Ozone-Based Oxidation Treatment to Enhance Food Drying Rate and Quality: Mechanisms, Current Knowledge, and Future Outlook

Agriculture is a significant part of the gross domestic product of almost all nations. Food production is a priority to sustain ever-increasing populations. Since food production is seasonal, long-term storage is imperative. Drying is a predominant processing technique for effective storage, used in the agri-food sector for moisture reduction, hence inactivating the numerous microorganisms (both spoilage and pathogenic) in food products and increasing shelf life. This technique, however, is known to cause significant changes in the natural quality of treated products. Ozone processing is a potential pretreatment technique that can drive the drying process affirmatively in terms of processing factors and overall keeping quality without leaving any trace residues. This review covers recent research and applications and focuses on the effectiveness, pros and cons, challenges, and limitations of ozone pretreatment on the drying of agricultural products. Alongside the numerous mathematical models demonstrating the behavior of pretreated products during the drying process, it is shown how ozonation can enhance drying, save energy, and shorten the drying time. It extends the shelf life and improves textural properties, antioxidant activity, phenolic content, nutritional, and color profile of dehydrated products. However, excessive ozone concentration and prolonged treatment time can have detrimental effects. Overall, it is an efficient hurdle technology for preserving products with better retention of natural properties. However, the challenges to scaling up ozonation need to be addressed to bring this technology to commercial implementation.