Plasma Jet Treatment Research Articles

In situ surface formation of TiO2/Ti(NO2) hybrid nanocomposites with N2 APPJ treatment for efficient C2H4 photodegradation.

TiO2/Ti(NO2) hybrid films were prepared using N2 atmospheric pressure plasma jet treatment on TiO2 coating. The film structure and morphology have been investigated using optical emission spectra, Fourier-transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The formed TiO2/Ti(NO2) photocatalystic thin films were applied for C2H4 photodegradation under UV irradiation. The results showed that the composite films exhibited superior photocatalytic activity over the untreated TiO2 film. The C2H4 concentration after 120min varied from 12 to 6.2mg/L, 6.7mg/L, 7mg/L for TiO2 with 1min, 2min and 3min plasma treatment, respectively. In the banana storage experiment, the concentration of C2H4 was reduced from 15 to 9ppm after 36h with TiO2/Ti(NO2) nanocomposite film illuminated by UV light. The photocatalytic mechanism has been discussed. The composite film is able to more effectively separate the photo-excited electrons and holes, thus leading to the much high activity in C2H4 degradation. The current work has paved a way towards postharvest fruit preservation.

Effect of corona discharge plasma jet treatment on the degradation of aflatoxin B1 on glass slides and in spiked food commodities

Aflatoxins are a class of mycotoxins produced predominantly by fungal species such as Aspergillus flavus, Aspergillus parasiticus and Aspergillus nomius. These fungi and their toxins are usually found in a variety of agricultural products. Some mycotoxins are highly toxic, mutagenic, teratogenic and carcinogenic to humans and animals. Due to their recalcitrant nature, mycotoxins continue to survive through food processing and storage steps. In this study, corona discharge plasma jet (CDPJ) was used to degrade aflatoxin B1 (AFB1), a potent hepatotoxic and hepato-carcinogenic mycotoxin, on glass slides and in spiked food commodities since corona discharges are one of the simplest and best-reproducible source of multiple oxidants. Discharges of the plasma were generated using air as working gas under atmospheric pressure conditions and at different currents (1.00, 1.25 and 1.50 A). Optimal AFB1 degradation was observed upon using CDPJ generated at 1.50 A current and at 15 mm sample-to-electrode distance. Under these conditions, initial AFB1 concentration on slides was decreased maximally by 95% in 30 min. The degradation kinetics were well fitted by Weibull tail model compared with others. In spiked food commodities (rice and wheat), the average levels of AFB1 degradation ranged between 45 and 56% following CDPJ treatment for 30 min.

Ethanolic extract of the natural product of Daun sirih (Piper betle) leaves may impede the effectiveness of the plasma jet contact style for acute wounds

PurposeAn investigation was carried out to determine the effect of an ethanolic extract of the natural product of Daun sirih or Piper betle leaves on the effectiveness of plasma jet treatment for cutaneous acute wound healing in a small animal model mimicking a clinical setting. MethodAn atmospheric plasma jet using medical grade argon gas as a carrier gas was developed. The ethanolic extract of Piper betle leaf (EPB) was formulated. Optical emission spectroscopy and chemical methods were applied to evaluate the presence of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the gas phase and in aqueous and ethanolic media. Small animals were classified into 5 groups, namely, Control (C), Plasma jet (P), Ethanolic extract of Piper betle leaf (EPB), Plasma jet followed by EPB (P-EPB) and EPB followed by plasma jet (EPB-P). The contact and meander styles of plasma jet treatment for wounds were applied daily on acute wounds for 1 min, either alone or before or after EPB treatments. Visual evaluation of wounds was conducted for 14 days. Microscopic evaluation was conducted on days 7, 11 and 14. General staining, namely, haematoxylin-eosin and Azan staining, was conducted to evaluate neoepithelialisation and new collagen formation. ResultsThis research showed that wound healing in the P group was faster than that in the other groups, while that in groups containing EPB was the same as that in C. In the P group, the number of days to reach peak inflammation was the fewest. On day 7, neoepithelialisation and new collagen formation in P were significantly higher than those in other groups. ConclusionPlasma jet treatment alone is able to promote inflammation, neoepithelialisation and new collagen formation to accelerate acute wound healing; however, its admixture with EPB may impede such effectiveness. Based on the characterization of the ROS and RNS results, the ethanol solvent may play a primary role in impeding its effectiveness.

Investigation of the mechanism of enhanced and directed differentiation of neural stem cells by an atmospheric plasma jet: A gene-level study

Cold atmospheric plasmas (CAPs) have been shown to be capable of enhancing stem cell differentiation, especially directed differentiation of neural stem cells (NSCs). Consequently, one-step CAP treatment shows promise as an aid to tissue transplantation. However, the mechanisms involved in the enhancement of NSCs differentiation by CAP treatment are not yet fully understood. We have previously shown that in atmospheric helium plasma jet treatment, nitric oxide (NO) is the main factor involved in promoting NSC differentiation. This article further investigated the possible signaling pathways stimulated by NO in the neuronal differentiation of C17.2-NSCs after plasma treatment. Extracellular and intracellular NO concentrations were measured at different time points of incubation to monitor NO production. Meanwhile, the expressions of related genes and proteins were detected by quantitative real-time polymerase chain reaction and western blot, respectively. It is found that plasma treatment could both generate extracellular NO and increase extracellular NO concentration by inducing inducible nitric oxide synthase expression. The synergetic effect of extracellular and intracellular NO then downregulated Notch1 and Id2, and upregulated Ngn2 and Ascl1, thereby activating downstream NeuroD expression and finally enhancing and directing differentiation of NSCs into neurons.Cold atmospheric plasmas (CAPs) have been shown to be capable of enhancing stem cell differentiation, especially directed differentiation of neural stem cells (NSCs). Consequently, one-step CAP treatment shows promise as an aid to tissue transplantation. However, the mechanisms involved in the enhancement of NSCs differentiation by CAP treatment are not yet fully understood. We have previously shown that in atmospheric helium plasma jet treatment, nitric oxide (NO) is the main factor involved in promoting NSC differentiation. This article further investigated the possible signaling pathways stimulated by NO in the neuronal differentiation of C17.2-NSCs after plasma treatment. Extracellular and intracellular NO concentrations were measured at different time points of incubation to monitor NO production. Meanwhile, the expressions of related genes and proteins were detected by quantitative real-time polymerase chain reaction and western blot, respectively. It is found that plasma treatment could both genera...

Plasma treatment to improve the hydrophobicity of contaminated silicone rubber — the role of LMW siloxanes

Silicone rubber is widely used in power system insulation for its hydrophobicity and hydrophobicity transfer to prevent pollution flashover. The influence of low molecular weight (LMW) siloxanes on hydrophobicity of contaminated silicone rubber after plasma jet treatment was investigated in this study. Experimental results show that plasma jet treatment for several seconds can significantly improve the hydrophobicity of contaminated silicone rubber. LMW siloxanes play an important role in the quick recovery of hydrophobicity induced by plasma jet treatment. Extraction of the LWM siloxanes from the silicone rubber decreases the contact angle after plasma treatment. Fourier transform infrared (FTIR) spectroscopy shows that hydrophobic groups appear on the surface of the contamination layer. The hydrophobicity improvement of contaminated silicone rubber results from LMW siloxanes transferred to the contamination layer during plasma treatment and the LMW siloxanes are mostly original uncrosslinked siloxanes in the silicone rubber. The molar mass distributions of the LMW siloxanes in hydrophobic contamination of treated specimens were similar with naturally transferred ones. X-ray photoelectron spectroscopy shows that an inorganic layer appears after plasma aging, which obscures the transfer of LMW siloxanes and reduce the hydrophobicity during plasma treatment.

When plasma jet is effective for chronic wound bacteria inactivation, is it also effective for wound healing?

PurposeThis investigation aimed to compare the effectiveness of two styles of plasma jet treatment (i.e., contact and non-contact styles) for two biological materials, namely, wound related bacteria and acute wounds. MethodAn atmospheric plasma jet operated at a frequency of 18.32 kHz and high AC voltage with a peak-to-peak voltage of 9.58 kV and a current of 55.2 mA was applied. Argon gas was used as the carries gas of plasma jet generation and was fixed at a flow rate of 1 standard liters per minute (slm).Two biological materials (i.e., wound related bacteria and acute wound) were applied as experimental objects. The sample groups were based on the two styles of plasma jet treatment: contact and non-contact styles. Microbial inhibition zone calculation and macroscopic and histological observations were also performed. ResultsThis investigation emphasized that the contact and non-contact styles of plasma jet treatment had significantly different effects for wounds and wound-related chronic bacteria. On the one hand, the contact style was visually attractive and more effective for inactivate bacteria. On the other hand, it caused negative effects, such as damaging normal tissue, significantly impeding wound healing and impeding the growing of new epithelial tissue. The non-contact style, however, was less effective at inactivating bacteria; however, it could accelerate wound healing. ConclusionIn the context of wound healing, the non-contact style of plasma jet treatment may be better than the contact style of plasma jet treatment.

Cold Atmospheric Pressure Nitrogen Plasma Jet for Enhancement Germination of Wheat Seeds

The possibility to improve the germination characterization of the wheat seeds by cold atmospheric nitrogen plasma jet treatment was report. Spectroscopic measurements were performed to identify the constituent particles of a nitrogen atmospheric plasma jet. Spectroscopic measurements revealed that the particles with relatively high energy excited states exist inside the jet nozzle. During this study the cold atmospheric plasma parameters were set for attain the highest rate of the germination seeds. The nitrogen used in this system as carrier gas. The nitrogen cold atmospheric plasma operated at 14 l/min as a fixed flow rate. The operation of plasma jet at 14 l/min was represented the suitable plasma dose to enhancement the germination parameters. The N2 first positive system (N2 1+), N2 second positive system (N2 2+) and N2 ion first negative system (N2+ 1−) were represented the emission spectra observed inside the jet nozzle. The germination characteristics of wheat seeds have been significantly enhanced after cold atmospheric plasma treatment. The mean weight of fresh sprout was 823.82 mg for untreated seeds and increased to 1231.80, 1369.50 and 1342.46 mg for 2 min, 4 min, and 6 min treatments respectively. The effects of nitrogen cold atmospheric plasma jet on the growth parameter depended on exposure time.

Effect of a novel cold atmospheric plasma jet treatment with different temperatures on resin-dentin bonding

To investigate the effect of different treatment temperatures of a novel cold atmospheric plasma jet treatment on the resin-dentin bonding. (1) Fifty-two freshly extracted, non-carious and intact third molars were collected. The occlusal one-third of the crown was removed by means of a water-cooled low-speed Isomet saw. One dentin disc [(900 ±100) μm] was prepared for each tooth. The fifty-two dentin discs were randomly divided into control group and experimental groups, of which four were in control group, and forty-eight were divided into four experimental groups according to the different treatment temperatures (4 °C, 10 °C, 20 °C and 30 °C) of the novel radio-frequency atmospheric-pressure glow discharge (RF-APGD) plasma jet, twelve in each group. Each experimental group was divided into three subgroups according to different treatment time (10 s, 20 s and 30 s), with four in each subgroup. The occlusal one-third of the crown was removed by means of a water-cooled low-speed Isomet saw. The morphology of demineralized dentin surfaces was analyzed using field emission scanning electron microscopy. (2) Twenty unerupted, non-carious and intact third molars were randomly divided into five groups, four in each group: control group, untreated; 4 °C, 10 °C, 20 °C and 30 °C experimental groups, each group was treated with the RF-APGD plasma jet for 20 s. The micro-tensile resin dentin bond strength was tested after 20 s RF-APGD plasma jet treatment with different temperatures, using a universal mechanical machine. (1) The field emission scanning electron microscopy results indicated that when compared with the control group, a 10 s RF-APGD plasma jet treatment with 30 °C and 20 °C collapsed the collagen scaffold. Collagen fibrils maintained an uncollapsed three-dimensional structure after the 4 °C RF-APGD plasma jet treatment for even 30 s treatment. (2) The microtensile resin dentin bond strength results of the 4 °C RF-APGD plasma jet treatment group (57.8±0.7) MPa were significantly higher than that of the control group [(47.4±0.5) MPa] and 10 s, 20 s and 30 s RF-APGD plasma treatment group [(51.9±0.7) MPa,(29.7±1.0) MPa and (22.2±1.5) MPa] with statistically significant difference (P<0.05). Compared with the control group, the micro-tensile bond strength increased about 21.9% and 9.5% after 4 °C and 10 °C RF-APGD plasma jet treatment, respectively. Compared with other treatment temperatures, this novel RF-APGD plasma jet treatment with the temperature of 4 °C can preserve the three-dimensional morphology of demineralized dentin better, and can improve the resin-dentin bonding.

Research on the Gas Effect of Octafluorocyclobutane Plasma Jet at Atmospheric Pressure for Silicon Etching

The capacitively coupled radio frequency double-pipe plasma discharge jet is used for the etching process. An argon carrier gas is fed through the atmospheric-pressure plasma source; octafluorocyclobutane (C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sub> ) etch gas is injected into the plasma. Etchings were carried out on a crystalline silicon substrate. The etching characteristics are discussed and the etch rate tendency shows the reliance of C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sub> gas flow rate and oxygen addition. The optimum etching rate of 7.2 μm/min was obtained at a plasma power level of 100 W and C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sub> gas flow rate was 250 sccm. From surface profile detection, it displays the etch profile under this atmospheric-pressure plasma jet treatment. This plasma technique could offer a breakthrough for chamber-free dry etching processing.

Changes in physicochemical properties of corn starch upon modifications by atmospheric pressure plasma jet

The influences of atmospheric pressure plasma jet on different physicochemical properties of corn starch were evaluated after treated with the plasma jet (30 min) at different strengths (400 W–800 W). Our results demonstrated that residual aging effects of plasma on starch could be eliminated by washing the treated samples with distilled water at a ratio of 1:30, w/v. After plasma and washing treatments, significant (p < 0.05) reductions in pasting properties including peak viscosity, final viscosity, and setback of starch samples (up to −87.1%, −92.0%, and −93.3%, respectively) were observed with increasing plasma intensity. Apparently, plasma jet could increase the solubility and paste clarity of starch sample. Surface morphological characterization illustrated that plasma etching resulted in some physical changes on starch granules. Modifications in these physicochemical properties of corn starch by employing the plasma jet treatment might be useful in food applications requiring starch ingredients of low viscosity and high paste clarity.

Atmospheric pressure plasma needle jet treated on aluminium thin film for semiconductor industries

Atmospheric pressure plasma jet has been explored for pre-treatment applications especially in replacing the conventional vacuum plasma cleaning in semiconductor industries. The pre-treatment of plasma is needed to reduce or eliminate adventitious surface contamination on the thin film. This paper shows that the atmospheric pressure plasma jet treatment is highly effective in activating the surface of aluminium (Al) thin film. The image of Al thin film surface topography shows that the treated surface roughness was reduced however the grain size of the particles was unchanged. The XRD pattern of treated Al thin film also remained the same as before of the atmospheric pressure plasma jet treatment. This shows that the atmospheric pressure plasma jet introduce activation layer on the thin film surface without given impact to the thin film crystality.

Effect of an Atmospheric Pressure Plasma Jet on the Structure and Physicochemical Properties of Waxy and Normal Maize Starch.

In present study, a novel physical modification of waxy maize starch (WMS) and normal maize starch (NMS) was investigated by using an atmospheric pressure plasma jet (APPJ) treatment. The effect on the structure and physicochemical properties of both starches was demonstrated by treatment with a 5% starch suspension (w/w) with APPJ for short periods of time (1, 3, 5, or 7 min). The pH of WMS and NMS was decreased after APPJ treatment from 5.42 to 4.94, and 5.09 to 4.75, respectively. The water-binding capacity (WBC) (WMS: 105.19%–131.27%, NMS: 83.56%–95.61%) and swelling volume (SV) (WMS: 2.96 g/mL–3.33 g/mL, NMS: 2.75 g/mL–3.05 g/mL) of the starches were obviously increased by APPJ treatment. The surfaces of starch granules were wrecked, due to plasma etching. No changes in the crystalline types of both starches were observed. However, the relative crystallinities (RCs) of WMS and NMS were reduced from 46.7% to 42.0%, and 40.1% to 35.7%, respectively. Moreover, the short-range molecular orders of both starches were slightly reduced. In addition, APPJ treatment resulted in lower gelatinization temperature and enthalpies. Therefore, APPJ provides a mild and green approach to starch modification, showing great potential for applications in the food and non-food industry.

Modulating the concentrations of reactive oxygen and nitrogen species and oxygen in water with helium and argon gas and plasma jets

We employed UV–vis spectroscopy to monitor real-time changes in the oxygen tension and concentration of reactive oxygen and nitrogen species (RONS) in deionized (DI) water during treatments with helium (He) and argon (Ar) gas plasma jets. He and Ar gas jets are both shown to de-oxygenate DI water with He being more efficient than Ar, whilst the plasma jets deliver and regulate the concentrations of hydrogen peroxide (H2O2), nitrite (NO2−) and nitrate (NO3−) in DI water. The H2O2 and NO3− production efficiency varied between He and Ar plasma jets, but was similar for NO2−. Whilst DI water fully equilibrated with ambient air prior to treatment (de-oxygenated by both plasma jets) when DI water was first de-oxygenated by an inert gas jet treatment, both plasma jets were found to be capable of oxygenating DI water. These insights were then used to show how different combinations of plasma jet and inert gas jet treatments can be used to modulate O2 tension and RONS chemistry. Finally, potential further improvements to improve control in the use of plasma jets in regulating O2 and RONS are discussed.

Fabrication of PEOT/PBT Nanofibers by Atmospheric Pressure Plasma Jet Treatment of Electrospinning Solutions for Tissue Engineering.

This study focuses on the enhanced electrospinning of 300-Polyethylene oxide-polyethylene oxide terephthalate/polybutylene terephthalate (PEOT/PBT). An atmospheric pressure plasma jet for liquid treatment is applied to a solution with 9 w/v% PEOT/PBT dissolved in either chloroform (CHCl3 ), CHCl3 +N,N-dimethylformamide (DMF), CHCl3 +methanol (MeOH), or CHCl3 +hexafluoroisopropanol (HFIP). For all conditions, the plasma-treated samples present better-quality fibers: less or no-beads and uniform fiber diameter distribution. Except for CHCl3 +DMF, no significant changes to the material bulk are detected, as shown with size exclusion chromatography (SEC). X-ray photoelectron spectroscopy (XPS) spectra performed on nanofibers record an increase in C-C bonds for the CHCl3 +DMF combination upon plasma modification, while a shift and slight increase in oxygen-containing bonds is found for the CHCl3 +HFIP and CHCl3 +MeOH mixtures. MTT assay shows no-cytotoxic effects for CHCl3 +DMF, while a better cellular adhesion is found on nanofibers from CHCl3 +MeOH and CHCl3 +HFIP. Among the examined additives, MeOH is preferable as it produces beadless electrospun nanofibers with an average diameter of 290±100nm without causing significant changes to the final nanofiber surface properties.

Nonthermal Plasma Jet Treatment Negatively Affects the Viability and Structure of Candida albicans SC5314 Biofilms.

Microorganisms are predominantly organized in biofilms, where cells live in dense communities and are more resistant to external stresses than are their planktonic counterparts. With in vitro experiments, the susceptibility of Candida albicans biofilms to a nonthermal plasma treatment (plasma source, kINPen09) in terms of growth, survival, and cell viability was investigated. C. albicans strain SC5314 (ATCC MYA-2876) was plasma treated for different time periods (30 s, 60 s, 120 s, 180 s, 300 s). The results of the experiments, encompassing CFU, fluorescence Live/Dead, and 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide salt (XTT) assays, revealed a negative influence of the plasma treatment on the proliferation ability, vitality, and metabolism of C. albicans biofilms, respectively. Morphological analysis of plasma-treated biofilms using atomic force microscopy supported the indications for lethal plasma effects concomitant with membrane disruptions and the loss of intracellular fluid. Yielding controversial results compared to those of other publications, fluorescence and confocal laser scanning microscopic inspection of plasma-treated biofilms indicated that an inactivation of cells appeared mainly on the bottom of the biofilms. If this inactivation leads to a detachment of the biofilms from the overgrown surface, it might offer completely new approaches in the plasma treatment of biofilms. Because of plasma's biochemical-mechanical mode of action, resistance of microbial cells against plasma is unknown at this state of research.IMPORTANCE Microbial communities are an increasing problem in medicine but also in industry. Thus, an efficient and rapid removal of biofilms is becoming increasingly important. With the aid of the kINPen09, a radiofrequency plasma jet (RFPJ) instrument, decisive new findings on the effects of plasma on C. albicans biofilms were obtained. This work showed that the inactivation of biofilms takes place mainly on the bottom, which in turn offers new possibilities for the removal of biofilms by other strategies, e.g., mechanical treatment. This result demonstrated that nonthermal atmospheric pressure plasma is well suited for biofilm decontamination.

Preparation of Polyester Fabric with Asymmetric Wettability by Atmospheric Pressure Plasma Jet Treatments

Preparation of Polyester Fabric with Asymmetric Wettability by Atmospheric Pressure Plasma Jet Treatments

NO2- and NO3- enhance cold atmospheric plasma induced cancer cell death by generation of ONOO-

Cold atmospheric plasma (CAP) is a rapidly developed technology that has been widely applied in biomedicine especially in cancer treatment. Due to the generation of various active species in plasma, CAP could induce various tumor cells death and showed a promising potential in cancer therapy. To enhance the biological effects of gas plasma, changing the discharging parameters is the most commonly used method, yet increasing discharging power will lead to a higher possibility of simultaneously damage surrounding tissues. In this study, by adding nontoxic concentration of additional nitrite and nitrate in the medium, we found that anti-tumor effect of CAP treatment was enhanced in the same discharging parameters. By microplate reader and cell flow cytometer we measured several extracellular and intracellular RONS and found that ONOO- was mostly correlated with the enhanced cancer cell killing effect. We proposed that more nitrogen supplies such as nitrite and nitrate could increase the production of RNS especially ONOO- and resulted in a better killing effect to cancer cells. Our results provided a new strategy to enhance the antitumor effect by plasma jet treatment without changing the discharging parameters.

Enhanced bonding strength of heat-treated wood using a cold atmospheric-pressure nitrogen plasma jet

In this work, the bonding strength enhancement of heat-treated wood using a cold atmospheric-pressure nitrogen plasma jet for several lengths of treatment time was investigated. The enhancement of bonding strength was assessed by measurement of the contact angle of aqueous adhesive and water borne finish along with determination of compressive shear strength of wood samples bonded with an aqueous adhesive and pull-off strength of a water borne finish coating on wood samples. Additionally, the elemental composition and crystallinity index of the heat-treated wood surface were characterized using X-ray photoelectron spectroscopy and X-ray diffraction. As expected, the measurements demonstrated that contact angle decreased after atmospheric-pressure nitrogen plasma jet treatment, and the optimal treatment time was 100 s. X-ray photoelectron spectroscopy shows that hydrophilic groups such as C=O, OH, and COOH appeared on the surface of the HW. The atmospheric-pressure nitrogen plasma jet treatment had a positive effect on the crystallinity of heat-treated wood because of a slight degradation of hemicelluloses. Increasing the bonding strength of heat-treated wood is beneficial for broadening the fields of its applications.

Influence of atmospheric pressure plasma jet on the structure of microcrystalline starch with different relative crystallinity

SummaryThis study demonstrated the effect on microcrystalline starch (MS) with different relative crystallinity (RC) by atmospheric pressure plasma jet (APPJ) treatment for 1, 3, 5 or 7 min. The morphology of MS granules was destroyed according to Scanning electron microscopy (SEM) analysis. APPJ treatment did not change the crystalline type of MS, but obviously decreased the RC of MS. Short‐range molecular order of MS was clearly decreased after APPJ treatment though the Fourier transform infrared (FTIR) and Raman spectroscopy. Notably, the effect of APPJ on crystalline and short‐range order structure of MS was gradually increased with the increase of RC, which revealed that the crystalline region of MS might be destroyed by APPJ. Furthermore, the pH of MS was decreased while water binding capacity (WBC) and swelling volume (SV) of MS were increased. Therefore, the APPJ treatment could be used as an alternative physical technology for starch modification.

Effects of atmospheric pressure plasma jet on the conformation and physicochemical properties of myofibrillar proteins from king prawn (Litopenaeus vannamei)

The aim of this study was to ascertain the impact of atmospheric pressure plasma jet treatment (APPJ) as a function of treatment times (0, 2, 4, 6, 8 and 10 min) on the conformation and physicochemical properties of myofibrillar proteins (MPs) extracted from king prawn (Litopenaeus vannamei). The results showed that the pH and protein solubility were decreased after 10 min treatment of APPJ. These results were also confirmed by dynamic light scattering, which indicated an increase in mean particle diameter of MPs from 654 to 2297 nm. Complementary methodologies used to characterize the structural changes confirmed the exposure of hydrophobic groups and promotion of protein-protein interactions. These occurrences were particularly more intense at the longest treatment duration. The high energetic and oxidizing species contained in the plasma gas may have considerable implications on the physical and structural characteristics of MPs from king prawn.