Effect Of Plasma-activated Water Research Articles

Effect of plasma-activated water on microbial quality and physicochemical properties of fresh beef

Abstract This work studies the influence of plasma-activated water (PAW) on the decontamination of beef and its influence on the color, pH, the thiobarbituric acid reactive substance values (TBARS), and total volatile basic nitrogen (TVBN) values of meat. PAW was generated using non-thermal atmospheric pressure plasma jet (NTAPPJ). He + 0.2% N2 and He + 0.2% O2 were used as worker gas to generate PAW. The PAW produced by the He + O2 plasma system exhibited a higher potential for decontamination of beef than that produced by the He + N2 plasma system. The lightness value (L*) of treated beef does not exhibit a noticeable difference with the control one. TBARS values of all treated beef were lower than the rancidity threshold but significantly greater than that of control samples. The TVBN value of control beef samples reached the decay threshold after 18 days of stockpiling, but treated beef remained good. This work reveals that PAW can potentially inhibit the growth of microorganisms in beef.

Plasma-Activated Water for Food Safety and Quality: A Review of Recent Developments.

Plasma-activated water (PAW) has received a lot of attention lately because of its antibacterial efficacy and eco-friendly nature. Compared to traditional disinfectants, this novel and intriguing option has a high disinfectant capacity while causing little to no modifications to the foodstuffs. Until now, PAW has successfully demonstrated its effectiveness against a broad range of microorganisms on a wide variety of food items. Though the efficacy of PAW in microbial reduction has been extensively reviewed, a relatively significant issue of food quality has been largely overlooked. This review aims to summarize the current studies on the physicochemical characteristics and antimicrobial potential of PAW, with an in-depth focus on food quality and safety. According to recent studies, PAW can be a potential microbial disinfectant that extends the shelf life of various food products, such as meat and fish products, fruits and vegetables, cereal products, etc. However, the efficacy varies with treatment conditions and the food ingredients applied. There is a mixed opinion about the effect of PAW on food quality. Based on the available literature, it can be concluded that there has been no substantial change in the biochemical properties of most of the tested food products. However, some fruits and vegetables had a higher value for the enzyme superoxide dismutase (SOD) after PAW treatment, while only a few demonstrated a decrease in the Thiobarbituric acid reactive substances (TBARS) value. Sensory properties also showed no significant difference, with some exceptions in meat and fish products.

Antimicrobial effects of microwave plasma-activated water with skin protective effect for novel disinfectants in pandemic era

Skin antiseptics have important implications for public health and medicine. Although conventional antiseptics have considerable antimicrobial activity, skin toxicity and the development of resistance are common problems. Plasma-treated water has sterilization and tissue-regenerative effects. Therefore, the aim of this study was to identify whether plasma-activated water (PAW) manufactured by our microwave plasma system can be used as a novel antiseptic solution for skin protection. PAW was produced by dissolving reactive nitrogen oxide gas using microwave plasma in deionized water. The antibacterial effects of PAW against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, and Salmonella typhimurium and effective concentrations were investigated by a solid agar plate assay. The factors mediating the effects of PAW were evaluated by the addition of reactive species scavengers. Cytotoxicity and cell viability assays were performed to examine the protective effect of PAW on normal skin cells. PAW exhibited excellent sterilization and no toxicity in normal skin cells. Experiments also confirmed the potential of PAW as a sanitizer for SARS-CoV-2. Our findings support the use of PAW as an effective skin disinfectant with good safety in the current situation of a global pandemic.

Inactivation effects of plasma-activated water on Fusarium graminearum

The continuous usage of fungicides poses a potential threat to the environment, ranging from mere irritation to being very toxic to human beings and organisms. Plasma-activated water (PAW) has recently gained much interest as a promising candidate to inactivate phytopathogens. However, the inactivation mechanisms of PAW are still not well understood. In this study, the effect of PAW on the cellular responses of Fusarium graminearum and the efficacy of PAW against F. graminearum in vivo and in vitro were investigated. The results showed that microbial activity of spores was significantly inhibited by PAW treatment (P<0.05). The symptoms caused by F. graminearum were significantly reduced on the wheat spikelets. PAW could induce cell wall sculpturing, membrane permeability changes, and mitochondrial dysfunction. Differential gene expression analysis also confirmed that the cell membrane, the cell wall and the mitochondria were the organelles most affected by PAW. The results from this study facilitate the understanding of the mechanisms underlying the responses of F. graminearum to PAW and indicate the potential of PAW as a fungicidal agent or an effective supplement to fungicides.

Effect of Plasma-activated Water as Thawing Media on the Sterilization and Quality of Beef

Effect of Plasma-activated Water as Thawing Media on the Sterilization and Quality of Beef

Effects of Plasma-Activated Water on Soybean and Wheat: Germination and Seedling Development

Effects of Plasma-Activated Water on Soybean and Wheat: Germination and Seedling Development

Application of plasma-activated water forEscherichia colidecontamination and shelf-life extension of kale

AbstractThe aim of this study was to examine the effectiveness of plasma-activated water (PAW) for inactivating Escherichia coli (E. coli) and retention of key quality factors for kale. Different plasma discharge times (1, 2, 3, 4, 5, and 10 min) and different exposure times (2, 4, 6, 8, 10, and 15 min) were used to investigate the inactivation effect of E. coli spot-inoculated on kale. The influence of different exposure times on the pH, hardness and color of kale was studied post-treatment. In addition, the effects of PAW on the shelf-life of kale over 12 d of storage at 4 °C were investigated. The results showed that after the treatment of 5-PAW-8 (8 min treatment by PAW generated by 5 min plasma discharge), the population of E. coli on kale was reduced by approximately 1.55 log colony-forming units (CFU)/g and the changes in pH, hardness and color of kale were not significant (P&amp;gt;0.05). During the storage period after 5-PAW-8 treatment, the hardness, weight loss, color, surface morphology and ascorbic acid were found to be better than those of the two control groups (P&amp;lt;0.05). Furthermore, no significant changes were observed in pH values, the content of total phenols, or 1,1-dipheny1-2-picrylhydrazyl radical scavenging capacity (P&amp;gt;0.05). It is indicated that PAW treatment is a promising method for improving microbiological safety and extending the shelf-life of kale.

Effects of plasma-activated water on overall quality of fresh goji berries during storage

Plasma-activated water (PAW), the solution combined with a large number of active substances through plasma discharge. The aim of this study was to use PAW to treat goji berries and evaluate the effects of PAW treatment on storability, quality attributes and nutritive properties of goji berries during storage. The data indicated that, as compared to the control samples, PAW could increase the respiration rate and reduce the content of malondialdehyde (MDA), retard the occurrences of weight losing, and the growth of microorganism on the fruit surface, keep a higher rate of commercially acceptable. Additionally, PAW treatment could suppress the decrease of chromaticity values of L*, a* and b* of the fruit surface, maintain good taste and texture by keeping higher amounts of bioactive compounds, such as polysaccharides, polyphenols, flavonoids, vitamin C (VC) and β-carotene, and delaying the fruits from becoming soft and sticky. These results demonstrated that PAW treatment could maintain higher quality attributes and nutritive properties, and display better storability of goji berries.

Effect of Plasma-Activated Water on Shewanella putrefaciens Population Growth and Quality of Yellow River Carp (Cyprinus carpio) Fillets

Plasma-activated water (PAW) is a new sanitizer that has received considerable attention for application in food industries. This research aimed to evaluate the effect of PAW on the inactivation of Shewanella putrefaciens and quality attributes of Yellow River carp (Cyprinus carpio) fillets. The carp fillet samples were immersed in sterile deionized water (SDW) or SDW activated by plasma discharge for 120 s (PAW120) for 1.5, 3.0, 4.5, or 6.0 min. After being treated by PAW120 for 6 min, the population of S. putrefaciens on carp fillets was significantly (P < 0.05) decreased by 1.03 log CFU/g. Compared with SDW-treated samples, the L* value of PAW120-treated carp fillets was increased and the a* value was decreased after PAW120 treatment, whereas there was no significant (P > 0.05) difference in the b* value. Compared with SDW, PAW120 caused no significant (P > 0.05) changes in sensory properties and texture attributes of carp fillets including hardness, springiness, gumminess, and cohesiveness. However, 6-min PAW120 treatment caused a significant increase in the lipid oxidation level and a decrease in the pH value of the carp fillets. This work provides a basis for the potential application of PAW in the preservation of aquatic products.

The Effects of Plasma-Activated Water on Heavy Metals Accumulation in Water Spinach

Toxic heavy metals accumulate in crops from the environment through different routes and may interfere with biochemical reactions in humans, causing serious health consequences. Plasma technology has been assessed for the promotion of seed germination and plant growth in several past studies. Therefore, the aim of the present study was to evaluate whether the growth rate of plants can be increased with the application of non-thermal plasma, as well as to reduce the accumulation of heavy metals in leafy vegetables (water spinach). In this study, several kinds of plasma treatments were applied, such as treatment on the seeds (PTS + NTW), irrigation water (NTS + PAW) or both (PTS + PAW). The results of the study showed that the heavy metals accumulated in water spinach were affected by the heavy metals available in the soil. The bioconcentration factor (BCF) of Cd in water spinach decreased from 0.864 to 0.543 after plasma treatment in seed or irrigating water, while the BCF of Pb was low and did not show any significant changes. Therefore, the results suggest that plasma treatment may suppress Cd absorption, but not for Pb. In this study, plasma treatment did not help to improve the product yield of water spinach planted in Cd-added soil. In the future, fertilizers can be used to supply nutrients that are not provided by plasma-activated water to support the growth of water spinach.

Inactivation of Penicillium italicum on kumquat via plasma-activated water and its effects on quality attributes

Plasma-activated water (PAW) has good liquidity and uniformity and may be a promising candidate to inactivate Penicillium italicum and maintain the quality attributes of kumquat. In this study, the effect of plasma-activated water (PAW) on the viability of Penicillium italicum on kumquat and quality attributes of PAW-treated kumquats were then systematically investigated to elucidate the correlation between PAW and kumquat quality attributes. The effects of PAW on fruit decay, microbial loads, and firmness of postharvest kumquats during the 6-week storage were also investigated. The results showed that the viability of Penicillium italicum was notably inhibited by PAW on kumquats. Moreover, PAW did not significantly change the surface color of kumquats. No significant reductions in ascorbic acid, total flavonoid, and carotenoids were observed in kumquats after the PAW treatment. Results from nitrate and nitrite residue analyses showed that PAW did not leave serious nitrate and nitrite residues after treatment. The decay analysis results demonstrated that PAW has the potential to control kumquat decay and fungal contamination as well as maintain the firmness of postharvest kumquats throughout 6-week storage. Transmit electron microscope observation confirmed that PAW could cause the surface sculpturing in the skin cell wall of kumquat. The information obtained from this research may provide insight into the utilization of PAW to fight against fungal infection during the storage of citrus fruit.

Plasma activated water-induced formation of compact chicken myofibrillar protein gel structures with intrinsically antibacterial activity

The poor gel strength and microbial infection of conventional chicken myofibrillar protein (CMP) gels have severely limited the application. Here, plasma activated water (PAW) instead of normal water was used to prepare CMP gels. PAW prepared by treating deionized water with plasma jet was incubated with CMPs and followed by heating to prepare CMP gels. Effects of PAW on CMP gels were assessed in terms of basic physicochemical properties, network structure, and antibacterial activity. The results showed that PAW treatment accelerated the aggregation of CMPs and increased the strength and water holding capacity of CMP gels. Due to the presence of NO and NO2 free radicals in PAW, the prepared CMP gels were endowed with antibacterial activity against Salmonella Enteritidis and Staphylococcus aureus. The new method of PAW-induced CMP gels will have the prospect of improving the quality of gels and extending the shelf life of chicken gel products.

The effect of water activated by nonthermal air plasma on the growth of farm plants: Case of maize and barley

AbstractThe effects of plasma‐activated water (PAW) generated by nonthermal air plasmas of transient spark with water electrospray or atmospheric glow discharge were investigated on maize (Zea mays L. var Saccharata) and barley (Hordeum vulgare L.) seedlings. PAW is characterized by measuring concentrations of reactive oxygen and nitrogen species (H2O2, , ). After 4 weeks of plants growth, the effects of PAW are analyzed by measuring plant growth and physiological parameters: plant length and fresh weight, photosynthetic pigments concentration and photosynthesis rate, total soluble proteins, antioxidant enzyme activity, and DNA damage. The results suggest that PAW, depending on chemical composition, has the potential to improve the plant growth and influence the physiological parameters, while causing no harmful DNA damage.

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.

Effects of plasma-activated water on microbial growth and storage quality of fresh-cut apple

Fresh-cut ‘Fuji’ apples were immersed for 5 min in plasma-activated water (PAW) generated, by plasma generated with sinusoidal voltages at 7.0 kHz with amplitudes of 6 kV, 8 kV, and 10 kV, designated PAW-6, PAW-8, and PAW-10, respectively. The control group was soaked in distilled water for 5 min instead of PAW. The results indicated that the growth of bacteria, molds, and yeasts was inhibited by PAW treatments during storage at 4 ± 1 °C, especially the microbial inactivation with PAW-8, which was the most efficient. PAW-8 reduced the microbial counts by 1.05 log10CFU g−1, 0.64 log10CFU g−1, 1.04 log10CFU g−1 and 0.86 log10CFU g−1 for aerobic bacteria (aerobic plate counts), molds, yeasts and coliforms on day 12, respectively. In addition, the bacterial counts of fresh-cut apples treated with PAW were <5 log10CFU g−1, which did not exceed to the existing China Shanghai local standard (DB 31/2012–2013) during 12 days of storage. PAW treatments reduced superficial browning of fresh-cut apples without affecting their firmness and titratable acidity. In addition, no significant change was observed in antioxidant content and radical scavenging activity between the PAW-treated and control groups. It is suggested that PAW is a promising method for preservation of fresh-cut fruits and vegetables, which is usually beneficial to the quality maintenance of fresh-cut fruits and vegetables during storage.

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.

Effect of Plasma-Activated Water on the Microbial Decontamination and Food Quality of Thin Sheets of Bean Curd

Thin sheets of bean curd may serve as an excellent source of nutrition for microorganisms and are therefore prone to contamination, which can be harmful to public health. This study evaluated the influence of plasma-activated water (PAW) on the microbial load and food quality of thin sheets of bean curd. Treatment for 30 min with PAW that was activated for 90 s reduced the microbial count by 1.26 and 0.91 log10 CFU/g for total aerobic bacteria and total yeasts and molds on thin sheets of bean curd, respectively. The effect of PAW on microbial inactivation strongly depended on the activation time for PAW generation and the soaking time of the thin sheets of bean curd in PAW. Further, PAW could maintain total isoflavone content, sensory properties, and most of the textural properties of the thin sheets of bean curd. Although PAW treatments caused significant changes in color parameters of the thin sheets of bean curd, the appearance acceptance was not significantly influenced. This work highlights the potential application of PAW in the microbial decontamination of thin sheets of bean curd.

Effect of Plasma-Activated Water on Soaking, Germination, and Vigor of Erythrina velutina Seeds

Effect of Plasma-Activated Water on Soaking, Germination, and Vigor of Erythrina velutina Seeds

Effect of plasma-activated water on microbial quality and physicochemical characteristics of mung bean sprouts

Abstract The efficacy of nonthermal plasma-activated water (PAW) in the decontamination of mung bean sprouts was evaluated in this work. After being treated with PAW for 30 min, the populations of total aerobic bacteria and total yeasts and moulds on mung bean sprouts were decreased by 2.32- and 2.84- log10 CFU/g, respectively. The PAW treatment had no significant effect on the antioxidant potential of mung bean sprouts as shown by using 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH•) scavenging activity assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) method, and ferric reducing antioxidant power (FRAP) assay (p > 0.05). Additionally, the PAW treatment caused no significant changes in the total phenolic and flavonoid contents, nor the sensory characteristics of mung bean sprouts (p > 0.05). Reactive species such as nitrates, nitrites, and H2O2 were generated in PAW, which presumably contributed to the disinfection efficacy of PAW. These data show that PAW can be used as a promising nonthermal technology for the control of microbial contamination in sprouts. Industrial relevance Edible sprouts are common food ingredients across the world. However, sprouts can be contaminated by pathogenic microorganisms, which may result in health risks to humans. Recently, PAW has been shown to be a safe and effective method for food surface sanitation. However, the application of PAW in the microbial control for sprouts is less investigated. In this study, the influences of PAW on the microbial load, chemical and sensory quality of mung bean sprouts were investigated for the first time. The results showed that PAW could effectively inactivate bacteria and yeasts and moulds on mung bean sprouts without resulting in significant changes in the antioxidant capacities, total phenolic and flavonoid contents, and sensory characteristics of mung bean sprouts. These data indicated that PAW can be used as a promising nonthermal technology for reducing microbial populations on sprouts.