Billions of dollars of discarded marigold flowers could become a new source of sustainable food

Billions of dollars of discarded marigold flowers could become a new

Researchers found marigold proteins can withstand heat, bind oil and water, and support more sustainable food production

Edited By: Joshua Shavit/
UGA Writer: Savannah Peat

Published Aug 2, 2026 1:07 PM PDT

Researchers found marigold proteins can withstand heat, bind oil and water, and support more sustainable food production. (CREDIT:

• University of Georgia researchers found that pot marigold flowers contain useful proteins with levels comparable to quinoa and strong heat stability.
• Marigold proteins can hold water and oil, form emulsions, and provide antioxidant and savory properties, making them promising for baked goods, sauces, soups, and dressings.
• Using discarded flowers as a food ingredient could reduce billions of dollars in floral waste, though more safety testing and large-scale manufacturing research are needed.

Billions of dollars’ worth of flowers are discarded each year. Some may contain useful proteins

A University of Georgia study found that common marigold flowers carry protein levels comparable toheat, held water and oil, and helped form emulsions

Those traits could make marigold protein useful in baked goods, sauces, salad dressings, soups, and other foods

The research examined Calendula officinalis, commonly called pot marigold

“Billions of dollars of flowers are thrown away each year,” said Anand Mohan, the study’s corresponding author

“Can you imagine if we were able to take those flowers and use them for food instead?”

Mohan is an associate professor in UGA’s College of Agricultural and Environmental Sciences

A Flower with More than Decorative Value

Marigolds usually enter homes, gardens, ceremonies, and holiday displays as decoration

Their petals have also appeared in food for centuries across several cultures. The stems and leaves taste bitter, so people generally eat only the petals

Dried marigold can flavor tea and soup. Fresh petals add a tangy, citrus-like taste with a note similar to tarragon. The flowers also contain fiber, calcium, potassium, iron, and antioxidant compounds

Still, researchers wanted to know whether their proteins could perform useful jobs during food processing. Plant proteins must do more than add nutrition

Food manufacturers often need them to trap moisture, bind oil, create foam, or keep ingredients from separating. Heat resistance matters in baking and other high-temperature processes

The study found that marigold proteins could handle several of those tasks

The dried flowers contained 9.71% crude protein, alongside carbohydrates, fiber, minerals, and fat. Their protein level resembled that of other edible flowers and plant materials under consideration as food ingredients

Researchers recovered 92.17% of the available protein during extraction. That high recovery rate suggested that much of the flower’s protein could be separated for further use

Four Proteins, Four Different Behaviors

The team divided the extracted protein into four groups: albumin, globulin, glutelin, and prolamin

Albumin made up the largest share at 65.47%. Globulin accounted for 22.46%, while glutelin represented 10.94%

Prolamin formed only 1.12% of the recovered protein. The fractions behaved differently when researchers tested their food-related properties

Albumin performed especially well. It held 2.37 grams of water per gram of protein. Its oil-holding capacity reached 2.49 grams per gram

Those abilities could help foods retain moisture and manage fats during storage and preparation

Albumin also produced the strongest emulsifying result, reaching 65.22 milliliters per gram. An emulsion combines ingredients that normally separate, such as oil and water. Salad dressings provide a familiar example

Glutelin also performed well in water retention, oil binding, and emulsification

Prolamin gave the weakest results. Its compact structure limited its ability to interact with water and oil. The differences were not minor details

They helped identify which parts of the flower protein might work best in particular foods

Heat Brings out an Unexpected Strength

Marigold protein also tolerated temperatures that can damage other plant proteins

Albumin reached a peak denaturation temperature of 105.28 degrees Celsius. Prolamin reached 97.6 degrees, while glutelin reached 91.8 degrees

Globulin had the lowest value at 88.4 degrees. These temperatures exceeded those reported for several other plant proteins. That resistance could prove useful in baking or extrusion, where food ingredients face intense heat

Pea and chickpea proteins can lose useful properties during high-temperature processing. The marigold fractions, especially albumin, remained more stable

The protein structure helped explain why

Albumin had a porous and irregular surface. That shape gave it more space to interact with water and oil

Glutelin formed tighter, sheet-like structures linked to heat resistance. Prolamin appeared densely packed and crystalline. Its closed structure reduced hydration and weakened its performance

Researchers also examined alpha-helices and beta-sheets, two patterns found within proteins

Fractions containing more beta-sheets generally resisted heat and supported emulsification better. Those dominated by alpha-helices tended to perform less effectively

Savory Notes Inside a Flower

The amino acid profile added another possible food application. Researchers detected 13 amino acids across the four protein fractions

Proline, cysteine, and glutamic acid appeared among the most abundant. Albumin and glutelin contained especially notable amounts

Glutamic acid and aspartic acid can contribute to savory flavor. That raises the possibility that marigold protein could add an umami quality to certain products

Its flavor contribution would depend on the final food and processing method. The study did not test finished commercial recipes

Still, taste could become a useful feature rather than a problem to hide

Some plant proteins need extensive flavor masking. A naturally savory ingredient might fit more easily into soups, sauces, or meat alternatives

Cysteine and other sulfur-containing amino acids may also contribute antioxidant activity. Albumin and glutelin produced the strongest antioxidant results

That property could help slow oxidation in foods where fats or other ingredients lose quality over time

Hundreds of Proteins in One Flower

The team identified about 622 proteins in marigold flowers. Among them were 33 short proteins containing fewer than 120 amino acids

These included proteins involved in stress response, transport, energy metabolism, and oxidation control

Some may help explain the flower’s oil-binding, emulsifying, and antioxidant properties. The researchers also found many low-molecular-weight proteins ranging from 10 to 37 kilodaltons

Their small size may help them move quickly toward the boundary between oil and water

Once there, they can help form smaller droplets and steadier emulsions. The flower’s useful behavior therefore did not come from one protein alone

It arose from a mixture of structures with different strengths

“What excites me most about this research is that it challenges how we think about flowers,” said first author Fidele Benimana

Benimana is a doctoral student in UGA’s Department of Food Science and Technology

“Most people see marigolds as ornamental plants, but they also contain proteins with unique functional properties that could be useful in food formulation.”

Not Every Marigold Belongs on a Plate

The researchers included an important warning. Not every plant called a marigold should be eaten

The study used Calendula officinalis. Edible options also include true marigolds from the Tagetes genus

Other varieties may taste unpleasant or cause stomach problems. Any food ingredient would also require careful processing and safety testing

The study examined extracted proteins rather than asking people to eat large quantities of flowers. Industrial food use remains a future possibility, not a product already available

Researchers still need to test how marigold proteins behave during large-scale manufacturing

Commercial development would also require work on flavor, texture, storage, safety, and consistency between harvests

The team did not claim that marigolds will replace established crops. Instead, the findings identify a discarded material that may deserve more attention

Study co-authors included Nancy Alila, Kentaro Kawata, Christopher Kucha, and Anupam Roy of the Indian Institute of Technology-Delhi

Practical Implications of the Research

Marigold protein could offer two benefits at once. It may provide a functional plant ingredient while reducing flower waste

Manufacturers could potentially recover protein from flowers that would otherwise be discarded after harvest, ceremonies, or decorative use

Albumin and glutelin appear especially promising for foods that need moisture retention, foaming, heat stability, or emulsification. Possible uses include baked products, dressings, soups, sauces, dairy alternatives, and meat substitutes

The flower’s minerals, fiber, and antioxidant properties may add further value, though commercial products would require more testing

Waste reduction could become equally important. Rather than growing a new crop only for protein, producers might use part of an existing flower supply

“I don’t know if the marigold is a super flower,” Mohan said

“But to me, I feel like maybe all these beautiful flowers are super flowers.”

The next major plant protein may not come from a field of beans. It may begin as a flower that someone planned to throw away

Research findings are available online in the journal ACS Food Science & Technology

The original story “Billions of dollars of discarded marigold flowers could become a newws

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Joshua ShavitScience & Technology Writer and Editor

Joshua ShavitWriter and Editor

Joshua Shavit is a NorCal-based science and technology writer with a passion for exploring the breakthroughs shaping the future. As a co-founder of The Brighter Side of News, he focuses on positive and transformative advancements in technology, physics, engineering, robotics, and astronomy. Having published articles on AOL.com, MSN, Yahoo News, and Ground News, Joshua’s work highlights the innovators behind the ideas, bringing readers closer to the people driving progress

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