Marigold flowers as a new source of plant protein ^{CEFR B2}

Researchers led by the University of Georgia isolated proteins from the common marigold, Calendula officinalis, and compared them with other plant proteins. They report that marigold petals contain roughly the same protein levels as conventional plant sources such as quinoa, suggesting a potential role for these flowers in food systems.

Key functional findings include greater thermal stability of marigold protein extracts compared with chickpea and pea proteins, a property that could make them useful in baked goods. Several marigold proteins also improved emulsification, aiding ingredient binding in products like salad dressings, and the amino acid profile of some proteins may add an umami note to foods.

The flowers also supply hydration, antioxidants, dietary fibre and minerals such as calcium, potassium and iron. Petals can be eaten raw, cooked or dried for tea and soups, and they contribute a tangy, citrusy, almost tarragon-like flavour; stems and leaves tend to be bitter. The authors caution that not every marigold is safe to eat and note that both Calendula (pot marigold) and true marigolds from the Tagetes genus are the edible types.

• Possible uses: baking (heat-stable proteins), emulsifiers in dressings, and flavour enhancement.
• Nutrition: protein, fibre, minerals and antioxidants.
• Research note: study published in ACS Food Science & Technology; coauthors from UGA and IIT-Delhi.

Corresponding author Anand Mohan highlighted the waste of billions of dollars of flowers each year and asked whether discarded blooms could be used for food. Doctoral student Fidele Benimana said the work highlights the untapped potential of edible flowers for nutrition and food formulation.