Ready-To-Eat Blueberry Preservation Technology: Synergistic Sequential Plasma Treatment for Microbial Inactivation...

For the preservation of ready-to-eat blueberries, a sequential treatment combining plasma-activated water (PAW) followed by dielectric barrier discharge (DBD) plasma was applied. After optimizing the processing parameters of the combined plasma by the response surface method, a comprehensive assessment was conducted on the storage-induced changes in microbial load, physicochemical properties, and antioxidant systems. Results demonstrated that the optimized process led to reductions of 1.78 and 1.63 lg CFU/g in total viable bacteria and mold/yeast counts, respectively, without adversely affecting color parameters, firmness, or total soluble solids during storage. This method enhanced the biosynthesis of antioxidant compounds, including ascorbic acid (9%), total phenolics (9%), and glutathione (32%). Concurrently, the activities of antioxidant enzymes were elevated by 27%-81%, while the generation of reactive oxygen species decreased by approximately 40%. These synergistic effects collectively improved the antioxidant capacity of blueberries throughout the storage, validating the potential of combined cold plasma as a non-thermal preservation strategy for ready-to-eat blueberries. PRACTICAL APPLICATIONS: This study demonstrates a non-thermal sanitization strategy combining plasma-activated water and dielectric barrier discharge plasma treatments to prolong shelf life of ready-to-eat blueberries. The sequential treatment effectively controls microbial proliferation while preserving color, firmness, and bioactive compounds throughout storage, avoiding thermal degradation or chemical residues. The methodology provides a viable strategy for commercial fresh-cut fruit processors to enhance product safety and shelf stability while preserving key quality attributes.