To preserve the quality and shelf life of sweet cherries after harvest, numerous technological innovations in packaging and preservation are being implemented. Indeed, interest is increasing in edible coatings, particularly biopolymer-based edible coatings, which are being used as alternative packaging materials.
In recent years, there has been significant interest in pullulan, a polysaccharide produced through the fermentation of Aureobasidium pullulans. This is due to its potential as an ecological substrate for food coating. It is an edible, non-toxic, non-mutagenic, non-carcinogenic, non-ionic, and non-hygroscopic compound that is suitable for human consumption.
Moreover, it is odorless and tasteless. The purified form of pullulan is not widely but frequently used due to its high cost and inferior mechanical properties. Consequently, it is frequently combined with compatible polymers that are relatively less expensive and possess superior mechanical properties.
Today we present the results of a research conducted at the University of Kashmir (India) that examined the impact of pullulan and pullulan-chitosan edible coatings on the post-harvest quality of sweet cherries during a 20-day storage period.
All quality parameters were evaluated, such as weight loss, total soluble solids, color intensity, total phenolic content, flavonoids, anthocyanins, antioxidant activity, and enzymatic activity.
The results indicated that cherries with a 3% pullulan coating showed the least weight loss (25% compared to 26.33% in the control) and the lowest decay percentage (25% compared to 47% in the control) and exhibited superior firmness and stability compared to the control and other coatings tested.
Image 1: Pullulan molecule, 3D illustration.
In general, the coated cherries showed a smaller increase in total soluble solids content compared to the control cherries, and in particular, the cherries treated with 3% pullulan showed the smallest increase, suggesting a delayed ripening process. The 3% coating also effectively delayed the color loss of the cherries.
Moreover, the pullulan coating delayed the decrease in antioxidant activity and maintained higher levels of ascorbic acid, phenolic compounds, and flavonoids. Cherries treated with 3% pullulan showed the highest antioxidant activity (88.97%) and the highest total phenolic compound content at the end of the storage period.
The activity of the enzymes, particularly peroxidase, increased less in the coated cherries, highlighting the effect of the coatings in delaying oxidative stress. In general, pullulan coatings were the most effective in preserving quality and extending the shelf life of cherries, particularly at a concentration of 3%.
These results indicate that the application of a pullulan-based coating is a promising method for preserving product quality during storage, thus extending their shelf life. By maintaining quality and reducing post-harvest losses, these coatings can help improve economic gains, increase consumer acceptability, and reduce food waste.
Future research should focus on formulation, consumer acceptability, and scalability to optimize pullulan-based coatings for their commercial application.
Source: Shoib M. Wani, Danish Rizwan, F.A. Khanday, Sajad A. Mir, F.A. Masoodi, Effect of pullulan and pullulan-chitosan composite coating on the antioxidant activity, texture, color and shelf-life of a local cultivar of sweet cherry, Food and Humanity, Volume 3, 2024, 100432, ISSN 2949-8244, https://doi.org/10.1016/j.foohum.2024.100432.
Images: SL Fruit Service; DR MICROBE
Melissa Venturi
University of Bologna (IT)
16 Jan 2024
Pretreatments (such as ultrasound) and edible coatings are used to reduce processing time and/or preserve the quality of food products. Experimental data of drying curves were adapted to various widely used models.
24 Apr 2025
Over the past 80 years, Estonia has developed dozens of sweet and sour cherry varieties suited to its northern climate. From Tartu University’s research to breeding at Polli Research Center, discover the challenges and success of this unique Baltic fruit cultivation.
24 Feb 2026
A 2025 US review examines the nutraceutical properties of sour cherry (Prunus cerasus L.), highlighting its rich polyphenol, anthocyanin and flavonoid content. Evidence supports antioxidant and anti-inflammatory effects, while gaps remain in bioavailability and processing impact.
24 Feb 2026
South Africa’s cherry industry is expanding fast: acreage increased from 185 to 819 hectares, low-chill varieties reshaped production and exports reached 37%. The Western Cape leads output as new strategic opportunities emerge in China and Asian markets worldwide ahead.
