Recent advances in the degradation efficacy and mechanisms of mycotoxins in food by atmospheric cold plasma.

Food contaminated by mycotoxins has become a worldwide public problem with political and economic implications. Although a variety of traditional methods have been used to eliminate mycotoxins from agri-foods, the results have been somewhat less than satisfactory. As an emerging non-thermal processing technology, atmospheric cold plasma (ACP) has great potential for food decontamination. Herein, this review mainly presents the degradation efficiency of ACP on mycotoxins in vitro and agri-foods as well as its possible degradation mechanisms. Meanwhile, ACP effects on food quality, factors affecting the degradation efficiency and the toxicity of degradation products are also discussed. According to the literatures, ACP could efficiently degrade many mycotoxins (e.g., aflatoxin, deoxynivalenol, zearalenone, ochratoxin A, fumonisin, and T-2 toxin) both in vitro and various foods (e.g., hazelnut, peanut, maize, rice, wheat, barley, oat flour, and date palm fruit) with little effects on the nutritional and sensory properties of food. The degradation efficacy was dependent on many factors including ACP treatment parameter, working gas, mycotoxin property, and food substrate. The mycotoxin degradation by ACP was mainly attributed to the reactive oxygen and nitrogen species in ACP, which can damage the chemical bonds of mycotoxins, consequently reducing the toxicity of mycotoxins.

Enhancement effect of carvacrol on yeast inactivation by mild pressure carbon dioxide.

Saccharomyces cerevisiae is one of the common spoilage microorganisms in fruit juices. This paper investigated the influences of carvacrol on S. cerevisiae inactivation by mild pressure carbon dioxide (MPCO2). The results demonstrated that carvacrol synergistically enhanced the antifungal activity against S. cerevisiae of MPCO2. With the increase of carvacrol concentration (20-160 µg/mL), CO2 pressure (1.5-3.5 MPa), process temperature (20-40 °C), and treatment time (15-60 min), the inactivation effect of carvacrol combined with MPCO2 on S. cerevisiae was gradually increased and significantly stronger than either single treatment. In the presence of carvacrol, MPCO2 severely disordered the plasma membrane of S. cerevisiae, including the increase of membrane permeability, and the loss of membrane potential and integrity. MPCO2 and carvacrol in combination also aggravated the mitochondrial depolarization of S. cerevisiae and reduced intracellular ATP and protein content. This study suggests the potential of carvacrol and pressurized CO2 as an alternative technology for food pasteurization.

Feasibility of atmospheric cold plasma for the elimination of food hazards: Recent advances and future trends.

In recent decades, food safety has emerged as a worldwide public health issue with economic and political implications. Pesticide residues, mycotoxins, allergens, and antinutritional factors are the primary concerns associated with food products due to their potential adverse health effects. Although various conventional processing methods (such as washing, peeling, and cooking) have been used to reduce or eliminate these hazards from agricultural food materials, the results obtained are not quite satisfactory. Recently, atmospheric cold plasma (ACP), an emerging low -temperature and green processing technology, has shown great potential for mitigating food hazards. However, detailed descriptions of the effects of ACP treatment on food hazards are still not available. Thus, the current review aims to highlight recent studies on the efficacy and application of ACP in the reduction or elimination of pesticide residues, mycotoxins, allergens, and antinutritional factors in various food products. The possible working mechanisms of ACP and its effect on food quality, and the toxicity of degradation products are emphatically discussed. In addition, multiple factors affecting the efficacy of ACP are summarized in detail. At the same time, the major technical challenges for practical application and future development prospects of this emerging technology are also highlighted.

A review on recent advances in plasma-activated water for food safety: current applications and future trends.

Plasma-activated water (PAW), the water or solutions treated with atmospheric cold plasma, is an eco-friendly technique with minimal changes in food products, making it a befitting alternative to traditional disinfection methods. Due to its potential microbicidal properties, PAW has been receiving increasing attention for applications in the food, agricultural, and biomedical fields. In this article, we aimed at presenting an overview of recent studies on the generation methods, physicochemical properties, and antimicrobial activity of PAW, as well as its application in the food industry. Specific areas were well discussed including microbial decontamination of food products, reduction of pesticide residues, meat curing, sprouts production, and disinfection of food contact materials. In addition, the factors influencing PAW efficiency were also well illustrated in detail, such as discharge parameters, types and amounts of microorganisms, characteristics of the liquid solution and food products, and treatment time. Moreover, the strategies to improve the efficacy of PAW were also presented in combination with other technologies. Furthermore, the salient drawbacks of this technology were discussed and the important areas for future research were also highlighted. Overall, the present review provides important insights for the application of PAW in the food industry.

Comparative structural and techno-functional elucidation of full-fat and defatted flaxseed extracts: implication of atmospheric pressure plasma jet.

BACKGROUND: The relatively inferior techno-functionality of flaxseed protein/polysaccharide complexes, especially regarding emulsifying and antioxidant activities, has partially limited their implication in the health food system. The present study aimed to investigate the effects of an atmospheric pressure plasma jet (APPJ) on the physicochemical, structural and selected techno-functional properties of flaxseed extracts. RESULTS: The results obtained showed that the full-fat and defatted flaxseed extract solutions (5 mg mL-1 ) displayed a sustainable decline in pH (-54.06%, -48.80%, P < 0.05) and zeta potential values (-29.42%, -44.28%, P < 0.05), but a gradual increase in particle sizes, as visualised by an optical microscope, during 0-120 s of APPJ treatment. Moreover, the APPJ led to initial decrease but subsequent increase in protein carbonyls and secondary lipid oxidation products, and concurrently changed the spatial conformation and microstructure of flaxseed extracts, as indicated by endogenous fluorescence properties and scanning electron microscopy (SEM). Additionally, the protein subunit remodeling and gum polysaccharides depolymerization were different for full-fat and defatted flaxseed extracts after 30 s of APPJ exposure. Importantly, the emulsifying and antioxidant activities of defatted flaxseed extract were particularly improved, as assessed by cyro-SEM and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity following 15-30 s of APPJ treatment, as a result of the changing interactions between protein and gum polysaccharides, as well as the release of specific phenolic compounds. CONCLUSION: APPJ could serve as a promising strategy for tailoring the specific techno-functionality of flaxseed extracts based on mild structural modification. © 2021 Society of Chemical Industry.

Solvothermal synthesis of α-Fe2O3 polyhedrons and its application in an immunochromatographic strip test for the detection of foodborne pathogen Listeria monocytogenes.

The immunochromatographic strip test (ICST) is a powerful on-site detection technology due to its unique advantages of simplicity, rapidity, and readability by the naked eye. Here we illustrate the potential of α-Fe2O3 polyhedrons as a novel visual label, which exhibit advantages of high stability and economy, for the detection of Listeria monocytogenes (L. monocytogenes) as a model foodborne pathogen. A low-cost and simple one-step solvothermal approach was developed for the synthesis of α-Fe2O3 polyhedrons; the average diameter of the α-Fe2O3 polyhedrons is about 200 nm. The crystal structure and morphology of α-Fe2O3 polyhedrons were characterized by x-ray diffraction and transmission electron microscope. α-Fe2O3 polyhedrons were immunized with anti-L. monocytogenes antibody to prepare an antibody-colloidal α-Fe2O3 polyhedron ICST. Visual detection can be obtained directly by the naked eye within 10 min. The detection limit of L. monocytogenes by α-Fe2O3 polyhedron ICST assay was 3.8 × 106 and 5.6 × 106 CFU/ml of pure culture and artificially spiked orange juice drink sample, respectively. Results indicated that the antibody-colloidal α-Fe2O3 polyhedron ICST is a rapid, simple, and low-cost assay. This approach showed great potential in the application of foodborne pathogen detection concerning food safety.

Inactivation effects and mechanisms of plasma-activated water combined with sodium laureth sulfate (SLES) against Saccharomyces cerevisiae.

The present study aimed to elucidate the antifungal effect and underlying mechanism of plasma-activated water (PAW) combined with sodium laureth sulfate (SLES) against Saccharomyces cerevisiae. S. cerevisiae, initially at 6.95 log10 colony-forming unit (CFU)/mL, decreased to an undetectable level following the synergistic treatment of PAW and SLES (0.50 mg/mL) for 20 min. After PAW treatment combined with SLES (2.5 mg/mL) for 30 min, the S. cerevisiae cells on polyethylene films also reduced to an undetectable level from the initial load of 5.84 log10 CFU/cm2. PAW + SLES treatment caused severe disruption of membrane integrity and increased lipid oxidation within the cell membrane and the intracellular reactive oxygen species levels in S. cerevisiae cells. Besides, the disruption of the mitochondrial membrane potential (∆ψm) was also observed in S. cerevisiae cells after treatment of PAW and SLES at 0.01 mg/mL for 5 min. These data suggest that the combined treatment of PAW and SLES causes oxidation injury to cell membranes and abnormal ∆ψm in S. cerevisiae, which may be eventually responsible for cell death. This study demonstrates the potential application of PAW combined with SLES as an alternative disinfection method. Key Points • PAW + SLES exhibited synergistic antifungal activity against S. cerevisiae. • PAW + SLES resulted in severe disruption of membrane integrity and permeability. • PAW + SLES induced accumulation of reactive oxygen species in S. cerevisiae cells.

Effect of rosemary extract on lipid oxidation of cooked pork during simulated gastric digestion.

BACKGROUND: Oxidation of food lipids occurs in the gastrointestinal tract, resulting in potential adverse health effects. Rosemary extract (RE), as one of the most popular naturally sourced antioxidants, is widely used in the food industry. However, the effect of RE on lipid oxidation during gastrointestinal digestion has not been well investigated. Therefore, this study aimed to evaluate the effect of RE on lipid oxidation of cooked pork during simulated gastric digestion. RESULTS: Results showed that RE at 12.5, 25, 50, and 100 mg kg-1 pork effectively decreased the formation of malondialdehyde during simulated gastric digestion of cooked pork. RE also effectively mitigated the decline of fatty acids during the simulated gastric digestion of pork. The total phenolic content in RE was calculated to be 170.67 mg gallic acid equivalent (GAE) g-1 . RE dissolved in distilled water (pH 6.5) or potassium hydrogen phthalate-hydrochloric acid buffer solution (0.2 mol L-1 , pH 3.0) both exhibited strong 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activities as well as ferric reducing capacity. The inhibitory effects of RE on lipid oxidation of cooked pork during simulated gastric digestion may be attributed to the phenolic compounds with antioxidant properties. CONCLUSION: The results lend support to the possible application of rosemary or RE as a rich source of natural antioxidants to inhibit the oxidation of food lipids during gastrointestinal digestion. © 2019 Society of Chemical Industry.

Inactivation of Pseudomonas deceptionensis CM2 on chicken breasts using plasma-activated water.

The aim of this study was to examine the effectiveness of plasma-activated water (PAW) for inactivating Pseudomonas deceptionensis CM2 on chicken breasts. Sterile distilled water (SDW) was activated by gliding arc discharge plasma for 60 s, which was defined as PAW60. The chicken breast samples inoculated P. deceptionensis CM2 were dipped in PAW60 or SDW for the indicated time intervals, respectively. After the treatment of PAW60 for 12 min, the population of P. deceptionensis CM2 on chicken breast was significantly reduced by 1.05 log10 CFU/g (p < 0.05), which was higher than that of SDW-treated samples for the same time intervals (p < 0.05). The L* value of chicken breasts were increased whereas a* and b* values were decreased following PAW60 treatment, while there was no significant differences in the values of a* and b* between PAW60- and SDW-treated samples for the same time intervals (p > 0.05). As compared with SDW, PAW60 caused no significant changes in the texture characteristics (e.g. hardness, springiness, cohesiveness and gumminess) and sensory properties (e.g. appearance, color, odor, texture, acceptability). Thus, PAW can be very effective to improve microbiological safety of chicken breasts with resulting slight changes to the sensory qualities. This synergistic treatment of PAW with other non-thermal technologies should be well investigated in order to improve inactivation efficacy of PAW.

Effects of Nonthermal Plasma Technology on Functional Food Components.

Understanding the impact of nonthermal plasma (NTP) technology on key nutritional and functional food components is of paramount importance for the successful adoption of the technology by industry. NTP technology (NTPT) has demonstrated marked antimicrobial efficacies with good retention of important physical, chemical, sensory, and nutritional parameters for an array of food products. This paper presents the influence of NTPT on selected functional food components with a focus on low-molecular-weight bioactive compounds and vitamins. We discuss the mechanisms of bioactive compound alteration by plasma-reactive species and classify their influence on vitamins and their antioxidant capacities. The impact of NTP on specific bioactive compounds depends both on plasma properties and the food matrix. Induced changes are mainly associated with oxidative degradation and cleavage of double bonds in organic compounds. The effects reported to date are mainly time-dependent increases in the concentrations of polyphenols, vitamin C, or increases in antioxidant activity. Also, improvement in the extraction efficiency of polyphenols is observed. The review highlights future research needs regarding the complex mechanisms of interaction with plasma species. NTP is a novel technology that can both negatively and positively affect the functional components in food.

Influences of cold atmospheric plasma on microbial safety, physicochemical and sensorial qualities of meat products.

Meat and meat products can be contaminated with pathogenic microorganisms, which cause serious health problems and economic loss. Recently, numerous novel non-thermal technologies have been developed to respond to growing consumer demand for high quality and safe meat products. Cold atmospheric plasma (CAP) is a novel and emerging non-thermal technology, showing great potential for applications in the food industry. This review presents recent advances on the developments and applications of CAP in meat products, including generation and microbial inactivation effects of CAP as well as its influences on physicochemical qualities and sensory attributes of meat products. Furthermore, the safety assessment of CAP-treated meat products and challenges in industrial application of CAP are also discussed.

Carnosic acid induces apoptosis associated with mitochondrial dysfunction and Akt inactivation in HepG2 cells.

Carnosic acid (CA), a phenolic diterpene isolated from rosemary, shows potential benefits in health promotion and disease prevention. In the present study, the cytotoxic and apoptotic-inducing effects of CA on human hepatocellular carcinoma HepG2 cells were investigated. The MTT assay results indicated that CA decreased cell viability in HepG2 cells in a dose-dependent manner. Treatment with CA caused a rapid Caspase-3 activation and subsequently proteolytic cleavage of poly (ADP-ribose) polymerase (PARP), both of which were markers of cells undergoing apoptosis. CA also dissipated mitochondrial membrane potential and decreased the ratio of Bcl-2/Bax protein, which mediated cytosolic translocation of cytochrome c from the mitochondria. Furthermore, CA reduced the phosphorylation of Akt, which was partially inhibited by insulin, an activator of phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway. In conclusion, our data suggest that the mitochondrial dysfunction and deactivation of Akt may contribute to the apoptosis-inducing effects of CA.

Europium functionalized porphyrin-based metal-organic framework heterostructure and hydrogel for visual ratiometric fluorescence sensing of sulfonamides in foods.

Protecting human health and ensuring food security require the swift and accurate detection of sulfonamides (SAs) residues in foods. Herein, we proposed an Eu-postfunctionalized bimetallic porphyrin metal-organic framework (PCN-221(Zr/Ce)@Eu-DPA-H4btec) synthesized solvothermally for fluorescence sensing. The PCN-221(Zr/Ce)@Eu-DPA-H4btec fluorescent sensor demonstrated excellent stability and high selectivity to SAs, and the detection limits of sulfamethazine (SM2), sulfamerazine (SMR), and sulfamethoxydiazine (SMD) were as low as 56 nmol/L, 45 nmol/L, and 56 nmol/L, respectively. The PCN-221(Zr/Ce)@Eu-DPA-H4btec fluorescent sensor was successfully applied for the detection of SM2, SMR, and SMD in real pork and milk samples, with satisfactory recoveries (81.2-118.3%) and high precisions (RSDs <8.2, n = 3). Combining the optical properties of the nanohybrids, PCN-221(Zr/Ce)@Eu-DPA-H4btec integrated fluorescent hydrogels were innovatively prepared for visual sensing of SM2, SMR, and SMD. This study provides an uncomplicated and sensitive method for SAs detection in food matrices.

Antibacterial activity and mechanism of cinnamon essential oil nanoemulsion against Pseudomonas deceptionensis CM2.

This work aimed to evaluate the antibacterial activity and mechanism of cinnamon essential oil nanoemulsion (CON) against Pseudomonas deceptionensis CM2. The results revealed that CON could effectively inhibit the proliferation of P. deceptionensis CM2 cells in a time- and concentration-dependent manner. After 4 h of incubation with CON at the minimum inhibitory concentration (0.125 mg/mL), the relative fluorescence intensity of propidium iodide and 1-N-phenylnapthylamine (NPN) was increased by 32.0% and 351.4%, respectively. The membrane permeability of P. deceptionensis CM2 cells was significantly disrupted after CON treatment, resulting in the leakage of intracellular substances (such as proteins and electrolytes). CON also caused significant increases in the DiBAC4(3) fluorescence intensity of P. deceptionensis CM2 cells. These results demonstrate that CON induced inactivation of P. deceptionensis CM2 by destroying the integrity and function of bacterial membrane. A higher level of intracellular reactive oxygen species (ROS) was observed in CON-treated cells (p < 0.05), compared with control cells. Moreover, the addition of glutathione to the growth medium remarkably decreased the antimicrobial activity of CON against P. deceptionensis CM2, further confirming that oxidative stress played an important role in the antimicrobial activity of CON. Overall, CON may exhibit antibacterial effects by causing damage to the bacterial membranes and oxidative stress.

Corrigendum: Ethyl lauroyl arginate: an update on the antimicrobial potential and application in the food systems industry: a review.

[This corrects the article DOI: 10.3389/fmicb.2023.1125808.].

Lauric arginate ethyl ester: An update on the antimicrobial potential and application in the food systems.

Lauric arginate ethyl ester (LAE), a cationic surfactant with low toxicity, displays excellent antimicrobial activity against a broad range of microorganisms. LAE has been approved as generally recognized as safe (GRAS) for widespread application in certain foods at a maximum concentration of 200 ppm. In this context, extensive research has been carried out on the application of LAE in food preservation for improving the microbiological safety and quality characteristics of various food products. This study aims to present a general review of recent research progress on the antimicrobial efficacy of LAE and its application in the food industry. It covers the physicochemical properties, antimicrobial efficacy of LAE, and the underlying mechanism of its action. This review also summarizes the application of LAE in various foods products as well as its influence on the nutritional and sensory properties of such foods. Additionally, the main factors influencing the antimicrobial efficacy of LAE are reviewed in this work, and combination strategies are provided to enhance the antimicrobial potency of LAE. Finally, the concluding remarks and possible recommendations for the future research are also presented in this review. In summary, LAE has the great potential application in the food industry. Overall, the present review intends to improve the application of LAE in food preservation.

The Stability, Rheological Properties and Interfacial Properties of Oil-in-Water (O/W) Emulsions Prepared from Dielectric Barrier Discharge (DBD) Cold Plasma-Treated Chickpea Protein Isolate and Myofibrillar Protein Complexes.

In order to increase the development and utilization of chickpea protein isolate (CPI) and improve the stability of myofibrillar protein (MP) emulsions, the effect of dielectric barrier discharge (DBD) plasma-modified CPI on the emulsifying properties of MP was investigated. Three different O/W emulsions were prepared using MP, MP + CPI complex, or MP + DBD-treated CPI complex as the emulsifier. Compared with the emulsion prepared from MP, the emulsifying activity index and stability of DBD-treated CPI and MP complex (MP + CPIDBD) were increased (p < 0.05) from 55.17 m2/g to 74.99 m2/g and 66.31% to 99.87%, respectively. MP + CPIDBD produced more stable emulsions with the lowest Turbiscan stability index (TSI) values for a given 3600 s. At shear rates from 0 to 1000-1, MP + CPIDBD-stabilized emulsions had higher viscosities, which helped to reduce the chance of aggregation between oil droplets. The optical microscope and particle size distribution of emulsions showed that MP + CPIDBD emulsions had the lowest droplet size (d4,3) and exhibited more uniform distribution. MP + CPIDBD emulsions had lower interfacial tension. DBD pretreatment increased the adsorbed protein content in the emulsion stabilized by MP + CPIDBD as compared to the MP + CPI complex and promoted the adsorption of CPI by higher ratios of adsorbed proteins as indicated by its intensity in SDS-PAGE. Scanning electron microscopy confirmed that the emulsion prepared from MP + CPIDBD had smaller particle size and more uniform dispersion. Therefore, using DBD-modified CPI could enhance the stability of MP emulsions.

Electrospinning and Electrospraying: Emerging Techniques for Probiotic Stabilization and Application.

Probiotics are beneficial for human health. However, they are vulnerable to adverse effects during processing, storage, and passage through the gastrointestinal tract, thus reducing their viability. The exploration of strategies for probiotic stabilization is essential for application and function. Electrospinning and electrospraying, two electrohydrodynamic techniques with simple, mild, and versatile characteristics, have recently attracted increased interest for encapsulating and immobilizing probiotics to improve their survivability under harsh conditions and promoting high-viability delivery in the gastrointestinal tract. This review begins with a more detailed classification of electrospinning and electrospraying, especially dry electrospraying and wet electrospraying. The feasibility of electrospinning and electrospraying in the construction of probiotic carriers, as well as the efficacy of various formulations on the stabilization and colonic delivery of probiotics, are then discussed. Meanwhile, the current application of electrospun and electrosprayed probiotic formulations is introduced. Finally, the existing limitations and future opportunities for electrohydrodynamic techniques in probiotic stabilization are proposed and analyzed. This work comprehensively explains how electrospinning and electrospraying are used to stabilize probiotics, which may aid in their development in probiotic therapy and nutrition.

Comparative Composition Structure and Selected Techno-Functional Elucidation of Flaxseed Protein Fractions.

This study aimed to comparatively elucidate the composition structure and techno-functionality of flaxseed protein isolate (FPI), globulin (FG), and albumin (FA) fractions. The results showed that FA possessed smaller particle dimensions and superior protein solubility compared to that of FG (p < 0.05) due to the lower molecular weight and hydrophobicity. FA and FG manifested lamellar structure and nearly spherical morphology, respectively, whereas FPI exhibited small lamellar strip structure packed by the blurring spheres. The Far-UV CD, FTIR spectrum, and intrinsic fluorescence confirmed more flexible conformation of FA than that of FG, followed by FPI. The preferential retention of free phenolic acids was observed for FA, leading to excellent antioxidant activities compared with that of FG in FPI (p < 0.05). FA contributed to the foaming properties of FPI, relying on the earlier interfacial adsorption and higher viscoelastic properties. FA displayed favorable emulsifying capacity but inferior stability due to the limited interfacial adsorption and deformation, as well as loose/porous interface. By comparison, an interlayer anchoring but no direct interface coating was observed for lipid droplets constructed by FG, thereby leading to preferable emulsion stability. However, FPI produced lipid droplets with dense interface owing to the effective migration of FA and FG from bulk phase, concomitant with the easy flocculation and coalescence. Thus, the techno-functionality of flaxseed protein could be tailed by modulating the retention of albumin fraction and specific phenolic acids.

Removal of Alternaria mycotoxins exposed to different food components by cold plasma.

Alternariol (AOH) and alternariol monomethyl ether (AME), the two Alternaria mycotoxins with the highest outbreak rates in food systems, could be effectively reduced by cold plasma. This research evaluated the impact of food components on the plasma removal of AOH and AME. The results showed that 6% whey protein or ovalbumin almost completely inhibited the reduction of AOH or AME. Polyphenols inhibited the removal of AOH and AME by up to 90.8% and 83.4%, respectively. Organic acids and Vc reduced AME removal by up to 43.4% and 31.9%, respectively, but had little effect on AOH removal. Sugars and amino acids could decrease both toxin removal by less than 10%. Proteins exhibited the most inhibitory effect on plasma removal of AOH and AME, followed by polyphenols, while the effect of other components was relatively small. AOH and AME removal by cold plasma was highly related to H2O2 produced during plasma discharge.