We occasionally use flowers to decorate food, but few people would think of flowers themselves as food. Now a new study challenges that, finding that the common marigold contains protein levels similar to other plant-based sources.
This potentially opens up a new sustainable protein alternative to meat, especially as the new research finds that these flowers could have diverse uses in food.
For their experiments the researchers sourced an abundant supply of dried marigold flowers, and then set about extracting protein from their petals. First they blitzed these into a powder, creating a mixture that was distilled, centrifuged, and filtered. Next, they applied different chemical compounds including alcohol and sodium chloride to separate and extract ingredients from the mix. Among these were four types of protein: albumin, globulin, glutelin and prolamin. In each case the researchers measured how much protein they had extracted, and examined its structural composition.
From this, they found they could extract almost 9 grams of protein per every 100 grams. These levels make marigolds nutritionally similar, in protein terms, to other edible flowers like the banana flower, which is commonly used in South Asian cuisine. Perhaps more familiar to many people is quinoa, a grain valued for its relatively high protein content: marigolds had similar protein levels to this popular foodstuff, too.
This means marigolds could add to the increasing array of plant-based proteins, perhaps diversifying the options to attract people away from meat. But it wasn’t just the nutritional content that struck the researchers: they found that marigolds contained other properties which could make them a valuable additive for the food industry.
For example, the experiments showed that some proteins in marigolds have a low pH which make them a good emulsifying agent. This would be useful for making foods like mayonnaise and salad dressings where oil needs to be mixed into water. Other marigold proteins were found to remain stable at high temperatures of up to 105 °C—making them more reliable under heat pressure than other plant proteins like chickpeas—suggesting that it could be useful in baking applications. The researchers also highlight that the high globulin content in marigolds gives them a good foaming capacity, which is valuable for making aerated ingredients like whipped toppings for baked goods.
Finding markets for this food stuff could be a challenge, as with any relatively new and unfamiliar food. But something that drove the researchers’ original interest in marigolds is the ready and abundant supply: huge quantities of these flowers end up as waste each year, especially in India and Mexico where millions of decorative marigolds are used in events and festivals. The researchers estimate that roughly 40% of used marigolds end up being thrown away.
This is potentially a huge untapped supply of sustainable protein. “People are increasingly aware of food waste and are seeking innovative solutions,” says study lead author Anand Mohan, associate professor of food science and technology at the University of Georgia.
“Demonstrating that something as common and overlooked as a flower can be transformed into a valuable food ingredient makes science both relatable and impactful.”
Mohan et. al. “Assessing Structural, Thermal, and Functional Characteristics of Marigold Flower Protein as a Sustainable Food Ingredient.” ACS Food Science & Technology. 2026.
Image: ©Anthropocene Magazine
