Chemical, physical and physiological quality attributes of fruit and vegetables induced by cold plasma treatment: Mechanisms and application advances

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.

Effect of Glow Discharge Cold Plasma Treatment on the Physicochemical Properties and Antioxidant Capacity of Maize

This study evaluated the effect of cold plasma (CP) on the physicochemical properties and antioxidant capacity of maize. CP treatments were performed using a glow discharge, applying argon and/or nitrogen at 50 W, with different working pressures (75, 100, and 125 Pa) and exposure times (1, 5, and 10 min). The maize samples were analyzed before and after treatments for color, fatty acid value (FAV), malondialdehyde content, superoxide dismutase and catalase activities, total phenol content (TPC), ascorbic acid content, reduced glutathione content, and antioxidant activity. The antioxidant activity was further evaluated during storage (25 °C for 180 days). After treatments, color parameters (brightness, yellowness, and saturation) showed measurable enhancement, while FAV and malondialdehyde content were significantly reduced by 14.95-56.37% and 11.38-43.71%, respectively. The optimal treatment conditions (100 Pa working pressure and 5 min exposure) maximized antioxidant enzyme activities and bioactive compound levels, accompanied by substantial increases in TPC. Under these conditions, maize samples had the highest organic radical scavenging capacities (DPPH), reaching 1.31-fold (argon plasma) and 1.25-fold (nitrogen plasma) that of untreated sample. During storage, all samples subjected to the optimal combined treatment exhibited higher DPPH radical scavenging capacity and ferric reducing antioxidant potential, along with lower FAVs and malondialdehyde contents compared to the untreated sample. Additionally, the DPPH radical scavenging capacity exhibited statistically inverse correlations with both FAV (r2 = -0.49) and malondialdehyde content (r2 = -0.15), as quantified through Pearson correlation analysis. These findings indicated that glow discharge cold plasma is a potentially effective non-thermal processing technique to enhance bioactive compound accumulation and antioxidant enzyme activity for preserving maize's physicochemical properties, with possible use in the food industry for sustainable grain preservation strategies, particularly in delaying oxidative deterioration.

Cold Plasma-A Sustainable Energy-Efficient Low-Carbon Food Processing Technology: Physicochemical Characteristics, Microbial Inactivation, and Industrial Applications

Nonthermal technologies, mostly utilized for microbial inactivation and quality preservation in food, are attracting increased interest, particularly in nonthermal plasma. Cold plasma (CP) demonstrates favorable results, such as increased germination, enhanced functional and rheological characteristics, and the eradication of microorganisms. Consequently, CP is a novel technology in food processing that has significantly contributed to the prevention of food spoilage. This study highlights contemporary research on CP technology in food processing. This includes its use in microbial decontamination, shelf life extension, mycotoxin degradation, enzyme inactivation, and surface modification of food products. The CP generation techniques under low pressure, including glow discharge, radio frequency and microwave techniques, and atmospheric pressure, including dielectric barrier discharge (DBD), plasma jet, and corona discharge, are discussed. Additionally, the source for the generation of plasma-activated water (PAW) with its significant role in food processing is critically discussed. The CP is an effective method for the decontamination of several food materials like fruits, vegetables, meat, and low-moisture food products. Also, the review addressed the effects of CP on the physicochemical properties of foods and CP for pretreatment in various aspects of food processing, including drying of food, extraction of bioactive compounds, and oil hydrogenation. CP improved the drying kinetics of food, resulting in reduced processing time and improved product quality. Similarly, CP is effective in maintaining food safety and quality, removing the formation of biofilm, and also in reducing protein allergenicity. The review also underscored the importance of CP as a sterilizing agent for food packaging materials, emphasizing its role in enhancing the barrier characteristics of biopolymer-based food packaging materials. Therefore, it is concluded that CP is effective in the reduction of pathogenic microorganisms from food products. Moreover, it is effective in maintaining the nutritional and sensory properties of food products. Overall, it is effective for application in all aspects of food processing. There is a critical need for ongoing research on upscaling for commercial purposes.

Reduced graphene oxide prepared by cold plasma green treatment in liquid phase for fluorescence biosensing of tropomyosin in shrimp

Graphene oxide (GO), renowned for its two-dimensional structure and exceptional fluorescence quenching capabilities, is a preferred choice for the construction of fluorescence biosensors. As the sensitivity demands for these sensors escalate, enhancing the fluorescence quenching performance of GO and reducing background fluorescence become paramount to optimize the sensor sensitivity. In this study, the use of cold plasma (CP) treatment with glucose solution as a reducing agent to refine GO into reduced graphene oxide (r-GO) with optimal fluorescence quenching abilities was explored. The efficacy of CP treatment was comprehensively analyzed, encompassing fluorescence quenching capacity, morphological alterations, and structural composition. The findings revealed that the ideal conditions for achieving r-GO with superior fluorescence quenching were achieved by treating a mixture of 0.5 mg/mL GO and 0.2 g/mL glucose with CP at 100 kV and 1 A for 10 min. Notably, the resulting r-GO demonstrated remarkable performance in the specific detection of tropomyosin in shrimp, achieving a detection limit of 0.0657 μg/mL, demonstrating its potential for highly sensitive biosensing applications.

Low-pressure cold plasma pretreatment: Impact on quality attributes of "Fan Retief" guava and efficacy against Colletotrichum gloeosporioides

This work investigated the impact of low-pressure cold plasma (CP) as a pretreatment with polyethylene terephthalate (PET) plastic trays or open corrugated cardboard (OCC) boxes on the overall quality of "Fan Retief" guava fruits stored for 28 days at 13°C. Untreated samples placed in PET and OCC served as control. Guava fruits followed typical climacteric responses, but CP-treated samples significantly slowed down respiration (RRCO2) and ethylene production rate during storage (p ≤ 0.05). On day 28, CP-treated samples retained the highest titratable acidity and total phenolics compared to untreated samples (p ≤ 0.05). Overall, CP pretreatment better maintained the relative abundance of characteristic volatile compounds for guava fruits during storage, effectively delayed decay incidence, and inhibited the growth of Colletotrichum gloeosporioides in vivo compared to control. PRACTICAL APPLICATION: This study demonstrated low-pressure cold plasma as a potential alternative phytosanitary tool for the postharvest handling of guava fruit.

Modifying of non-nutritional compounds in legumes: Processing strategies and new technologies

Legumes are consumed worldwide, are notable for their nutritional quality, however, contain certain non-nutritional compounds (NNCs) that can affect the absorption of nutrients, though these may exhibit bioactive properties. Various processing methods can modify the concentration of NNCs, including soaking and germination. These methods can be combined with other thermal, non-thermal, and bioprocessing treatments to enhance their efficiency. The efficacy of these methods is contingent upon the specific types of NNCs and legume in question. This work examines the effectiveness of these processing methods in terms of modifying the concentration of NNCs present in legumes as well as the potential use of emerging technologies, to enhance the level of NNCs modification in legumes. These technologies could increase the functional use of legume flours, potentially leading to new opportunities for incorporating legume-based ingredients in a range of culinary applications, thereby enhancing the diets of many individuals worldwide.

Prospects of cold plasma in enhancing food phenolics: analyzing nutritional potential and process optimization through RSM and AI techniques

Consumption of plant-based food is steadily increasing and follows an augmented trend owing to their nutritive, functional, and energy potential. Different bioactive fractions, such as phenols, flavanols, and so on, contribute highly to the nutritive profile of food and are known to have a sensitivity toward higher temperatures. This limits the applicability of traditional thermal treatments for plant products, paving the way for the advancement of innovative and non-thermal techniques such as pulsed electric field, microwave, ultrasound, cold plasma, and high-pressure processing. Among these techniques, cold plasma would be an operative choice in plant-based applications due to their higher efficacy, greenness, chemical exclusivity, and quality retention. The efficiency of the plasma process in ensuring the bioactive potential depends on several factors, such as feeding gas, input voltage, exposure time, pressure, and current flow. This review explains in detail the optimization of process parameters of the cold plasma technique, ensuring greater extractability or retention of total phenols and antioxidant potential. Response surface methodology (RSM) is one of the common techniques involved in the optimization of these course factors. It also covers the convention of artificial intelligence-based methods, such as artificial neural networks (ANN) and genetic algorithms (GA), in evaluating the data on process parameters. The review critically examines the strengths of each optimization tool in determining the optimal process parameters for maximizing phenol retention and antioxidant activity. The ascendancy of these techniques was mentioned in the studies regarding fruit, vegetables, and their products, and they can also be applied to other food products.

Enhancing drying characteristics and quality of fruits and vegetables using biochemical drying improvers: A comprehensive review

Traditional drying is a highly energy-intensive process, accounting for approximately 15% of total manufacturing cost, it often resulting in reduced product quality due to low drying efficiency. Biological and chemical agents, referred to as biochemical drying improvers, are employed as pretreatments to enhance both drying characteristics and quality attributes of fruits and vegetables. This article provides a thorough examination of various biochemical drying improvers (including enzymes, microorganisms, edible film coatings, ethanol, organic acids, hyperosmotic solutions, ethyl oleate alkaline solutions, sulfites, cold plasma, carbon dioxide, ozone, inorganic alkaline agents, and inorganic salts) and their effects on improving the drying processes of fruits and vegetables. Additionally, it introduces physical drying improvers (including ultrasonic, pulsed electric field, vacuum, and others) to enhance the effects of biochemical drying improvers. Pretreatment with biochemical agents not only significantly enhances drying characteristics but also preserves or enhances the color, texture, and bioactive compound content of the dried products. Meanwhile, physical drying improvers reduce moisture diffusion resistance through physical modifications of the food materials, thus complementing biochemical drying improvers. This integrated approach mitigates the energy consumption and quality degradation typically associated with traditional drying methods. Overall, this review examines the role of biochemical agents in enhancing the drying characteristics and quality of fruits and vegetables, offering a comprehensive strategy for energy conservation and quality improvement.

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.

Investigation of the impact of cold plasma pretreatments, long term storage and drying on physicochemical properties, bioactive contents and microbial quality of 'Keitt' mango

There is heightened demand for dried mango fruits with desired nutritional and physicochemical qualities, microbiologically stable and chemical residue free. This has led to the exploration of innovative preservation technologies for the extension of storability prior to processing. This study investigated the impact of cold plasma (CP) treatment on physicochemical properties and microbial stability in fresh and dried 'Keitt' mango during long term storage. Freshly harvested 'Keitt' mangoes were subjected to: CP treatment (for 5 min (CP5) and 10 min, CP10), dipping in "Chronos Prochloraz" for 30 s (industry practice), and untreated group (control). All samples were stored at 11 °C for 30 days, prior to minimal processing and hot air drying at 60 °C. Results after 30 days of storage demonstrated that untreated samples (control) had the highest TSS (15.06 ± 0.32 °Brix), while CP10 pretreated samples had the lowest TSS (13.80 ± 0.06 °Brix) value (p ≤ 0.05). In comparison to the fresh samples post storage, all pretreated dried mango slices retained lower total flavanols with CP5 (13.49 ± 1.64 mg GAE 100/g), CP10 (20.12 ± 1.42 mg GAE 100/g) and SMB (23.89 ± 3.35 mg GAE 100/g), but higher than the dried untreated samples (6.68 ± 0.53 mg GAE 100/g). Yellowness (b∗) of the fresh pulp (38.53 ± 1.73) increased significantly (p ≤ 0.05) with the long-term storage (39.88-46.74) and drying (55.01-64.90). CP pre-treatment combined with drying resulted in ≥2 Log reduction in microbial count. This study shows the potential of cold plasma as a pretreatment for extending storability and maintaining the quality of 'Keitt' mangoes.

Dielectric Barrier Discharge Cold Plasma Improves Storage Stability in Paddy Rice by Activating the Phenylpropanoid Biosynthesis Pathway

A nonthermal pretreatment using dielectric barrier discharge cold plasma (DBD-CP) was developed to improve the stress resistance of paddy rice during postharvest storage. The physicochemical properties, bioactive characteristics, and secondary metabolites of paddy rice were assessed after applying an optimized DBD-CP procedure, with enzyme activities and gene expression monitored over a 60 day storage period at 35 °C. A 17.06% reduction in the total color change index was noted in the DBD-CP group. Bioactive compounds, particularly gallic acid, were significantly increased, enhancing the defense mechanisms against high-temperature stress. Nontargeted metabolomics analysis indicated an upregulation of phenylpropanoid metabolism in DBD-CP-treated rice compared to controls, with notable increases in secondary metabolites such as coumaric acid, caffeic acid, and sinapic acid, suggesting potential biomarkers for stress resistance. Further verification showed significant enhancements in key enzymes of phenylpropanoid metabolism, including phenylalanine ammonia lyase (PAL), cinnamic acid-4-hydroxylase (C4H), plant coumaric acid-3-hydroxylase (C3H), and cinnamyl alcohol dehydrogenase (CAD), with increases ranging from 1.71 to 2.28 times. Gene expression levels of OsPAL7, OsC4H4, and OsCAD2 aligned with these enzymatic changes post-DBD-CP treatment. In conclusion, DBD-CP treatment can modulate phenylpropanoid metabolism in paddy rice, thereby enhancing bioactive compound levels to reduce stress damage during high-temperature storage.

Functional Nutrients and Jujube-Based Processed Products in Ziziphus jujuba

Jujube (Ziziphus jujuba Mill.) is the first tree species in China, with a long history and abundant yield. However, fresh jujubes have a short shelf-life and are not resistant to storage. Therefore, more and more processed jujube products are being studied. These processed products can extend the shelf-life of jujubes and attract widespread attention for their rich functional nutrients. This review summarized changes in nutrients of fresh jujube and processed products and the research progress of different preparation methods of jujubes. Meanwhile, the pharmacological effects of bioactive components in jujube-based products were concluded. Jujube and its processed products contain rich polysaccharides, vitamin C, and other functional nutrients, which are beneficial to humans. As the initial processing method for jujubes, vacuum freezing or microwave drying have become the most commonly used and efficient drying methods. Additionally, processed jujube products cannot be separated from the maximum retention of nutrients and innovation of flavor. Fermentation is the main deep-processing method with broad development potential. In the future, chemical components and toxicological evaluation need to be combined with research to bring consumers higher quality functional jujube products and ensure the sustainable development of the jujube industry.

Chemical and physical changes induced by cold plasma treatment of foods: A critical review

Cold plasma treatment is an innovative technology in the food processing and preservation sectors. It is primarily employed to deactivate microorganisms and enzymes without heat and chemical additives; hence, it is often termed a "clean and green" technology. However, food quality and safety challenges may arise during cold plasma processing due to potential chemical interactions between the plasma reactive species and food components. This review aims to consolidate and discuss data on the impact of cold plasma on the chemical constituents and physical and functional properties of major food products, including dairy, meat, nuts, fruits, vegetables, and grains. We emphasize how cold plasma induces chemical modification of key food components, such as water, proteins, lipids, carbohydrates, vitamins, polyphenols, and volatile organic compounds. Additionally, we discuss changes in color, pH, and organoleptic properties induced by cold plasma treatment and their correlation with chemical modification. Current studies demonstrate that reactive oxygen and nitrogen species in cold plasma oxidize proteins, lipids, and bioactive compounds upon direct contact with the food matrix. Reductions in nutrients and bioactive compounds, including polyunsaturated fatty acids, sugars, polyphenols, and vitamins, have been observed in dairy products, vegetables, fruits, and beverages following cold plasma treatment. Furthermore, structural alterations and the generation of volatile and non-volatile oxidation products were observed, impacting the color, flavor, and texture of food products. However, the effects on dry foods, such as seeds and nuts, are comparatively less pronounced. Overall, this review highlights the drawbacks, challenges, and opportunities associated with cold plasma treatment in food processing.

Evaluation of degradation efficacy and toxicity mitigation for 4-nitrophenol using argon and air-mixed argon plasma jets

This paper investigates the effects of argon (Ar) and that of Ar mixed with ambient air (Ar-Air) cold plasma jets (CPJs) on 4-nitrophenol (4-NP) degradation using low input power. The introduction of ambient air into the Ar-Air plasma jet enhances ionization-driven processes during high-voltage discharge by utilizing nitrogen and oxygen molecules from ambient air, resulting in increased reactive oxygen and nitrogen species (RONS) production, which synergistically interacts with argon. This substantial generation of RONS establishes Ar-Air plasma jet as an effective method for treating 4-NP contamination in deionized water (DW). Notably, the Ar-Air plasma jet treatment outperforms that of the Ar jet. It achieves a higher degradation rate of 97.2% and a maximum energy efficiency of 57.3 gkW-1h-1, following a 6-min (min) treatment with 100 mgL-1 4-NP in DW. In contrast, Ar jet treatment yielded a lower degradation rate and an energy efficiency of 75.6% and 47.8 gkW-1h-1, respectively, under identical conditions. Furthermore, the first-order rate coefficient for 4-NP degradation was measured at 0.23 min-1 for the Ar plasma jet and significantly higher at 0.56 min-1 for the Ar-Air plasma jet. Reactive oxygen species, such as hydroxyl radical and ozone, along with energy from excited species and plasma-generated electron transfers, are responsible for CPJ-assisted 4-NP breakdown. In summary, this study examines RONS production from Ar and Ar-Air plasma jets, evaluates their 4-NP removal efficacy, and investigates the biocompatibility of 4-NP that has been degraded after plasma treatment.

Novel Post-Harvest Preservation Techniques for Edible Fungi: A Review

Edible fungi are well known for their rich nutrition and unique flavor. However, their post-harvest shelf-life is relatively short, and effective post-harvest preservation techniques are crucial for maintaining their quality. In recent years, many new technologies have been used for the preservation of edible fungi. These technologies include cold plasma treatment, electrostatic field treatment, active packaging, edible coatings, antimicrobial photodynamic therapy, and genetic editing, among others. This paper reviews the new methods for post-harvest preservation of mainstream edible fungi. By comprehensively evaluating the relative advantages and limitations of these new technologies, their potential and challenges in practical applications are inferred. The paper also proposes directions and suggestions for the future development of edible fungi preservation, aiming to provide reference and guidance for improving the quality of edible fungi products and extending their shelf-life.

In vivo biological analysis of cold plasma on allergenicity reduction of tropomyosin in shrimp

In vivo biological regulations of the allergenicity of tropomyosin (TM) treated by cold plasma (CP) were investigated by in vivo mouse model. The sensitization models of Balb/c mice were successfully established. CP treatment reduced the allergic symptoms of mice and regulated the Th1/Th2 balance to prevent allergy by activating Treg cells, which was deduced by serum and cytokines analysis. For intestinal flora analysis, allergy occurrence was accompanied by the decreased species abundance and the increased species diversity of intestinal flora. The significant species composition difference between the TM group and the PBS group showed a possible connection between bacterial diversity and allergy. Furthermore, Firmicutes, Bacteroidetes, Parabacteroides, Alloprevotella, Bacteroides, and Lachnospiraceae could relate to allergy occurrence. Intestinal section analysis suggested that allergy occurrence was accompanied by the damaged intestinal structure, and CP treatment could relieve the damage caused by an allergy.

Cold atmospheric plasma fumigation suppresses postharvest apple Botrytis cinerea by triggering intracellular reactive oxygen species and mitochondrial calcium

Infection by Botrytis cinerea poses a great threat to the postharvest life of apple fruit. In this study, the effects of cold atmospheric plasma (CAP) fumigation on apple B. cinerea under different exposure times and intensities were investigated. The growth of B. cinerea in vitro and in vivo was significantly suppressed by the CAP fumigation at least 700 μL/L for 5 min. To reveal the possible mechanism of antifungal activity of CAP fumigation, the pathogen was exposed to 700 μL/L and 1000 μL/L for 5 min, respectively. The results indicated that the CAP-treated spores of the pathogen underwent shrinkage, cell membrane collapse and cytoplasmic vacuolation. The results obtained from the fluorescent probe assay and flow cytometry indicated that CAP caused the accumulation of reactive oxygen species (ROS), the elevation of mitochondrial and intracellular Ca2+ levels, and the decrease in mitochondrial membrane potential of the pathogen. Investigation on statues of cell life showed that typical hallmarks of apoptosis in the CAP-treated B. cinerea spores occurred, as indicted by a large degree of increased phosphatidylserine externalization, dysfunction of membrane permeability, DNA fragmentation, distortion of morphology, chromatin condensation, and metacaspase activation observed in B. cinerea spores after CAP fumigation. Overall, CAP fumigation triggered a metacaspase-dependent apoptosis of B. cinerea spores mediated by intracellular ROS burst and Ca2+ elevation via mitochondrial dysfunction and disruption, and therefore reduced the pathogenicity of B. cinerea and suppressed postharvest Botrytis rot of apple fruit. These results would provide an insight into the underlying mechanism of CAP fumigation acting on the pathogen. The CAP fumigation makes much convenient application of CAP in storage environment to deactivate microorganism.

Metabolomic and transcriptomic analysis of cold plasma promoting biosynthesis of active substances in broccoli sprouts

INTRODUCTION

Broccoli sprouts have great health and commercial value because they are rich in sulforaphane, a special bioactive compound that helps to prevent chronic diseases, such as cancer and cardiovascular disease.

OBJECTIVE

The aim of this study was to increase the levels of active substances in broccoli sprouts and understand their metabolic mechanisms.

METHODOLOGY

Metabolomics based on liquid chromatography-tandem mass spectrometry and transcriptome analysis were combined to analyse the enrichment of metabolites in broccoli sprouts treated with cold plasma.

RESULTS

After 2 min of cold plasma treatment, the contents of sulforaphane, glucosinolates, total phenols, and flavonoids, as well as myrosinase activity, were greatly improved. Transcriptomics revealed 7460 differentially expressed genes in the untreated and treated sprouts. Metabolomics detected 6739 differential metabolites, including most amino acids, their derivatives, and organic acids. Enrichment analyses of metabolomics and transcriptomics identified the 20 most significantly differentially expressed metabolic pathways.

CONCLUSIONS

Overall, cold plasma treatment can induce changes in the expression and regulation of certain metabolites and genes encoding active substances in broccoli sprouts.

Efficacy of cold plasma technology on the constituents of plant-based food products: Principles, current applications, and future potentials

Cold plasma (CP) is one of the novel non-thermal food processing technologies, which has the potential to extend the shelf-life of plant-based food products without adversely affecting the nutritional value and sensory characteristics. Besides microbial inactivation, this technology has been explored for food functionality, pesticide control, and allergen removals. Cold plasma technology presents positive results in applications related to food processing at a laboratory scale. This review discusses applications of CP technology and its effect on the constituents of plant-based food products including proteins, lipids, carbohydrates, and polar and non-polar secondary plant metabolites. As proven by the publications in the food field, the influence of CP on the food constituents and sensory quality of various food materials are mainly based on CP-related factors such as processing time, voltage level, power, frequency, type of gas, gas flow rate as well as the amount of sample, type, and content of food constituents. In addition to these, changes in the secondary plant metabolites depend on the action of CP on both cell membrane breakdown and increase/decrease in the scavenging compounds. This technology offers a good alternative to conventional methods by inactivating enzymes and increasing antioxidant levels. With a waterless and chemical-free property, this sustainable and energy-efficient technology presents several advantages in food applications. However, scaling up CP by ensuring uniform plasma treatment is a major challenge. Further investigation is required to provide information regarding the toxicity of plasma-treated food products.

Inhibition of cell wall pectin metabolism by plasma activated water (PAW) to maintain firmness and quality of postharvest blueberry

Blueberry is a class of berries with high nutritional and economic value but has short shelf life due to its rapid softening at room temperature. This study investigated the effects of plasma-activated water (PAW) treatment on the softening quality and cell wall pectin metabolism of blueberries stored for 10 d at 25 °C after being immersed in PAW for 10 min. PAW was generated by plasma with different times (1 and 2 min), fixed frequency (10 kHz) and fixed voltage (50 kV). The analysis showed that the firmness of PAW-treated fruit significantly increased (P < 0.05) by 36.4% after 10 d storage. PAW treatment controlled the solubilization of pectin from water-insoluble to water-soluble. The activities of cell wall pectin-degrading enzymes like polygalacturonase (PG), β-galactosidase (β-Gal) and pectin methylesterase (PME) in PAW-treated blueberries decreased by 15.7%, 18.3%, and 27.9%, respectively, on day 10. After PAW treatment, blueberries also maintained better postharvest quality (firmness, colour, soluble solid content and anthocyanin content) and intact epidermal waxy and cell wall structure. These results suggested that PAW showed great potential for postharvest fresh-keeping of blueberry.

Technological innovations enhance postharvest fresh food resilience from a supply chain perspective

Fresh food is rich in nutrients but is usually seasonal, perishable, and challenging to store without degradation of quality. The inherent limitations of various preservation technologies can result in losses in all stages of the supply chain. As consumers of fresh foods have become more health-conscious, new technologies for intelligent, energy-efficient, and nondestructive preservation and processing have emerged as a research priority in recent years. This review aims to summarize the quality change characteristics of postharvest fruits, vegetables, meats, and aquatic products. It critically analyzes research progress and applications of various emerging technologies, which include: the application of high-voltage electric field, magnetic field, electromagnetic field, plasma, electrolytic water, nanotechnology, modified atmosphere packaging, and composite bio-coated film preservation technologies. An evaluation is presented of the benefits and drawbacks of these technologies, as well as future development trends. Moreover, this review provides guidance for design of the food supply chain to take advantage of various technologies used to process food, reduce losses and waste of fresh food, and this improve the overall resilience of the supply chain.

Cold Plasma Controls Nitrite Hazards by Modulating Microbial Communities in Pickled Radish

The hazard of nitrite caused by microorganisms is the main food safety problem in the pickle production. To seek a method to control the nitrite hazards of pickles by regulating microbial community without additional substances, we focused on cold plasma because Gram-negative and Gram-positive bacteria have different degrees of sensitivity to the sterilization of cold plasma. Using radish pickles as the experimental object, based on colony counting, dynamic monitoring of pH and nitrite, qPCR and high-throughput sequencing, it was found that when the raw material was treated with dielectric barrier discharge (DBD) cold plasma at 40 kV for 60 s, Gram-negative bacteria with the potential to produce nitrite were preferentially sterilized. Meanwhile, Gram-positive bacteria dominated by the lactic acid bacteria were retained to accelerate the acid production rate, initiate the self-degradation of nitrite in advance and significantly reduce the peak value and accumulation of nitrite during the fermentation process of pickled radish. This study preliminarily verified that DBD cold plasma can inhibit the nitrite generation and accelerate the self-degradation of nitrite by regulating the structure and abundance of microbial community in radish pickles, which provides an important reference for the control of nitrite hazards in the fermentation process of pickles without additives.

New preservation and detection technologies for edible mushrooms: A review

Edible mushrooms are nutritious, tasty, and have medicinal value, which makes them very popular. Fresh mushrooms have a high water content and a crisp texture. They demonstrate strong metabolic activity after harvesting. However, they are prone to textural changes, microbial infestation, and nutritional and flavor loss, and they therefore require appropriate post-harvest processing and preservation. Important factors affecting safety and quality during their processing and storage include their quality, source, microbial contamination, physical damage, and chemical residues. Thus, these aspects should be tested carefully to ensure safety. In recent years, many new techniques have been used to preserve mushrooms, including electrofluidic drying and cold plasma treatment, as well as new packaging and coating technologies. In terms of detection, many new detection techniques, such as nuclear magnetic resonance (NMR), imaging technology, and spectroscopy can be used as rapid and effective means of detection. This paper reviews the new technological methods for processing and detecting the quality of mainstream edible mushrooms. It mainly introduces their working principles and application, and highlights the future direction of preservation, processing, and quality detection technologies for edible mushrooms. Adopting appropriate post-harvest processing and preservation techniques can maintain the organoleptic properties, nutrition, and flavor of mushrooms effectively. The use of rapid, accurate, and non-destructive testing methods can provide a strong assurance of food safety. At present, these new processing, preservation and testing methods have achieved good results but at the same time there are certain shortcomings. So it is recommended that they also be continuously researched and improved, for example through the use of new technologies and combinations of different technologies. © 2023 Society of Chemical Industry.

Insight into the IgE-binding sites of allergenic peptides of tropomyosin in shrimp (Penaeus chinensis) induced by cold plasma active particles

Tropomyosin (TM) is a major allergen in crustaceans, and its allergenicity mainly depends on epitopes. In this study, the locations of IgE-binding sites between plasma active particles and allergenic peptides of TM in shrimp (Penaeus chinensis) during cold plasma (CP) treatment were explored. Results showed that the IgE-binding ability of two critical peptides (P1 and P2) increased and then decreased by 9.97 % and 19.50 % after 15 min of CP treatment. It was the first time to show that the contribution rate of target active particles was •O > e_(aq)^- > •OH for reducing IgE-binding ability by 23.51 %-45.40 %, and the contribution rates of other long-lived particles including NO₃^- and NO₂^- was about 54.60 %-76.49 %. In addition, Glu131 and Arg133 in P1 and Arg255 in P2 were certified as the IgE sites. These results were helpful for accurately controlling TM allergenicity, shedding more light on allergenicity mitigation during food processing.

In-package cold plasma treatment for microbial inactivation in plastic-pouch packaged steamed rice cakes

In-package atmospheric cold plasma (ICP) treatment was investigated as a method to inactivate microorganisms in Korean steamed rice cakes (SRCs) packaged in plastic pouches. The effect against Escherichia coli O157:H7 increased with increasing ICP treatment power and time and using nylon-containing pouches. Moreover, E. coli O157:H7 growth was effectively inhibited at 4 and 25 °C when SRCs were in a pouch filled with an O₂-CO₂ (70 % and 30 %) gas. Under optimal treatment power (30 W), treatment time (4 min), and headspace-to-SRC volume ratio (7:1) conditions, ICP effectively inactivated E. coli O157:H7, Bacillus cereus spores, Penicillium chrysogenum, and indigenous aerobic bacteria, as well as yeast and molds in SRCs packaged with air in the nylon/low density polyethylene pouch by 2.2 ± 0.2 log CFU/g, 1.4 ± 0.2 log spores/g, 2.2 ± 0.3 log spores/g, 1.1 ± 0.2 log CFU/g, and 1.0 ± 0.1 log CFU/g, respectively. Furthermore, post-treatment storage was effective in preventing the growth of E. coli O157:H7 in SRCs at 4 °C and 25 °C when the pouch was filled with N₂-CO₂ (50 % and 50 %) or O₂-CO₂ (70 % and 30 %). Collectively, these findings indicate that ICP treatment effectively decontaminates SRCs and represents a potential non-thermal microbial decontamination technology for SRCs in pouch packaging.

Plasma-activated liquids for mitigating biofilms on food and food contact surfaces

Plasma-activated liquids (PALs) are emerging and promising alternatives to traditional decontamination technologies and have evolved as a new technology for applications in food, agriculture, and medicine. Contamination caused by foodborne pathogens and their biofilms has posed challenges and concerns to the food industry in terms of safety and quality. The nature of the food and the food processing environment are major factors that contribute to the growth of various microorganisms, followed by the biofilm characteristics that ensure their survival in severe environmental conditions and against traditional chemical disinfectants. PALs show an efficient impact against microorganisms and their biofilms, with various reactive species (short- and long-lived ones), physiochemical properties, and plasma processing factors playing a crucial role in mitigating biofilms. Moreover, there is potential to improve and optimize disinfection strategies using a combination of PALs with other technologies for the inactivation of biofilms. The overarching aim of this study is to build a better understanding of the parameters that govern the liquid chemistry generated in a liquid exposed to plasma and how these translate into biological effects on biofilms. This review provides a current understanding of PALs-mediated mechanisms of action on biofilms; however, the precise inactivation mechanism is still not clear and is an important part of the research. Implementation of PALs in the food industry could help overcome the disinfection hurdles and can enhance biofilm inactivation efficacy. Future perspectives in this field to expand existing state of the art to seek breakthroughs for scale-up and implementation of PALs technology in the food industry are also discussed.

EFFECTS OF COLD PLASMA ON CHLOROPHYLLS, CAROTENOIDS, ANTHOCYANINS, AND BETALAINS

Plasma is considered by several researchers to be the fourth state of matter. Cold plasma has been highlighted as an alternative to thermal treatments because heat induces less degradation of thermolabile bioactive compounds, such as natural pigments. In this review, we provide a compilation of the current information about the effects of cold plasma on natural pigments, such as the changes caused by plasma to the molecules of chlorophylls, carotenoids, anthocyanins, and betalains. As a result of the literature review, it is noted that can degrade cell membrane and promote damage to pigment storage sites; thereby releasing pigments and increasing their content in the extracellular space. However, the reactive species contained in the cold plasma can cause degradation of the pigments. Cold plasma is a promising technology for extracting pigments; however, case-by-case optimization of the extraction process is required.

Toxic reactive oxygen species stresses for reconfiguring central carbon metabolic fluxes in foodborne bacteria: Sources, mechanisms and pathways

The toxic reactive oxygen species (toxROS) is the reactive oxygen species (ROS) beyond the normal concentration of cells, which has inactivation and disinfection effects on foodborne bacteria. However, foodborne bacteria can adapt and survive by physicochemical regulation of antioxidant systems, especially through central carbon metabolism (CCM), which is a significant concern for food safety. It is thus necessary to study the antioxidant regulation mechanisms of CCM in foodborne bacteria under toxROS stresses. Therefore, the purpose of this review is to provide an update and comprehensive overview of the reconfiguration of CCM fluxes in foodborne bacteria that respond to different toxROS stresses. In this review, two key types of toxROS including exogenous toxROS (exo-toxROS) and endogenous toxROS (endo-toxROS) are introduced. Exo-toxROS are produced by disinfectants, such as H₂O₂ and HOCl, or during food non-thermal processing such as ultraviolet (UV/UVA), cold plasma (CP), ozone (O₃), electrolyzed water (EW), pulsed electric field (PEF), pulsed light (PL), and electron beam (EB) processing. Endo-toxROS are generated by bioreagents such as antibiotics (aminoglycosides, quinolones, and β-lactams). Three main pathways for CCM in foodborne bacteria under the toxROS stress are also highlighted, which are glycolysis (EMP), pentose phosphate pathway (PPP), and tricarboxylic acid cycle (TCA). In addition, energy metabolisms throughout these pathways are discussed. Finally, challenges and future work in this area are suggested. It is hoped that this review should be beneficial in providing insights for future research on bacterial antioxidant CCM defence under both exo-toxROS stresses and endo-toxROS stresses.

Plasma Surface Engineering of Natural and Sustainable Polymeric Derivatives and Their Potential Applications

Recently, natural as well as synthetic polymers have been receiving significant attention as candidates to replace non-renewable materials. With the exponential developments in the world each day, the collateral damage to the environment is incessant. Increased demands for reducing pollution and energy consumption are the driving force behind the research related to surface-modified natural fibers (NFs), polymers, and various derivatives of them such as natural-fiber-reinforced polymer composites. Natural fibers have received special attention for industrial applications due to their favorable characteristics, such as low cost, abundance, light weight, and biodegradable nature. Even though NFs offer many potential applications, they still face some challenges in terms of durability, strength, and processing. Many of these have been addressed by various surface modification methodologies and compositing with polymers. Among different surface treatment strategies, low-temperature plasma (LTP) surface treatment has recently received special attention for tailoring surface properties of different materials, including NFs and synthetic polymers, without affecting any of the bulk properties of these materials. Hence, it is very important to get an overview of the latest developments in this field. The present article attempts to give an overview of different materials such as NFs, synthetic polymers, and composites. Special attention was placed on the low-temperature plasma-based surface engineering of these materials for diverse applications, which include but are not limited to environmental remediation, packaging, biomedical devices, and sensor development.

Enhancement of Wheat Seed Germination, Seedling Growth and Nutritional Properties of Wheat Plantlet Juice by Plasma Activated Water

Previous studies have shown the great potential of using plasma-activated water (PAW) on improving agriculture seed germination, however, information on the influence of PAW on crop plantlet juice remains scanty. In this research, the effect of PAW generated by atmosphere pressure Ar-O₂ plasma jet for 1-5 min on wheat seed germination, seedling growth and nutritional properties of wheat plantlet juice was investigated. Results revealed that all PAWs could enhance wheat seed germination and seedling growth in 7 days by improving the germination rate, germination index, fresh weight, dry weight and vigour index, and especially that PAW activated for 3 min (PAW-3) showed the best overall performance. In addition, the application of PAWs enhanced the nutritional properties of wheat plantlet juice from those grown for 14 days by improving total soluble solids, protein content, photosynthetic pigments, total phenolic content, antioxidant activity, enzyme activity, free amino acids and minerals content, and the best enhancement was also observed in PAW-3. It was concluded that PAWs would be an effective technique to enhance the growth and nutritional properties of crop sprouts, which could be served as functional foods in many forms.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s00344-022-10677-3.

Investigation on the impact of quality characteristics and storage stability of foxtail millet induced by air cold plasma

The aim of this work was to investigate the effects of dielectric barrier discharge-air cold plasma (DBD-ACP, 15-35 kV, 2-12 min) on the quality of foxtail millets. The L and b* values were evaluated by a digital colorimeter representing that the color of millets was significantly changed at 25 kV for 4-12 min or at 35 kV for 2-12 min. The results were consistent with the change of total yellow pigment in millets, indicating that DBD-ACP damaged the carotenoids if the treatment condition was too high. The activity of lipoxygenase and lipase, involving the oxidation and hydrolysis of lipids of millet, decreased significantly induced by DBD-ACP. For example, the lipoxygenase and lipase activity of Mizhi millet was decreased from 44.0 to 18.7 U g^-1min^-1, 56.0-15.1 U/(mg pro) (p<0.05) after being exposed to 25 kV for 2-12 min, respectively. Changes of color, lipoxygenase and lipase activity, and malondialdehyde content of millets were determined during accelerated storage (40 ± 2°C and 75% Relative Humidity) for 15 days after being treated by DBD-ACP under 15 and 25 kV for 4 min. Results showed that millets treated by DBD-ACP at 15 kV kept a better color with lower malondialdehyde content, and lower lipoxygenase and lipase activity compared to control. This work implied that DBD-ACP is an underlying approach for the storage of foxtail millets.

Enzymatic browning in apple products and its inhibition treatments: A comprehensive review

Apple (Malus domestica) is widely consumed by consumers from various regions. It contains a high number of phenolic compounds (majorly hydroxybenzoic acids, hydroxycinnamic acids, flavanols, flavonols, dihydrochalcones, and anthocyanins) and antioxidant activity, which are beneficial for human health. The trends on healthy and fresh food have driven the food industry to produce minimally processed apple, such as fresh-cut, puree, juice, and so on without degrading the quality of products. Enzymatic browning is one of the problems found in minimally processed apple as it causes the undesirable dark color as well as the degradation of phenolics and antioxidant activity, which then reduces the health benefits of apple. Proper inhibition is needed to maintain the quality of minimally processed apple with minimal changes in sensory properties. This review summarizes the inhibition of enzymatic browning of apple products based on recent studies using the conventional and nonconventional processing, as well as using synthetic and natural antibrowning agents. Nonconventional processing and the use of natural antibrowning agents can be used as promising treatments to prevent enzymatic browning in minimally processed apple products. Combination of 2-3 treatments can improve the effective inhibition of enzymatic browning. Further studies, such on as other potential natural antibrowning agents and their mechanisms of action, should be conducted.

Recent processing of fruits and vegetables using emerging thermal and non-thermal technologies. A critical review of their potentialities and limitations on bioactives, structure, and drying performance

Fruits and vegetables have rich bioactive compounds and antioxidants that are vital for the human body and prevent the cell from disease-causing free radicals. Therefore, there is a growing demand for high-quality fruits and vegetables. Nevertheless, fruits and vegetables deteriorate due to their high moisture content, resulting in a 40-50% loss. Drying is a common food preservation technique in the food industry to increase fruits and vegetables' shelf-life. However, drying causes chemical modifications, changes in microstructure, and bioactives, thus, lowering the final product's quality as a considerable amount of bioactives compounds and antioxidants are lost. Conventional pretreatments such as hot water blanching, and osmotic pretreatment have improved fruit and vegetable drying performance. However, these conventional pretreatments affect fruits' bioactive compounds retention and microstructure. Hence, emerging thermal (infrared blanching, microwave blanching, and high-humidity hot-air impingement blanching) and non-thermal pretreatments (cold plasma, ultrasound, pulsed electric field, and edible films and coatings) have been researched. So the question is; (1) what are the mechanisms behind emerging non-thermal and thermal technologies' ability to improve fruits and vegetables' microstructure, texture, and drying performance? (2) how do emerging thermal and non-thermal technologies affect fruits and vegetables' bioactive compounds and antioxidant activity? and (3) what are preventing the large-scale commercialization of these emerging thermal and non-thermal technologies' for fruits and vegetables, and what are the future recommendations? Hence, this article reviewed emerging thermal blanching and non-thermal pretreatment technologies, emphasizing their efficacy in improving dried fruits and vegetables' bioactive compounds, structural properties, and drying performance. The fundamental mechanisms in emerging thermal and non-thermal blanching pretreatment methods on the fruits and vegetables' microstructure and drying performance were delved in, as well as what are preventing the large-scale commercialization of these emerging thermal and non-thermal blanching for fruits and vegetables, and the future recommendations. Emerging pretreatment approaches not only improve the drying performance but further significantly improve the retention of bioactive compounds and antioxidants and enhance the microstructure of the dried fruits and vegetables.

Oxidative lesions and post-treatment viability attenuation of listeria monocytogenes triggered by atmospheric non-thermal plasma

AIMS

The aim of the current study was to investigate the effect of plasma-mediated oxidative stress on the post-treatment viability of Listeria monocytogenes at the physiological and molecular levels.

METHODS AND RESULTS

10⁷  CFU/ml L. monocytogenes in 10 ml phosphate-buffered saline (PBS) was treated with atmospheric non-thermal plasma for 0, 30, 60, 90 and 120 s respectively. Optical diagnostics using optical emission spectroscopy (OES) confirmed that dielectric barrier discharge (DBD) plasma was a significant source of ample exogenous reactive oxygen and nitrogen species (RONS). The development of extracellular main long-lived species was associated with plasma exposure time, accompanied by a massive accumulation of intracellular ROS in L. monocytogenes (p < 0.01). With the exception of virulence genes (hly), most oxidation resistance genes (e.g. sigB, perR, lmo2344, lmo2770 and trxA) and DNA repair gene (recA) were upregulated significantly (p < 0.05). A visible fragmentation in genomic DNA and a decline in the secretion of extracellular proteins and haemolytic activity (p < 0.01) were noticed. The quantitate oxygen consumption rates (OCRs) and extracellular acidification rates (ECARs) confirmed the viability attenuation from the aspect of energy metabolism. Survival assay in a real food system (raw milk) further suggested not only the viability attenuation, but also the resuscitation potential and safety risk of mild plasma-treated cells during post-treatment storage.

CONCLUSION

DBD plasma had the potential to inactivate and attenuate the virulence of L. monocytogenes, and it was recommended that plasma exposure time longer than 120 s was more suitable for attenuating viability and avoiding the recovery possibility of L. monocytogenes in raw milk within 7 days.

SIGNIFICANCE AND IMPACT OF THE STUDY

The current results presented a strategy to inactivate and attenuate the viability of L. monocytogenes, which could serve as a theoretical basis for better application of non-thermal plasma in food in an effort to effectively combat foodborne pathogens.

Spectroscopic Investigation of the Impact of Cold Plasma Treatment at Atmospheric Pressure on Sucrose and Glucose

When exposing food and feedstuff to cold atmospheric pressure plasmas (CAPP), e.g., for decontamination purposes, possible unwanted effects on the contained nutrients might occur. In the present study, we thus concentrated on CAPP-induced degrading effects on different sugars, namely glucose and sucrose. The treatments were performed using admixtures of argon and synthetic air over durations of up to 12min. Continuous degradation of sucrose and glucose was determined using ATR-FTIR and XPS analyses. OH stretching bands showed notable broadening in the ATR-FTIR spectra, which possibly indicates reduced crystallinity of the sugars caused by the CAPP treatment. In the fingerprint regions, most bands, especially the more intense C-O bands, showed decreases in peak heights. In addition, two new bands occurred after CAPP treatment. The bands were detectable in the range between 1800 and 1600cm−1 and potentially can be assigned to C=C and, after comparison with the results of the XPS measurements, O-C=O bindings. The XPS measurements also showed that the O-C=O bonds probably originated from earlier C-O bonds.

Improving food drying performance by cold plasma pretreatment: A systematic review

Drying is an important and influential process to prolong the shelf-life of food in the food industry. Recent studies have shown that cold plasma (CP) as an emerging drying pretreatment technology can improve drying performance, reduce drying energy consumption, and improve dried food quality. This paper comprehensively reviewed the mechanism of CP improving drying performance, related equipment, energy consumption, influencing factors, and impact on drying quality. This review also discusses the advantages and disadvantages and proposes possible challenges and suggestions for future research. Most studies indicated that CP pretreatment could improve the drying rate and quality and reduce the drying energy consumption. CP can promote moisture diffusion and improve drying efficiency by etching the surface and affecting the internal microstructure. In addition, CP can enhance the quality of dried products by reducing drying time and enzyme activity. Further research is needed to explore the drying mechanisms and equipment innovations to promote the application of CP in the food drying industry.

Hybridising plasma functionalized water and ultrasound pretreatment for enzymatic protein hydrolysis of Larimichthys polyactis: Parametric screening and optimization

Hybridising plasma functionalized water and ultrasound pretreatment for the enzymatic hydrolysis (HPUEH) of Larimichthys polyactis was evaluated by adopting Plackett-Burman design for parametric screening of six key variables, and Box-Behnken design for optimizing three most significant variables including plasma generating voltage (P_V), ultrasound treatment time (U_T), and enzyme concentration (E_C). The models developed for predicting the degree of hydrolysis (DoH), protein recovery (PVY), and soluble protein content (SPC) were sufficiently fitted to the experimental data (R² ≥ 0.966) with non-significant lack of fit and used for determining the optimum conditions as P_V of 70 V, U_T of 15 min, and E_C of 1.787%, with predictive values of 27.74%, 85.62%, and 3.28 mg/mL for DoH, PVY, and SPC, respectively. HPUEH presented hydrolysates with smaller peptide sizes and molecular weights, enhanced DoH, PVY, SPC, amino acids and antioxidant activity, but reduced emulsifying and foaming properties when compared with conventional enzymatic hydrolysis.

Modelling of inactivation kinetics of Escherichia coli and Listeria monocytogenes on grass carp treated by combining ultrasound with plasma functionalized buffer

Linear (first-order) and non-linear (Weibull, biphasic, and log-logistic) models were evaluated for predicting the inactivation kinetics of Escherichia coli and Listeria monocytogenes on grass carp treated by a novel technique (UPFB) combining ultrasound (US) with plasma functionalized buffer (PFB). Results showed that UPFB was more effective for inactivating bacteria when compared with individual applications of US or PFB with reductions of 3.92 and 3.70 log CFU/g for Escherichia coli and Listeria monocytogenes, respectively. Compared with the linear model, the three non-linear models presented comparable performances and were more suitable for describing the inactivation kinetics with superior adj-R² (0.962-0.999), accuracies (0.970-1.006) and bias factors (0.995-1.031), and by assessing the strengths of evidence, weights of evidence and evidence ratios for the models, the biphasic model was identified as the best fit model. The current study provided new insights into the effective evaluation of decontamination methods.

Subcellular damages of Colletotrichum asianum and inhibition of mango anthracnose by dielectric barrier discharge plasma

Colletotrichum asianum (C. asianum) is a new pathogenic fungus that causes mango anthracnose. Cold plasma is a novel non-thermal decontamination technology, which has been proven to be effective in controlling postharvest fungus. Herein, dielectric barrier discharge (DBD) plasma was used to treat C. asianum spores in sterile phosphate-buffered saline, the damages in subcellular structures of C. asianum and inhibition of mango anthracnose were evaluated. Results showed that after 9 min treatment, the spore germination rate and spore viability were decreased by 95.48% and 98.82%, respectively, and the subcellular structures were damaged (P < 0.05), leading to spores death. Besides, DBD plasma treatments could control mango anthracnose and maintain mango quality, and the disease incidence and lesion diameter of mango treated for 9 min were decreased by 48.00% and 62.95%, respectively. Therefore DBD plasma inactivated C. asianum spore, providing an alternative technique for preventing and controlling mango anthracnose.

Structure modification and property improvement of plant cellulose: Based on emerging and sustainable nonthermal processing technologies

Cellulose has attracted high attention due to its advantages of abundant resources, renewable and biodegradable. Modification of natural plant cellulose has become a hot topic worldwide. Conventional chemical modification methods commonly cause great damage to the environment. The current review presents the effects of innovative, eco-friendly and sustainable nonthermal processing technologies on cellulose structure and properties. Typical techniques include high pressure processing, cold plasma, ultrasonic and irradiation treatment. Their superiorities in the modification of cellulose are highlighted, and the advantages and limitations of nonthermal processing technologies for plant cellulose modification are also discussed. Nonthermal processing technologies can improve cellulose functional properties by playing an important role in the chemical bonds of the molecular chains, crystalline regions or amorphous parts through energy or active particles generated in the process, or promoting the crosslinking and graft copolymerization of cellulose molecules. The development of modified cellulose functional materials will have wider applications.

Functional and bioactive properties of Larimichthys polyactis protein hydrolysates as influenced by plasma functionalized water-ultrasound hybrid treatments and enzyme types

The effects of plasma functionalized water (PFW) and its combination with ultrasound (UPFW) on the functional and bioactive properties of small yellow croaker protein hydrolysates (SYPHs) produced from three enzymes were investigated. Fluorescence and UV-Vis spectroscopy indicated that SYPHs tended to unfold with increasing intensity and shift in wavelengths to more flexible conformations under PFW and UPFW treatments. Particle size distribution and microstructure analysis revealed that treatments could disrupt aggregation of protein molecules to increase the roughness, specific surface area, and decrease the particle size of peptides during hydrolysis. The partially denatured structure of SYPHs induced by treatments increased the susceptibility of the fish proteins to exogenous enzymes, thereby accelerating the hydrolytic process to yield peptides with improved solubility, decreased emulsifying and foaming properties, and improved enzyme-specific antioxidant properties. The results revealed that the functionality of SYPHs was influenced by the treatment method and the enzyme type employed.

Applications of Plasma-Activated Water in Dentistry: A Review

The activation of water by non-thermal plasma creates a liquid with active constituents referred to as plasma-activated water (PAW). Due to its active constituents, PAW may play an important role in different fields, such as agriculture, the food industry and healthcare. Plasma liquid technology has received attention in recent years due to its versatility and good potential, mainly focused on different health care purposes. This interest has extended to dentistry, since the use of a plasma–liquid technology could bring clinical advantages, compared to direct application of non-thermal atmospheric pressure plasmas (NTAPPs). The aim of this paper is to discuss the applicability of PAW in different areas of dentistry, according to the published literature about NTAPPs and plasma–liquid technology. The direct and indirect application of NTAPPs are presented in the introduction. Posteriorly, the main reactors for generating PAW and its active constituents with a role in biomedical applications are specified, followed by a section that discusses, in detail, the use of PAW as a tool for different oral diseases.