSA, consult relevant studies, such as the one published in PLoS ONE by He et al.(https://pmc.ncbi.nlm.nih.gov/articles/PMC3796638/).

Frequently Asked Questions

No, natural plant-based albumins (like 2S albumins) are structurally and functionally different from human serum albumin (HSA) found in blood. However, recombinant HSA can be produced in engineered plants, such as transgenic rice, to be identical to the human version for medical use.

Quinoa and hemp seeds are excellent sources, containing significant amounts of naturally occurring 2S albumins. Legumes like peas, lentils, and chickpeas also contain both albumin and globulin proteins, making them valuable sources of plant-based protein.

Recombinant human serum albumin (rHSA) is produced by genetically engineering plants, such as rice, with the human albumin gene. The plant is then grown, and the rHSA is expressed in the seeds, from which it can be extracted and purified.

Plant albumins, particularly from sources like peas and rapeseed, have excellent functional properties such as foaming and emulsification. This makes them useful for stabilizing various food products, including foams, emulsions, and plant-based dairy or meat alternatives.

The allergenicity of plant albumins varies by source. Some 2S albumins, such as those found in peanuts and Brazil nuts, are major food allergens. However, other sources like hemp protein are considered to have a low allergenic potential.

Albumins are water-soluble proteins and are traditionally extracted using water during the Osborne fractionation process. Modern methods, including enzymatic and ultrasonic assistance, are now used to improve extraction yield and efficiency from plant seeds.

Yes, the albumin in hemp seeds is somewhat sensitive to heat, meaning it is best preserved in raw or minimally processed hemp products. By contrast, the other primary hemp protein, edestin, is heat-stable.