Gaseous ozone shows promise as a postharvest tool but requires crop-specific protocols

The use of gaseous ozone as a postharvest treatment is attracting increasing attention due to its ability to extend the shelf life of fruits and vegetables, reduce pathogen development and delay ripening processes.

A recent scientific review examines the current knowledge on this technology, discussing its mechanisms of action, potential benefits and the main limitations that still hinder its large-scale commercial application.

A powerful tool for quality preservation

Ozone acts as a strong oxidising agent capable of interacting with microorganisms, ethylene and several cellular components of plant tissues. These interactions help reduce microbial populations and slow physiological processes associated with fruit ripening and senescence.

According to the authors, these responses are strongly influenced by factors such as ozone concentration, exposure time, temperature, relative humidity and the physiological characteristics of each horticultural product.

Effects on ripening and metabolism

One of the key aspects reviewed is ozone's influence on ethylene metabolism, the hormone responsible for ripening in many fruit species.

Evidence indicates that ozone can reduce both ethylene synthesis and activity while suppressing enzymes involved in cell wall degradation. As a result, fruit firmness is maintained for longer and the ripening process is delayed.

In some crops, ozone has also been shown to promote the accumulation of antioxidant compounds and other bioactive metabolites, helping preserve nutritional quality during storage.

Performance depends on application conditions

Despite its advantages, ozone does not provide the same results across all commodities. Its high oxidative capacity means that even small changes in application conditions may significantly alter its effectiveness or even cause physiological damage if improperly applied.

Furthermore, ozone stability is affected by environmental conditions and storage atmosphere composition, making it difficult to establish standardised treatment protocols for different crops and cultivars.

Challenges for commercial implementation

The review highlights that successful industrial adoption requires appropriate facilities and carefully designed operating procedures.

Among the main challenges are the use of ozone-resistant materials, the installation of systems to remove residual ozone before workers enter storage rooms, and strict monitoring of occupational exposure to ensure safe working conditions.

Study conclusions

The authors conclude that gaseous ozone has considerable potential as a postharvest technology because it can control microorganisms, delay ripening and help preserve the quality of fresh fruits and vegetables.

However, they emphasise that there is no universal application protocol. Treatment effectiveness depends on the crop species and storage conditions, making it essential to optimise parameters such as ozone concentration, exposure time, temperature and relative humidity for each product.

Finally, the review recommends that future research should focus on developing standardised protocols and evaluating ozone in combination with other postharvest technologies, including controlled atmosphere storage and 1-methylcyclopropene (1-MCP), to maximise its commercial potential.