Human coronavirus 229E inactivation on porous and nonporous materials using dielectric barrier discharge (DBD) plasma.

Viruses can spread through contaminated aerosols and contaminated surface materials, and effective disinfection techniques are essential for virus inactivation. Nonthermal plasma-generated reactive oxygen and nitrogen species can effectively inactivate the coronavirus. We aim to interpret the coronavirus inactivation level and mechanism of surface interaction with materials with and without dielectric barrier discharge (DBD) plasma treatment. Nonthermal plasma, particularly surface-type DBD plasma, can inactivate human coronavirus 229E (HCoV-229E) on porous (paper, wood, mask) and nonporous (plastic, stainless steel, glass, Cu) materials. Virus inactivation was analyzed using a 50% tissue culture infectivity dose (TCID50) using cell line, flow cytometry, and immunofluorescence. Surfaces contaminated with HCoV-229E were treated at different time intervals (0-5 h) with and without plasma exposure (natural decay in ambient air conditions). HCoV-229E persistence conformed to the following order: plastic > cover glass > stainless steel > mask > wood > paper > Cu with and without plasma exposure. HCoV-229E was more stable in plastic, cover glass, and stainless steel in 5 h, and the viable virus titer gradually decreased from its initial log10 order of 6.892 to 1.72, 1.53, and 1.32 TCID50/mL, respectively, under plasma exposure. No virus was observed in Cu after treatment for 5 h. The use of airflow, ambient nitrogen, and argon did not promote virus inactivation. Flow cytometry and immunofluorescence analysis demonstrated a low expression level of spike protein (fluorescence intensity) during plasma treatment and in E and M genes expression compared with the virus control.

Modeling the growth of Aspergillus brasiliensis affected by a nonthermal plasma.

AIM: The main objective of the study was to develop and validate a model for the growth of Aspergillus brasiliensis on surfaces, specifically on agar culture medium. An additional aim was to determine conditions for complete growth inhibition of this micromycete using two different nonthermal plasma (NTP) sources. METHODS AND RESULTS: The developed model uses two key parameters, namely the growth rate and growth delay, which depend on the cultivation temperature and the amount of inoculum. These parameters well describe the growth of A. brasiliensis and the effect of NTP on it. For complete fungus inactivation, a single 10-minute exposure to a diffuse coplanar surface barrier discharge was sufficient, while a point-to-ring corona discharge required several repeated 10-minute exposures at 24-h intervals. CONCLUSIONS: The article presents a model for simulating the surface growth of A. brasiliensis and evaluates the effectiveness of two NTP sources in deactivating fungi on agar media.

Nonthermal plasma air disinfection for the inactivation of airborne microorganisms in an experimental chamber and indoor air.

AIMS: Airborne transmission of diseases presents a serious threat to human health, so effective air disinfection technology to eliminate microorganisms in indoor air is very important. This study evaluated the effectiveness of a non-thermal plasma (NTP) air disinfector in both laboratory experiments and real environments. METHODS AND RESULTS: An experimental chamber was artificially polluted with a bioaerosol containing bacteria or viruses. Additionally, classroom environments with and without people present were used in field tests. Airborne microbial and particle concentrations were quantified. A 3.0 log10 reduction in the initial load was achieved when a virus-containing aerosol was disinfected for 60 min and a bacteria-containing aerosol was disinfected for 90 min. In the field test, when no people were present in the room, NTP disinfection decreased the airborne microbial and particle concentrations (P < 0.05). When people were present in the room, their constant activity continuously contaminated the indoor air, but all airborne indicators decreased (P < 0.05) except for planktonic bacteria (P = 0.094). CONCLUSIONS: NTP effectively inactivated microorganisms and particles in indoor air.

A Single-Step Bottom-up Approach for Synthesis of Highly Uniform Mie-Resonant Crystalline Semiconductor Particles at Visible Wavelengths.

Optically Mie-resonant crystalline silicon nanoparticles have long attracted interest for their unique scattering behaviors. Here, we report a bottom-up nonthermal plasma process that produces highly monodisperse particles, with diameters controllable between 60 and 214 nm, by temporarily electrostatically trapping nanoparticles inside a continuous-flow plasma reactor. The particle size is tuned by adjusting the gas residence time in the reactor. By dispersing the nanoparticles in water, optical extinction measurements indicate colloidal solutions of a particle-based metafluid in which particles support both strong magnetic and electric dipole resonances at visible wavelengths. The spectral overlap of the electric and magnetic resonances gives rise to directional Kerker scattering. The extinction measurements show excellent agreement with Mie theory, supporting the idea that the fabrication process enables particles with narrow distributions in size, shape, and composition. This single-step gas-phase process can also produce Mie-resonant nanoparticles of dielectric materials other than silicon and directly deposit them on the desired substrates.

Chemical and physical changes induced by cold plasma treatment of foods: A critical review.

Cold plasma treatment is an innovative technology in the food processing and preservation sectors. It is primarily employed to deactivate microorganisms and enzymes without heat and chemical additives; hence, it is often termed a "clean and green" technology. However, food quality and safety challenges may arise during cold plasma processing due to potential chemical interactions between the plasma reactive species and food components. This review aims to consolidate and discuss data on the impact of cold plasma on the chemical constituents and physical and functional properties of major food products, including dairy, meat, nuts, fruits, vegetables, and grains. We emphasize how cold plasma induces chemical modification of key food components, such as water, proteins, lipids, carbohydrates, vitamins, polyphenols, and volatile organic compounds. Additionally, we discuss changes in color, pH, and organoleptic properties induced by cold plasma treatment and their correlation with chemical modification. Current studies demonstrate that reactive oxygen and nitrogen species in cold plasma oxidize proteins, lipids, and bioactive compounds upon direct contact with the food matrix. Reductions in nutrients and bioactive compounds, including polyunsaturated fatty acids, sugars, polyphenols, and vitamins, have been observed in dairy products, vegetables, fruits, and beverages following cold plasma treatment. Furthermore, structural alterations and the generation of volatile and non-volatile oxidation products were observed, impacting the color, flavor, and texture of food products. However, the effects on dry foods, such as seeds and nuts, are comparatively less pronounced. Overall, this review highlights the drawbacks, challenges, and opportunities associated with cold plasma treatment in food processing.

Plasma-Activated Solutions Regulate Surface-Terminating Groups Enhancing Pseudocapacitive Ti3 C2 Tx Electrode Performance.

2D transition metal carbides and nitrides (MXenes) are actively pursued as pseudocapacitive materials for supercapacitors owing to their advantages in electronic conductivity and surface reactivity. Increasing the fraction of ─O terminal groups in Ti3 C2 Tx is a promising approach to improve the pseudocapacitive charge storage in H2 SO4 electrolytes, but it suffers from a lack of effective functionalization methods and stability of the groups in practical operation. Here a low-temperature and environment-friendly approach via the interaction of nonequilibrium plasmas with Ti3 C2 Tx dispersion is demonstrated to generate abundant and stable surface-terminating O groups. The impact of the discharge environment (Ar, O2 , and H2 ) on the structural characteristics and electrochemical performance of Ti3 C2 Tx nanosheets is studied. The Ti3 C2 Tx modified in Ar and H2 maintains their original morphology but a significantly lower F content. Consequently, an extraordinarily high content (78.5%) of surface-terminating O groups is revealed by the high-resolution X-ray photoelectron spectroscopy spectra for the Ti3 C2 Tx samples modified in H2 plasma-treated solutions. Additionally, the Ti3 C2 Tx treated using H2 plasmas exhibits the best capacitive performance of 418.3 F g-1 at 2 mV s-1 , which can maintain 95.88% capacity after 10 000 cycles. These results contribute to the development of advanced nanostructured pseudocapacitive electrode materials for renewable energy storage applications.

Capacitively coupled nonthermal plasma synthesis of aluminum nanocrystals for enhanced yield and size control.

Uniform-size, non-native oxide-passivated metallic aluminum nanoparticles (Al NPs) have desirable properties for fuel applications, battery components, plasmonics, and hydrogen catalysis. Nonthermal plasma-assisted synthesis of Al NPs was previously achieved with an inductively coupled plasma (ICP) reactor, but the low production rate and limited tunability of particle size were key barriers to the applications of this material. This work focuses on the application of capacitively coupled plasma (CCP) to achieve improved control over Al NP size and a ten-fold increase in yield. In contrast with many other materials, where NP size is controlled via the gas residence time in the reactor, the Al NP size appeared to depend on the power input to the CCP system. The results indicate that the CCP reactor assembly, with a hydrogen-rich argon/hydrogen plasma, was able to produce Al NPs with diameters that were tunable between 8 and 21 nm at a rate up ∼ 100 mg h-1. X-ray diffraction indicates that a hydrogen-rich environment results in crystalline metal Al particles. The improved synthesis control of the CCP system compared to the ICP system is interpreted in terms of the CCP's lower plasma density, as determined by double Langmuir probe measurements, leading to reduced NP heating in the CCP that is more amenable to NP nucleation and growth.

Regulating oxygen vacancies and hydroxyl groups of α-MnO2 nanorods for enhancing post-plasma catalytic removal of toluene.

Although nonthermal plasma (NTP) technology has high removal efficiency for volatile organic compounds (VOCs), it has limited carbon dioxide (CO2) selectivity, which hinders its practical application. In this study, α-MnO2 nanorods with tunable oxygen vacancies and hydroxyl groups were synthesized by two-step hydrothermal process to enhance their activity for deep oxidation of toluene. Hydrochloric acid (HCl) was used to assist in synthesis of α-MnO2 nanorods with tunable oxygen vacancies, furtherly, more hydroxyl groups were introduced to HCl-assisted synthesized α-MnO2 by K+ supplement. The results showed that the as-synthesized nanorods exhibited superior activity, improved by nearly 30% removal efficiency of toluene compared to pristine MnO2 at SIE = 339 J/L, and reaching high COx selectivity of 72% at SIE = 483 J/L, successfully promoting the deep oxidation of toluene. It was affirmed that oxygen vacancies played an important role in toluene conversion, improving the conversion of ozone (O3) and resulting in higher mobility of surface lattice oxygen species. Besides, the enhancement of deep oxidation performance was caused by the increase of hydroxyl groups concentration. In-situ DRIFTS experiments revealed that the adsorbed toluene on catalyst surface was oxidized to benzyl alcohol by surface lattice oxygen, and hydroxyl groups were also found participating in toluene adsorption. Overall, this study provides a new approach to designing catalysts for deep oxidation of VOCs.

Nonthermal plasma-irradiated polyvalent ferromanganese binary hydro(oxide) for the removal of uranyl ions from wastewater.

Nonthermal plasma (NTP) irradiation was employed to adjust the morphological structures and valence distribution of ferromanganese (Fe-Mn)-based binary hydro (oxide) to enhance the heterogeneous adsorption of uranyl ions. The output voltage and the liquid-plate distance played a more vital role among the NTP factors in the irradiation system in influencing the polyvalent Fe-Mn binary hydro (oxide) (poly-Fe-Mn). The formation of plates, flakes, and nanoscale nodules was specifically observed, which caused more pores and fractures in the poly-Fe-Mn binary hydro (oxide). The poly-Fe-Mn performed explicitly better in the adsorption of uranium ions in comparison with the counterpart of the Fe-Mn, which was appropriately fitted by the pseudofirst-order kinetic and Elovich models. Maximum equilibrium adsorption capacities of 663.92 and 923.45 mg/g were obtained for the Fe-Mn and poly-Fe-Mn binary hydro (oxides) toward U ions in the orthogonal design, respectively. The maximum monolayer adsorption capacity achieved by the fitting of the Langmuir model was 1091.10 mg/g. Both physisorption and chemisorption contributed to the heterogeneous process of the poly-Fe-Mn toward uranium ions. The employment of NTP irradiation changed the monolayer adsorption of the traditional Fe-Mn materials and diversified the reaction mechanisms between the interface of the Fe-Mn materials and uranium ions. The elements, including O, N, and U exhibited higher compatibility and overlapped in the samples. The highly effective capture of uranium ions from the solution by the poly-Fe-Mn binary hydro (oxide) was mainly related to the chemical deposition of O and N radicals.

Catalytic degradation of benzene over non-thermal plasma coupled Co-Ni binary metal oxide nanosheet catalysts.

Non-thermal plasma (NTP) has been demonstrated as one of the promising technologies that can degrade volatile organic compounds (VOCs) under ambient condition. However, one of the key challenges of VOCs degradation in NTP is its relatively low mineralization rate, which needs to be addressed by introducing catalysts. Therefore, the design and optimization of catalysts have become the focus of NTP coupling catalysis research. In this work, a series of two-dimensional nanosheet Co-Ni metal oxides were synthesized by microwave method and investigated for the catalytic oxidation of benzene in an NTP-catalysis coupling system. Among them, Co2Ni1Ox achieves 60% carbon dioxide (CO2) selectivity (SCO2) when the benzene removal efficiency (REbenzene) reaches more than 99%, which is a significant enhancement compared with the CO2 selectivity obtained without any catalysts (38%) under the same input power. More intriguingly, this SCO2 is also significantly higher than that of single metal oxides, NiO or Co3O4, which is only around 40%. Such improved performance of this binary metal oxide catalyst is uniquely attributed to the synergistic effects of Co and Ni in Co2Ni1Ox catalyst. The introduction of Co2Ni1Ox was found to promote the generation of acrolein significantly, one of the key intermediates found in NTP alone system reported previously, suggest the benzene ring open reaction is promoted. Compared with monometallic oxides NiO and Co3O4, Co2Ni1Ox also shows higher active oxygen proportion, better oxygen mobility, and stronger low-temperature redox capability. The above factors result in the improved catalytic performance of Co2Ni1Ox in the NTP coupling removal of benzene.

Review of Developments in Combating COVID-19 by Vaccines, Inhibitors, Radiations, and Nonthermal Plasma.

Global society has been highly pressured by the COVID-19 pandemic, which has exposed vulnerabilities in supply chains for disinfection products, personal protective equipment, and medical resources worldwide. It is critically necessary to find effective treatments and medications for these viral infections. This review summarizes and emphasizes critical features of recent breakthroughs in vaccines, inhibitors, radiations, and innovative nonthermal atmospheric plasma (NTAP) technologies to inactivate COVID-19. NTAP has emerged as an effective, efficient, and safe method of viral inactivation. NTAP can be used to inactivate viruses in an environmentally friendly manner, as well as activate animal and plant viruses in a variety of matrices. Researchers and engineers desire to help the medical world deal with the ongoing COVID-19 epidemic by establishing techniques that make use of widely available NTAP technologies. NTAP technology is not dependent on viral strain, and it does not necessitate months or years of research to develop specific vaccines for each novel or arising viral disease. We believe the NTAP is a highly promising technique for combating COVID-19 and other viruses. Thus, NTAP technology could be a significant breakthrough in the near future in assisting humans in combating COVID-19 infections. We hope that this review provides a platform for readers to examine the progress made in the fight against COVID-19 through the use of vaccines, inhibitors, radiation, and NTAP.

Multimodal treatment combining cold atmospheric plasma and acidic fibroblast growth factor for multi-tissue regeneration.

Cold atmospheric plasma (CAP) is an emerging technology for biomedical applications, exemplified by its antimicrobial and antineoplastic potentials. On the contrary, acidic fibroblast growth factor (aFGF) has been a long-standing potent mitogen for cells from various origins. In this study, we are the first to develop a multimodal treatment combining the aforementioned physicochemical and pharmacological treatments and investigated their individual and combined effects on wound healing, angiogenesis, neurogenesis, and osteogenesis. This work was performed at the tissue, cellular, protein, and gene levels, using histochemical staining, flow cytometry, ELISA, and PCR, respectively. Depending on the type of target tissue, various combinations of aforementioned methods were used. The results showed that the enhancement on would healing and angiogenesis by CAP and aFGF were synergistic. The former was manifested by increased murine fibroblast proliferation and reduced cutaneous tissue inflammation, whereas the latter by upregulated proangiogenic markers in vivo, for example, CD31, VEGF, and TGF-ß, and downregulated antiangiogenic proteins in vitro, for example, angiostatin and angiopoietin-2, respectively. In addition, aFGF outperformed CAP during neurogenesis, which was evidenced by superior neurite outgrowth, while CAP exceeded aFGF in osteogenesis which was demonstrated by more substantial bone nodule formation. These novel findings not only support the fact that CAP and aFGF are both multipotent agents during tissue regeneration, but also highlight the potential of our multimodal treatment combining the individual advantages of CAP and aFGF. The versatile administration route, that is, topical and/or systemic, might further broaden its applications.

Osseointegration Properties of Titanium Implants Treated by Nonthermal Atmospheric-Pressure Nitrogen Plasma.

Pure titanium is used in dental implants owing to its excellent biocompatibility and physical properties. However, the aging of the material during storage is detrimental to the long-term stability of the implant after implantation. Therefore, in this study, we attempted to improve the surface properties and circumvent the negative effects of material aging on titanium implants by using a portable handheld nonthermal plasma device capable of piezoelectric direct discharge to treat pure titanium discs with nitrogen gas. We evaluated the osteogenic properties of the treated samples by surface morphology and elemental analyses, as well as in vitro and in vivo experiments. The results showed that nonthermal atmospheric-pressure nitrogen plasma can improve the hydrophilicity of pure titanium without damaging its surface morphology while introducing nitrogen-containing functional groups, thereby promoting cell attachment, proliferation, and osseointegration to some extent. Therefore, nitrogen plasma treatment may be a promising method for the rapid surface treatment of titanium implants.

Nonthermal Plasma Effects on Fungi: Applications, Fungal Responses, and Future Perspectives.

The kingdom of Fungi is rich in species that live in various environments and exhibit different lifestyles. Many are beneficial and indispensable for the environment and industries, but some can threaten plants, animals, and humans as pathogens. Various strategies have been applied to eliminate fungal pathogens by relying on chemical and nonchemical antifungal agents and tools. Nonthermal plasma (NTP) is a potential tool to inactivate pathogenic and food-contaminating fungi and genetically improve fungal strains used in industry as enzyme and metabolite producers. The NTP mode of action is due to many highly reactive species and their interactions with biological molecules. The interaction of the NTP with living cells is believed to be synergistic yet not well understood. This review aims to summarize the current NTP designs, applications, and challenges that involve fungi, as well as provide brief descriptions of underlying mechanisms employed by fungi in interactions with the NTP components.

Microwave Radiation and the Brain: Mechanisms, Current Status, and Future Prospects.

Modern humanity wades daily through various radiations, resulting in frequent exposure and causing potentially important biological effects. Among them, the brain is the organ most sensitive to electromagnetic radiation (EMR) exposure. Despite numerous correlated studies, critical unknowns surround the different parameters used, including operational frequency, power density (i.e., energy dose), and irradiation time that could permit reproducibility and comparability between analyses. Furthermore, the interactions of EMR with biological systems and its precise mechanisms remain poorly characterized. In this review, recent approaches examining the effects of microwave radiations on the brain, specifically learning and memory capabilities, as well as the mechanisms of brain dysfunction with exposure as reported in the literature, are analyzed and interpreted to provide prospective views for future research directed at this important and novel medical technology for developing preventive and therapeutic strategies on brain degeneration caused by microwave radiation. Additionally, the interactions of microwaves with biological systems and possible mechanisms are presented in this review. Treatment with natural products and safe techniques to reduce harm to organs have become essential components of daily life, and some promising techniques to treat cancers and their radioprotective effects are summarized as well. This review can serve as a platform for researchers to understand the mechanism and interactions of microwave radiation with biological systems, the present scenario, and prospects for future studies on the effect of microwaves on the brain.

Inductively coupled nonthermal plasma synthesis of aluminum nanoparticles.

Metallic nanoparticles of aluminum (Al), a nontoxic and earth-abundant element, are relevant to plasmonic and energetic applications. However, monodisperse Al nanoparticles are difficult to synthesize using all gas-phase approaches, especially in the 10 to 20 nm size range; yet, many applications require particles of this size due to their enhanced properties. Here, an inductive nonthermal plasma reactor fed with aluminum trichloride (AlCl3) and Ar is used to synthesize single-crystal aluminum nanoparticles. The particles can be produced with or without hydrogen. Several reactor conditions such as AlCl3vapor concentration, flow rates, and power are found to strongly influence particle properties such as the oxide shell thickness, particle mono-dispersity, and particle size. Significant quantities of Ar relative to AlCl3, short residence times of 10 s of ms, and pressures in excess of 4.7 Torr are required to form Al particles with geometric mean sizes of 10-20 nm and geometric standard deviations as low as 1.3. While the Al nanoparticles are covered with 2-4 nm thick oxide shells, the best synthesis conditions yield particle sizes determined by electron microscopy that are comparable to crystallite sizes determined from x-ray diffraction.

Applications of nonthermal plasma technology on safety and quality of dried food ingredients.

Cold plasma technology is an efficient, environmental-friendly, economic and noninvasive technology; and in recent years these advantages placed this novel technology at the centre of diverse studies for food industry applications. Dried food ingredients including spices, herbs, powders and seeds are an important part of the human diet; and the growing demands of consumers for higher quality and safe food products have led to increased research into alternative decontamination methods. Numerous studies have investigated the effect of nonthermal plasma on dried food ingredients for food safety and quality purposes. This review provides critical review on potential of cold plasma for disinfection of dried food surfaces (spices, herbs and seeds), improvement of functional and rheological properties of dried ingredients (powders, proteins and starches). The review further highlights the benefits of plasma treatment for enhancement of seeds performance and germination yield which could be applied in agricultural sector in near future. Different studies applying plasma technology for control of pathogens and spoilage micro-organisms and modification of food quality and germination of dried food products followed by benefits and current challenges are presented. However, more systemic research needs to be addressed for successful adoption of this technology in food industry.

Nonthermal plasma-activated water: A comprehensive review of this new tool for enhanced food safety and quality.

Nonthermal plasma (NTP) is an advanced technology that has gained extensive attention because of its capacity for decontaminating food from both biological and chemical sources. Plasma-activated water (PAW), a product of NTP's reaction with water containing a rich diversity of highly reactive oxygen species (ROS) and reactive nitrogen species (RNS), is now being considered as the primary reactive chemical component in food decontamination. Despite exciting developments in this field recently, at present there is no comprehensive review specifically focusing on the comprehensive effects of PAW on food safety and quality. Although PAW applications in biological decontamination have been extensively evaluated, a complete analysis of the most recent developments in PAW technology (e.g., PAW combined with other treatments, and PAW applications in chemical degradation and as curing agents) is nevertheless lacking. Therefore, this review focuses on PAW applications for enhanced food safety (both biological and chemical safeties) according to the latest studies. Further, the subsequent effects on food quality (chemical, physical, and sensory properties) are discussed in detail. In addition, several recent trends of PAW developments, such as curing agents, thawing media, preservation of aquatic products, and the synergistic effects of PAW in combination with other traditional treatments, are also presented. Finally, this review outlines several limitations presented by PAW treatment, suggesting several future research directions and challenges that may hinder the translation of these technologies into real-life applications.

Nonthermal Plasma Induces the Viable-but-Nonculturable State in Staphylococcus aureus via Metabolic Suppression and the Oxidative Stress Response.

As a novel nonthermal technology, nonthermal plasma (NTP) has attracted a lot of attention. However, it could induce microorganisms into a viable but nonculturable (VBNC) state, posing a potential risk to food safety and public health. In this study, the molecular mechanisms of VBNC Staphylococcus aureus induced by NTP were investigated. With the use of a propidium monoazide quantitative PCR (PMA-qPCR) technique combined with a plate count method, we confirmed that 8.1 to 24.3 kJ NTP induced S. aureus into a VBNC state at a level of 7.4 to 7.6 log10 CFU/ml. The transcriptomic analysis was conducted and revealed that most energy-dependent physiological activities (e.g., metabolism) were arrested in VBNC S. aureus, while the oxidative stress response-related genes (katA, dps, msrB, msrA, and trxA) were significantly upregulated. In addition, this study showed that the ATP depletion by carbonyl cyanide m-chlorophenyl hydrazone (CCCP) pretreatment could accelerate the formation of VBNC S. aureus The NTP-generated oxidative stress triggers the staphylococcal oxidative stress response, which consumes part of cellular energy (e.g., ATP). The energy allocation is therefore changed, and the energy assigned for other energy-dependent physiological activities (cell growth and division, etc.) is reduced, subsequently forcing S. aureus into a VBNC state. Therefore, the alterations of energy allocation should be some of the major contributors to the induction of VBNC S. aureus with NTP exposure. This study provides valuable knowledge for controlling the formation of VBNC S. aureus during NTP treatment.IMPORTANCE In recent years, nonthermal plasma (NTP) technology has received a lot of attention as a promising alternative to thermal pasteurization in the food industry. However, little is known about the microbial stress response toward NTP, which could be a potential risk to food safety and impede the development of NTP. A viable but nonculturable (VBNC) state is one of the most common survival strategies employed by microorganisms against external stress. This study investigated the mechanisms of the formation of VBNC Staphylococcus aureus by NTP in a more comprehensive and systematic aspect than had been done before. Our work confirmed that the NTP-generated oxidative stress induced changes in energy allocation as a driving force for the formation of VBNC S. aureus This study could provide better knowledge for controlling the occurrence of VBNC S. aureus induced by NTP, which could lead to more rational design and ensure the development of safe foods.

Nonthermal Plasma-Liquid Interactions in Food Processing: A Review.

Nonthermal processing methods are often preferred over conventional food processing methods to ensure nutritional quality. Nonthermal plasma (NTP) is a new field of nonthermal processing technology and seeing increased interest for application in food preservation. In food applications of NTP, liquid interactions are the most prevalent. The NTP reactivity and product storability are altered during this interaction. The water activated by NTP (plasma-activated water [PAW]) has gained considerable attention during recent years as a potential disinfectant in fruits and vegetable washing. However, detailed understanding of the interactions of NTP reactive species with food nutritional components in the presence of water and their stability in food is required to be explored to establish the potential of this emerging technology. Hence, the main objective of this review is to give a complete overview of existing NTP-liquid interactions. Further, their microbial inactivation mechanisms and the effects on food quality are discussed in detail. Most of the research findings have suggested the successful application of NTP and PAW for microbial inactivation and food preservation. Still, there are some research gaps identified and a complete analysis of the stability of plasma reactive species in food is still missing. By addressing these issues, along with the available research output in this field, it is possible that NTP can be successfully used as a food decontamination method in the near future.