Marigold flowers: A potential new superfood

By Priyanjana Pramanik, MSc.Reviewed by Lily Ramsey, LLMFeb 12 2025

Packed with antioxidants, vitamins, and minerals, marigolds could be the next superfood!

Study: Nutrients, bioactive compounds and antinutritional properties of marigold genotypes as promising functional food. Image Credit: photo acorn/Shutterstock.com

In a recent article in Scientific Reports, researchers analyzed eight variants of marigolds to evaluate their usefulness as functional foods.

Their assessment of bioactive properties and nutritional composition highlighted beneficial compounds such as antioxidants, minerals, vitamins, lutein, carotenoids, and anthocyanins.

Background

In recent years, ‘functional foods’ that provide health benefits going beyond mere nutritional value have become increasingly popular. Such foods are rich in bioactive compounds that boost immunity, prevent diseases, and promote overall health and well-being.

One group of potential functional foods is edible flowers, which, when incorporated into diets, can increase nutrient intake.

Edible flowers, a part of traditional diets in many cultures, are high in water content and low in protein and fat. However, they are rich in healthy phytochemicals such as flavonoids, carotenoids, anthocyanins, and various other antioxidants. These compounds can protect heart health, reduce inflammation, and potentially reduce the risk of cancer.

Marigold is one such edible flower, which has been widely used in folk medicine and as a natural flavoring agent and colorant. It contains crucial phytochemicals, with lutein being particularly important for disease prevention and eye health.

Its antioxidant properties have led researchers to explore its potential as a functional food, particularly in Bangladesh, where the flowers are discarded as waste, raising environmental concerns.

About the study

Researchers sought to identify suitable variants or genotypes of marigolds that can be used to enhance health and dietary diversity, as antinutritional factors like tannins can make some species unsafe for consumption.

They chose eight genotypes of marigolds, which they named M1 and M8, each of a different color and size. Seeds were planted, and plants were grown before harvesting fully bloomed flowers. After the petals were separated and collected, color attributes were measured, and levels of lutein, carotenoids, and anthocyanins were extracted.

Researchers also measured whether the petals were acidic or alkaline, moisture content, total soluble solids, sugar, beta-carotene, vitamins C and E, and mineral content. Antioxidant activity and levels of phenolic compounds and flavonoids were analyzed.

Assessment of suitability as a functional food included measurements of anti-nutritional factors such as phytate content.

Findings

Researchers found significant differences between the eight variants. In terms of color, M6 was the lightest hue in light yellow, while the deepest was M1, which was deep red. Similarly, variants showed differences in redness, yellowness, and intensity of coloring.

Differences in coloring were reflected in the pigment content. The variant M1 had the highest anthocyanin content, while M4 had the least. While M6 had the most carotenoids, M2 had the lowest level.

Conversely, M4 was most rich in lutein but M6 was the least. Darker genotypes contained more anthocyanins, while sugar content was correlated with the levels of lutein.

All the genotypes were slightly acidic, and moisture content ranged from 85.68% to 88.52%. Some variants had as much as 43.43 mg of sugar for every 100 g (M4), while others had only 13.66 mg (M6).

M5 had the highest levels of beta-carotene, calcium, and vitamin C, while vitamin E, magnesium, and sodium were similar across the variants. M8 contained the most potassium and iron but the least calcium.

In terms of bioactive compounds, M3 had the highest level of flavonoids, while M5 had the most phenolic compounds, and antioxidant activity was highest in M3.

In terms of anti-nutritional factors, none of the variants contained oxalate, but M5 had the most saponins, M6 had the most tannins, M7 had the most alkaloids, and M1 had the most phytates. These antinutrients could reduce the bioavailability and absorption of minerals, particularly calcium and iron.

Conclusions

The research showed that marigolds have significant levels of anthocyanins, carotenoids, and lutein, though these differed between variants. Anthocyanins have antiallergic, antimicrobial, anticancer, antioxidant, and anti-inflammatory benefits, while lutein can reduce eye issues associated with aging and support heart health.

Marigold’s sugar content is lower than that of other edible flowers, while beta-carotene levels are comparable to chrysanthemums and some roses. They contain the same levels of vitamin C as tomatoes or apples.

The most abundant mineral was potassium, and marigolds had higher mineral content than quinoa grains and other edible flowers. Notably, they contained more iron than that measured in well-known sources such as amaranth or spinach.

The high moisture content of marigolds suggests that appropriate storage must be available to promote its use as a functional food. They also contain significant levels of alkaloids and phytates that reduce the absorption of nutrients and can be toxic if consumed in large amounts. However, antinutrient levels can be reduced through processing methods such as cooking, boiling, and soaking.

Marigold flowers appear to be a valuable source of antioxidants and essential nutrients and show strong potential as functional foods.