Uta Schnabel

• Doctor of Philosophy
• Researcher at Leibniz Institute for Plasma Science and Technology

Plasma-treated water (PTW) possess anti-microbial potential against Pseudomonas fluorescence, which is observable for both suspended cells and cells organized in biofilms. Against that background, the chemical composition of PTW tends to focus. Various analytical techniques have been applied for analyses, which reveal various traceable reactive oxy...

Non-thermal plasma research has gained significant attention as a promising technology for food-related decontamination. However, the lack of standardization in reporting key parameters restricts the applicability and reusability of results in this field. To address this, the present study introduces a metadata schema (MDS) that standardizes critic...

Plasma-treated water (PTW) recently entered science as a sanitizing agent, which possess the capability for on-demand production. It offers interesting possibilities for sustainable and resource-saving applications in healthcare and food production. The present study monitors the impact of PTW on suspended cells before the biofilm formation of the...

By integrating contemporary plasma-based technology into classical food-monitoring procedures, those procedures offer additional food-safety treatments that are advantageous under certain conditions. Plasma based techniques are feasible for surface modification, chemical degradation, and antimicrobial treatments of surfaces. For the deactivation of...

Non-thermal plasma technology is recognized for its strong antimicrobial efficacy on food and food production environment-associated microorganisms and its ability to enhance food safety and food shelf-life [1]. However, the lack of scientific knowledge regarding the differences in physical and chemical processes at various upscaling levels hinders...

Foods consumed raw, such as lettuce, can host food-borne human-pathogenic bacteria. In the worst-case, these diseases cause to death. To limit illness and industrial losses, one innovative sanitation method is non-thermal plasma, which offers an extremely efficient reduction of living microbial biomass. Unfortunately, the total viable count (TVC),...

The consumer demand for organic food including apples is increasing worldwide. Despite favorable environmental and health benefits, organic farming bears also disadvantages like high amounts of fruit losses due to storage rot. A novel treatment with plasma-processed air (PPA) to sanitize organic apples is investigated. The plasma source for the gen...

Plant-based foods like lettuce are an important part of the human diet and worldwide industry. On a global scale, the number of food-associated illnesses increased in the last decades. Conventional lettuce sanitation methods include cleaning either with tap or chloritized water. Beside these water-consuming strategies, physical plasma is an innovat...

The control of the pathogenic load on foodstuffs is a key element in food safety. Particularly, seafood such as cold-smoked salmon is threatened by pathogens such as Salmonella sp. or Listeria monocytogenes. Despite strict existing hygiene procedures, the production industry constantly demands novel, reliable methods for microbial decontamination....

Methods, which use an indirect plasma treatment for the inactivation of microorganisms in foods, claim a vastly growing field of research. This paper presents a method that uses plasma-processed air (PPA) as a sanitizer. In addition to a sanitation concept for the decontamination of produce in the value chain, the presented method offers a possible...

Sustainable and microbiologically secure foodstuff production lines are of increasing scientific interest and are in the focus of recent research programs. Additionally, they are of great importance for the production industry due to the prevention of food-borne illnesses caused by pathogens such as Salmonella sp., Listeria monocytogenes, or Escher...

The microbiological profiles and responses of native microflora of endive were investigated using a model process line, to establish where a defined PFW should be optimally applied to retain or improve produce microbiological quality. The PFW processes were compared with tap water and ClO2. The antimicrobial efficacy of PFW was quantified by determ...

Background: Plasma-generated compounds (PGCs) such as plasma-processed air (PPA) or plasma-treated water (PTW) offer an increasingly important alternative for the control of microorganisms in hard-to-reach areas found in several industrial applications including the food industry. To this end, we studied the antimicrobial capacity of PTW on the vit...

Fresh-cut produce like lettuce may contain a very high microbial load, including human pathogens. Therefore, the need for antimicrobial agents at post-harvest stages to mitigate microbial cross-contamination and growth is evident. Sanitation based on non-thermal plasma (NTP) reveals innovative food processing possibilities by application at differe...

This study evaluated the impact of a defined plasma treated water (PTW) when applied to various stages within fresh-cut endive processing. The quality characteristic responses were investigated to establish the impact of the PTW unit processes and where PTW may be optimally applied in a model process line to retain or improve produce quality. Diffe...

Plasma generated products (PGC) conceived by microwave induced plasma (MidiPLexc) were physicochemical investigated in their molecular composition. Therefore, plasma treated water (PTW) was generated by treatment with the MidiPLexc within a 1 l glass bottle for a pre treatment time of 100 s, 300 s and 900 s. The PTW was further investigated in its...

Plasma-generated compounds (PGCs) such as plasma-processed air (PPA) or plasma-treated water (PTW) offer an increasingly important alternative for the treatment of microorganisms in hard-to-reach areas found in several industrial applications including the food industry. To this end, we studied the antimicrobial capacity of plasma-treated water on...

Microwave-induced plasma was used for the generation of plasma-processed air (PPA) and plasma-treated water (PTW). By this way, the plasma was able to functionalize the compressed air and the used water to antimicrobial effective agents. Their fungicidal effects by single and combined application were investigated on Candida albicans strain SC5314....

For the decontamination of surfaces in the food production industry, plasma-generated compounds such as plasma-treated water or plasma-processed air offer many promising possibilities for future applications. Therefore, the antimicrobial effect of water treated with microwave-induced plasma (MidiPLexc) on Pseudomonas fluorescens biofilms was invest...

For the decontamination of surfaces in the food production industry, plasma generated compounds (PGCs) such as plasma-treated water (PTW) or plasma processed air (PPA) offer many promising possibilities for future applications. Therefore, the antimicrobial effect of water treated with microwave-induced plasma (MidiPLexc) on Pseudomonas fluorescens...

The susceptibility of Candida albicans biofilms to a non-thermal plasma treatment has been investigated in terms of growth, survival and cell viability by a series of in vitro experiments. For different time periods , the C. albicans strain SC5314 was treated with a microwave-induced plasma torch (MiniMIP). The MiniMIP treatment had a strong effect...

The susceptibility of Candida albicans biofilms to a non‐thermal plasma treatment has been investigated in terms of growth, survival and cell viability by a series of in vitro experiments. For different time periods, the C. albicans strain SC5314 was treated with a microwave‐induced plasma torch (MiniMIP). The MiniMIP treatment had a strong effect...

The synergistic antimicrobial effects of plasma-processed air (PPA) and plasma-treated water (PTW), which are indirectly generated by a microwave-induced non-atmospheric pressure plasma, were investigated with the aid of proliferation assays. For this purpose, microorganisms (Listeria monocytogenes, Escherichia coli, Pectobacterium carotovorum, spo...

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 tha...

Atmospheric pressure plasma spraying (APS) is an established method of surface modification, which has a variety of advantages. In this case, large work- pieces can be equipped with a layer of up to several millimeters in thickness. The scope of application ranges from implants with enhanced ingrowth, with and without antimicrobial effect, in medic...

Microorganisms are predominantly organized in biofilms, where cells live in dense communities and are more resistant to external stresses compared to their planktonic counterparts. With in vitro experiments, the susceptibility of Candida albicans biofilms to a non-thermal plasma treatment (plasma source kINP ® 09), in terms of growth, survival, and...

The poster was presented at an in-house board presentation

Front Cover: The idea to use non‐thermal atmospheric pressure plasmas for food decontamination is one of the most innovative research fields at food science nowadays. However, some plasmas like microwave discharges are too hot (5000 K) to use them directly at the (fresh) food surface. Therefore, the indirect modus, plasma processed gases, here plas...

The decontamination and sanitation methods currently used are mainly antimicrobial ineffective, generate high costs with a high consumption of water and chemicals (additives). As an alternative, non-thermal plasma at atmospheric pressure could be a versatile tool. Therefore, a pilot-scaled set-up based on a microwave-plasma source that generates pl...

The biological effects of atmospheric cold plasma generated reactive species are mediated through and at a liquid interface. The diversity of antimicrobial efficacy or intensity of effects may differ with respect to the plasma device or set up, and it is important to understand how these differences occur to advance understanding and successful app...

The increasing demands of society for healthy nutrition in combination with continuously decreasing willingness to spend time for food preparation leads to a rising consumer demand for minimal processed ready-to-eat (RTE) products (convenient food). The USA is the leading nation in the consumption and therefore, the biggest market for these kinds o...

Currently used methods for decontamination and sanitation of fresh/fresh-cut food as well as food processing surfaces are antimicrobial ineffective, generate high costs with a high consumption of water, and chemicals additionally. As an alternative, non-thermal plasma at atmospheric pressure could be a versatile tool. Therefore, an experimental set...

Currently used disinfection and sanitation methods for fresh fruits and vegetables lack antimicrobial effectiveness and are high in cost, water consumption, or chemicals. One alternative may be nonthermal plasma at atmospheric pressure. The plasma setup used depends on microwave plasma, which generates plasma-processed air (PPA) with manifold chemi...

Currently used methods for decontamination and sanitation are antimicrobial ineffective, generate high costs with a high consumption of water and chemicals additionally. As an alternative, non-thermal plasma at atmospheric pressure could be a versatile tool. Therefore, an experimental setup based on a microwave-plasma source which generates plasma...

Inanimate surfaces serve as a permanent reservoir for infectious microorganisms, which is a growing problem in areas in everyday life. Coating of surfaces with inorganic antimicrobials, such as copper, can contribute to reduce the adherence and growth of microorganisms. The use of a DC operated air plasma jet for the deposition of copper thin films...

Plasma treatments are known for their antimicrobial effectiveness for more than 100 years. The invention of ozone tube by Werner von Siemens in 1857 leads to technical applications in the fields of communal tap water purification in small villages in Germany and in 1916 in St. Petersburg. Nikola Tesla was filed a patent for a corona discharge ozone...

Currently used methods for decontamination and sanitation are antimicrobial ineffective, generate high costs with a high consumption of water and chemicals additionally. As an alternative, non-thermal plasma at atmospheric pressure could be a versatile tool. Therefore, an experimental setup based on a microwave-plasma source which generates plasma...

The development of atmospheric pressure microwave plasma sources has opened a wide range of new applications. Most of them are based on high density of charged particles and active species combined with low thermal load. To design and optimize applications and plasma sources the knowledge of plasma parameters and the electromagnetic field distribut...

Plasma is well-known for its antimicrobial capacity and moreover, it is successfully used in manifold industrial fields such as packaging industry. Microwave plasma processed gas with shares of reactive nitrogen species (RNS) was investigated for its decontamination efficiency against vegetative bacteria, conidia and bacterial endospores packed in...

Medical devices need to submit stringent controls to gain a high quality standard. Therefore, international comparability has to be ensured between the laboratories or the producing industries via globally standardized assays. For medically used plasma sources, we developed a microbial assay that allows comparison of plasma sources with different d...

Foodborne diseases are often related to the consumption of microbially contaminated fresh produce. Infections occur due to Norovirus, Listeria or Samonella. However, contaminations with Escherichia coli and its pathovar EHEC (enterohemorrhagic Escherichia coli) also result in serious health problems. To reduce/prevent microbial contaminations, clea...

Currently used disinfection or sanitation methods for fresh fruits and vegetables lack antimicrobial effectiveness, but are high in costs, water consumption or chemicals. One alternative could be to apply nonthermal plasma at atmospheric pressure to the described issue. The experimental set-up implements microwave plasma, which generates plasma pro...

Plasma is used as a common technology for the treatment and modification of surfaces in a variety of industrial branches. Decontamination of inorganic materials by plasma is possible with deterioration of the materials properties of a few nanometres. The inactivation efficacy of microwave plasma processed air against vegetative bacteria and bacteri...

Current problems with outbreaks of serious infections caused by human pathogens on fresh-cut greens highlight the need for new, optimized postharvest sanitation treatments to effectively meet recent food safety standards. In contrast to various chemical treatments, non-thermal plasma (NTP) has a high potential as a gentle target sanitation techniqu...

The rapid progress in the development of new devices for minimal invasive surgery leads to more complex and fragile instruments including a mixture of different materials most of them thermo labile. In consequence these instruments become more and more expensive which increases the demand for reuse. By now, the manufacturers are obligated to specif...

Minimal invasive treatment using tubes such as catheters and endoscopes is well-established. Since the introduction of flexible endoscopy into medical practice, many cases of infectious complications involving bacteria, fungi and viruses have been linked to endoscopic procedures. Inadequate cleaning and disinfection during the reprocessing of the i...

The majority of seed related outbreaks of human illnesses have been associated with Escherichia coli or Samonella spp. To achieve the production of pathogen-free seeds, it is necessary to find an effective method to inactivate such bacteria. One alternative can be non-thermal plasmas at atmospheric pressure. The here presented plasma setup is based...

The research and development of plasma sources, which can be used for therapeutic applications in the new and emerging field of plasma medicine, has gained more and more interest during recent years. These applications require cold non-thermal plasmas operating at atmospheric pressure. Due to the fact that, in general, plasma on or in the human bod...

Atmospheric pressure plasma can facilitate microbiological inactivation while maintaining the product quality due to low temperature operation. Indirect plasma treatment offers new perspectives for large scale application. The aim of this study was to determine the impact of indirect plasma treatment on quality (color, pH, fluorescence, and reflect...

Introduction The rapid progress in the development of new devices for minimal invasive surgery leads to more complex and fragile instruments including a mixture of different materials most of them thermo labile. In consequence these instruments become more and more expensive which increases the demand for reuse. By now, the manufacturer are obligat...

Medical endoscopes are most complex and expensive devices for intracorporeal diagnostic and surgery. A treatment with such a device always includes the risk of endoscopic associated nosocomial infections. A consequent infection prophylaxis mainly includes safe cleaning and sterilization methods for the endoscopes. Conventional used chemical gases a...

Gentle sanitation of fresh fruits and vegetables is highly demanded. Currently used methods lead to losses in product amounts and quality. Furthermore, these methods go along with high costs and chemical residues. One reason for such problems is microbial contamination. Due to the fact that conventional decontamination processes are not suitable fo...

Today more and more thermo‐labile medical devices are applied, which have to be decontaminated with low‐temperature sterilization methods. One method under development is the low‐temperature plasma. For the comparability of the antimicrobial efficacy of two low‐temperature plasma setups in fine‐lumen polytetrafluoroethylene (PTFE) tubes, independen...

An innovative device capable of generating a cold atmospheric pressure plasma inside a 5?m long flexible tube with 2?mm inner diameter is presented. In order to analyze the inner-tube plasma, optical emission spectroscopy in the (vacuum) ultraviolet spectral range and Fourier transformed infrared spectroscopy were performed. By admixing small conce...

form only given. In modern medicine endoscopes are essential diagnostic and therapeutic tools. Due to their complex geometry, the thermolability of the used materials and the integrated sensitive electronics only a few sterilization techniques are applicable for this high cost medical product, e.g. sterilization with ethylene oxide (ETO) or the low...

Fine PTFE tubes are used in high-end and high cost devices like flexible Endoscopes where no standard sterilization procedure like autoclaving applies due to material properties. The study of innovative decontamination processes like plasma sterilization request appropriate analysis methods in order to verify the process functionality. In a related...

The aim of this article is to provide a survey of plasma sources at atmospheric pressure used for microbicidal treatment. In order to consider the interdisciplinary character of this topic an introduction and definition of basic terms and procedures is given for plasma as well as for microbicidal issues. The list of plasma sources makes no claim to...

Zunehmende Transportwege aufgrund sich ausdehnender urbaner Zonen und wachsender Märkte im Zuge der Globalisierung führen zu steigenden Ansprüchen an Verpackungen für verderbliche Produkte. Die Haltbarkeit vieler Produkte wird bestimmt einerseits durch die mikrobiologische Belastung, andererseits durch Diffusion initiierte Abbauprozesse. Auf die Ve...

The use of the new cytoplasmic male sterility (CMS) source PEF1 in sunflower hybrid breeding requires markers closely linked to the restorer gene Rf_PEF1 necessary for fertility restoration of hybrids based on the PEF1 cytoplasm as well as diagnostic markers to distinguish the PEF1 cytoplasm from other cytoplasms. Bulked segregant analyses of 256 A...

Introduction: Failure to induce apoptosis is a hallmark of cancer. Exogenous TNFrelated apoptosis inducing ligand (TRAIL) administration has therefore been proposed as novel approach for the treatment of tumors. While first clinical reports confirm the safety of TRAIL administration, the issue of resistance of many tumors to TRAIL still represents...