A Cold Plasma Technology for Ensuring the Microbiological Safety and Quality of Foods

A Review of Non-thermal Interventions in Food Processing Technologies

Foodborne pathogens and spoilage microorganisms continue to be a concern throughout the food industry. As a result, these problematic microorganisms are the cause of foodborne outbreaks, foodborne illness, and premature spoilage-related issues. To address these, thermal technologies have been applied and have a documented history of controlling these microorganisms. Although beneficial, some of these technologies may result in adverse quality effects that can interfere with consumer acceptability. Processors of fresh produce also need technologies to mitigate pathogens with the ability to retain raw quality. In addition, thermal technologies can also result in the reduction or depletion of key nutrients. Consumers of today are health conscious and are concerned with key nutrients in food products necessary for their overall health; this reduction and depletion of nutrients could be considered unacceptable in the eyes of consumers. As a result of this, the food industry works to increase the use of nonthermal technologies to control pathogens and spoilage microorganisms in varying sections of the industry. This review paper will focus on the control of foodborne pathogens and spoilage organisms along with the effects on quality in various food products by the use of pulsed electric field, pulsed light, ultraviolet light, ozonation, cold atmospheric plasma, ultrasound, and ionizing radiation.

The Application of Cold Atmospheric Plasma (CAP) in Barley Processing as an Environmentally Friendly Alternative

Cold atmospheric plasma (CAP) is a novel and versatile technology, which is not yet used in the food and agricultural sector for barley processing. In lab-scale applications, the technology shows potential in extending shelf life and ensuring food safety and quality, e.g., during storage. CAP reactive nature counteracts insect pests, fungi, and bacteria, but also improves seed germination and facilitates plant growth not only under stress conditions. Its generation does not require water, chemicals, or solvents and consumes little energy due to low operating temperatures (<60 °C) with a short time span that makes additional production steps (e.g., cooling) obsolete. Therefore, CAP is a sustainable technology capable of further optimising the use of limited resources with the potential of offering solutions for upcoming environmental challenges and political requirements for replacing existing practices and technologies due to the growing impact of climate change. This review summarises recent developments and findings concerning CAP application in barley production and processing with air as the process gas. Furthermore, this comprehensive overview could help identify further research needs to overcome its current technical limitations, e.g., efficiency, capacity, etc., that hamper the upscale and market introduction of this environmentally friendly technology.

Comprehensive review for aflatoxin detoxification with special attention to cold plasma treatment

Aflatoxins are potent carcinogens and pose significant risks to food safety and public health worldwide. Aflatoxins include Aflatoxin B1 (AFB1), Aflatoxin B2 (AFB2), Aflatoxin G1 (AFG1), Aflatoxin G2 (AFG2), and Aflatoxin M1 (AFM1). AFB1 is particularly notorious for its carcinogenicity, classified as a Group 1 human carcinogen by the International Agency for Research on Cancer (IARC). Chronic exposure to aflatoxins through contaminated food and feed can lead to liver cancer, immunosuppression, growth impairment, and other systemic health issues. Efforts to mitigate aflatoxin contamination have traditionally relied on chemical treatments, physical separation methods, and biological degradation. However, these approaches often pose challenges related to safety, efficacy, and impact on food quality. Recently, cold plasma treatment has emerged as a promising alternative. Cold plasma generates reactive oxygen species, which effectively degrade aflatoxins on food surfaces without compromising nutritional integrity or safety. This review consolidates current research and advancements in aflatoxin detoxification, highlighting the potential of cold plasma technology to revolutionize food safety practices. By exploring the mechanisms of aflatoxin toxicity, evaluating existing detoxification methods, and discussing the principles and applications of cold plasma treatment.

Cold plasma: A nonthermal pretreatment, extraction, and solvent activation technique for obtaining bioactive compounds from agro-food industrial biomass

The present review provides a comprehensive overview of cold plasma treatment and its applications in solvent activation and bioactive component extraction. The study has summarized the principles, types, uses, and mechanisms of cold plasma treatment in activating various solvents, extracting biomolecules, and affecting the characteristics of the extracted compound. This review also explores the environmental benefits of implementing this sustainable technology, highlighting the influence of key parameters such as gas type, treatment time, voltage, and plasma flow rate on the extraction process, providing insights into optimizing these conditions for maximum efficiency. In addition, future trends and research needs for advancing cold plasma-assisted extraction have also been proposed. All biomolecules exhibit specific characteristics; still, the influence of cold plasma treatment varies depending on treatment parameters and product properties, including the source material utilized in the extraction process. Most research has shown that cold plasma treatment can cause cell disruption due to reactive species generation and enhances solvent penetration; thereby, it helps in improving extraction yield with negligible effects on characteristics. With the growing demand for natural bioactive compounds in the nutraceutical, pharmaceutical, and food sectors, cold plasma offers a promising alternative to conventional thermal and chemical extraction techniques. This review concisely discusses the benefits and challenges of cold plasma treatment and the need for additional research.

Research Progress in Coconut Water: A Review of Nutritional Composition, Biological Activities, and Novel Processing Technologies

Coconut (Cocos nucifera L.) is a nutrient-rich plant extensively cultivated in tropical and subtropical regions. Coconut water (CW), the primary edible component of the fruit, has gained significant attention due to its nutritional value and increasing popularity as a functional beverage. In addition to its hydrating properties, CW is rich in essential nutrients such as sugars, minerals, and vitamins, which contribute to its diverse biological activities, including antioxidant, anti-inflammatory, anti-cancer, cardioprotective, and antimicrobial effects. However, CW's high perishability and susceptibility to rapid deterioration present significant challenges for its preservation. The growing demand for natural and fresh CW has driven the development of innovative technologies aiming at extending its shelf life while maintaining its nutritional quality and sensory attributes. This review highlights recent research advancements in CW, focusing on its nutritional composition, biological activities, and innovations in preservation technologies. The aim is to facilitate the optimization of CW beverage formulations, promote the adoption of effective preservation methods, and drive the development of high-quality and consumer-appealing CW products.

Cold plasma as an emerging catalytic route for oil modification

The effect of cold plasma on the oxidation, hydrogenation, transesterification, and pyrolysis reactions is investigated. Also, the effect of cold plasma parameters on these reactions and the advantages and challenges of cold plasma are investigated. Cold plasma can produce low-trans partial hydrogenated oil at low temperature without catalyst. Besides, oil modified through transesterification and pyrolysis processes using cold plasma technique can be used for biofuel production. Oxidation during cold plasma treatment can be inhibited by omitting the oxygen from carrier gas and applying the lowest possible input power and treatment time. One of the main challenges of using dielectric barrier discharge device at large scale is providing high plasma intensity for large amounts of raw materials. In microwave discharge plasma device, high capital investment is the main challenge for scaling up. In conclusion, cold plasma technique can hydrogenate and transesterify oils at low temperature.

Insight into formation and structure of wheat starch-lauric acid complexes by extrusion: Effect of plasma-activated water

The objective of this study is to examine how plasma-activated water (PAW) affects the formation of complexes between wheat starch (WS) and lauric acid (LA) during extrusion. The findings from various analysis, including complexing index, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and differential scanning calorimetry, revealed that PAW promoted the formation of WS-LA complexes during extrusion, resulting in a better long-range and short-range ordered structure, as well as higher gelatinization enthalpy. Consequently, PAW led to lower solubility, swelling power, gel property, and rapidly digestible starch content but higher resistant starch content. Notably, the promotional impact of PAW60 (distilled water underwent plasma treatment for 60 s) was greater than PAW120 (distilled water underwent plasma treatment for 120 s) and PAW180 (distilled water underwent plasma treatment for 180 s). This study provides an efficacious technique to enhance the formation of starch complexes, being of great value in starch-based functional foods.

The Effects of Cold-Plasma Technology on the Quality Properties of Fresh-Cut Produce: A Review

With improving economic conditions, consumer demand for fresh-cut produce is rising. The development of the fresh-cut industry has been hindered by pathogenic contamination and quality deterioration. Scientific communities have developed novel preservation technologies for fresh-cut produce. As an innovative non-thermal processing method, cold plasma effectively preserves the nutritional value and inactivates pathogens in fresh-cut produce. This review delineates the principles of cold-plasma generation and concludes with the primary factors influencing its efficacy. These factors include the specifications and parameters of the equipment utilized, the properties of the conductive gas utilized, the method of treatment, and the intrinsic properties of a sample subjected to treatment. Furthermore, this review delineates various scenarios for cold-plasma applications. This review focuses on its effects on enzymatic activities (including peroxidase, polyphenol oxidase, and pectin methylesterase), pathogenic microorganisms, and nutritional value. This review concludes with the potential application of cold-plasma technology in the processing of fresh-cut products. This study proposes advancing plasma technology in fresh-cut produce processing by (1) optimizing cold-plasma parameters for diverse fruit and vegetable varieties and (2) scaling up to facilitate industrial application.

Rapid changes in stress-related gene expression after short exposure of Arabidopsis leaves to cold plasma

Cold Atmospheric Plasma (CAP) technology has emerged as a promising tool in various biological applications due to its ability to generate a composite signal comprising reactive oxygen and nitrogen species, ultraviolet radiation, and electromagnetic fields, all while maintaining a stable temperature. Although CAP treatments have demonstrated significant effects on seed germination and plant growth, the direct molecular responses of plants to CAP exposure remain poorly understood. In this study, young Arabidopsis thaliana leaves were exposed to a brief 5- or 30-s localized CAP treatment, resulting in rapid and localized tissue damage without causing lethal effects on the entire plant. Molecular analyses conducted on the entire plant rosette revealed a notable increase in hydrogen peroxide levels, along with the upregulation of stress-related genes, akin to a wound response. Of particular interest, the activation of RelA/SpoT Homolog (RSH) genes encoding proteins that regulate the synthesis of the stress marker (p)ppGpp, also known as alarmone, and playing a major role in the energic regulation of photosynthesis, occurred shortly after CAP exposure. The expression of RSH genes was up-regulated after 5s CAP exposure, while the wound stress marker ZAT12 remained unaffected, highlighting a specific signalling pathway to activate RSH genes. This finding suggests the potential involvement of the alarmone signalling pathway in the plant's response to CAP exposure, thereby opening avenues for further exploration of metabolic pathways and signalling cascades induced by CAP treatment.

Possibilities of Application of Cold Atmospheric Pressure Plasmas in Dentistry—A Narrative Review

According to the World Human Organization (WHO), dental and periodontal diseases are common among the human population. Traditional dentistry offers a wide range of methods for treating oral diseases and performing esthetic procedures. In contrast, cold atmospheric pressure plasma (CAPP) has been found to be a promising technology in multiple fields, particularly in medical sciences such as dentistry. In this study, CAPP might be a promising adjunct to conventional dental treatments. A substantial number of studies have confirmed the effectiveness of both direct and indirect CAPP applications in dentistry. Because CAPP technology is fast, inexpensive, and noninvasive, we aim to review recent literature focused on the application of this methodology in dentistry.

Effects of different cold plasma treatments on chemical composition, phenolics bioaccessibility and microbiota of edible red mini-roses

This study evaluated the effect of dielectric barrier discharge (DBD) and glow discharge (glow) cold plasma treatments in color, sugars, organic acids, phenolics (concentration and bioaccessibility), antioxidant activity, volatiles, and microbiota of edible mini-roses. Plasma treatments did not affect the flowers' color, while they increased organic acids and phenolics. Flowers treated with DBD had a higher concentration of most phenolics, including hesperidin (84.04 μg/g) related to antioxidant activity, and a higher mass fraction of most volatiles, including octanal (16.46% after 5 days of storage). Flowers treated with glow had a higher concentration of pelargonidin 3,5-diglucoside (392.73 μg/g), greater bioaccessibility of some phenolics and higher antioxidant activity. Plasma treatments reduced the microbiota diversity in mini-roses. Regardless of the plasma treatment, phylum Proteobacteria, family Erwiniaceae, and genus Rosenbergiella were the dominant groups. Results indicate plasma treatments as promising technologies to improve the quality and increase phenolic and specific volatile compounds in mini-roses.

Cold plasma technology: does it have a place in food processing?

In recent years, there has been a growing demand for alternative food processing technologies that can improve food safety while preserving the nutritional quality of food products. Traditional thermal processing methods can lead to nutrient loss and degradation, prompting the exploration of novel approaches. Cold plasma (CP) technology, an emerging non-thermal food processing technique, has gained significant attention for its potential in the food industry. We provide herein, an introduction to CP and an overview of the technology, highlighting its potential advantages in safety, efficiency, and environmental friendliness.

Bioaerosol Inactivation by a Cold Plasma Ionizer Coupled with an Electrostatic Precipitator

Despite best efforts in air purification, airborne infectious diseases will continue to spread due to the continuous emission of bioaerosols by the host/infected person. Hence, a shift in focus from air purification to bioaerosol inactivation is urgently needed. To explore the potential of the cold plasma technology for preventing rapid spread of airborne infectious diseases, we studied a cold plasma ionizer (CPI) device and an electrostatic precipitator (ESP)-coupled CPI (CPI-ESP) device for the inactivation and cleaning of surface-spread microorganisms and bioaerosols, using porcine respiratory coronavirus (PRCV), Escherichia coli (E. coli), and aerosolized E. coli as representatives. We firstly demonstrated that CPI coupled with ESP is an effective technology for inactivating virus and bacteria spread on surfaces in an in-house test chamber. We then demonstrated the efficacy of CPI-coupled ESP for the inactivation of aerosolized E. coli in the same chamber. Furthermore, we have demonstrated the efficiency of a CPI-ESP coupled device for the inactivation of naturally occurring airborne microbials in a few indoor settings (i.e., a living room, a discussion room, a schoolroom, and an office) to determine the treatment duration- and human activity-dependent efficacy. To understand the disinfection mechanism, we conducted a fluorescence microscopy study to reveal different degrees of E. coli bacteria cell membrane damage under CPI treatment.

Study on hand disinfection in inpatient geriatric care on the superiority of cold plasma aerosol versus alcohol-based disinfection methods in a parallel group design

The introduction of fundamental hygiene protocols within the healthcare sector during the nineteenth century led to a significant reduction in mortality rates. Contemporary advancements, such as alcohol-based sanitizers, have further enhanced hand hygiene practices. However, these measures are often overlooked in nursing facilities, resulting in low staff compliance rates and increased cross-infection rates. Novel approaches, such as cold plasma hand disinfection, present promising alternatives due to their minimal skin damage and economic benefits. This study aims to compare the disinfectant efficacy of cold plasma aerosol under practical application conditions with an alcoholic hand disinfectant listed by the Association for Applied Hygiene. The microbial count on participants' hands was measured, with particular attention paid to the spontaneous occurrence of fecal indicators and the presence of potentially infectious bacteria. A t-test for independent samples was conducted to determine whether there was a significant difference between the two cohorts regarding the research question. Statistical analysis revealed that the mean log colony-forming unit (CFU) values were significantly lower in the test cohort using only the cold plasma method for hand disinfection compared to the cohort using conventional alcohol-based hand disinfection. Moreover, it was demonstrated that, unlike alcohol-based hand disinfection, cold plasma application ensures the effective elimination of Staphylococcus aureus. The findings indicate that staff utilizing plasma disinfection have an average bacterial count that is 0.65 log units lower than those who regularly use alcohol-based hand disinfection. In addition to the efficacy of cold plasma disinfection, its superiority over alcohol-based hand disinfection was also established. Beyond offering economic and logistical advantages, cold plasma disinfection provides additional health benefits as it does not induce skin damage, unlike alcohol-based hand disinfection.

Transcriptome analysis of Candida albicans planktonic cells in response to plasma medicine

Introduction. Cold plasma is frequently utilized for the purpose of eliminating microbial contaminants. Under optimal conditions, it can function as plasma medicine for treating various diseases, including infections caused by Candida albicans, an opportunistic pathogen that can overgrow in individuals with weakened immune system.Gap Statement. To date, there has been less molecular study on cold plasma-treated C. albicans.Research Aim. The study aims to fill the gap in understanding the molecular response of C. albicans to cold plasma treatment.Methodology. This project involved testing a cold plasma generator to determine its antimicrobial effectiveness on C. albicans' planktonic cells. Additionally, the cells' transcriptomics responses were investigated using RNA sequencing at various treatment durations (1, 3 and 5 min).Results. The results show that our cold plasma effectively eliminates C. albicans. Cold plasma treatment resulted in substantial downregulation of important pathways, such as 'nucleotide metabolism', 'DNA replication and repair', 'cell growth', 'carbohydrate metabolism' and 'amino acid metabolism'. This was an indication of cell cycle arrest of C. albicans to preserve energy consumption under unfavourable conditions. Nevertheless, C. albicans adapted its GSH antioxidant system to cope with the oxidative stress induced by reactive oxygen species, reactive nitrogen species and other free radicals. The treatment likely led to a decrease in cell pathogenicity as many virulence factors were downregulated.Conclusion. The study demonstrated the major affected pathways in cold plasma-treated C. albicans, providing valuable insights into the molecular response of C. albicans to cold plasma treatment. The findings contribute to the understanding of the antimicrobial efficiency of cold plasma and its potential applications in the field of microbiology.

Cold plasma: A success road to mycotoxins mitigation and food value edition

Mycotoxins are common in many agricultural products and may harm both animals and humans. Dietary mycotoxins are reduced via physical, chemical, and thermal decontamination methods. Chemical residues are left behind after physical and chemical treatments that decrease food quality. Since mycotoxins are heat-resistant, heat treatments do not completely eradicate them. Cold plasma therapy increases food safety and shelf life. Cold plasma-generated chemical species may kill bacteria quickly at room temperature while leaving no chemical residues. This research explains how cold plasma combats mold and mycotoxins to guarantee food safety and quality. Fungal cells are damaged and killed by cold plasma species. Mycotoxins are also chemically broken down by the species, making the breakdown products safer. According to a preliminary cold plasma study, plasma may enhance food shelf life and quality. The antifungal and antimycotoxin properties of cold plasma benefit fresh produce, agricultural commodities, nuts, peppers, herbs, dried meat, and fish.

Cold Atmospheric Pressure Plasma Solutions for Sustainable Food Packaging

Increasing the number of resistant bacteria resistant to treatment is one of the leading causes of death worldwide. These bacteria are created in wounds and injuries and can be transferred through hospital equipment. Various attempts have been made to treat these bacteria in recent years, such as using different drugs and new sterilization methods. However, some bacteria resist drugs, and other traditional methods cannot destroy them. In the meantime, various studies have shown that cold atmospheric plasma can kill these bacteria through different mechanisms, making cold plasma a promising tool to deactivate bacteria. This new technology can be effectively used in the food industry because it has the potential to inactivate microorganisms such as spores and microbial toxins and increase the wettability and printability of polymers to pack fresh and dried food. It can also increase the shelf life of food without leaving any residue or chemical effluent. This paper investigates cold plasma's potential, advantages, and disadvantages in the food industry and sterilization.

Insights into Cold Plasma Treatment on the Cereal and Legume Proteins Modification: Principle, Mechanism, and Application

Cereal and legume proteins, pivotal for human health, significantly influence the quality and stability of processed foods. Despite their importance, the inherent limited functional properties of these natural proteins constrain their utility across various sectors, including the food, packaging, and pharmaceutical industries. Enhancing functional attributes of cereal and legume proteins through scientific and technological interventions is essential to broadening their application. Cold plasma (CP) technology, characterized by its non-toxic, non-thermal nature, presents numerous benefits such as low operational temperatures, lack of external chemical reagents, and cost-effectiveness. It holds the promise of improving proteins' functionality while maximally retaining their nutritional content. This review delves into the pros and cons of different cold plasma generation techniques, elucidates the underlying mechanisms of protein modification via CP, and thoroughly examines research on the application of cold plasma in augmenting the functional properties of proteins. The aim is to furnish theoretical foundations for leveraging CP technology in the modification of cereal and legume proteins, thereby enhancing their practical applicability in diverse industries.

Innovative Application of Cold Plasma Technology in Meat and Its Products

The growing demand for sustainable food production and the rising consumer preference for fresh, healthy, and safe food products have been driving the need for innovative methods for processing and preserving food. In the meat industry, this demand has led to the development of new interventions aimed at extending the shelf life of meats and its products while maintaining their quality and nutritional value. Cold plasma has recently emerged as a subject of great interest in the meat industry due to its potential to enhance the microbiological safety of meat and its products. This review discusses the latest research on the possible application of cold plasma in the meat processing industry, considering its effects on various quality attributes and its potential for meat preservation and enhancement. In this regard, many studies have reported substantial antimicrobial efficacy of cold plasma technology in beef, pork, lamb and chicken, and their products with negligible changes in their physicochemical attributes. Further, the application of cold plasma in meat processing has shown promising results as a potential novel curing agent for cured meat products. Understanding the mechanisms of action and the interactions between cold plasma and food ingredients is crucial for further exploring the potential of this technology in the meat industry, ultimately leading to the development of safe and high-quality meat products using cold plasma technology.

Effect of Plasma On-Time with a Fixed Duty Ratio on Reactive Species in Plasma-Treated Medium and Its Significance in Biological Applications

Optimizing the therapeutic range of nonthermal atmospheric pressure plasma (NTAPP) for biomedical applications is an active research topic. For the first time, we examined the effect of plasma on-times in this study while keeping the duty ratio and treatment time fixed. We have evaluated the electrical, optical, and soft jet properties for two different duty ratios of 10% and 36%, using the plasma on-times of 25, 50, 75, and 100 ms. Furthermore, the influence of plasma on-time on reactive oxygen and nitrogen species (ROS/RNS) levels in plasma treated medium (PTM) was also investigated. Following treatment, the characteristics of (DMEM media) and PTM (pH, EC, and ORP) were also examined. While EC and ORP rose by raising plasma on-time, pH remained unchanged. Finally, the PTM was used to observe the cell viability and ATP levels in U87-MG brain cancer cells. We found it interesting that, by increasing the plasma on-time, the levels of ROS/RNS dramatically increased in PTM and significantly affected the viability and ATP levels of the U87-MG cell line. The results of this study provide a significant indication of advancement by introducing the optimization of plasma on-time to increase the efficacy of the soft plasma jet for biomedical applications.

Nonthermal Biocompatible Plasma Inactivation of Coronavirus SARS-CoV-2: Prospects for Future Antiviral Applications

The coronavirus disease (COVID-19) pandemic has placed a massive impact on global civilization. Finding effective treatments and drugs for these viral diseases was crucial. This paper outlined and highlighted key elements of recent advances in nonthermal biocompatible plasma (NBP) technology for antiviral applications. We searched for papers on NBP virus inactivation in PubMed ePubs, Scopus, and Web of Science databases. The data and relevant information were gathered in order to establish a mechanism for NBP-based viral inactivation. NBP has been developed as a new, effective, and safe strategy for viral inactivation. NBP may be used to inactivate viruses in an ecologically friendly way as well as activate animal and plant viruses in a number of matrices. The reactive species have been shown to be the cause of viral inactivation. NBP-based disinfection techniques provide an interesting solution to many of the problems since they are simply deployable and do not require the resource-constrained consumables and reagents required for traditional decontamination treatments. Scientists are developing NBP technology solutions to assist the medical community in dealing with the present COVID-19 outbreak. NBP is predicted to be the most promising strategy for battling COVID-19 and other viruses in the future.

Nonthermal Plasma Effects on Fungi: Applications, Fungal Responses, and Future Perspectives

The kingdom of Fungi is rich in species that live in various environments and exhibit different lifestyles. Many are beneficial and indispensable for the environment and industries, but some can threaten plants, animals, and humans as pathogens. Various strategies have been applied to eliminate fungal pathogens by relying on chemical and nonchemical antifungal agents and tools. Nonthermal plasma (NTP) is a potential tool to inactivate pathogenic and food-contaminating fungi and genetically improve fungal strains used in industry as enzyme and metabolite producers. The NTP mode of action is due to many highly reactive species and their interactions with biological molecules. The interaction of the NTP with living cells is believed to be synergistic yet not well understood. This review aims to summarize the current NTP designs, applications, and challenges that involve fungi, as well as provide brief descriptions of underlying mechanisms employed by fungi in interactions with the NTP components.