Ketchup could soon become more than a condiment, with scientists developing a protein-enriched version using Chlorella vulgaris, a protein-rich microalgae that can be cultivated with relatively little land and freshwater.
The research, published in ACS Food Science & Technology, explored whether algae protein could be added to homemade tomato ketchup without significantly changing its familiar taste and appearance.
Algae protein gives ketchup a nutritional boost
Regular ketchup contains about 1.6 per cent protein by weight. Researchers increased this to 6.3 per cent by adding protein extracted from Chlorella vulgaris.
The fortified ketchup also contained amino acids, minerals and antioxidants, potentially giving the everyday condiment an additional nutritional benefit.
Study author Perais Adadi said the researchers chose microalgae instead of more traditional protein sources such as whey, peas or soy. Chlorella vulgaris can be cultivated throughout the year and requires relatively little land and freshwater, making it a potentially resource-efficient protein source.
Too much algae changes the taste
Researchers prepared ketchup with algae protein concentrations ranging from 1 to 13 per cent before testing the samples with a 15-member taste panel.
Ketchup containing between 1 and 3 per cent algae protein retained the appearance and taste of conventional ketchup. However, the algae flavour became noticeable at higher concentrations.
At 13 per cent, the ketchup became darker and thicker, while the algae flavour dominated, reducing its popularity among tasters.
Could algae become a future protein source?
The researchers believe moderate amounts of algal protein could improve the nutritional value of everyday foods while offering a potentially sustainable source of protein.
However, the study is still at an early stage. Further research will include larger taste tests, shelf-life studies and investigation into industrial-scale production.
If successful, the humble ketchup bottle could become an unexpected vehicle for adding sustainable protein to everyday diets.