Fresh fruit for longer with natural coatings
Have you ever bought pre-cut apples that turned brown, mushy, and unappetizing within hours? This is one of the biggest challenges for those who want to enjoy ready-to-eat fruit: its short shelf life.
But a group of researchers in the United Kingdom found a natural, effective solution without artificial additives: an edible coating made with chitosan and essential oils of oregano and cinnamon. A truly promising invention that could extend the shelf life of fruits like apples.
The problem with "ready-to-eat" fruits
Cut apples, like many minimally processed fruits, deteriorate quickly. Why does this happen?
- They lose water, soften, and become less crisp.
- They oxidize upon contact with air, generating an unappealing brown color.
- They are more vulnerable to microbial contamination.
- They lose vitamins and antioxidants.
This not only affects the visual and nutritional quality, but also reduces the food safety of the fruit and increases the likelihood of food waste.
What is an edible coating?
An edible coating is a thin, natural film applied to the surface of a food to protect it from the environment. It's like a biodegradable "second skin" that has several properties:
- It reduces contact with oxygen.
- It slows water loss.
- It incorporates natural antimicrobial and antioxidant ingredients.
The power of chitosan and essential oils
In a study published in July 2025 in the journal Foods, a group of researchers developed an edible coating for sliced apples that combines three natural ingredients:
Chitosan
Derived from chitin, a compound present in the exoskeleton of crustaceans. It has antimicrobial properties, is biodegradable, and forms a semipermeable film that protects food from water loss and contact with oxygen.
Ascorbic acid and citric acid
Both help prevent fruit browning by inhibiting enzymes such as polyphenol oxidase, which are responsible for browning when exposed to air.
Cinnamon leaf and oregano essential oils
Rich in natural antioxidant and antimicrobial compounds, such as carvacrol and cinnamaldehyde.
Study
This edible coating was applied to freshly cut 'Braeburn' apples, which were then stored cold for 9 days. The objective was to test whether the coating could preserve their color, texture, freshness, and microbiological safety.
Result
The results were good:
| Parameter evaluated | What happened to the coating? |
|---|---|
| Water loss | It was reduced by up to 80% compared to untreated apples. |
| Browning | Browning was virtually prevented during the 9 days. |
| Texture | The apples retained their firmness and crunch. |
| Microbiology | Reduced growth of bacteria and mold. |
| Color | Improved brightness and freshness. |
The most effective combination was the one containing 0.1% cinnamon essential oil, followed by 0.06% oregano.
Does this replace artificial preservatives?
Potentially, yes. The results of the study suggest that this combination of chitosan and essential oils not only performs an effective protective function, but does so naturally and without the need for synthetic additives.
Chitosan forms a thin, edible film that acts as a physical barrier to oxygen and moisture loss. This slows oxidation processes, fruit softening, and the proliferation of microorganisms. The essential oils, meanwhile, provide bioactive compounds that reinforce the antimicrobial and antioxidant action, prolonging the product's shelf life without significantly altering its flavor or aroma when used in controlled doses.
This synergy between chitosan and essential oils makes the coating a real alternative to chemical preservatives and plastic packaging, especially for fresh and minimally processed products such as cut fruits, which are highly perishable.
Furthermore, it responds to a growing consumer trend: preferring foods with clean labels, without "E-numbers" or artificial additives, and with a more natural and healthy profile. In this context, bioactive coatings could not only replace artificial preservatives but also contribute to reducing food waste by keeping food fresher for longer.
Conclusion
This technology, which combines efficiency, sustainability, and safety, responds to both the challenges of the food industry and the demands of today's consumers.
However, important steps remain to be taken. It will be necessary to scale its application to an industrial level, test its effectiveness on a wider variety of fruits and fresh produce, and ensure that its use complies with each country's food regulations. Furthermore, it will be key to evaluate its economic and sensory viability on a large scale, especially if it is to be offered as a viable commercial solution.
What is clear is that science is getting closer to offering us natural, effective, and sustainable solutions to extend the shelf life of food. And perhaps, in the not-too-distant future, these types of coatings will become as common as washing fruit before eating it.
Written by Sara Montaner. We rely on AI technology.