Food Decontamination Research Articles

Evaluation of the potential of phage phSE-5 to fight Salmonella typhimurium in milk, liquid whole egg and eggshell.

This study aimed to evaluate the potential of phage phSE-5 to inactivate Salmonella enterica serovar Typhimurium in milk (at 4, 10 and 25°C), liquid whole egg and eggshell (at 25°C for both matrices). Since the success of phage treatment in food depends on maintaining phage viability towards different food conditions, firstly the stability of phage phSE-5 at different temperatures and pHs was assessed. The effect of phage phSE-5 against S. Typhimurium was then assessed in vitro (liquid culture medium-TSB) and finally in the selected food matrices. Phage phSE-5 was stable for long storage periods (56 days) at pH 7-8 and 4-25°C. At 25°C, the efficacy of phage phSE-5 was matrix-dependent with differences in the sample, relatively to the bacterial control, of 2.7, 4.6, 1.8 and 1.3 log colony-forming units (CFU) mL-1 in TSB, milk, liquid whole egg and eggshell, respectively. Also, phage phSE-5 led to reductions relatively to the initial bacterial concentration only in TSB and milk with 1.9 and 2.1 log CFU mL-1 reduction, respectively. Additionally, this phage was more efficient at 25°C in the tested matrices than at 10°C (no reduction and 1.7 log CFU mL-1 reduction in TSB and milk respectively; maximum difference of 1.7 and 3.3 log CFU mL-1 in TSB and milk, respectively) and 4°C (no bacterial reduction/difference was observed in both TSB and milk). However, the decrease in temperature from 25 to 10°C slowed down bacterial regrowth after phage treatment. Our results show that phages are promising and environmentally friendly candidates for use as biocontrol agents against S. Typhimurium in milk, liquid whole egg and eggshell, allowing a reduction in energy costs if carried out at 10°C. Salmonella Typhimurium is frequently found in contaminated milk and eggs. Despite the available food decontamination methods, these are usually associated with changes in the organoleptic properties of the food. Phages can be applied as an alternative option to inactivate foodborne bacteria and improve food safety, without affecting food organoleptic properties.

Potential of Postbiotics for the Biodegradation of Xenobiotics: A Review

In modern times, individuals are frequently subjected to a wide range of environmental and chemical pollutants that are generated by industrial and agricultural activities. The contamination of food by pesticides, biogenic amines, and mycotoxins represents a significant concern for global food safety, and has economic and public health implications, particularly in newly industrialized nations. A growing body of evidence suggests that prolonged exposure to food contaminants, known as xenobiotics, can have adverse effects on human health. Although many strategies for food decontamination are frequently used, they require specific conditions that are often difficult to meet in many industrial sectors. Currently, a promising strategy for mitigating the potential hazards associated with xenobiotics in food items involves the implementation of a biological detoxification method utilizing probiotic strains and their corresponding enzymes. Numerous investigations have corroborated the efficacy, practicality, and cost-effectiveness of postbiotics in impeding xenobiotic-induced dysbiosis and mitigating their toxicological effects. This review aims to summarize the current knowledge of the direct mechanisms by which postbiotics can influence the detoxification of xenobiotics. Moreover, the effects of postbiotics on host response to exposure to xenobiotics were discussed.

Non-Thermal Treatment Mediated by Curcumin for Enhancing Food Product Quality.

Increasing antibiotic resistance is one of the world's greatest health problems, and biocide use in food disinfection, alongside other application fields, could increase antibiotic resistance. Effective and eco-friendly food decontamination treatment with minimal chemical intervention in food production is urgently needed. Synergistic antimicrobial interaction of photoactive compounds and blue-light-emitting diodes have recently been proven effective in agricultural and environmental applications. Curcumin-based non-thermal treatment has been reviewed in this work for the development of a safe and effective decontamination tool that could be adapted to the food industry. The antimicrobial mechanism of the synergistic interaction and the inhibitory efficacy against foodborne pathogens (bacteria in both vegetative form and spore, as well as in biofilms) are discussed. Further studies on curcumin and its derivative, as well as light illumination patterns, were compared for enhanced bactericidal efficacy. Moreover, studies relating to photodynamic inactivation treatment for food sanitation and food quality enhancement (cereal grains and other food products) were summarized, as well as the impact on food organoleptic and nutritional quality.

Starch modification by low-dose electron beam irradiation: A comprehensive study between buckwheat starch, potato starch and pea starch

Electron Beam Irradiation (EBI) is an emerging technique for food decontamination and starch modification, but a comprehensive evaluation at safe doses (<10kGy) for different starch sources is lacking. This study investigated the effects of low-dose EBI (2-8kGy) on the physicochemical properties of buckwheat starch (BS), potato starch (POS), and pea starch (PS), each with different crystalline types (A-, B-, and C-type, respectively). EBI significantly reduced moisture and amylose content, decreased pasting viscosity, and retarded retrogradation dose-dependently for all starches. It also altered relative crystallinity (RC), thermal properties, rheological properties, and in vitro digestion, with effects varying by starch source. EBI-treated BS and POS showed decreased RC, gelatinization temperature and enthalpy, and increased paste flowability, while EBI-treated PS exhibited the opposite trend. Digestibility of EBI-treated BS initially decreased then increased with dose, while POS digestibility increased, and PS digestibility remained unchanged. This study highlights the versatility of EBI in starch modification, emphasizing its potential in developing low-viscosity starchy foods.

Inactivation of bacteria using synergistic hydrogen peroxide with split-dose nanosecond pulsed electric field exposures.

The use of pulsed electric fields (PEF) as a nonthermal technology for the decontamination of foods is of growing interest. This study aimed to enhance the inactivation of Escherichia coli, Listeria innocua, and Salmonella enterica in Gomori buffer using a combination of nsPEF and hydrogen peroxide (H2O2). Three sub-MIC concentrations (0.1, 0.3, and 0.5%) of H2O2 and various contact times ranging from 5-45 min were tested. PEF exposures as both single (1000 pulse) and split-dose (500+500 pulse) trains were delivered via square-wave, monopolar, 600 ns pulses at 21 kV/cm and 10 Hz. We demonstrate that >5 log CFU/mL reduction can be attained from combination PEF/H2O2 treatments with a 15 min contact time for E. coli (0.1%) and a 30 min contact time for L. innocua and S. enterica (0.5%), despite ineffective results from either individual treatment alone. A 5 log reduction in microbial population is generally the lowest acceptable level in consideration of food safety and represents inactivation of 99.999% of bacteria. Split-dose PEF exposures enhance lethality for several tested conditions, indicating greater susceptibility to PEF after oxidative damage has occurred.

A Honeycomb Film Template-Based Method for High-Throughput Preparation of Anti-Salmonella typhimurium 14,028 Phage Microgels.

Developing efficient anti-microbials for thoroughly addressing Salmonella contamination is essential for the improvement of food safety. Phage-built materials have shown great potential for biocontrol in environments. Due to challenges in delivery and stability, their widespread use has remained unattainable. Here, we have developed a honeycomb film template-based method for the high-throughput preparation of phage microgels. The honeycomb film template can be simply fabricated in a humid chamber based on a well-established breath figure method. The bacteriophage microgels can be further manufactured by dropping a pre-gelation solution containing bacteriophages into a honeycomb film template. This method can produce over 210,000 phage microgels in every square centimeter template with each microgel containing 1.04 × 107 phages. They can kill 99.90% of the contaminated S. typhimurium 14,028 on chicken samples. This simple, heat-free, and solvent-free method can maintain the strong anti-bacterial efficiency of phages, which can expand the wide application of phage-built microgels for food decontamination.

Experimental Investigation of Bacterial Inactivation of Beef Using Indirect Cold Plasma in Cold Chain and at Room Temperature.

Pathogen contamination is a severe problem in maintaining food safety in the cold chain. Cold plasma (CP) is a novel non-thermal disinfection method that can be applied for the bacterial inactivation of food in appropriate contexts. Currently, research on CP used on food at cold chain temperatures is rare. This work investigated the bacterial inactivation effect of CP on beef at typical cold storage temperatures of 4 and -18 °C and room temperature (25 °C). The reactive species in CP were indirectly tested by evaluating O3, NO3- and NO2- in cold plasma-activated water (PAW), which indicated the highest concentrations of reactive species in CP at 25 °C and the lowest at -18 °C. The bactericidal efficacy of CP treatment against beef inoculated with Escherichia coli at -18 °C, 4 °C, and 25 °C was 30.5%, 60.1%, and 59.5%, respectively. The 4 °C environment was the most appropriate treatment for CP against beef, with the highest bactericidal efficacy and a minor influence on beef quality. The indirect CP treatment had no significant effect on the texture, color, pH, or cooking loss of beef at -18 °C. CP shows significant potential for the efficient decontamination of food at cold chain temperatures.

Sustainable processing technologies (pulsed light, electrolysed water and ozonation) for microbial decontamination of muscle foods

Sustainable processing technologies (pulsed light, electrolysed water and ozonation) for microbial decontamination of muscle foods

Oxygen and air cold plasma for the inactivation of Bacillus cereus in low-water activity soy powder

Cold plasma (CP) technology is a promising alternative to thermal treatments for the microbial decontamination of foods with low-water activity. The aim of this work is study the application of low-pressure CP (0.35mbar) for the inactivation of Bacillus cereus in a soybean powder matrix using O₂ and synthetic air as ionizing gases. The parameters tested were an input power of 100, 200 and 300W and an exposure time of 10 to 30min. The excited reactive species formed were monitored by optical emission spectroscopy, and survival data were analyzed using the Weibull mathematical model. Treatments with both gases were effective in inactivating B. cereus. Air plasma resulted in a maximum 3.71-log reduction in bacterial counts at 300W and 30min, while O2 plasma showed the strongest inactivation ability, achieving levels higher than 5 log cycles at 300W and>25min. This is likely due to the strong antimicrobial activity of oxygen-derived radicals together with carbon monoxide as an oxidation by-product. In addition, the Weibull distribution function accurately modeled the inactivation of B. cereus. Cold plasma technology is a promising approach for the decontamination of bacteria in low-water activity foods.

Recent Advances in Non-Contact Food Decontamination Technologies for Removing Mycotoxins and Fungal Contaminants.

Agricultural food commodities are highly susceptible to contamination by fungi and mycotoxins, which cause great economic losses and threaten public health. New technologies such as gamma ray irradiation, ultraviolet radiation, electron beam irradiation, microwave irradiation, pulsed light, pulsed electric fields, plasma, ozone, etc. can solve the problem of fungal and mycotoxin contamination which cannot be effectively solved by traditional food processing methods. This paper summarizes recent advancements in emerging food decontamination technologies used to control various fungi and their associated toxin contamination in food. It discusses the problems and challenges faced by the various methods currently used to control mycotoxins, looks forward to the new trends in the development of mycotoxin degradation methods in the future food industry, and proposes new research directions.

Micellar-type aggregates of HP-β-CD/GML inclusion complex: Increased water-solubility and effective antibacterial capabilities

The inclusion complex (IC) was successfully obtained by encapsulating glycerol monolaurate (GML) into the cavity of hydroxypropyl-β-cyclodextrin (HP-β-CD). Compared with solubility of pure GML <80μg/mL in water, and the water-solubility of encapsulated GML was significantly improved and reached to 270,000μg/mL. IC can form nanoparticles by self-assembly, probably assigned to its strong capability to form micellar-type aggregates. A Higuchi's AL-type phase-solubility diagram indicated the strong interaction between host and guest molecules with the formation of 1:1 GML/HP-β-CD complex and the stability constant at 6248L/mol. Compared with pure GML, encapsulated GML at the same concentration can also show good antibacterial capabilities against S. aureus and E. coli in sterile water, and the effective preservative capabilities towards beef meatballs. The boosted enhancement in water-solubility of GML and the effective antibacterial capabilities endowed IC with potential in the application of food decontamination.

Inactivation of Salmonella Typhimurium and Listeria monocytogenes in dairy systems: Effect of fat and food matrix structure under radio frequency heating

Inactivation of Salmonella Typhimurium and Listeria monocytogenes in dairy systems: Effect of fat and food matrix structure under radio frequency heating

High-throughput fabrication of antimicrobial phage microgels and example applications in food decontamination.

Engineered by nature, biological entities are exceptional building blocks for biomaterials. These entities can impart enhanced functionalities on the final material that are otherwise unattainable. However, preserving the bioactive functionalities of these building blocks during the material fabrication process remains a challenge. We describe a high-throughput protocol for the bottom-up self-assembly of highly concentrated phages into microgels while preserving and amplifying their inherent antimicrobial activity and biofunctionality. Each microgel is comprised of half a million cross-linked phages as the sole structural component, self-organized in aligned bundles. We discuss common pitfalls in the preparation procedure and describe optimization processes to ensure the preservation of the biofunctionality of the phage building blocks. This protocol enables the production of an antimicrobial spray containing the manufactured phage microgels, loaded with potent virulent phages that effectively reduced high loads of multidrug-resistant Escherichia coli O157:H7 on red meat and fresh produce. Compared with other microgel preparation methods, our protocol is particularly well suited to biological materials because it is free of organic solvents and heat. Bench-scale preparation of base materials, namely microporous films (the template for casting microgels) and pure concentrated phage suspension, requires 3.5 h and 5 d, respectively. A single production run, that yields over 1,750,000 microgels, ranges from 2 h to 2 d depending on the rate of cross-linking chemistry. We expect that this platform will address bottlenecks associated with shelf-stability, preservation and delivery of phage for antimicrobial applications, expanding the use of phage for prevention and control of bacterial infections and contaminants.

Assessment of lipid oxidation and microbial decontamination of sardine (Sardina pilchardus) fillets processed by plasma-activated water (PAW)

Assessment of lipid oxidation and microbial decontamination of sardine (Sardina pilchardus) fillets processed by plasma-activated water (PAW)

On the evaluation of the antimicrobial effect of grape seed extract and cold atmospheric plasma on the dynamics of Listeria monocytogenes in novel multiphase 3D viscoelastic models

The demand for products that are minimally processed and produced in a sustainable way, without the use of chemical preservatives or antibiotics have increased over the last years. Novel non-thermal technologies such as cold atmospheric plasma (CAP) and natural antimicrobials such as grape seed extract (GSE) are attractive alternatives to conventional food decontamination methods as they can meet the above demands. The aim of this study was to investigate the microbial inactivation potential of GSE, CAP (in this case, a remote air plasma with an ozone-dominated RONS output) and their combination against L. monocytogenes on five different 3D in vitro models of varying rheological, structural, and biochemical composition. More specifically, we studied the microbial dynamics, as affected by 1% (w/v) GSE, CAP or their combination, in three monophasic Xanthan Gum (XG) based 3D models of relatively low viscosity (1.5%, 2.5% and 5%w/v XG) and in a biphasic XG/Whey Protein (WPI) and a triphasic XG/WPI/fat model. A significant microbial inactivation (comparable to liquid broth) was achieved in presence of GSE on the surface of all monophasic models regardless of their viscosity. In contrast, the GSE antimicrobial effect was diminished in the multiphasic systems, resulting to only a slight disturbance of the microbial growth. In contrast, CAP showed better antimicrobial potential on the surface of the complex multiphasic models as compared to the monophasic models. When combined, in a hurdle approach, GSE/CAP showed promising microbial inactivation potential in all our 3D models, but less microbial inactivation in the structurally and biochemically complex multiphasic models, with respect to the monophasic models. The level of inactivation also depended on the duration of the exposure to GSE. Our results contribute towards understanding the antimicrobial efficacy of GSE, CAP and their combination as affected by robustly controlled changes of rheological and structural properties and of the biochemical composition of the environment in which bacteria grow. Therefore, our results contribute to the development of sustainable food safety strategies.

Reduction of Staphylococcus aureus in vitro and in milk by photodynamic inactivation using riboflavin and curcumin as photosensitizers: Cell damage and effects on product quality

Reduction of Staphylococcus aureus in vitro and in milk by photodynamic inactivation using riboflavin and curcumin as photosensitizers: Cell damage and effects on product quality

APPLICATION OF ULTRAVIOLET LED SYSTEMS IN THE GRAIN PROCESSING AND COMPOUND FEED INDUSTRIES

The materials of the article outline the features of the use of ultraviolet LED systems in industry, and propose a solution for their use in the grain processing and compound feed industry. Ultraviolet light (UV) is a well-researched and widely used means of decontamination and disinfection of surfaces, air, water, and food. Usually, far ultraviolet radiation (or ultraviolet C, UVC) with a wavelength of 254 nm is used, which corresponds to the peak absorption of wave energy by the DNA of a living cell. There is a mathematical mechanism for calculating the parameters of radiation in relation to its effect on microorganisms: a curve describing the microbial death depending on the increase in the radiation dose received by the bacteria and formulae for the relationship between the three main parameters (dose, radiation flux and exposure duration). Ultraviolet lamps (tubes) are commonly used, on the basis of which a large number of emitters have been developed for different needs. There are also emitters for grain and feed disinfection in use, but only outside of industrial production lines. Ultraviolet irradiation is not used directly on manufacturing lines so far. However, it can be used to reduce the microbial burden of a feed or food product prior to packaging the finished product. For this purpose, ultraviolet light-emitting diodes (LEDs) available on the world market today can be used. However, their use faces difficulties: ultraviolet LEDs emit wavelengths longer than lamps (at about 275 nm or more), which requires an increase in the duration of irradiation, which is undesirable for industrial processing of products directly on the line. However, the small size of the UVC LEDs will allow them to be installed in grain processing and feed mills inside equipment (magnetic separators, gravity feeders, etc.) with appropriate protection against damage by moving material. In addition, suspended emitters of any configuration can be placed above belt conveyors that move material at a certain speed. This approach will require certain measures to control the efficiency of irradiation (requires microbiological studies) and to protect personnel from the harmful effects of ultraviolet rays (means of personal and collective protection, measurement of radiation intensity).

Poly(vinyl alcohol) antibacterial films containing cross‐linked chitosan‐citric and photosensitive curcumin

AbstractComposite films PVA‐CS‐Curx (x = 0, 0.01, 0.06 and 0.12%) were successfully obtained by using vacuum‐drying at 80°C. The occurrence of nonenzymatic browning and cross‐linking of chitosan‐citric improved the thermal stability, water‐resistance, and mechanical property of films. Under the same humidity, the oxygen permeability of PVA‐CS‐Curx showed the dependence of test temperature and curcumin concentration (P &lt; 0.05). Relative to other films, the oxygen permeability (10−14 cc μm cm−2 s−1 Pa−1) of PVA‐CS‐Cur0.12 was 3.47 ± 0.55, 4.72 ± 0.94, and 7.29 ± 0.45 at 23, 30, and 40°C, respectively, showing gentle upward trend as temperature increased. Under white light irradiation, excellent antibacterial capability of PVA‐CS‐Curx demonstrated that polycationic chitosan‐citric complex and curcumin immobilized in films played the roles as synergistic antibacterial agents. Upon white irradiation of 20 min at 60 mW cm−2, the bactericidal rate of PVA‐CS‐Cur0.12 reached to 94.0 ± 3.09%. The excellent decontamination in meat preservation endowed films with the possibility in application of food decontamination.

Plasma-Activated Water: Physicochemical Properties, Generation Techniques, and Applications

Plasma-activated water (PAW) is water that has been treated with atmospheric pressure plasma. Due to the presence of reactive oxygen and nitrogen species (RONS), PAW can be used in various applications such as (1) surface disinfection and food decontamination, (2) enhancement in seed germination, and (3) enhancement in surface cooling in the nucleate boiling regime. Briefly, for surface disinfection, the reactive species in PAW can induce oxidative stress on microbes; for enhancement of seed germination, the reactive species in PAW can trigger seed germination and provide nutrients; for enhancement in surface cooling, the reactive species cause a reduction in the surface tension of PAW, facilitating the phase-change heat transfer and, quite unexpectedly, minimizing the surface oxidation. Here, we review the physicochemical properties of PAW, the three commonly used techniques (plasma jet, dielectric barrier discharge, and corona discharge) for generating atmospheric pressure plasma, and the use of PAW for the above three applications. In particular, we review the recent development of the miniaturization of the plasma generator integrated with an acoustic neutralizer to produce plasma-activated aerosols, elimination of the need for storage, and the interesting physicochemical properties of PAW that lead to cooling enhancement.

Influence of diluent on antimicrobial activity of cinnamon bark essential oil vapor against Staphylococcus aureus and Salmonella enterica on a laboratory medium and beef jerky

The influence of chemical diluents on the antimicrobial activity of plant essential oil (EO) vapors was evaluated. We first determined if vapors generated from 22 chemical diluents not containing EO had antimicrobial activities. Ethyl ether vapor retarded the growth of S. aureus. The minimal inhibitory concentrations (MICs) and the minimal lethal concentrations (MLCs) of cinnamon bark EO vapor, which was diluted in and generated from 21 diluents, against S. aureus and S. enterica were determined. Cinnamon bark EO vapor showed significantly (P≤0.05) lower MICs against S. aureus when diluted in dimethyl sulfoxide (DMSO), ethanol, ethyl acetate, or jojoba oil, and against S. enterica when diluted in DMSO, ethanol, or jojoba oil, compared to those in other diluents. We compared antimicrobial activities of cinnamon bark EO vapor diluted in DMSO, ethanol, ethyl acetate, or jojoba oil against S. aureus and S. enterica on beef jerky as a food model. Antimicrobial activity was significantly (P≤0.05) higher when vaporized from DMSO. These results indicate that antimicrobial activity of cinnamon bark EO vapor may vary significantly (P≤0.05) depending on the type of diluent from which it is vaporized. These observations provide basic information when developing food and food-contact surface decontamination strategies using EO vapors.