Plasma-activated Water Treatment Research Articles

Plant growth promotion effect of plasma activated water on Lactuca sativa L. cultivated in two different volumes of substrate

Plasma activated water (PAW) can represent an alternative to chemical fertilizers in agriculture. The effects of PAW treatment applied in two concentrations (1.5 or 3.0 mg L−1 NO3−) on some morphological, physiological, biochemical parameters and yield of Lactuca sativa L. grown in two different pot volumes (400 or 3200 cm3) were investigated in this study. The results showed that both PAW concentrations did not influence the germination, once the process was initiated. Positive effects of the treatments were registered on the length of radicle and hypocotyls of lettuce at a concentration of 1.5 mg L−1 NO3− (PAW I), the chlorophyll content was significantly increased at a concentration of 3.0 mg L−1 NO3− (PAW II) and bigger pot volume, also the foliar weight and area. No significant differences between the treated and untreated plants were recorded for the root weight, leaf length and width. The dry weight was significantly higher for the lettuce treated with PAW I and II grown in big volume pots at 57 days after transplanting (DAT) and small volume pots at 64 DAT. The nitrites content of the lettuce grown in big pots was lower than of the lettuce grown in small pots, regardless of the PAW treatment. Contrary, the nitrates content was higher in the lettuce grown in big pots (up to 36.4 mg KNO3/g DW), compared to small pots (under 0.3 mg KNO3/g DW).

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.

Plasma activated water triggers plant defence responses

Nowadays, one of the main challenges is moving towards an eco-sustainable agriculture, able to preserve the food production through a reduced use of pesticides. Current global food sustenance by intensive agriculture is mainly based on economic crop monocultures and drastically reduces the biodiversity, increasing the yield losses due to the presence of biotic and abiotic stresses. A technology based on plasma activated water (PAW), characterized by the presence in liquid of reactive oxygen and nitrogen species, was tested to try to ensure yield stability also enhancing the plant resistance responses and to promote an eco-sustainable management of plant diseases. In PAW-treated micropropagated periwinkle shoots, periwinkle and grapevine plants, qRT-PCR and small RNAs high-throughput sequencing were used to analyse the differential expression of genes involved in the major plant defence pathways. The results indicate that PAW treatment enhances the plant defence responses and provide an encouraging framework for future applications in plant disease management programs.

The Antibacterial Efficacy and Mechanism of Plasma-Activated Water Against Salmonella Enteritidis (ATCC 13076) on Shell Eggs.

Eggs are one of the most commonly consumed food items. Currently, chlorine washing is the most common method used to sanitize shell eggs. However, chlorine could react with organic matters to form a potential carcinogen, trihalomethanes, which can have a negative impact on human health. Plasma-activated water (PAW) has been demonstrated to inactivate microorganisms effectively without compromising the sensory qualities of shell eggs. For this study, various amounts (250, 500, 750, or 1000 mL) of PAW were generated by using one or two plasma jet(s) at 60 watts for 20 min with an air flow rate at 6 or 10 standard liters per minute (slm). After being inoculated with 7.0 log CFU Salmonella Enteritidis, one shell egg was placed into PAW for 30, 60, or 90 s with 1 or 2 acting plasma jet(s). When 2 plasma jets were used in a large amount of water (1000 mL), populations of S. Enteritidis were reduced from 7.92 log CFU/egg to 2.84 CFU/egg after 60 s of treatment. In addition, concentrations of ozone, hydrogen peroxide, nitrate, and nitrite in the PAW were correlated with the levels of antibacterial efficacy. The highest concentrations of ozone (1.22 ppm) and nitrate (55.5 ppm) were obtained with a larger water amount and lower air flow rate. High oxidation reduction potential (ORP) and low pH values were obtained with longer activation time, more plasma jet, and a lower air flow rate. Electron paramagnetic resonance (EPR) analyses demonstrated that reactive oxygen species (ROS) were generated in the PAW. The observation under the scanning electron microscope (SEM) revealed that bacterial cells were swollen, or even erupted after treatment with PAW. These results indicate that the bacterial cells lost control of cell permeability after the PAW treatment. This study shows that PAW is effective against S. Enteritidis on shell eggs in a large amount of water. Ozone, nitrate, and ROS could be the main causes for the inactivation of bacterial cells.

Plasma-activated water regulates root hairs and cotyledon size dependent on cell elongation in Nicotiana tabacum L.

Tobacco is an excellent model plant to study developmental processes and cellular biology. Surface dielectric barrier discharge (sDBD) was used to generate plasma activated water (PAW), and the PAW was indirectly applied to study tobacco plant growth during the early developmental stages. Solid media were treated with the PAW for 8- and 18-day-old seedlings, and the effects on both the vegetative and root phenotypes were observed during the early developmental stages. In the vegetative tissue, the cotyledon size was large for the seedling that was cultivated by plasma activated water for the 12 min PAW (PAW12) treatment. The PAW dramatically elongated the cotyledon by 40% due to increased cell expansion in the leaf-length direction, not cell proliferation. In addition to the vegetative tissue, the root length due to the PAW was significantly enhanced at the primary root with elongated root hairs. According to molecular analysis, the NT_ COBRA-LIKE 9 (COBL) and two NT_ XYLOGLUCAN ENDO-TRANSGLYCOSYLASE/HYDROLASE (XTH) genes, NT_XTH9 and NT_XTH15, were significantly over-expressed by the PAW treatment compared with untreated deionized water (DW), indicating that the PAW effects are from modulating the expression of target genes. These results demonstrate that PAW might promote tobacco plant growth both in the cotyledon and root hair tissues via the NT_COBL, NT_XTH9 and NT_XTH15 genes.

Inactivation efficacy of plasma‐activated water: influence of plasma treatment time, exposure time and bacterial species

SummaryThis study aimed to evaluate the influence of plasma treatment time, bacterial exposure time to PAW and bacterial species on the inactivation efficacy of plasma‐activated water (PAW), with additional investigation of the inactivation mechanisms of PAW. Six bacterial species, including Listeria innocua, Staphyloccus aureus, Escherichia coli, Pseudomonas fluorescens, Shewanella putrefaciens and Aeromonas hydrophila were selected as the representative bacteria. The initial bacterial concentration was around 7 log CFU ml−1 after mixing with PAW, and the inactivation efficacy was measured after different exposure times during the 4 °C storage. Scanning electron microscopy (SEM) images of the bacteria after PAW treatment were carried out to inspect the cell structure damage, and physicochemical properties of PAW, including pH, conductivity and long‐living reactive species of H2O2, , and , were examined. The results showed that the inactivation efficacy of PAW was positively correlated with plasma treatment time and bacterial exposure time, and for the species examined in this study, the Gram‐negative species were more sensitive to PAW than the Gram‐positive species. Cell structure damage, including shrinkage, distortion, or holes, was observed after PAW treatment. The pH of PAW was acidified to 2.5–2.9, and conductivity was significantly increased to 518.0 μs cm−1. and H2O2 were reduced during the 48 h storage, while an increased concentration was observed for . This study demonstrated that the processing parameters of plasma treatment time, exposure time and characteristics of bacteria can significantly affect the inactivation efficacy of PAW.

Synergistic Inactivation Mechanism of Combined Plasma-Activated Water and Mild Heat against Saccharomyces cerevisiae

This study aimed to elucidate the mechanism of synergistic inactivation of Saccharomyces cerevisiae by the combined use of plasma-activated water (PAW) and mild heat (40 to 50°C). A reduction of 4.40 log CFU/mL in S. cerevisiae was observed after the synergistic combination of PAW and mild heat at 50°C for 6 min, whereas the individual treatments of PAW at 25°C and mild heat at 50°C for 6 min resulted in a reduction of 0.27 and 1.92 log CFU/mL, respectively. The simultaneous application of PAW and mild heat caused significant increases in membrane permeability, resulting in the leakage of intracellular components (such as nucleic acids and proteins) and increased uptake of propidium iodide. The combined treatment of PAW and mild heat also resulted in significant increases in the intracellular levels of reactive oxygen species and disruption of mitochondrial membrane potential in S. cerevisiae cells. In summary, this study illustrates the potential of PAW treatment combined with mild heat to rapidly inactivate microorganisms in food products.

Effects of Plasma-Activated Water on Skin Wound Healing in Mice.

Cold atmospheric plasma (CAP) has been widely used in biomedicine during the last two decades. While direct plasma treatment has been reported to promote wound healing, its application can be uneven and inconvenient. In this study, we first activated water with a portable dielectric barrier discharge plasma device and evaluated the inactivation effect of plasma-activated water (PAW) on several kinds of bacteria that commonly infect wounds. The results show that PAW can effectively inactivate these bacteria. Then, we activated tap water and examined the efficacy of PAW on wound healing in a mouse model of full-thickness skin wounds. We found that wound healing in mice treated with PAW was significantly faster compared with the control group. Histological analysis of the skin tissue of mice wounds showed a significant reduction in the number of inflammatory cells in the PAW treatment group. To identify the possible mechanism by which PAW promotes wound healing, we analyzed changes in the profiles of wound bacteria after PAW treatment. The results show that PAW can significantly reduce the abundance of wound bacteria in the treatment group. The results of biochemical blood tests and histological analysis of major internal organs in the mice show that PAW had no obvious side effects. Taken together, these results indicate that PAW may be a new and effective method for promoting wound healing without side effects.

In vitro antimicrobial effects and mechanism of air plasma‐activated water on Staphylococcus aureus biofilm

AbstractThe deactivation effects and mechanism of plasma‐activated water (PAW) against Staphylococcus aureus biofilm and the inhibitory effect on the biofilm regrowth capacity for the surviving S. aureus post PAW treatment were investigated in vitro. Systematic measurements on bacterial cultivability, metabolic capacity, membrane integrity and intracellular reactive oxygen species (ROS) concentration under two different experimental categories were carried out after PAW treatment. Considerable deactivation effects were discovered on biofilm S. aureus on both prolonging the PAW inducement or treatment time. The rising concentration of intracellular ROS and the PAW‐contained RS might exert synergistic effects in deactivating the biofilm S. aureus. Moreover, the biomass, bacterial cultivability and metabolic capacity of the regrown S. aureus biofilm all significantly declined along with the increasing PAW inducement or treatment time. Therefore, except for the short‐term rapid inactivation effects on the biofilm, the PAW treatment could also exert long‐term inhibitory effects on the regeneration of S. aureus biofilm.

Microbial inactivation and quality of grapes treated by plasma-activated water combined with mild heat

Saccharomyces cerevisiae is often associated with spoilage of fresh fruits and vegetables. This study aimed to evaluate the synergistic effect of plasma-activated water (PAW) and mild heat on the survival of S. cerevisiae and quality attributes of grapes. The combination of PAW and mild heat (50, 52.5, and 55 °C, 30 min) showed full synergistic fungicidal activity against S. cerevisiae on grapes. For S. cerevisiae cells, maximum inactivation was 5.85 log10 CFU/g after the PAW treatment at 55 °C for 30 min, which was significantly higher than that of individual treatment of PAW at 25 °C (0.39 log10 CFU/g) or sterile distilled water at 55 °C (2.39 log10 CFU/g) (p < 0.05). The levels of H2O2 and NO2− in PAW significantly decreased, while NO3− content remarkably increased after the mild heating at 25–55 °C for 30 min. Meanwhile, no significant changes were observed in the total soluble solids, reducing sugar, pH, titratable acidity, firmness, surface color, total phenolics, vitamin C, and antioxidant properties of grapes treated with PAW at 25–55 °C for 30 min. In summary, the combination of PAW and mild heat may be considered as an alternative to traditional preservation methods for fresh produce.

Effect of plasma-activated water, used as a disinfectant, on the hatch rate of dormant cysts of the Artemia salina

Various disinfectants have been used to sterilize fish eggs, breeding water, and aquaculture facilities. These disinfectants exert a considerable negative effect on the environment when used in large amounts and, thus, are a public-health concern. In this study, eco-friendly plasma-activated water (PAW) was produced using non-thermal plasma technology and used as a disinfectant in an aquaculture experiment using the cysts of the Artemia salina. We used bacterial strains (Vibrio alginolyticus rm-8420, Vibrio harveyi SFC-BS, Vibrio parahaemolyticus CRS 09–17, and Edwardsiella tarda ATCC 15947) as opportunistic pathogens. The PAW rapidly reduced the number of these bacteria in cyst samples for up to 3 h after treatment, and thereafter, there was no reduction in bacterial counts. The effect was the highest in brine shrimp cyst samples inoculated with V. harveyi and treated with PAW; a similar trend was observed for the other three strains. In addition, the hatch rate of A. salina cysts infected with V. harveyi was reduced, which was recovered after PAW treatment. The cysts in the group treated with bacteria and seawater (VhS) showed a 17.6% reduction in the hatch rate relative to the control group treated with seawater, but the group inoculated with bacteria and treated with PAW showed a significant increase in the hatch rate relative to the VhS group. The results suggest that PAW can be used as an alternative disinfectant in aquaculture to sterilize fish eggs.

Plasma-Activated Water Treatment of Fresh Beef: Bacterial Inactivation and Effects on Quality Attributes

Nonthermal plasma has been widely considered as an effective method for bacterial inactivation in food safety. In this paper, the preservation of fresh beef was investigated using plasma-activated water (PAW) with different treatment time intervals ranging from 6 to 192 h. The effects of PAW on fresh beef preservation were evaluated with the microbial counts on the surface of fresh beef and its quality attributes. The bactericidal efficiency of PAW on fresh beef was found to be strongly dependent on the PAW treatment intervals and storage time. Results show that 24-h PAW treatment could achieve a reduction around 3.1 log for bacteria on the surface of fresh beef at 24-day storage and effectively extend the shelf life of fresh beef for four to six days. Moreover, when the PAW treatment interval time was greater than or equal to 24 h, there did not exist any significant changes in the quality attributes of fresh beef. Meanwhile, the overtreatment of PAW also had a negative effect on beef quality. In conclusion, the PAW could be a promising alternative to the traditional sanitizers applied in the fresh produce industry.

Towards the Next-Generation Disinfectant: Composition, Storability and Preservation Potential of Plasma Activated Water on Baby Spinach Leaves.

Plasma activated water (PAW) has rapidly emerged as a promising alternative to traditional sanitizers applied in the fresh produce industry. In the present study, PAW chemistry and storage stability were assessed as a function of plasma operating conditions. Increasing plasma exposure time (5, 12.5, 20 min) and power (16, 26, 36 W) led to a significant drop in pH (2.4) and higher nitrates and nitrites levels (320 and 7.2 mg/L, respectively) in the PAW. Non-detectable hydrogen peroxide concentration, irrespective of the treatment conditions, was attributed to its instability in acidic environments and the remote PAW generation mode. pH, nitrates and nitrites levels in the PAW remained unaffected after two weeks at 4 °C. The potential of PAW for microbial inactivation and quality retention was demonstrated on baby spinach leaves. Rinsing steps influenced colour development during chilled storage to a greater extent than PAW treatment itself. About 1 log reduction in total bacterial counts (5 log CFU/g) was achieved through PAW rinsing, with no variability after eight days at 4 °C (typical shelf-life at retailers). Moreover, microbial levels on PAW-treated samples after storage were significantly lower than those on control samples, thus contributing to extended product shelf-life and reduced food waste generation.

The application of plasma-activated water combined with mild heat for the decontamination of Bacillus cereus spores in rice (Oryza sativa L. ssp. japonica)

This study applied the combination of plasma-activated water (PAW) and mild heat (40 °C and 55 °C) for the decontamination of Bacillus cereus spores in rice (Oryza sativa L. ssp. japonica). In this study, PAW combined with 40 °C and 55 °C (PAW-40 and PAW-55) achieved 1.54 and 2.12 log10 CFU g−1 reductions of B. cereus spores in rice after 60 min exposure, which was significantly higher than the inactivation level (0.72 log10 CFU g−1) induced by PAW treatment alone. The assays for the leakage of intracellular contents (nucleic acids, proteins, dipicolinic acid-DPA) and the propidium iodide (PI) fluorescence probe confirmed that the combination of PAW and mild heat caused significant damages on the intact multilayered structure of B. cereus spores than the individual PAW did. The application of scanning electron microscope (SEM) and transmission electron microscope (TEM) provided a direct observation for the visible disruption of external structure and leakage of intracellular components caused by the combination of PAW and mild heat. Besides, the combination of PAW and mild heat caused no adverse effect on the texture and sensory qualities of the rice after cooking. These findings provide some knowledge for the application of PAW combined with mild heat for the decontamination of spores in rice.

Effect of cold atmospheric pressure plasma-activated water on the microbial safety of Korean rice cake

We evaluated the effect of plasma-activated water (PAW) on the populations of foodborne pathogens and food-spoilage microorganisms on Korean rice cake. PAW was produced by treating distilled water with two atmospheric dielectric-barrier discharges (51.7 W, 14.4 kHz, air discharge) for 20 min. The inactivation effect of PAW on indigenous microorganism and inoculated Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, Penicillium chrysogenum and Candida albicans on Korean rice cake were measured and their effect on the color and texture values of the samples were determined. PAW treatment for 20 min reduced the numbers of the three foodborne pathogens by about 2.0 log CFU/g. PAW treatment for 20 min reduced the numbers of total aerobes, P. chrysogenum, and C. albicans by 2.78, 1.97, and 1.00 log CFU/g, respectively. The antimicrobial effect of PAW was not significantly different from 0.2 ppm of sodium hypochlorite solution, which is used in Korean rice cake production. PAW treatment did not affect the color, texture, or pH of Korean rice cake. Therefore, PAW treatment can be used as an alternative method to reduce safety risk and spoilage of Korean rice cake without deteriorating its quality.

Effect of Nonthermal Plasma-Activated Water on Quality and Antioxidant Activity of Fresh-Cut Kiwifruit

Recently, plasma-activated water (PAW) has received extensive attention in food safety field due to its advantages of eco-friendly and high sterilization efficiency. In this paper, the effects of PAW on microbe loads and quality of fresh-cut kiwifruit (FCK) were studied, and the preservation mechanism of PAW on FCK was explored. A 1 mL of PAW and 1 mL of sterile water as control sample were separately sprayed on FCK and stored at 4 °C for 8 days. Compared to the control sample, the microbial population of FCK was reduced by approximately 1.8 log CFU/g after the PAW treatment. The activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in PAW-treated FCK samples were improved. Further test results showed that H2O2 and O2− accumulation rates of PAW-treated FCK were slower than that of the control sample. Finally, by analyzing the effect of pH and H2O2 on the activity of antioxidant enzymes in FCK, it was found that either pH or H2O2 treatment could enhance the activities of antioxidant enzymes in FCK. Concerning the fruit quality, our measurement shows that the PAW treatment had no significant effect on the firmness and $b^\ast $ value of FCK.

Morphological risk assessment of cold atmospheric plasma-based therapy: bone marrow mesenchymal stem cells in treatment zone proximity

Cold atmospheric plasma (CAP), modern technology for medical purposes, has recently established its potential in cancer therapy both in vitro and in vivo, thanks to the plasma-induced formation of free radicals. Due to its growing demand and extensive use, comprehensive studies are necessary to ensure its safety, especially for healthy cells adjacent to the treatment area. To this end, in this paper and for the first time, use has been made of morphological analysis, including the cell/nucleus shape index (CSI/NSI) and fractal dimension (FD), to assess the risk of CAP therapy on normal bone marrow mesenchymal stem cells (BMMSCs). To find the best protocol of plasma treatment, BMMSCs were subjected to direct and indirect (adding plasma-activated-water (PAW) to the culture medium) treatments. Our bioassay and morphological assessments results showed that the PAW treatment was the better method for the optimal dosage equal to 80% of the culture media, provided that the maximum power was 30 W and the exposure time was 90 s. Our research showed that high-dose PAW results in significant changes in FD, e.g. an equal proportion of PAW and culture medium increases the FD 1.38-fold, with respect to the control. Furthermore, while in the low-power direct treatment (<30 W) NSI did not change significantly, in the high-power one (>30 W) it approached 1, which is an indicator of apoptosis. It was also seen that high-dose PAW elongates the cells and therefore diminishes CSI. Any change in cell/nucleus shape could results in cancer initiation. Therefore, the observed changes in shape index and FD number might indicate cancer initiation. Our measurements of the BAX and BCL2 expression ratio were in favor of our results. Taken together, all of our results showed cell damage in high powers of plasma source and high-dose PAW. Moreover, it is concluded that the probability of cancer initiation is a severe issue that should be investigated in all CAP-based cancer therapies, even in the optimized indirect methods.

The Effects of Cold Plasma-Activated Water Treatment on the Microbial Growth and Antioxidant Properties of Fresh-Cut Pears

Herein, we examined the effects of plasma-activated water (PAW) treatment on the native microflora survival, quality maintenance, and antioxidant activity of fresh-cut pears, which were washed with PAW under three different conditions (peak voltage = 6, 8, and 10 kV) for 5 min and then stored at 4 °C for 12 days. Distilled water and sodium hypochlorite treatment were used as control and comparison, respectively. Results showed that all PAW treatments significantly inhibited the growth of aerobic bacteria, yeast, and mold during storage, with the 8-kV PAW treatment maintaining the lowest growth rate. Additionally, no significant change was observed in the soluble solid content and titratable acidy of fresh-cut pears treated with PAW. Treatment by 6-kV PAW significantly slowed down the softening of fresh-cut pears, while the 8-kV PAW treatment significantly reduced the mass loss and the total phenolic content (P 0.05). Furthermore, PAW outperformed sodium hypochlorite in antimicrobial effectiveness and quality maintenance. Taken together, these results suggest that PAW treatment might be a promising strategy to control microbial growth and maintain the quality of fresh-cut pears.

Reduction of phoxim pesticide residues from grapes by atmospheric pressure non-thermal air plasma activated water.

In this study, we propose a novel strategy, plasma activated water (PAW) to reduce pesticide residues on agricultural products. To validate its feasibility and effectiveness, we employee high-performance liquid chromatography (HPLC) to detect phoxim on grapes. HPLC results suggest that the reduction of phoxim on grapes achieve 73.60% after treated 10 min by PAW prepared 30 min, and the concentration of phoxim decreased significantly (p < 0.05) with the preparation time of PAW. Furthermore, HPLC-MS analysis shows that the reduction effect of phoxim by PAW is dominated by the degradation of phoxim. Combined with analyzing the physicochemical properties of PAW, one possible degradation pathway is proposed under the present experimental conditions, mediated by reactive oxygen and nitrogen species. The acidic environment (pH < 3) and high oxidation capacity (ORP > 500 mV) are suggested to be a benefit to the reduction of phoxim. Besides, the experimental results regarding color, firmness, sugar, vitamin C, and superoxide dismutase of grapes demonstrate that the PAW treatment will not significantly affect the quality of grapes. In conclusion, phoxim pesticide residues on grapes could be effectively reduced by the PAW strategy and without a significant (p < 0.05) effect on grapes quality.

Influence of organic matters on the inactivation efficacy of plasma-activated water against E. coli O157:H7 and S. aureus

In recent years, the potential application of plasma-activated water (PAW) in the food industry has received increasing attention as a promising alternative to traditional sanitizers. The objective of this work was to evaluate the effect of organic matters in the form of beef extract or peptone on the inactivation efficacy of PAW against Escherichia coli O157:H7 and Staphylococcus aureus. PAW was mixed with beef extract or peptone (final concentration: 0–5.0 g/L) and the mixture was allowed to stand at room temperature for 15 min. Subsequently, 100 μL of each bacterial suspension was treated with 900 μL of the PAW/organic matters solutions at room temperature for another 6 min. The results showed that PAW treatment without organic matters could effectively inactivate the tested bacteria, resulting in 3.70-and 2.32-log reduction of E. coli O157:H7 and S. aureus in comparison to the control group, respectively. Beef extract or peptone severely quenched the inactivation efficacy of PAW against E. coli O157:H7 and S. aureus in a dose-dependent way. The addition of beef extract and peptone significantly decreased the oxidation-reduction potential and NO2− concentration of PAW, increased the pH values of PAW in a dose-dependent manner (p < 0.05), but did not significantly affect its hydrogen peroxide (H2O2) content (p > 0.05). Thus, more attention should be paid to the effect of interfering substances on the disinfection efficacy of PAW before its practical application.