Cold Plasma Treatment: A Novel Approach for Microbial Inactivation and Shelf-Life Enhancement of Strawberries

Background: Strawberries is a fruit rich in various nutrients. Their thin skin structure and high respiratory activity make them susceptible to microbial contamination and rapid spoilage. Traditional preservation techniques still have limitations. Therefore, this study aims to investigate the effect of plasma-processed air (PPA) on strawberry preservation. Methods: The efficacy of plasma-processed air generated via sliding arc discharge, with treatment times of 15 s, 30 s, and 60 s, was compared to untreated controls in terms of microbial suppression and quality preservation of fresh strawberries during cold storage. Results: PPA treatment significantly reduced surface microbial colonies, with a 60 s exposure achieving the lowest colony count (1.18 log colony-forming units (CFU)/g), representing approximately a 95% reduction compared to control (2.49 log CFU/g). While PPA exposure maintained nutritional parameters (total soluble solids (TSS), titratable acid (TA), pH, ascorbic acid (ASA)) at levels not significantly different from those of the untreated fruit (p > 0.05), PPA exposure effectively mitigated quality deterioration. PPA-treated strawberries were firmer, showed better color retention and less weight loss, maintained cell membrane integrity, and had lower ethylene production (p < 0.05). Notably, shelf-life extension was dose-dependent, reaching 15, 18, and 16 days at 4 °C for the treated strawberries (15 s, 30 s, and 60 s treatments, respectively) compared to 9 days for the untreated control fruit. Conclusion: PPA can effectively extend strawberry shelf-life by maintaining fruit quality and inactivating microorganisms. Furthermore, this continuous industrialized green treatment technology could ultimately be used as a standard and applied linearly during the cold chain transportation of fresh produce.