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This study aimed to investigate the effect of the cold atmospheric plasma torch (CAPT) nozzle distance from the surface of Olivier salad and the treatment time in the reduction of microbial load and sensory properties of the product simultaneously. In this study, the CAPT nozzle was placed at 3, 5, and 7 cm distances from the surface of the Olivier salad, and its efficiency in inactivating the microbial population, decimal reduction time (D-value), and sensory evaluation of the product were evaluated. The results showed that reducing the distance and increasing the plasma treatment time (30, 60, 90, and 120 s) both reduced the microbial load of the product. The maximum inactivation and the minimum D-value are related to the 3 cm distance for 120 s, which has been 3.77, 2.91, and 1.52 log CFU/g for Coliform , Total viable count (TVC), mold and yeast, respectively. The lowest D-value was related to Coliform (4.41 s). CAPT treatment had no significant sensible effect on the product's sensory characteristics compared to the control sample. The treated sample at a 3 cm distance for 90 s and the microbial reduction to an acceptable amount and high acceptancy from sensory evaluators were selected as the superior treatment in this study. Also, the results showed that CAPT could be used successfully in ready-to-eat (RTE) products.

Nowadays, cold atmospheric plasma shows interesting results in dermatology. In the present study, a new portable cold plasma was designed for plasma skin rejuvenation (PSR) purposes. This device is safe and easy to use at beauty salons and homes. The effects of this device were investigated on the rat skins. Also, as a new method to improve PSR results, vitamin C ointment was combined with plasma. In this study, there were four groups of 5 Wistar rats. The first group received vitamin C ointment, the second received 5 min of high-voltage plasma, and the third and the fourth groups received 5 min of high- and low-voltage plasma and vitamin C ointment. This process was done every other day (3 sessions per week) for 6 weeks. To evaluate the thermal effect of plasma, the skin temperature was monitored. Also, the presence of reactive species was demonstrated by the use of optical spectroscopy. In addition, mechanical assays were performed to assess the effect of plasma and vitamin C on the tissue's mechanical strength. The mechanical assays showed a positive impact of plasma on the treated tissue compared to the control group. Also, changes in the collagen level and thickness of the epidermal layer were examined in histological studies. The results indicated an increase in collagen levels after using plasma alone and an accelerated skin reaction after using vitamin C combined with plasma therapy. The epidermal layer's thickness increased after applying high-voltage plasma, which indicates an increase in skin elasticity. This study demonstrates the positive effect of using the portable plasma device with vitamin C ointment on effective parameters in skin rejuvenation., (© 2021. The Author(s).)

The aim of this study is to evaluate the efficacy and safety of cold atmospheric plasma (CAP) as a novel therapy for diabetic foot ulcers. This was an investigator-blinded, randomized controlled trial of 14 weeks (6 weeks of treatment and 8 weeks of follow-up). Twenty patients with diabetic foot ulcers were divided into two groups: the control group receiving standard wound care and the plasma group, which received CAP twice a week for six consecutive weeks in addition to standard wound care. The ulcer size, amount of exudate, and wound grading were determined weekly. Cold plasma was produced by applying a high voltage (4.5 kV) and a high frequency (22 kHz) to helium gas. Exudate from wounds treated with CAP showed a significant reduction in the third week after complete treatment (p = 0.039). The wound grading of the ulcers improved by the sixth week (p = 0.019), and the sizes of ulcers significantly decreased in the plasma group at the end of the treatment period (p = 0.007). In this randomized clinical trial, CAP was an effective treatment option for diabetic foot ulcers in terms of wound surface reduction and antibacterial effects., (© 2021 Wiley Periodicals LLC.)

In this study, the effect of different cold plasma treatments was investigated as a novel method for the modification of starch film properties. The films were prepared from wheat starch using a solvent casting method and then treated with air and O 2 glow discharge plasma at different durations (4, 8, and 12 min). A significant increase in the hydrophilicity of the films was observed due to the formation of oxygen-containing groups after plasma treatment. Fourier transform infrared analysis illustrated a decrease in C-H groups that caused an increase in C-O and C-O-C groups in air-treated films and carbonyl groups in O 2 -treated films. The surface roughness of the treated films increased from 17.6 nm to 22.5 and 20.6 nm after air and O 2 treatments, respectively. Plasma treatments decreased oxygen permeability of the films but no significant difference in the water vapor permeability was observed. After plasma treatment, tensile strength of films was improved due to crosslinking and etching at the surface, although elongation at break remains unchanged.

Cold plasma assay was potentially useful persuade surface modification. In this study, antimicrobial properties of chitosan and low density polyethylene bilayer film with method cold plasma incorporated with summer savory essential oil (SEO) (1, 2 and 3%) for extending shelf life of chicken breast fillets was investigated. Moreover, mechanical and physical properties of film were assessed. Result showed that plasma treatment could improvement properties film and increase shelf life processing. After plasma treatment chitosan/polyethylene film containing 3% summer savory essential oil decreased water vapor permeability and oxygen transmission rate chitosan film. Addition of summer savory essential oil to the two-layer film, also improved tensile strength and elongation at break of film. The bilayer film with 3% of essential oil treatment cold plasma was chosen for microbial analysis during storage. All samples plasma-treated, films for this study included polyethylene (PE), bilayer of polyethylene and chitosan (PE/Ch) and Chitosan containing essential oil in direct contact (D) and gas phase (G). Result showed that shelf life of fillets were extended in direct contact and gas phase treatments to 13 days at refrigerator. It was 6 days for polyethylene and 8 days for Chitosan treatments. Essential oil incorporated film also decreased thiobarbitoric acid value of sample during storage. Cold plasma has a high potential in active packaging and food preservation., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this research, the influence of different cold plasma treatments was investigated as a novel method for modification of protein film properties. The films were prepared from whey and gluten proteins using solvent casting method and then treated with vacuum low-pressure glow plasma using air and argon gases at 50 KW for 5, 10, and 15 min and further analyzed mechanically and physicochemically. The images of atomic force microscopy (AFM) revealed a significant increase in roughness of whey protein films after plasma treatment, while the roughness of treated gluten films diminished dramatically. Furthermore, the tensile strength of films improved significantly after 10 min of process, from 6.902 to 10.772 MPa and from 1.854 to 2.571 MPa for whey protein and gluten films, respectively. Introduction of functional groups such as CO and OC bonds plus cross link creation was observed by FTIR which could lead to changes in different film features. Although gas permeability of both edible polymers decreased significantly, other parameters including solubility and water vapor permeability of control and plasma treated (PT) films did not show dramatic differences. Therefore, the optimum condition and time of low-pressure glow plasma has the potential for modifying protein films., (Copyright © 2019. Published by Elsevier B.V.)

In this study cold low pressure radiofrequency oxygen plasma was used for the first time to inactivate toxicogenic fungi proliferation on saffron. Varieties of plasma produced reactive oxygen species which were investigated by optical emission spectroscopy. The data were indicative of the absence of UV radiation. Effects of plasma treatment on antioxidant activity, metabolic content, colour, odour and flavour parameters and physical impact on saffron were investigated. A range of plasma powers and exposure times were assayed in suppression of fungal growth. Amongst which power of 60 W for 15 min was used to eradicate Aspergillus and other microorganisms. The ferric reducing antioxidant power was changed from 1778.21 to 1674.25 mM/g dry weight following plasma treatment. Moreover, crocin ester, picrocrocin and safranal metabolites reduced insignificantly. Additionally, plasma had no significant impact on colour, odour and flavour of saffron., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

This study was aimed to develop and characterize carboxymethyl cellulose-coated polypropylene (PP/CMC) films with Zataria multiflora essential oil (ZEO) as a new antimicrobial food packaging. For better attachment of CMC on polypropylene (PP) film surface, atmospheric plasma pretreatment was used. Results showed the formation of polar groups such as CO and OH in the PP surface following the plasma treatment. Plasma-treated PP had rougher surfaces and their contact angle reduced from 88.92° to 52.15° indicating increased surface hydrophilicity. Plasma-treated PP/CMC films showed lower water vapor permeability (WVP) and higher tensile strength compared to untreated bilayer films. Results revealed that antimicrobial PP/CMC films with higher content of ZEO had lower WVP, but was more sensitive to breakage. Antimicrobial characteristics in the direct contact and vapor phase represented great inhibition for all the tested bacteria. Our findings suggest that plasma-treated PP/CMC films have the potential for application in food antimicrobial packaging., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Cold atmospheric-pressure plasma jets (APPJ) have excellent applications in biomedicine. Advantages of APPJ include lack of need for vacuum systems, capability of operation for a long time, and safe to be directly touched by living tissues such as a human body. In this study, an APPJ was generated by a dielectric barrier and applied for the treatment of chemical wounds. This APPJ worked with argon and was driven by high-voltage pulses. This paper compares the spontaneous healing of wounds and a stimulated healing using daily APPJ treatment. Biological data, such as hematological, biochemical, and histological parameters, were remarked. The mortality and morbidity of the untreated samples were reported after 20 days in comparison with the plasma-treated samples, which were alive after these days. Experimental results demonstrated that an increase in the oxidative stress could result in the decreased destruction of lesions by controlling the infection growth. These results were related to the presence of reactive oxygen species and reactive nitrogen species in the plasma volume, which were detected by optical emission spectroscopy.

The main process in oil refinery technologies is the cracking of the heavy fraction of oil into light and valuable hydrocarbons. Dielectric barrier discharge (DBD) reactors, working at atmospheric pressure and low temperature, is one of the newest methods for cracking hydrocarbons, which has been successfully used to crack low-carbon-containing molecules. Therefore, in this paper, the cracking of n-hexadecane as a heavy hydrocarbon fed by using the cylindrical DBD reactor (nonthermal plasma) has been investigated. We studied the effects of gas type, applied voltage, and gas flow rate quantitatively and qualitatively by using gas chromatography with flame ionization detector and mass spectrometry detector. Results showed that methane has better effects on both conversion and cracking percentage in comparison with air. Also, it has been shown that increasing the applied voltage and working gas flow rate enhances the conversion and the cracking percentages. The highest conversion percentage obtained was 9.26% when the applied voltage and methane flow rate were 12 kV and 50 sccm. In this condition, the cracking percentage obtained was 84.34% of the products. [ABSTRACT FROM PUBLISHER]