Authors
Department of biology
Abstract
Introduction
Atmospheric cold plasma (ACP) technology represents a groundbreaking non-thermal innovation in industrial microbiology and food engineering, generating reactive oxygen and nitrogen species (RONS) under ambient conditions to enable chemical-free processing. This approach effectively reduces microbial loads, inactivates pathogens like bacteria, fungi, and spores, and eliminates contaminants while outperforming thermal methods in retaining nutritional value, color, texture, and sensory attributes of foods. In agriculture, ACP enhances seed germination, plant growth, stress resistance, and yield by modifying surface properties and stimulating physiological responses, thus promoting sustainable practices across the food supply chain from production to packaging. Studies demonstrate ACP's role in minimizing chemical use, improving food safety, and boosting environmental sustainability, positioning it as a versatile tool for microbial control and quality preservation.
Materials and Methods
ACP systems typically employ configurations such as dielectric barrier discharge (DBD), plasma jets, gliding arc, corona discharge, radio frequency, microwave-induced plasma, and atmospheric glow discharge, operating at atmospheric pressure with gases like air, argon, or helium. Key parameters include voltage (5-20 kV), frequency (50 Hz-13.56 MHz), treatment time (seconds to minutes), gas flow rate (1-10 L/min), and distance from plasma source to sample (1-10 cm), optimized for specific applications like surface decontamination or seed treatment. Microbial inactivation is assessed via plate counts (e.g., CFU/mL reduction >4-6 log for E. coli, Salmonella), while food quality evaluates nutritional retention (e.g., vitamins via HPLC), sensory changes (colorimetry, texture analysis), and physicochemical properties (pH, water activity). Plant responses measure germination rate, seedling vigor, and gene expression via qPCR; low-moisture foods like spices and grains test mycotoxin degradation (ELISA) and spore inactivation.
Results and Discussion
ACP achieves >5-log reductions in pathogens on food surfaces, such as Salmonella on poultry (up to 6.5 log in 5 min) and Aspergillus spores on grains, with minimal quality impact due to non-thermal RONS action (e.g., OH- , NO- , O3) etching cell membranes and DNA. In low-moisture foods, treatments reduce mycotoxins like aflatoxins by 70-90% via reactive species breakdown, extending shelf life without altering texture or nutrition. Agricultural applications show 20-50% improved seed germination (e.g., tomatoes, wheat) and 15-30% yield increases through enhanced wettability and hormone signaling, alongside biotic/abiotic stress tolerance. Food packaging benefits from plasma-modified films with improved barrier properties and antimicrobial coatings, reducing microbial migration. Challenges include non-uniformity on complex surfaces, scale-up for industry, and RONS residue safety, addressed by combining with ultrasound or optimizing feeds. Mechanisms involve UV radiation, electric fields, and etching, outperforming heat in preserving heat-labile compounds like vitamins (retention >90%).
Conclusion
ACP emerges as a pivotal technology for sustainable food processing, offering superior microbial decontamination, quality preservation, and agricultural enhancements without chemicals or heat damage. Future prospects include hybrid systems, real-time monitoring, and regulatory standardization to fully integrate ACP into industry, reducing post-harvest losses by 20-40% and supporting global food security.
Keywords
- Atmospheric cold plasma
- industrial microbiology
- food safety
- sustainable agriculture
- reactive oxygen and nitrogen species
Main Subjects
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