Decontamination and Preservation of Lettuce Using Atmospheric Cold Plasma, Plasma‐Activated Water, and Plasma‐Activated Mist Treatments

Abstract

This study comparatively evaluated the efficacy of atmospheric cold plasma (ACP), plasma‐activated water (PAW), and plasma‐activated mist (PAM) in microbial decontamination and quality preservation of fresh lettuce. ACP treatment for 20 min exhibited the highest bactericidal activity, reducing Escherichia coli O157:H7 and Salmonella typhimurium by 3.19 and 3.69 log CFU/g, respectively. However, ACP treatment (80 kV, 20 min) impaired storage quality. After 10 days of storage at 4°C, ACP‐treated lettuce exhibited a 24% weight loss and a firmness of 246 g, while PAW and PAM produced comparable quality improvements, lowering weight loss to approximately 11% and increasing firmness to 321 g. Mechanistically, both PAM and PAW treatments extended lettuce shelf life by enhancing antioxidant enzyme activities (superoxide dismutase, catalase), inhibiting polyphenol oxidase, and suppressing respiration, thereby preserving firmness and visual quality. Overall, PAM and PAW achieve an optimal balance of microbial safety and quality retention, demonstrating as sustainable technologies for fresh produce preservation.