Design of a continuous plasma activated water (PAW) disinfection system for fresh produce industry

• Published in: Innovative food science & emerging technologies 2024-10, Vol.97, p.103845, Article 103845
• Main Authors: Misra, N.N., Naladala, Tejas, Alzahrani, Khalid J., Sreelakshmi, V.P., Negi, P.S.
• Format: Article
• Language: English
• Subjects: Disinfection; Fresh-produce; Postharvest; Process Economics; Sustainability
• ISSN: 1466-8564
• DOI: 10.1016/j.ifset.2024.103845

This study introduces an innovative, industrial-scale continuous Plasma Activated Water (PAW) system, specifically designed for the fresh produce industry and optimized for micro to small enterprises. The system leverages a novel non-uniform electrode design to enhance average field strength, driving the efficient generation of reactive oxygen and nitrogen species (RONS) for steady-state PAW production. Key components include a venturi bubble generator for optimized gas-liquid interaction and a plasma reactor integrated with a continuous spray and drying setup, enabling consistent PAW production and application. Our preliminary results indicate about 1.5 log10 CFU/g decrease in microbial load on treated produce, which further decreased to 2.5 log10 CFU/g towards the end of storage life for tomatoes, with 20 kV applied to the reactors and a total residence time of 20 min. An evaluation of the maximum energy consumption of system indicated a process cost contribution of less than $0.5 per ton of treated produce. The promising initial results, scalable design, cost-effectiveness and sustainability aspects make this technology suitable for improving food safety while reducing chemical usage. •Continuous PAW system for scalable food disinfection developed and validated.•Innovative electrode design enhances cold plasma discharge efficacy.•Significant microbial inactivation achieved on fresh produce using PAW.•Economic analysis confirms cost-effectiveness of the process.