Last Updated on July 23, 2026 by Staff
Strawberries are some of the fragile fruits in the world. Their soft feel, lots of water and natural sweetness make them very easy to go even when kept in refrigerators. Farmers and shops often have a time because strawberries can go bad in just a few days.
Now scientists from São Paulo State University (UNESP) in Brazil have found a natural way to help. They found that a peptide from a frog that lives in Brazil’s Cerrado area can make strawberries stay fresh for longer without changing how they taste or their good nutrients. The results, written in Applied Food Research show this natural molecule might one day be a way to keep fruits fresh instead of using man-made chemicals.
Ancient Protection
The peptide, called Ctx(Ile21)-Ha was first taken from the skin of the Brazilian tree frog (Boana albopunctata) in 2006. Amphibians use their skin to breathe so they are always meeting bacteria, fungi and other bad things. To stay safe they make a lot of peptides that work as a natural shield.
Scientists have been looking at Ctx(Ile21)-Ha for 20 years because it has strong antimicrobial powers. Earlier work looked at using it as a replacement for antibiotics in farm animals. Recently scientists started looking at if the peptide could also help keep foods like strawberries fresh.
Strawberry Test
To check how good the peptide is, scientists made water mixtures with three amounts of Ctx(Ile21)-Ha. They put Oso Grande strawberries into the mixture for only five minutes. Another group of strawberries only went into water to act as a control.
After that the strawberries were. Put into clean PET boxes with plastic on top. They were then kept at 5°C in a lab that’s like the cool rooms shops use.
For six days scientists checked things like pH, sugar levels, breathing, vitamin C and other good stuff. Every test was done three times so the results would be correct.
Amazing Findings
The scientists found that strawberries with the peptide stayed looking and feeling like ones for at least five days. That is a good result because strawberries usually get worse quickly when stored.
Importantly the peptide didn’t change how the fruit tasted, how sweet it was or the antioxidants. The treated strawberries also stayed firmer than the others meaning they didn’t break down fast.
Even though they didn’t check for bacteria in this study the scientists think the peptide’s known ability to fight germs might have helped stop the ones that make fruit go bad. More work will look into this.
Keeping the sugars is really important because these sugars are usually eaten by bacteria and fungi when fruit goes bad. Keeping them means the peptide may help slow down germs while still keeping the fruit good.
Future Possibilities
The scientists think Ctx(Ile21)-Ha could be a way to keep strawberries and other fragile fruits fresh after they are picked. Unlike man-made preservatives the peptide is made from amino acids and can be broken down by the body so it might be safe to eat.
There are still problems to solve before it can be sold. The peptide hasn’t been approved in Brazil yet and more tests on safety and germs are needed.
Scientists are also looking at ways to make the peptide in amounts using yeast, which might make it cheaper. Another idea is to mix the peptide into coatings or packages for fruits with skin that can be eaten.
Looking Ahead
This discovery shows how natural things from animals can help solve farming issues. If more studies confirm it works and is safe, the frog-made peptide could help cut food waste, keep fruit during transport and save money for those who grow and sell fruit.
Scientists have already put in patents for some ways to use the peptide in farming. Are still checking out its other uses in keeping food fresh and helping animals stay healthy.
Even though this is still early the results show how nature keeps giving ideas for today’s problems. A small defense molecule made by a frog millions of years ago might one day help keep strawberries fresh, for longer helping farmers, food companies and people who buy food.