Protein has become one of the food industry’s favorite selling points, showing up in everything from cereal and pasta to snack foods and desserts. Now researchers have pushed the trend into a less obvious corner of the grocery aisle: ketchup.
In a small food-formulation study published in ACS Food Science & Technology, researchers added protein extracted from the microalgae Chlorella vulgaris to tomato ketchup. The algae boosted the condiment’s protein content and some other nutrients, while lower concentrations still tasted reasonably familiar to a panel of 15 people. But the study did not test health effects, and it remains unclear whether the extra protein would amount to much in a typical serving.
“We wanted to improve the nutritional value of a widely consumed condiment using a sustainable protein source,” said corresponding author Parise Adadi. “Ketchup is familiar, shelf-stable and suitable for incorporating functional ingredients.”
That makes ketchup an interesting test case for the broader protein-enrichment boom. Technically, adding protein can improve a product’s nutrient profile. Practically, the effect depends on how much of that food people actually eat.
The researchers found that ketchup containing 3% or 5% algae extract had roughly two to three times as much protein as the plain version used for comparison. It also contained more essential amino acids, iron and antioxidants.
Sodium increased, too.
The more important missing number is how much protein that would provide in an ordinary serving. Ketchup is typically eaten by the tablespoon, not the bowl, so even a large percentage increase may translate into only a modest amount of protein on the plate.
That is worth keeping in mind as more foods are reformulated to carry protein claims. “Higher protein” can be technically accurate without turning a food into a meaningful protein source.
Taste also placed a limit on how far the researchers could push the idea.
At lower concentrations, tasters said the ketchup kept much of its familiar sweet, tangy flavor and reddish appearance, with only a subtle algae note. As more algae protein was added, the condiment became greener and tasted more noticeably of algae, and participants liked it less.
That trade-off may matter as much as the nutritional numbers. Food developers can add functional ingredients to familiar products, but consumers still expect those foods to taste like what they know.
The researchers also point to microalgae as a potentially resource-efficient protein source because it can be cultivated quickly with relatively little land and freshwater.
“Chlorella vulgaris can be cultivated rapidly throughout the year using comparatively little land and freshwater, making it a potentially more resource-efficient protein source than many terrestrial crops,” Adadi said.
The study itself did not compare the environmental footprint of algae protein with whey, soy, pea or other protein sources, so it cannot show whether algae-enriched ketchup would ultimately be the more sustainable option.
For now, protein-enhanced ketchup remains a food science experiment rather than a new nutrition recommendation. Larger consumer studies, shelf-life testing and commercial-scale development would still be needed.
The research was funded by the Ministry of Science and Higher Education of the Russian Federation through the Ural Federal University Program of Development within the Priority-2030 Program.