Once known as the “poor man’s saffron,” pot marigolds are receiving new attention as pigments, fibers and bioactive compounds that could expand their role in food.
Calendula as a source of bioactive compounds in functional foods: a review. Image credit: 1777177 / Shutterstock
In a recent review published in a magazine applied scienceThe authors summarized the current evidence on the phytochemical composition, biological activity, agronomic factors, nutritional value, and functional food applications of Calendula officinalis L. (pot marigold), highlighting its potential as a functional food ingredient.
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Many edible flowers contain hundreds of natural compounds that may support both nutrition and food quality. Calendula officinalis L. has been used for centuries in traditional medicine and as a natural food coloring, hence the name “poor man’s saffron.” Flowers contain numerous bioactive compounds that have attracted interest due to their antioxidant, anti-inflammatory, antibacterial, and nutritional properties. As people become more interested in natural rather than synthetic ingredients, some edible flowers, such as pot marigolds, are becoming important to functional food producers. Further research is needed to understand practical applications.
Literature search
The authors conducted a structured literature review using Scopus and Web of Science databases, focusing on papers published from 2003 to 2026, but also citing older basic research. Search terms included Calendula officinalis L., as well as terms related to bioactive compounds, antioxidant activity, antibacterial activity, functional foods, cultivation, and pharmaceutical and food applications. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for literature search. Of the 86 records screened against the inclusion and exclusion criteria, 76 publications were included in the evidence synthesis.
bioactive compounds
More than 500 secondary metabolites have been reported in Calendula, mainly through floral studies. Their composition varies depending on the variety, growing conditions, flower maturity, processing and analytical methods.
Flavonoids such as quercetin, kaempferol, isorhamnetin, rutin, and isoquercitrin primarily contribute to its antioxidant properties, and their concentrations vary depending on the extraction method. In addition, the flowers contain about 100 carotenoids, including beta-carotene and lutein, which are responsible for their antioxidant properties and yellow-orange color. Additionally, essential oils, triterpenoids, carbohydrates, amino acids, and fatty acids are some of the components that contribute to the chemical and nutritional profile of the plant.
Total flavonoid content on dry basis calendula Flowers reported in selected recent studies
Flavonoid content Solvent Raw material unit 0.21-0.68% DM Methanol
(spectroscopy, 370 nm) Dried flowers,
20 varieties % per dry raw material up to 1.7% DM Methanol (Spectrum) Dried flowers, “Radio” % per dry raw material 12.12 ± 0.02 mg QE/g Ethanol 80% Dry extract per 1 g dry flowers mg QE 13.61 ± 0.54 mg QE/g Ethanol 80% dried flowers mg QE dry extract g 15.2 ± 0.3 mg/g (flower). 12 ± 0.02 mg/g (leaf) Methanol mg dried flowers and leaves per 1 g of dried plant material 147.82 mg QE/100 g (≈1.48 mg QE/g) Ethanol 50% dried extract mg dried flowers per 100 g QE
QE – Quercetin equivalent (total flavonoid content performed by comparing the assay response of a sample to a calibration curve created using quercetin as a reference standard). DM – Dry matter, the material that remains after moisture has been removed. This allows measurements to be compared without differences in sample moisture affecting the results. Due to different solvents, plant parts, and expression standards, values cannot be directly compared.
Experimental studies show diverse biological activities
The diverse phytochemical composition of Calendula officinalis L. contributes to the wide range of biological activities reported in laboratory and animal studies. Various flavonoids, phenolic acids, carotenoids, and saponins contribute to antioxidant activity. Flower extracts were used to enhance the antioxidant activity of foods such as bread and yogurt by increasing their phenolic content. Calendula extract also showed anti-inflammatory effects in experimental models, with triterpenoids, flavonoids, carotenoids, polysaccharides, and sterols reducing the inflammatory response and inhibiting inflammatory mediators.
Additionally, cell and rodent studies have found that calendula extract promotes wound healing, fibroblast proliferation, connective tissue repair, and recovery from burns and tendon injuries. In vitro studies have also shown that the extract exhibits activity against Gram-positive and Gram-negative bacteria and fungi, supporting further investigation of its potential as a natural preservative. Experimental studies have also reported cytotoxic, antiproliferative, antidepressant, gastrointestinal protective, and neuroprotective effects, including findings in models related to Parkinson’s disease, but this review highlights that these findings are primarily based on laboratory and animal studies and require further research before confirming clinical relevance.
Application to functional foods
The reviewed evidence confirmed that Calendula officinalis is a promising candidate for use as a functional food ingredient due to its natural pigments, antioxidant compounds, dietary fiber, and pleasant floral aroma. These properties have the potential to improve the nutritional composition, oxidative or microbial stability, and sensory properties of selected foods, supporting their potential as replacements for selected synthetic colors, antioxidants, or preservatives in suitable products.
Yogurt is one of the most widely studied application areas. Supplementation with freeze-dried hydrous ethanolic flower extract increased total phenolic content, flavonoid levels, and antioxidant capacity in standard laboratory assays. The extract also maintained the viability of beneficial lactic acid bacteria and produced a yellow-orange color and good sensory properties at 0.25 g/100 g of yogurt, but increased astringency at excessive amounts.
Bakery products also showed promising results. Replacing 10–15% of the water in wheat bread with aqueous flower extract increased phenolic content, enhanced antioxidant activity in standard laboratory assays, and reduced the growth of Aspergillus niger, but did not inhibit Penicillium species. This addition had no negative effect on bread volume or baking loss, and the organoleptic properties remained acceptable. Fresh pasta made by replacing 5% of wheat flour with flour powder contained higher levels of fiber, protein, carotenoids, and phenolic compounds, and retained its antioxidant properties after cooking.
Application of additional applications to biscuits, grape juice, mustard oil, cold-pressed oil, and encapsulated extracts resulted in application-specific improvements in nutritional composition, antioxidant stability, or resistance to lipid oxidation. Moreover, the antibacterial and antifungal properties of this plant support its potential use as a natural food preservative, although its effectiveness varies depending on the food system, extraction method, and microorganism.
Agronomic factors, safety, and research gaps
The phytochemical composition and quality of Calendula officinalis L. is highly dependent on the variety, flower morphology, environmental conditions, harvest time, nutrient availability, and light exposure. Generally, orange-flowered varieties contain more carotenoids than yellow-flowered varieties, and ray petals tend to contain more flavonoids and carotenoids than tubular petals. However, the tubular petals may contain higher levels of caffeoylquinic acid, coumarins, and anthocyanins.
The use of new smart cultivation technologies, such as plant factories with artificial lighting (PFAL), may support controlled annual production and targeted management of phytochemical content, but the trade-off between crop yield and bioactive compound levels requires further research.
The review also reports that calendula flowers are considered a traditional food ingredient in the European Union, while marigold is listed as a generally recognized as safe (GRAS) flavoring substance in the United States. However, some people may have allergic reactions, especially sensitivities to other plants in the Asteraceae family.
Although animal studies generally support safety in food-related exposures, in some studies, long-term high-dose administration resulted in mild biochemical or tissue changes related to the liver and kidneys.
Further challenges include the impact on fabric quality due to high insoluble fiber content, increased astringency due to excessive extractive concentrations, and limitations in food testing. Further research is needed to optimize processing methods and establish standardized applications in functional foods.
conclusion
This review shows that calendula is a rich source of bioactive compounds and has great potential for the development of functional foods. The flavonoids, carotenoids, terpenoids, dietary fiber, and other phytochemicals found in Calendula officinalis have been shown to have antioxidant, anti-inflammatory, antibacterial, and regenerative properties in laboratory and animal studies.
This review identified promising applications for Calendula officinalis in yogurt, bread, pasta, beverages, edible oils, and natural food preservation. However, food research remains limited, with most applications relying on single studies, and no clinical studies have evaluated calendula-containing foods at realistic intakes. The content of bioactive compounds also depends on cultivation and processing methods. The bioavailability of these compounds from food matrices remains unknown, meaning that reported biological activity cannot support human health claims at this time.
This review concludes that further well-designed food application research is needed to establish standardized processing strategies and maximize the practical value of plants as functional food ingredients.
Reference magazines:
- Owczarek, A., Harasym, J. (2026). Calendula as a source of bioactive compounds in functional foods: a review. Applied Science, 16(15), 7466. Doi: 10.3390/app16157466. https://www.mdpi.com/2076-3417/16/15/7466
