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In this paper we investigate the influence of cold plasma as novel method on the external otitis treatment which is a frequent cause of earache. 24 infected external auditory canals in 24 rats were categorized in four experimental groups including control, plasma exposed, ciprofloxacin drug and mixed of plasma-ciprofloxacin groups. In plasma group, dielectric barrier discharge was employed as the source of cold plasma in 5 days. All rats were observed with otoscope daily and a scoring system was used to evaluate swelling and effusion of the ear canal. Number of colonies in microbiological culture were counted in each group during the first 5 days after treatment. For the multiple group comparisons of swelling and effusion measured in the external auditory canal, Kruskal–Wallis analysis was applied and one-way anova and Kruskal–Wallis analysis was used for the statistical analysis of the results of the cultures in different days. Also, Tukey and Mann–Whitney tests was applied for multiple comparisons. Our findings show that swelling and effusion were obviously reduced in plasma group compared to control group (P < 0.01). Number of colonies in control group was statistically different from those in drug, plasma, and mixed group on the second to fifth day (p < 0.001). According to the results cold plasma can be introduced as an impressive method for external otitis treatment. Moreover, when cold plasma joined to antibiotic method, it leads to a superior performance respecting plasma or antibiotic method alone. [ABSTRACT FROM AUTHOR]

In the last decades, to improve the CAP treatment efficiency, its biological effects in combination with other physical modalities have widely investigated. However, the physical insight into most of supposed synergistic effects remained elusive. In this regard, the synergetic effect of cold plasma and magnetic field has been used for different applications, especially due to considerable synergistic in biological media reactivity. In the present paper, using a 420 mT N42 magnet, the effect of the perpendicular external static magnetic field (SMF) on the cold atmospheric pressure plasma (CAP) characteristics, such as electron temperature and density, is investigated based on the optical emission spectroscopy, utilizing the Boltzmann plot method, Saha-Boltzmann equation, and Specair software simulation. Results showed that the rotational and electronic excitational temperatures experienced 100 K and 550 K increases in the presence of SMF, respectively. In contrast, the vibrational and translational temperatures remained constant. Moreover, electron temperature was estimated as 1.04 eV in the absence of SMF and increased up to 1.24 eV in the presence of SMF. In addition, the Saha-Boltzmann equation illustrated that the electron density increased in the presence of the additional SMF. The results of the present study indicated that the magnetic field could be an assistant to the cold plasma effect, beneficial in medical applications due to modifications in plasma temperature and electron density. [ABSTRACT FROM AUTHOR]

Starch is an important part of the human diet; however, this macromolecule has undesired physicochemical properties associated with its limited water solubility, low viscosity, and poor thermal stability, limiting its food applications. Cold plasma (CP) is an emerging and nonthermal technology used in recent years to modify the physicochemical properties of starch powders. This paper comprehensively reviewed the application of CP in starches, including information about reactors and gases used to modify starches with CP, the application in starch granules, and the combination with other treatments such as hydration, dry heat, chemical and enzymatic treatments, extrusion, ultra-high-pressure, and microwave. Modified starch granules by atmospheric CP showed depolymerization of starch molecules, impacting the amylose content, crystalline structure, water solubility, and thermal properties. Certain gases used in CP, such as hexamethyldisiloxane and helium, can induce cross-linking in starch granules, increasing thermal and mechanical properties. CP associated with physicochemical treatments is more efficient in inducing starch depolymerization, improving the modification of the physicochemical properties of this macromolecule. CP is a useful tool for modifying the properties of starch granules; however, further research and development are necessary to elucidate its industrial application. [ABSTRACT FROM AUTHOR]

Low-moisture foods such as spices, grains, and seeds constitute an important part of the human diet. Increased consumer concern for food safety and food quality has focused on the decontamination technologies required for low-moisture foods. Cold plasma treatment has been a promising novel technology in the food processing industry due to its advantages in safety, efficiency, versatility, and environmentally friendly nature. It has shown various capabilities on safety and quality control in low-moisture foods. This paper comprehensively reviewed the application of cold plasma in low-moisture foods, including inactivation of microorganisms, degradation of mycotoxins, influences on the quality of low-moisture foods, and promotion of seed germination. Cold plasma can inactivate the pathogenic microorganisms on the surface of low-moisture foods, by generating active species, ultraviolet radiation, and electric fields, which helps to extend the shelf life of foods while having minimal impact on food quality. Cold plasma technology is also an effective approach to detoxify mycotoxin-contaminated low-moisture foods by degrading various mycotoxins. With the manipulation of parameters for cold plasma generation, target functional properties of food products may be obtained. In addition, the application of cold plasma in seed germination is promising and could be of great significance to the global food crisis. This review also suggests that more systematic studies are needed to employ cold plasma in the low-moisture foods industry for selected applications. [ABSTRACT FROM AUTHOR]

In this paper, we propose a 1D ternary photonic crystal with Silicon/MCP/Air structure, whose transmission properties have been analyzed. By employing the TMM, the transmittance spectra are plotted for the introduced TPC in four cases by varying the parameters: angle of incidence, lattice constant, static magnetic field, and electron density. The focus of this analysis is to illustrate the PBGs or zero-transmission regions (GHz) exhibited by the TPC in these four cases. In the first case, there exist three PBGs at normal incidence in which the first two bands are enhanced with increase in the incident angle, while the third band shows reverse nature. At the incident angle 89°, three sets of multiple sharp peaks of transmission, showing multichannel filter characteristics, occur in place of allowed regions, and such abnormal feature of the TPC is attributed to the existence of MCP. Next it is demonstrated that such TPC can be exploited as multiband reflectors for a larger lattice parameter with increased thickness of the Si layer. In the third and fourth cases, the first bandgap is found to be least sensitive to the variations in the parameters, while the tunability in second and third bands in both cases is opposite to each other. By comparing the features of this TPC with a binary PC of Silicon/MCP structure, the tunablity in the second bandgap is far better in case of TPC. Based on the investigated results, the TPC under different conditions may be a good candidate for various applications, including highly tunable broadband and multiband reflectors; and multichannel filters for dense wavelength division multiplexing and high-speed signal processing. [ABSTRACT FROM AUTHOR]

Healthy foods with fresh-like appearances are nowadays demanded by consumers. To satisfy these requirements, the research has been focused on unconventional non-thermal technologies; particularly, in this paper, oxidative technologies (ozone, cold plasma, and ionization) are reviewed. The principles underlying their mechanisms of working, generation methods, and antimicrobial activity are revised. Thanks to their ability to explain a very strong oxidative activity, the effect on microbial reduction has been resulted promising, representing a good starting point for the application in the food industry as alternative technologies for sanitization. Thus, an overview of the application of these technologies in the different food categories is done. Particularly, it has resulted that for the application of ionization technology on food, the research is still in the early stages. [ABSTRACT FROM AUTHOR]

The most promising areas of research in the field of plasma aerodynamics are proposed. On the basis of the presented experimental data obtained recently, the possibilities of using the volumetric force effect on the gas flow in aerodynamic applications, which is realized with the help of near-surface electric discharges, are considered. One of these applications is to increase the length of the laminar section of the boundary layer on the swept wing in order to reduce the aerodynamic drag of the aircraft in the cruise flight mode. The second direction is associated with the control of the three-dimensional separation of the boundary layer on the elements of the mechanization of the swept wing in the take-off and landing modes. The third direction is the reduction of surface friction in the turbulent boundary layer, which is realized on most of the surface of modern near- and supersonic aircraft. The proposed studies are not only of applied, but also of fundamental importance due to the physical complexity of the studied phenomena. [ABSTRACT FROM AUTHOR]

Efficient generation of ozone by cold atmospheric plasmas is interesting for sterilisation and decontamination of thermally-sensitive surfaces. This paper presents a study of robust coplanar dielectric barrier discharge (DBD) for generating atmospheric pressure plasma in synthetic air and in oxygen. The atmospheric plasma generated by coplanar DBD in synthetic air showed considerably high ozone production of 2.41 g/h (2.25 slm, 45 W), while the production yield and energy cost were 54 g/kWh and 40.9 eV/molecule. The use of oxygen instead of synthetic air, at much lower discharge power (2.25 slm, 17 W), maintained the ozone production of 2.35 g/h, whereas the production yield significantly increased to 138 g/kWh with a corresponding energy cost of 12.9 eV/molecule. The temperature of coplanar DBD ceramics in synthetic air (45 W) and oxygen (17 W) plasma generation (continuous alternating-current operation) showed temperatures below 70 °C and 30 °C, respectively. The rotational temperatures obtained from optical emission spectroscopy indicated similar gas temperatures in the thin plasma layer close to the surface of the DBD ceramics. The low temperature of the plasma–ceramics interface evidences the applicability of coplanar DBD for the contact treatment of thermally sensitive surfaces where a high concentration of ozone is required. [ABSTRACT FROM AUTHOR]

R.F. Stebbings and F.B. Dunning were the editors of Rydberg States of Atoms and Molecules. Issued in 1983, this book actually reflected the emergence of a new field in atomic and molecular physics, which subsequently resulted in a number of applications in academic sciences and technology. In this paper, we analyze the results obtained in recent years for ionization processes in collisions of heavy particles with the participation of Rydberg atoms in a wide energy range. These results have been actively used in modern applications of atomic physics. In addition, we consider the influence of nonlinear resonant interaction of Rydberg complexes with electromagnetic waves on the rate of propagation of satellite signals in the atmosphere [ABSTRACT FROM AUTHOR]

The optimal conditions for polyphenol extraction from potato peel using conventional solvent extraction (CSE) and ultrasound-assisted extraction (UAE) methods were predicted to estimate the highest amounts of polyphenols by exploiting a response surface methodology (RSM). The effects of several independent variables, including extraction time, type, and concentration of solvents, on responses (yield, phenolic, flavonoid, and antioxidant activity) were investigated. In the next stage, the potato peel extract (PPE) was incorporated into the low-density polyethylene (LDPE) using plasma treatment to produce an active polymeric film containing natural antioxidants. Polynomial models were significantly fitted to the experimental data based on the Design-Expert software. The highest amounts of responses including yield (9.54%), total phenolic content (TPC) (969.22 mg GAE/100 g dried weight (DW)), total flavonoid content (TFC) (266.53 mg QE/100 g DW), and DPPH (92.36%) in the UAE method, and yield (8.88%), TPC (701.73 mg GAE/100 g DW), TFC (167.4 mg QE/100 g DW), and DPPH (72.28%) in the CSE method were achieved under optimal conditions. Overall, a good agreement between predicted and experimental values was observed under optimal conditions. Besides, the ATR-FTIR results showed the proper attachment of polyphenol compounds on the LDPE using plasma treatment. [ABSTRACT FROM AUTHOR]

The low temperature plasma (LTP) technique is used widely to modify polymer and textile materials. This paper describes the development of a plasma system for textile treatment. Polypropylene (PP) has a very low value of the surface free energy (approximately 20–25 mJ/m2). Due to low surface energy, Polypropylene has very weak hydrophilic properties. By controlling the plasma variables, such as the nature of gas, the discharge power, the pressure and the exposure time, a great variety of surface effects can be generated. In this paper, we report the effect of cold plasma of O2 and N2 gases at various time of exposure on the dyeing and physical properties of PP fabrics. The results show a significant increase in the color depth upon dyeing after treating PP fabrics with low temperature plasma of O2 and N2. For comparing the amount of fabrics dye exhaustion, we have used reflective spectrophotometer. The morphology of the modified surfaces has also been investigated using scanning electron microscopy (SEM). And also FTIR was used to examine the functional groups of the corresponding samples. [ABSTRACT FROM AUTHOR]

Cold plasma is an emerging novel non-thermal technology in the sector of food processing. In the present review we will discuss the recent scientific reports on properties of cold plasma treated starches. For industrial use native starch is subject to modification to enhance the properties. This paper reviews on the mechanism of starch modification by plasma reactive species, briefly discussing its effects on properties. The effect of cold plasma on starches depends on the type of feed gas, voltage applied and treatment time. The alteration in the properties is mainly due to depolymerization and cross linking of amylose and amylopectin side chains. After plasma treatment there is decrease in molecular weight, viscosity, and gelatinization temperatures. Plasma etching increased the surface energy and enhanced the hydrophilicity of the starch granules. We can conclude that cold plasma is as alternative technology to modify the properties of starch. [ABSTRACT FROM AUTHOR]

The present study investigates the mechanism of cold plasma modification (CP) of guar seed galactomannan on the structural, chemical, dietary fiber profile and the possibility to stabilize the orange juice. The cold plasma treatments were done at 170 and 230 V for 30 and 60 min and investigated for the modifications. The polar oxidative functionalities COOH- (283.36% rise) and OH- (16% rise) increased sequentially as a result of plasma-induced depolymerization with an increase in plasma voltage and time which was also supported by FTIR findings. The inclusion of COOH- reduced the pH from 7.09 ± 0.01 to a minimum of 4.96 ± 0.01. The cleavage of galactose side chains increased the free galactose content and reduced the M/G ratio from 2.38 ± 0.73 to 1.67 ± 0.19. The plasma etching phenomena reduced the average particle size to a minimum of 14.36 nm and is also seen in SEM. An increase in surface negative charges was shown with a decrease in zeta potential. The phenomenon of depolymerization, glycosidic cleavages at the side chains, and surface etching of cold plasma was exhibited with substantial evidence. Total dietary fiber was unaffected with an elevated soluble fiber content. Plasma treated guar gum has improved the stability of orange juice (rise in serum cloudiness with reduction in sedimentation and viscosity) without significant modifications in the quality (total soluble solids, pH, color). The obtained results demonstrate the CP interaction with guar gum and prove the potential of this green technology for the production of partially depolymerized guar gum. [ABSTRACT FROM AUTHOR]

Formaldehyde, a volatile organic compound (VOC), is one of the main gaseous pollutants from commercial cooking. The present study evaluated the effectiveness of a laboratory-scale ozone-assisted indirect plasma method for formaldehyde removal using response surface methodology (RSM). A dielectric barrier discharge (DBD) reactor was used for ozone generation. Inlet HCHO concentration, ozone concentration, and residence time were considered the design parameters, and formaldehyde removal efficiency (response 1) and energy yield (response 2) were considered response parameters. The optimized models showed a positive correlation between the predicted and experimental outcomes. Inlet ozone concentration, the most significant parameter in the removal efficiency model, represented a positive correlation with this response in most parts of the operating region. The optimal point with the highest desirability (i.e., D1 point) was obtained at the inlet HCHO concentration of 120 ppm, inlet ozone concentration of 40 ppm, and reaction time of 11.35 s within the parameter ranges studied, resulting in 64% removal efficiency and 2.64 g/kWh energy yield. At the point with the second highest desirability (D2), 100% removal efficiency along with 0.7 g/kWh energy yield was achieved indicating the very good performance of the process. The indirect plasma approach used in this study presented a successful performance in terms of removal efficiency along with acceptable energy yield compared to other plasma-assisted processes reported in the literature. The results suggested that ozone-assisted indirect plasma treatment can be utilized as an efficient alternative method for formaldehyde removal in commercial kitchens, while efficiency or energy yield should be prioritized for optimizing operating conditions. [ABSTRACT FROM AUTHOR]

Cold plasma (CP) has been used to accelerate seed germination. During this study, foxtail millet was exposed to low pressure air plasma at 1 kV and 2 kV for 1, 3, and 5 min, and its germination characteristics and nutrient composition were studied. Among the applied treatment conditions, 2 kV for 3 min showed a higher germination percentage of 84.00%, followed by 1 kV for 5 min with 77.33% after 48 h. In addition, a significant increase in other germination characteristics, such as germination speed, germination potential, seed length, and seed vigour indices I and II, was observed after CP exposure. Optical emission spectroscopy analysis asserted that reactive species generated during CP generation are responsible for hastening the foxtail millet germination through seed surface modification. Further, the CP exposure increased the soluble protein content of foxtail millet up to 19.00 g/100 g, γ-amino butyric acid content up to 62.27 mg/100 g, and reduced phytic acid and tannins to 1.1 mg/g and 0.8 mg/100 g, respectively, through germination. This research explores the potency of cold plasma in accelerating foxtail millet germination and enhancing its nutritional bioavailability. [ABSTRACT FROM AUTHOR]

This paper is devoted to investigate the cold plasma wave properties. The analysis has been restricted to the neighborhood of the pair production region of the Kerr magnetosphere. The Fourier analyzed general relativistic magnetohydrodynamical equations are dealt under special circumstances and dispersion relations are obtained. We find the x-component of the complex wave vector numerically. The corresponding components of the propagation vector, attenuation vector, phase and group velocities are shown in graphs. The direction and dispersion of waves are investigated. [ABSTRACT FROM AUTHOR]

Rice seeds (Oryza sativa L.) have been treated with cold atmospheric plasma in air both directly in a dielectric barrier discharge and indirectly by gliding arc discharge with plasma activated mist. Comparisons of impacts of the two methods on rice seeds germination and physiological parameters are presented. Plasma has been found to increase seeds hydrophilization and water uptake through decrease of liquid contact angle and increase of total surface free energy of seed's coat. Germination of treated seeds and their seedling growth parameters are enhanced by plasma application. After 20 min of seeds direct and indirect exposures respectively, germination potential increases by 36.73 and 50.4%, germination rate by 26.0 and 30.0%, and germination index by 25.92 and 36.53%. Also, total shoot length increases by 42.2 and 48.5%, and total root length by 15.93 and 22.42%. Plasma enhances physiological changes by increasing nonenzymatic antioxidants substances which in turn increase the tolerance against abiotic stresses. After 20 min for direct and indirect exposures respectively, free proline increases by 30.0 and 40.0%, total soluble carbohydrates by 49.7 and 54.6%. Also, cellular reactive oxygen species (ROS) increase by 52.0 and 60.0%, and malondialdehyde (MDA) decreases by 68.0 and 88.0%. Indirect exposure of rice seeds by plasma activated mist shows enhanced effects on germination and physiological parameters compared to direct one and could be more practical when applied to large scale seeds plasma treatment. [ABSTRACT FROM AUTHOR]

With 40% of the South African population experiencing moderate to severe food insecurity and climate change predicted to impact agriculture negatively, there is a future role for inland fisheries to help feed 60 million people. To support the expansion of inland fisheries, reducing the current postharvest losses of ~25% of fish requires improving the current preservation and storage techniques. This review aims to assess the potential benefits for Sub-Saharan Africa's freshwater aquaculture and fisheries to utilise an emerging technology to reduce postharvest losses, using South Africa as a case study. We demonstrate the potential for plasma activated water (PAW) for preserving fresh fish. PAW offers non-thermal and non-toxic bacterial inactivation. Considered safe for human use, PAW is currently used in medical applications and has been investigated as a postharvest sanitiser for many fruits and vegetables, effectively increasing the shelf life of fresh food. The limited studies of PAW treatment of fresh fish show increased shelf life with some generally insignificant changes to quality. This novel treatment's success depends on the optimisation of application methods, including PAW-derived ice (PAWDI). To strengthen the value chain of the fresh fish industry, PAW/PAWDI could extend the shelf life of fish from origin to market. Investment in food supply chain development would preserve more harvested fish and improve the quality. Utilising solar power to produce PAW or PAWDI in situ potentially offers benefits for the small communities of inland fisheries to commercial production. This technology as well as changes to traditional preservation and transport chains could be utilised in other Sub-Saharan African nations. [ABSTRACT FROM AUTHOR]

Lignin is the second most abundant and underutilized heterogeneous biopolymer. Current methods, to depolymerize lignin into valuable fuels and chemicals, are facing challenges. The major barriers to the commercialization of these methods are expensive catalysts, energy cost, and difficulty in the separation of a complex mixture of products. Targeted synthesis of chemicals is aimed to get selective compounds that may offer ease of separation. Vanillin is the only chemical that is manufactured commercially from lignin. A facile, highly efficient, room temperature, and metal-free route to the targeted synthesis of vanillin using ozone produced by non-thermal plasma is presented in the current study. The recovered lignin has been characterized by FTIR, SEM/EDX, and HSQC for determining structural changes. The recovered lignin with a loose structure can be further converted into more valuable products. Operational conditions have been investigated to optimize vanillin production. Under optimum conditions, ~ 60% of vanillin (based on GC–MS analysis) was obtained with only 10 min of treatment. The product selectivity has been controlled by reaction time and reactant lignin concentration. The recovered lignin having a partially oxidized structure can be further subject to depolymerization to get more value from this biopolymer. [ABSTRACT FROM AUTHOR]

The present work is devoted to the study of DBD discharge development in Ne–Xe gas mixture for optimization of UV source efficiency in excimer lamps. This study was based on a longitudinal on-dimensional model of the dielectric barrier discharge DBD with the aim to investigate the discharge conditions for excimer lamps working and VUV emissions optimization. The results of the present description show the concentration of charged particles, photonic species, and excited atoms and molecules. The effect of operation conditions such as applied voltage, gas mixture composition, and gas pressure, as well as the secondary electron emission due to ion impact at the cathode on DBD discharge characteristics and 173 nm photon generation have been also analyzed and discussed. [ABSTRACT FROM AUTHOR]

Global agriculture and food security are greatly impacted by climate change, water resource depletion, and a rising population. Cereals such as rice, wheat, maize, barley, oats, and rye account for the vast majority of food consumed worldwide. The requirement to shift from the current grain staples is necessitated by the significant water needs of above crops. Millets have the potential to strengthen food security due to their high nutritive quality, drought resistance, adaptability to local growing conditions, resistance to pests and diseases, and resilience to environmental shocks. Despite the benefits, the utilization of millets is constrained due to the poor shelf life of the flour caused by the activity of enzymes such as lipase, lipoxygenase, peroxidases, and polyphenol oxidase. Numerous food processing techniques have been explored in an effort to stabilize millet products while maintaining their nutritive characteristics. Microwave, radiofrequency, infrared, ohmic heating, as well as non-thermal methods like pulsed electric field, cold plasma, irradiation, high-pressure processing, ozonation, and ultrasound treatment, have drawn the most attention among these technologies due to their short processing time, minimal nutrient loss, and lower energy consumption. The work reviews recent developments in thermal and non-thermal millet processing technologies. It also discusses challenges, bottlenecks, and perspectives for further research. [ABSTRACT FROM AUTHOR]

Fruits and vegetables are essential for overall human health and nutrition, and there is a high quest for fruits and vegetables of superior quality. Nonetheless, the preservation of fruit is still challenging due to the high moisture content. Pretreatments have assisted fruit and vegetable drying in improving shelf-life and maintaining quality. However, conventional pretreatments affect the physicochemical properties and product qualities. Therefore, thermal and nonthermal pretreatments followed by drying have been researched to improve and enhance fruits and vegetables' physicochemical properties. This article evaluates sequential thermal (ohmic, electrohydrodynamic, infrared, etc.) or nonthermal (high-pressure processing, ultrasonic, pulsed-electric field, etc.) pretreatment technologies and drying in the last 5 years, underscoring their efficiency in augmenting the product qualities of fruits and vegetables. In addition, details of nonthermal and thermal pretreatment technologies are explained, and their success stories, drawbacks, and future studies on improving these technologies are provided. Besides, the safety evaluations of various pretreatments are also delved in. Finally, it is recommended that the next 5 years of research should also explore pulsed light, manothermosonication, ultraviolet light, oscillating magnetic field, thermosonication, and ionization radiation pretreatment to augment dried fruits and vegetables' product qualities and physicochemical properties. This will help better comprehend the impact of emerging technologies on fruits and vegetables' physicochemical properties. [ABSTRACT FROM AUTHOR]

In the paper we study propagation of light in general relativity through a spacetime filled with cold plasma with infinite conductivity. We use the geometric optics based on Synge's approach. As the main result we provide a formula for calculation of spectral flux of radiation emitted from a pointlike source. The formula employs connecting vectors that are obtained by integrating the ray deviation equation along the reference ray connecting the source and observation event. As a byproduct we formulate Etherington's reciprocity theorem with the inclusion of plasma, interrelating angular size distance and luminosity distance. We also discuss the Liouville theorem and its formulation in terms of connecting vectors. [ABSTRACT FROM AUTHOR]

Changing consumers' taste for chemical and thermally processed food and preference for perceived healthier minimally processed alternatives is a challenge to food industry. At present, several technologies have found usefulness as choice methods for ensuring that processed food remains unaltered while guaranteeing maximum safety and protection of consumers. However, the effectiveness of most green technology is limited due to the formation of resistant spores by certain foodborne microorganisms and the production of toxins. Cold plasma, a recent technology, has shown commendable superiority at both spore inactivation and enzymes and toxin deactivation. However, the exact mechanism behind the efficiency of cold plasma has remained unclear. In order to further optimize and apply cold plasma treatment in food processing, it is crucial to understand these mechanisms and possible factors that might limit or enhance their effectiveness and outcomes. As a novel non-thermal technology, cold plasma has emerged as a means to ensure the microbiological safety of food. Furthermore, this review presents the different design configurations for cold plasma applications, analysis the mechanisms of microbial spore and biofilm inactivation, and examines the impact of cold plasma on food compositional, organoleptic, and nutritional quality. [ABSTRACT FROM AUTHOR]

Cold plasma (CP) is a novel non-thermal technology and has marked a new trend in both the sectors of agriculture and food processing for their safety and quality. This review describes an overview on the effects of CP with respect to microbial decontamination, enzyme denaturation, pesticide degradation, food allergens, polyphenols, food packaging, and many other physiological processes. Furthermore, mechanisms and applications involving different aspects related to cold plasma are discussed. The recent studies on cold plasma referred mainly with the interactions of reactive species and target food commodity. Finally, the future prospects and challenges that could help in rendering substantial benefits of CP to the food industries and researchers, particularly in upscaling this eco-friendly technology, are discussed. [ABSTRACT FROM AUTHOR]

Sausage may be contaminated with spoilage microorganisms during the processing after cooking and during the chilling process. Non-thermal decontamination such as cold plasma (CP) can be used to prevent the growth of spoilage microorganisms in sausage after packaging. The objective of this study was to investigate the effects of CP on sliced chicken sausage during 60 days of storage. The sausages were divided into three groups: negative control, ultraviolet (UV)-radiated (positive control for 200 and 400 s), plasma (power of 30 and 70 w for 200 and 400 s). The microbial load, pH, color, peroxide value (PV), and textural parameters of the sausages were compared with those of the negative and positive controls. According to the results, total count decreased significantly (p < 0.05) about 1.87 log CFU/g after 400 s of the CP treatment and at the end of storage at 70 w. CP reduced the lightness (L*) and increased redness (a*) more than the UV rays. The PV more increased by UV rather than by plasma. There were no significant changes in pH value and textural parameters after the CP and UV treatments. Although CP more affected some of the physicochemical properties, compared with UV, CP was shown to efficiently inhibit the rapid growth of microorganisms, resulting in a longer shelf-life. [ABSTRACT FROM AUTHOR]

Salmonella enteritidis (S. enteritidis) and Listeria monocytogenes (L. monocytogenes) are two main foodborne pathogens. Cold plasma (CP), a non-thermal technology used for food decontamination, has attracted considerable attention in recent years. Hence, we studied the effects of CP treatment on S. enteritidis and L. monocytogenes growth and bacterial respiratory enzyme activities to elucidate the CP disinfection mechanism. Bacterial colonies were counted, respiratory enzyme activity and reactive species (RS) contents were measured, and relationships between these factors were assessed immediately after CP treatment. Both the colony numbers and enzymatic activities of the two bacterial species decreased as the treatment voltage increased from 60 to 80 kV, regardless of the treatment time. Moreover, similar increasing trends in RS were found in treated bacterial samples. The enzymatic activity of S. enteritidis was reduced to a greater extent than that of L. monocytogenes under the same treatment conditions. After CP treatment at 80 kV for 180 s the activity levels of both malate dehydrogenase (MDH) and succinate dehydrogenase (SDH) in S. enteritidis decreased below the detection limit. The RS levels showed a significant negative correlation with respiratory enzyme activities in these bacteria. Cold plasma displayed a high inhibitory effect on respiratory enzymes in both S. enteritidis and L. monocytogenes. SDH and hexokinase showed the highest correlation with the growth of treated S. enteritidis and L. monocytogenes, respectively. These results indicate that CP affects the growth of S. enteritidis and L. monocytogenes through different pathways, with CP disruption of normal aerobic respiration to induce cell death being the main antimicrobial mechanism. [ABSTRACT FROM AUTHOR]

Traditional disinfection methods against pathogens have numerous shortcomings, and inventive methods like cold plasma are required for virus inactivation. Here, an atmospheric pressure 13.56 MHz radio-frequency hollow cathode (RF–HC) cold plasma device has been used to build a cold plasma sterilization device, and its virucidal activity is assessed against P2 bacteriophage, a model surrogate for pathogenic viruses. The heart of this device contains a three-layered sterilization chamber which is a rectangular parallelopiped of 42 × 32 × 30 cm3. Optimization experiments were performed to make each corner of this chamber completely virus free after cold plasma treatment. This two-pronged study was conducted to establish the requirement of minimum vol. % H2O2 in minimum time for the complete elimination of phages inside this sterilization chamber even when plasma is not in the direct line of sight. In initial experiments, the effect of the direct plasma line of sight was seen as the top and bottom layers showing less phage killing as compared to the middle of the sterilization chamber. Complete sterilization of bacteriophage, in all the three layers inside the sterilization chamber, was achieved by plasma treatment with 6% H2O2 for 10 min in 80 watts of plasma operating power. It was also seen that 6% H2O2 mist alone is not sufficient to provide a high degree of sterilization, and normal water mist combined with cold plasma can provide a higher level of sterilization at each corner of the chamber. [ABSTRACT FROM AUTHOR]

The application of pesticides enhances food production vastly, and it cannot be prevented; longer fresh produce is contaminated with health-threatening pesticides even though traditional processing methods can remove these pesticides from food surfaces to a certain extent; novel emerging technologies such as cold plasma, ultrasound, electrolyzed water, and pulsed electric field could more effectively dissipate the pesticide content in food without the release of toxic residual on the food surface. The present review focuses on applying emerging technologies to degrade pesticide residues in great utility in the food processing industries. This review also discusses the pesticide removal efficacy and its mechanism involved in these technologies. The oxidation principle in cold plasma is recently gaining more importance for the degradation of pesticide residue in the food processing industries. Analysis of the emerging physical processing methods indicated greater efficacy in eradicating pesticide residues during agriculture processing. Even though the technologies such as EO (99% reduction in dimethoate), ultrasound (98.96% for chlorpyrifos), and irradiation (99.8% for pesticide in aqueous solution) can achieve promising results in pesticide degradation level, the rate and inactivation highly depend on the type of equipment and processing parameters involved in different techniques, surface characteristics of produce, treatment conditions, and nature of the pesticide. Therefore, to effectively remove these health-threatening pesticides from food surfaces, it is necessary to know the process parameters and efficacy of the applied technology on various pesticides. [ABSTRACT FROM AUTHOR]

This study aimed to forecast the optimum condition for polyphenols extraction from onion peel using conventional maceration extraction (CME) and ultrasound-assisted extraction (UAE) methods and incorporated these compounds in plasma-treated low-density polyethylene (LDPE) film. Response surface methodology (RSM) was employed to determine the effect of three independent variables, including the type of solvent (water, ethanol, methanol, and acetic acid), solvent concentration (0–100%), and extraction time (10–1440 min) on responses. The responses included extraction yield, phenolic content, flavonoids, and antioxidant activity. Finally, the model was optimized to predict the optimum condition that would yield maximum responses. In the next stage, the surface of LDPE was activated by normal air cold plasma treatment. The onion peel extract's 10 and 20% solutions were prepared and incorporated into the treated-LDPE films. The optimum conditions included the mixture of 83.57 ml ethanol, 1.01 ml methanol, 15.41 ml water, 30 min extraction time with a desirability value of 0.95 in the UAE method. The combination of 79.58 ml ethanol and 20.42 ml water at 1398 min extraction time with a desirability value of 0.94 for the CME method. The finding of this investigation achieving the highest yield, phenolic, flavonoid content, and antioxidant activity 0.75, 428.14, 390.41, and 550.19 mg/g, respectively, in UAE and 0.60, 388.75, 413.37, and 395.94 mg/g, respectively, in CME. The results indicated the highest yield, phenolic, flavonoid content, and antioxidant activity 0.75, 428.14, 390.41, and 550.19 mg/g, respectively, in UAE and 0.60, 388.75, 413.37, and 395.94 mg/g, respectively, in CME. Results of the present study showed a good agreement between predicted and experimental values at optimum conditions. Suitable attachment of phenyl compounds at the region 580–1740 cm−1 in ATR-FTIR results was observed. [ABSTRACT FROM AUTHOR]

In this article, an experimental study of a corona discharge generated with a tip-plane geometry and negative polarity in air at atmospheric pressure, is presented. The effects of the active electrode material and its curvature radius on the characteristics of the corona discharge are studied. Two different materials, aluminum and copper, are used to produce active electrodes. The current–voltage characteristics show a greater intensity of the current for the aluminum electrodes as compared to the copper ones. On another side, the current is greater with the tip having the smallest curvature radius. The current–voltage characteristics have a shape well approximated by a parabolic equation. Trichel pulses are more regular for aluminum electrodes than for the copper ones. Eventually, the use of aluminum electrodes to have a stronger regular discharge would be better to make a cold plasma reactor. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to evaluate the effect of non-thermal plasma (NTP) surface treatment in two composite inorganic fillers and evaluate their impact on the chemical-mechanical properties and bond strength ability of experimental resin cements. Materials and methods: Ytterbium fluoride (YF) and barium silicate glass (BS) were characterized and submitted to different surface treatments: non-thermal plasma (NTP); non-thermal plasma and 3-(trimethoxysilyl) propyl methacrylate silanization; and 3-(trimethoxysilyl) propyl methacrylate silanization. Untreated fillers were used as a control. The fillers were incorporated at 65wt% concentration into light-cured experimental resin cements (50wt% BisGMA; 25wt% UDMA; 25wt% TEGDMA; 1mol% CQ). The degree of conversion, the flexural strength, and the microshear bond strength (μSBS) were evaluated to characterize developed composites. Results: YF and BS were successfully cleaned with NTP treatment. Nor NTP neither the silanization affected the degree of conversion of resin cements. The NTP predicted an increase in YF-containing resin cements flexural strength, reducing the storage impact in these materials. NTP treatment did not affect the μSBS when applied to YF, while silanization was effective for BS-containing materials. Conclusion: NTP treatment of inorganic particles was possible and was shown to reduce the amount of organic contamination of the particle surface. YF surface treatment with NTP can be an alternative to improve the organic/inorganic interaction in resin composites to obtain materials with better mechanical properties. Clinical relevance: Surface cleaning with NTP may be an alternative for particle surface cleaning to enhance organic-inorganic interaction in dental composites resulting in improved mechanical strength of experimental resin cements. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of cold plasma in the oxygen and nitrogen atmospheres on oilseeds of sunflower and sesame, especially their physicochemical properties of extracted oils. Treated oilseeds were stored under controlled laboratory conditions, at 38% relative humidity and 20 °C. After 0, 7, 15, 21, and 30 days of storage, the oilseeds were subjected to oil extraction by Soxhlet. The results showed that free fatty acids and saturated fatty acid content in extracted oils increased even during 30 days storage at 20 °C by higher treatment times (30 min) in all oilseeds samples. However, after 15 min cold plasma treatment, unsaturated fatty acid content increased about 3.9 and 5% in sunflower and sesame oils, respectively. However, it can be decreased severely by 30 days storage of oilseeds with more prolonged treatment time (P > 0.05). Polyunsaturated fatty acids were more sensitive to plasma reactive species, decomposed with higher rates, and reduced iodine value in both oils. The saponification value of both oils increased after plasma treatment and during the storage time. The total phenolic compound in both oils drastically decreased as the exposure and storage times increased, mainly when oxygen gas was applied (P < 0.05). Accordingly, antioxidant activity and Induction period decreased in both samples. Cold plasma treatment significantly changed all color parameters (P < 0.05). Non-thermal plasma treatment increased red color intensity, browning index, and general discoloration. However, yellow color intensity, whiteness, and the color saturation degree decreased in plasma-treated samples. An increase in the treatment time made the effect more pronounced and reduced the shelf life of oils. The changes in the initial products of oxidation and induction period of the treated oil samples showed that cold plasma, regardless of the oilseed and gas used, can significantly intensify oxidation. [ABSTRACT FROM AUTHOR]

A novel material for hard tissue implants has been prepared. The ultra-high molecular weight polyethylene (UHMWPE) was grafted with collagen I, to improve its biocompatibility with soft tissue in case of its usage in bone engineering. Before collagen immobilization, commercial grade UHMWPE was treated with air plasma to introduce hydroperoxides onto the surface and subsequently grafted with carboxylic acid to functionalize the surface. Acrylic acid and itaconic acid were used for surface functionalization. After graft polymerization of carboxylic acids, collagen was immobilized covalently through the amide bonds between residual amino and carboxyl groups in the presence of water-soluble carbodiimide/hydroxysuccinimide cross-linking system. Each step of modification was characterized using spectroscopic (EPR, ATR-FTIR, and XPS), microscopic (SEM and CLSM), and contact angle measurement methods. The experimental results showed that plasma treatment led to a generation of free radicals on the UHMWPE surface resulting in the formation of unstable hydroperoxides. These reactive species were used to graft unsaturated carboxylic acids onto UHMWPE. Consequently, collagen was grafted via the-NH2 and-COOH reaction. The obtained experimental data along with microscopic observations confirmed the success of graft poly-merization of itaconic as well as of acrylic acid and collagen immobilization onto the UHMWPE surface. [ABSTRACT FROM AUTHOR]

Concerns on environmental issues are motivating the development of biodegradable materials and the use of sustainable processes. Among the most abundant biodegradable materials are lignocellulosic fibers, which could have widespread use as reinforcing fibers in polymer composites. On the other hand, cold plasma treatment is a sustainable process which is lately gaining great interest for the surface treatment of lignocellulosic fibers aimed at improving the mechanical properties of polymers. Despite such great interest, polymers reinforced with plasma-treated lignocellulosic fibers (PRPLF) remain unknown for most industries manufacturing polymer composites. This review summarizes published studies on PRPLF and discusses the effect of plasma treatment of lignocellulosic fibers on the mechanical properties of PRPLF. The interfacial shear strength, tensile and flexural strength, and stiffness of a variety of PRPLF composites are presented and compared in data tables. Additionally, the tensile strength and stiffness of some plasma-treated lignocellulosic fibers are compared in a data table. Finally, the use of micromechanical models is encouraged to estimate the micromechanical properties of PRPLF. [ABSTRACT FROM AUTHOR]

The effects of packaging materials, package shape, and secondary packaging on the inactivation of indigenous mesophilic aerobic bacteria in Korean steamed rice cakes using in-package atmospheric dielectric barrier discharge cold plasma (ADCP) treatment were investigated. Inactivation of indigenous mesophilic aerobic bacteria by ADCP treatment (21 kV, 3 min) was significantly increased by 0.6 and 0.8 log CFU/g (p < 0.05) from 0.7 ± 0.1 and 0.5 ± 0.1 CFU/g, respectively, when polypropylene (PP) and low-density polyethylene (LDPE) were laminated with nylon, respectively. Secondary packaging lowered the inactivation level by 0.7–0.8 log CFU/g from 1.1 to 1.3 log CFU/g. In-package ADCP treatment did not alter the water vapor permeability, oxygen transmission rate, and tensile properties of PP, LDPE, nylon/PP, and nylon/LDPE. Thus, the results demonstrated that lamination of PP or LDPE with nylon and treatment before secondary packaging may be effective strategies for microbial inactivation by in-package ADCP treatment. [ABSTRACT FROM AUTHOR]

This study the first study that compared the effects of zinc oxide medicine, infrared, ultaviolet, and cold plasma treatment on full thickness infected wounds in diabetic rats. Moreover this is the first study that show the Pathological studies on visceral tissues (such as: testicles, livers, spleens, cardiac, and kidneys) after cold plasma treatment. The rats (14–15 weeks old and weight range of 200 ± 10 g) was selected. Aloxan injection induced for diabetes induction. Anesthesia induced and a 10 mm round full thickness wound was made and then the wound infected with 1 ml Staphylococcus aureus. Rats were treated by zinc oxide, uv, infrared, cold plasma for 3,7,14, and 21 days. Samples were taken from visceral and skin and have been sent for histopathological analysis. After 3 days cold plasma treatment epithial cells start to migrate and collagen was seen in the dermis layer. After 7 days treatment the plasma treatment increased the neovascularization and production of collagen in the dermis layer. The infrared and uv treatment improved epithiatial formation, neovasular, fibroblat, and collagen proliferation but less than plasma treatment. After 14 days treatment the cold plasma treated wounds completely healed, while wound healing was observed after 21 days of the infrared and uv treatment. After 21 days zinc oxide treatment wounds were not completely healed. Pathological studies on visceral tissues shows that there were not any abnormal side effects due to helium plasma usage. The results showed a low wound healing after, UV, infrared, and zinc oxide treatment compared with the cold plasma treatment. [ABSTRACT FROM AUTHOR]

Objectives: In this clinical study, we aim to evaluate the effectiveness of non-thermal atmospheric pressure plasma (NAPP), which is a novel procedure used in periodontal pocket decontamination adjunctive to non-surgical periodontal treatment (NSPT). Methods: The study included 25 systemically healthy periodontitis patients. In the split-mouth design, NAPP application into the pockets, in addition to NSPT, was performed. Clinical periodontal data, gingival crevicular fluid, and subgingival plaque samples of patients were taken before and during the first and third months of treatment. Biochemical assays were conducted using enzyme-linked immunosorbent assay. Analysis of bacteria was performed with polymerase chain reaction method. Results: There was more clinical attachment level (CAL) gain in the 3rd month in the test group (deep pockets: 3.90 mm, pockets ≥ 5 mm: 2.72 mm) compared to the control group (deep pockets: 3.40 mm, pockets ≥ 5 mm: 2.58 mm) (p < 0.05), but no significant difference between groups in CAL. Clinical periodontal parameters improved in both study groups (p < 0.05). However, the gingival index (GI) and the bleeding on probing (BOP) rate decreased more in the test group (GI: 0.55, BOP: 9.48%, and GI: 0.38, BOP: 8.46% in the 1st and 3rd months, respectively) compared to the control group (GI: 0.68, BOP: 13.43%, and GI: 0.52, BOP: 14.58%) (p < 0.05). In addition, there was no significant difference in probing depth and biochemical markers between groups (p > 0.05). It was observed that NAPP reduced the number of bacteria more than the control group in the 1st and 3rd months. Conclusions: It was seen that the single-time NAPP application concurrent with NSPT provided additional CAL gain, elimination of putative periodontopathogens and reduced their recolonization. Longitudinal studies with larger population and longer time are required. Clinical relevance: NSPT is an effective method for the treatment of periodontitis but bacteria recolonization that causes recurrence of the periodontal disease occurs within a short period. NAPP can reduce the recurrence of periodontal disease by providing better bacterial elimination and should, therefore, be used in maintenance of periodontitis. [ABSTRACT FROM AUTHOR]

Global food production sustainability and the demand for fresh and nutritious food necessitate the development of novel technologies to provide food with a long shelf life. Hurdle technologies combing several interventions can ensure microbial safety without inducing notable changes to food quality. Cold plasma, as a promising nonthermal technology, has increasingly attracted attention in food industry. Recently, cold plasma–based hurdles have been proposed as novel intervention strategies for microbial decontamination. This review summarizes currently existing cold plasma–based hurdle strategies, including thermal treatment and nonthermal techniques (e.g., organic acids, essential oils, ultrasound) that have been reported in the literature. In addition, we highlight some critical issues, including the microbial stress response, the processing parameters, and the effects on food quality, that need to be taken into account during the optimization and implementation of cold plasma–based hurdles. Cold plasma–based hurdles overcome certain limitations of individual cold plasma treatment to improve the inactivation efficacy and retain the maximum food quality attributes. [ABSTRACT FROM AUTHOR]

The process conditions of dielectric barrier discharge cold plasma using nonlinear regression analysis for enhanced shelf life of tender coconut water (TCW) were optimized. Face centre composite design was used to optimise process condition of cold plasma treatment and desirability of treated TCW was determined on the basis of microbial load, DPPH scavenging activity, free fatty acid content and transmittance. Microbial load, DPPH scavenging activity and transmittance decreased with plasma treatment time and voltage whereas fatty acid content increased. However, TCW developed 'chemical' odour at the optimized cold plasma treatment condition of 18.00 kV voltage and 1.75 min treatment time. Pasteurized orange juice (1–4%) was added to the cold plasma treated coconut water to counter the off flavour and the developed blended beverage was subjected to sensory optimization using fuzzy logic. From the application of fuzzy logic, it was determined that cold plasma treated TCW with 1% orange juice has acceptable sensory properties. The study revealed that cold plasma was helpful in reducing microbial load of TCW and its blending with 1% orange juice gave beverage that was acceptable for sensory attributes besides being able to mask the 'chemical' odour. Cold plasma can therefore be used in place of thermal treatment for processing of TCW. [ABSTRACT FROM AUTHOR]

In the last decades, there have been numerous reports about the separate interactions of a magnetic field and cold atmospheric plasma (CAP) with the biological systems. We have investigated the combined effect of CAP with the static magnetic field (SMF) as an effective method for cancer cells treatment. MDA-MB-231 breast cancer cells were cultured and treated with CAP with different input power and exposure times in the presence and absence of the SMF. Vitamin C was also used in medium, and cell viability was investigated in the presence and absence of this antioxidant compound. The MTT assay was employed to measure cell survival, and a T-test or one-way ANOVA was used to assess the significance level of quantitative data. In order to determine the migration rate of cancer cells, wound healing assay was carried out. Results show that the presence of the SMF and vitamin C as well as increasing the input power significantly decrease the survival and migration rate of the cells. The results of the present investigation will greatly contribute to improve the CAP efficiency in cancer therapy by using the SMF and vitamin C as a complement to conventional CAP therapies. [ABSTRACT FROM AUTHOR]

Concerns related to foodborne pathogens necessitate the decontamination of avian eggs. Conventional decontamination methods, such as egg washing, usually use health-threatening chemicals (e.g. chlorine). Hence, innovative chemical-free decontamination approaches are interesting for the food industry, especially to decontaminate commonly Salmonella infected products such as duck eggs. The present study is the first attempt to evaluate the effectiveness of cold plasma against Salmonella enterica inoculated on the surface of duck eggshell. In this regard, Salmonella-contaminated duck eggs were treated by arc plasma for 10, 20, 30, and 40 s. The bacteria count, eggshell strength, color, pH, Haugh unit, acid value (AV), thiobarbituric acid reactive substances (TBARS), and fatty acid profile of the plasma-treated samples were then compared with those of untreated sample. According to the results, all the plasma treatments significantly decreased the Salmonella population and longer treatment times enhanced the bactericidal effects of plasma. A maximum bacterial reduction of 4.1 log cycle was observed when plasma was applied for 40 s. Furthermore, plasma treatments did not deteriorate the quality parameters of eggs such as eggshell strength, eggshell color, yolk color, Haugh unit, AV, and TBARS. These findings introduced arc plasma as an emerging tool for improving the safety of duck eggs with good potential for industrial application. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of cold atmospheric pressure plasma (CAPP) jet on Trichophyton rubrum growth, germination and adherence to nail. The effects of plasma jet on T. rubrum conidia germination and on mycelial growth were evaluated by in vitro assays. An ex vivo nail infection model was used to evaluate the effects on conidia adherence and infection. Biochemical analyses of nail fragments exposed or not to CAPP were performed by attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy. Plasma jet exposure for 10 and 15 min completely inhibited mycelial growth after only one exposure. Fifteen minutes of exposure could reduce conidia germination in suspension. Fungal suspensions exposed to plasma jet for 10 and 15 min were not able to infect nail specimens. These results were corroborated by ATR–FTIR analyses of nail fragments. In conclusion, single exposure to CAPP for 15 min was able to inhibit fungal growth, adherence and infection capacity. The results suggest that cold atmospheric plasma jet can be a promising alternative for the treatment of onychomycoses caused by T. rubrum. [ABSTRACT FROM AUTHOR]

Blueberry is an important health food, as it contains vitamins, anthocyanins, and antioxidative enzymes. However, post-harvest life of this fruit is very short, and its quality (in terms of microbial growth, antioxidant value, and decay rate) deteriorates rapidly during storage. In this work, air cold plasma at atmospheric pressure was evaluated as a pre-treatment approach for prolonging the shelf life and improving the quality of blueberries. After plasma treatment for 10 min, the number of bacteria and fungi decreased by 93.0% and 25.8%, respectively, which might be due to the increases in DNA damage and guanine oxidation. Accordingly, the blueberry decay rates reduced by 17.7%, 14.3%, and 5.2% in the plasma treatment groups of 6, 8, and 10 min, respectively, after 20 days of storage. Interestingly, the contents of sugar, vitamin C, and total anthocyanin as well as the superoxide dismutase activity level showed the maximum increases of 1.5-fold, 1.5-fold, 2.2-fold, and 79.3%, respectively, following different plasma discharge treatments and storage times compared with those in the control groups. Furthermore, in the treated samples, the degradation times for these four parameters to decrease to control levels were longer compared to the samples without treatment. These results indicated that air cold plasma at atmospheric pressure has excellent potential as a method for enhancing the quality and shelf life of fresh produce in the food industry. [ABSTRACT FROM AUTHOR]

Abstract: The linking between the initial activities of the Rome-Bari group to their present activities is discussed in different fields of plasma chemical-physics. Several topics are presented including (1) plasma catalysis, (2) the interaction of alumina particles with thermal plasmas and its linking with the thermodynamics and transport properties of plasmas, and (3) non-equilibrium vibrational kinetics coupled with the Boltzmann equation for the electron energy distribution functions (eedf) in aerospace and cold plasma applications. The old activities in plasma catalysis pointed out the importance of atomic species affecting catalytic reactions opening also to the possibility of non-equilibrium vibrational distributions on the chemisorbed ad-atoms. This last aspect is discussed also taking into account recent developments. The study of the interaction of alumina particles with thermal plasmas was rationalized assuming that the step controlling the reaction could be the heat transfer plasma-particle. The model used a simplified fluid dynamic approach with the insertion of accurate values of thermodynamic and transport properties of thermal plasmas. This kind of activity can be considered precursor on the intense work in the field with particular attention on the importance of electronic excited states in affecting thermodynamics and transport of plasmas. Moreover, the plasma-particle interactions can be recovered to a given extent in the modern aspects of hypersonics in the boundary layer of re-entering vehicles as well as in the nozzle flow expansion. In both cases, we underline the existence of vibrational distributions (vdf) far from the Boltzmann behaviour and rates presenting an anti-Arrhenius trend as a function of the inverse of gas temperature. Concerning the non-equilibrium vibrational kinetics, we discuss two case studies. The first one deals with the behaviour of cold nitrogen plasmas pointing out the role of superelastic vibrational and electronic collisions on vdf and eedf. In this case, we discuss also the same case study comparing the results obtained by a complete set of electron molecule cross-sections acting on the whole vibrational ladder with the corresponding ones which consider transitions starting and arriving to the vibrational ground state of the molecule. The last case study concerns the dissociation kinetics of CO2 in cold plasmas, a topic largely studied in the past to emphasize the role of vibrational excitation in CO2 destruction. Recent results obtained using a sophisticated model based on the coupling of Boltzmann equation for the eedf and a state-to-state vibrational kinetics of the asymmetric ladder of CO2 are reported. The interplay between dissociation process by direct electron impact collision and by heavy particle collisions with vibrationally excited CO2 molecules is discussed.Graphical abstract: [ABSTRACT FROM AUTHOR]

This research explored the capability of seed priming with the non-thermal plasma to modify reactions of Melissa officinalis, an important medicinal plant, to zinc oxide (nZnO) or selenium (nSe) nanoparticles. The germinating seeds were primed with the plasma (0.84Wcm−2 surface power densities) under different durations (0, 50, 90, and 120 s); after that the primed seeds were cultured in petri dish containing Hoagland nutrient solution manipulated with various concentrations of nSe (0, 2, 5, 10, and 20 mgl−1) or nZnO (0, 50, and 250 mgl−1). The plasma treatments not only improved growth-related characteristics (stem length, root length, and leaf wide) and biomass accumulation but also toxicity signs of nSe (5, 10, and 20 mgl−1) were partly mitigated by the plasma priming. Interestingly, the plasma treatments induced peroxidase activity about 46%. Similarly, inductions in the activity of phenylalanine ammonia lyase were recorded in the plasma-primed seedlings. The correlations between the evaluated traits were found to be significant. Taken collectively, it could be exploited for delivering a novel tool regarding seed priming, biofortification, and seed/seedling-derived foods. [ABSTRACT FROM AUTHOR]

The present study was designed to highlight the effects of cold plasma (10 kV) treatment and priming with 2 mM salicylic acid (SA) and their combination (10 kV of plasma + 2 mM SA) on the physiological parameters and metabolism of two cultivars of Oryza sativa, i.e., Zhu Liang You 06 (ZY) and Qian You No. 1 (QY), under salinity stress (150 mM NaCl) and normal growth condition (0 mM NaCl). Seed germination and seedling growth were enhanced by SA priming and cold plasma treatment either alone or in combination under salinity stress. Photosynthetic pigments, photosynthetic gas exchange, and chlorophyll fluorescence were improved by cold plasma treatment and SA priming under salinity stress as compared to the untreated seeds. The activities of antioxidant enzymes were significantly improved by the combination of SA priming and cold plasma treatment in both cultivars under salinity stress. There were rapid changes in the cellular content of sodium (Na+) and calcium (Ca+), where the plants grown under saline conditions accumulate more Na+ and less Ca+ contents resulting in ionic imbalances. Interestingly, cold plasma and SA treatments diminished this action by reducing Na+ accumulation and increasing K+ and Ca+ contents in the plant cell under salinity stress. The activities of enzymes involved in secondary metabolism assimilation were up-regulated with cold plasma and SA priming either alone or combination under salinity stress. An increase in reactive oxygen species (ROS) accumulation and malondialdehyde (MDA) content was also observed under salinity stress condition. On contrast, seed treated with SA and plasma alone or combined resulted in a significant decrease in ROS and MDA contents under salinity stress. Our results indicated that SA priming and cold plasma treatment either alone or combined improved plant uptake of nutrients in both cultivars under stress conditions. The ultrastructural changes were observed to be more prominent in ZY than QY cultivar. Plants without SA priming or cold plasma treatments have a big vacuole due to the movement of ions into the vacuole directly from the apoplast into the vacuole through membrane vesiculation leading to membrane destabilization. However, SA priming and cold plasma treatment alone or combined helped the plants to recover their cell turgidity under salinity stress. [ABSTRACT FROM AUTHOR]

There are currently limitations to storing and feeding distillers wet grains (DWG) due to their potential for spoilage and mycotoxin contamination in storage. In this study, in-package treatments of DWG using high-voltage atmospheric cold plasma (HVACP) treatment and storage in modified atmosphere with carbon dioxide were investigated with the primary purpose of increasing product shelf-life. The conditions investigated were (1) HVACP treatment and modified atmosphere packaging (MAP) storage, (2) carbon dioxide-modified atmosphere storage, and (3) HVACP treatment and carbon dioxide-modified atmosphere storage, compared with a control sample with no treatment under MAP storage. Treated samples and controls were stored for 0, 7, 14, 21, and 28 days at 10 and 25 °C, after which treated samples were evaluated for their efficacy to control mold growth indicated by pH, microbial count (CFU/g)/log reduction, and peroxide (HO) level. There was a significant difference among the treatments indicated by CFU/g ( P < 0.003) and pH ( P < 0.0001). The HVACP treatment alone and its combination with carbon dioxide-modified atmosphere storage provided a better control of microbial growth and preservation in the wet substrate (>60% moisture), DWG for up to 28 days of storage at 10 and 25 °C. Both HVACP and the combination treatment showed high peroxide levels (100 mg/L) after treatment, which degraded in storage over time. It is thought that a better strategy for the combination treatment would be to treat substrate using HVACP with MAP having a high O concentration (65%) and store samples post-treatment in-package in a high CO environment. [ABSTRACT FROM AUTHOR]

This study investigated the efficacy of high voltage atmospheric cold plasma (HVACP) treatment on degradation of aflatoxin in corn. Gas type (Air, MA65), relative humidity (5, 40, 80% RH), treatment time (1, 2, 5, 10, 20,and 30 min), mode of reaction, post-treatment storage, stirring of corn material were parameters investigated on degradation of aflatoxin by HVACP treatment. Generation of reactive gas species was characterized with optical emission spectroscopy and measured with dragger tubes. Generation of reactive gas species are influence by gas type and relative humidity. Higher concentration of ozone and NOx were generated during HVACP treatment in MA65 than in air and with lower relative humidity. Aflatoxin in corn could be rapidly degraded by HVACP treatment. Aflatoxin in corn was degraded by 62% and 82% by 1 and 10 min HVACP treatment in RH 40% air, respectively. The degradation kinetics of aflatoxin by HVACP treatment follows a logistic model. Higher degradation of aflatoxin was achieved in gas MA65, at higher relative humidities (40%, 80%). Direct or indirect HVACP treatment was equally effective in degrading aflatoxin in corn. Stirring the corn sample during HVACP treatment and post-treatment storage increased aflatoxin degradation in corn by HVACP treatment. [ABSTRACT FROM AUTHOR]