Hygienic design of food processing lines to mitigate the risk of bacterial food contamination with respect to environmental concerns

Potential of bacteriophage phT4A as a biocontrol agent against Escherichia coli in food matrices

Escherichia coli is one of the most prevalent foodborne pathogens, frequently found in meat and dairy products. Current decontamination methods are often associated with changes in organoleptic characteristics, nutrient loss, and potentially harmful side effects. Furthermore, despite the array of available methods, foodborne outbreaks still frequently occur. For this reason, bacteriophages (or simply phages) emerged as a natural alternative for the biocontrol of bacterial contamination in food without altering their organoleptic properties. In this study, the potential of phage phT4A was assessed in the biocontrol of E. coli in liquid (milk) and solid (ham) food matrices. Firstly, as foods have different pH and temperature values, the influence of these parameters on phage phT4A viability was also assessed to develop an effective protocol. Phage phT4A proved to be stable for long storage periods at pH 7-8 (56 days) and temperatures of 4-37 °C (21 days). Before application of phages to inactivate pathogenic bacteria in food, previous assays were carried out in Tryptic Soy Broth (TSB) to study the dynamics of phage-bacteria interaction. Then, the antibacterial potential of phage phT4A was evaluated in the two food matrices at different temperatures (4, 10 and 25 °C). This phage was more efficient at 25 °C in all tested matrices (maximum inactivation of 6.6, 3.9 and 1.8 log CFU/mL in TSB, milk and ham, respectively) than at 10 °C (maximum decrease of 4.7, 2.1 and 1.0 log CFU/mL in TSB, milk and ham, respectively) and 4 °C (maximum reduction of 2.6 and 0.7 log CFU/mL in TSB and milk, respectively). However, the decrease of temperature from 25 °C to 10 and 4 °C prevented bacterial regrowth. The results suggest that during phage treatment, a balance between an incubation temperature that provide effective results in terms of bacterial inactivation by the phages and at the same time prevents or delays bacterial regrowth, is needed. The application of phage phT4A at a temperature of 10 °C can be an effective strategy in terms of bacterial inactivation, delaying bacterial regrowth and also reducing energy costs.

Influence of slope, material, and temperature on Listeria monocytogenes and Pseudomonas aeruginosa mono- and dual-species biofilms

Understanding factors influencing Listeria monocytogenes biofilms aid in developing more effective elimination/prevention strategies. This study examined the effect of temperature (4 °C, 21 °C, 30 °C), materials (stainless steel 316 L with 2B and 2 R finishes, glass, and polypropylene), and slope (0°/horizontal or 90°/vertical) on mono- and dual-species biofilms using two L. monocytogenes strains and one Pseudomonas aeruginosa strain. All biofilms were grown in 10% TSB for 24 h and analyzed using culture-based methods. Additionally, the architecture of monospecies biofilms was studied using fluorescence microscopy. Overall, P. aeruginosa showed higher biofilm formation potential (6.2 log CFU/cm2) than L. monocytogenes (4.0 log CFU/cm2). Temperature greatly influenced P. aeruginosa and varied for L. monocytogenes. The slope predominantly influenced L. monocytogenes monospecies biofilms, with cell counts increasing by up to 2 log CFU/cm2. Surface material had little impact on biofilm formation. The study highlights the varying effects of different parameters on multispecies biofilms and the importance of surface geometry.

Evaluation of the Effectiveness of Aeration and Chlorination during Washing to Reduce E. coli O157:H7, Salmonella enterica, and L. innocua on Cucumbers and Bell Peppers

The attachment strength of bacteria to surfaces can affect the efficacy of sanitizers during washing. This study aimed to determine the effectiveness of chlorination and aeration in the removal of pathogens from the surface of produce. Cucumbers and bell peppers were inoculated with Listeria innocua, Escherichia coli O157:H7, or Salmonella enterica; afterwards, the produce was washed with or without chlorinated water (100 ppm) for 3 min in combination with or without aeration. Cucumbers washed with chlorinated water, with or without aeration, presented significant reductions of L. innocua (3.65 log CFU/cm2 and 1.13 log CFU/cm2, respectively) (p < 0.05). Similarly, bell peppers washed in chlorinated water with aeration (1.91 log CFU/g) and without aeration (2.49 log CFU/g) presented significant reductions of L. innocua. A significant reduction of L. innocua was observed on bell peppers washed with non-chlorinated water with aeration (2.49 log CFU/g) (p < 0.05). Non-chlorinated water was also effective in significantly reducing the level of Salmonella enterica (p < 0.05) on cucumbers and bell peppers. Washing with chlorinated water with aeration reduced Salmonella enterica levels from 4.45 log CFU/cm2 on cucumbers to below the detectable limit (0.16 log CFU/cm2). The highest reduction of Salmonella enterica from bell peppers occurred after washing with chlorinated water with aeration (2.48 log CFU/g). E. coli O157:H7, L. innocua, and Salmonella enterica levels present in non-chlorinated water after washing contaminated produce with or without aeration were significantly greater than those in chlorinated water (p < 0.05). After treatment, the population levels of all pathogens in chlorinated water with or without aeration were below the detectable limit for bell peppers (<1.10 log CFU/mL) and cucumbers (<1.20 log CFU/mL). Using chlorine in combination with forced aeration during washing minimizes cross-contamination of bacterial pathogens.

A Review of Food Contaminants and Their Pathways Within Food Processing Facilities Using Open Food Processing Equipment

This study focuses on the chemical, physical, and biological hazards that pose food contamination risks during the processing of food in facilities using open food processing equipment through a review of published literature from 2015 to 2023. Ten main pathways for food contamination were developed and a list of chemical, physical, and biological food hazards, along with descriptions of process parameters and inputs that can contribute to food contamination, and prevention strategies associated with each pathway were compiled. The paper briefly discusses the relation between food contamination and the sustainable development goals (SDGs). The presented overview of contamination pathways and their associated food hazards can provide insights for food safety management plans, food processing equipment design, food processing facility layout, HACCP programs, and further studies on hygienic monitoring methods.

Listeria monocytogenes in food businesses: From persistence strategies to intervention/prevention strategies-A review

In 2023, Listeria monocytogenes persistence remains a problem in the food business. A profound understanding of how this pathogen persists may lead to better aimed intervention/prevention strategies. The lack of a uniform definition of persistence makes the comparison between studies complex. Harborage sites offer protection against adverse environmental conditions and form the ideal habitat for the formation of biofilms, one of the major persistence strategies. A retarded growth rate, disinfectant resistance/tolerance, desiccation resistance/tolerance, and protozoan protection complete the list of persistence strategies for Listeria monocytogenes and can occur on themselves or in combination with biofilms. Based on the discussed persistence strategies, intervention strategies are proposed. By enhancing the focus on four precaution principles (cleaning and disinfection, infrastructure/hygienic design, technical maintenance, and work methodology) as mentioned in Regulation (EC) No. 852/2004, the risk of persistence can be decreased. All of the intervention strategies result in obtaining and maintaining a good general hygiene status throughout the establishment at all levels ranging from separate equipment to the entire building.

Comparative evaluation of the effectiveness of alcohol-based sanitizers, UV-C radiation and hot air on three-age Salmonella biofilms

Dry sanitation is recommended to control contamination and prevent microbial growth and biofilm formation in the low-moisture food manufacturing plants. The objective of this study was to evaluate the effectiveness of dry sanitation protocols on Salmonella three-age biofilms formed on stainless steel (SS) and polypropylene (PP). Biofilms were formed for 24, 48 and 96 h at 37 °C using a cocktail of six Salmonella strains (Muenster, Miami, Glostrup, Javiana, Oranienburg, Yoruba) isolated from the peanut supply chain. Then, the surfaces were exposed to UV-C radiation, hot air (90 °C), 70% ethanol and a commercial product based on isopropyl alcohol for 5, 10, 15 and 30 min. After 30min exposure, on PP the reductions ranged from 3.2 to 4.2 log CFU/cm² for UV-C, from 2.6 to 3.0 log CFU/cm² for hot air, from 1.6 to 3.2 log CFU/cm² for 70% ethanol and from 1.5 to 1.9 log CFU/cm² for the commercial product. On SS, after the same exposure time, reductions of 1.3-2.2 log CFU/cm², 2.2 to 3.3 log CFU/cm², 1.7 to 2.0 log CFU/cm² and 1.6 to 2.4 log CFU/cm² were observed for UV-C, hot air, 70% ethanol and commercial product, respectively. UV-C was the only treatment affected by the surface material (p < 0.05) whereas the biofilm age influenced the effectiveness of UV-C and hot air (p < 0.05). For most treatment, there was significant difference among the exposure times (p < 0.05). Overall, the fastest loss in the biofilm viability was noted in the first 5 min, followed by a tail phase. The time predicted by the Weibull model for the first decimal reduction ranged from 0.04 to 9.9 min on PP and from 0.7 to 8.5 min on SS. In addition, the Weibull model indicates that most of treatments (79%) required a long-term exposure time (>30 min) to achieve 3-log reductions of Salmonella biofilms. In summary, UV-C showed the best performance on PP whereas hot air was noted to be the most effective on SS.

Simulation Evaluation of Power of Sampling Plans to Detect Cronobacter in Powdered Infant Formula Production

Cronobacteris a hazard in Powdered Infant Formula (PIF) products that is hard to detect due to localized and low-level contamination. We adapted a previously published sampling simulation to PIF sampling and benchmarked industry-relevant sampling plans across different numbers of grabs, total sample mass, and sampling patterns. We evaluated performance to detect published Cronobacter contamination profiles for a recalled PIF batch [42% prevalence, -1.8±0.7 log(CFU/g)] and a reference, non-recalled, PIF batch [1% prevalence, -2.4±0.8 log(CFU/g)]. Simulating a range of numbers of grabs [n=1 to 22,000 (representing testing every finished package)] with 300 g total composite mass showed that taking 30 or more grabs detected contamination reliably (<1% median probability to accept the recalled batch). Benchmarking representative sampling plans ([n=30, mass grab=10g], [n=30, m=25g], [n=60, m=25g], [n=180, m=25g]) showed that all plans would reject the recalled batch (<1% median probability to accept) but would rarely reject the reference batch (>50% median probability of acceptance, all plans). Overall, (i) systematic or stratified random sampling patterns are equal to or more powerful than random sampling of the same sample size and total sampled mass, and, (ii) taking more samples, even if smaller, can increase the power to detect contamination.

Application of computational fluid dynamics simulations in food industry

Computational fluid dynamics (CFD) is a tool for modelling and simulating processes in many industries. It is usually used as a choice to solve problem involving flow of fluids, heat transfer, mass transfer and chemical reaction. Moreover, it has also found application in the optimization of processes in branches of the food industry, including bread baking, cooling beef roast, or spray drying. CFD has enormous potential and many opportunities to improve the quality and safety of food products, as well as to reduce the costs of production and the use of machines and production equipment. In addition, empirical models only permit data to be extracted at a limited number of locations in the system (where sensors and gauges are placed). CFD allows the designer to examine any location in the region of interest, and interpret its performance through a set of thermal and flow parameters. Computer simulations are the future of every field of science, and the presented overview provides the latest information on experts and experiences related to CFD application in food production. Despite some disadvantages, such as the need to have a large reserve of computing power, the development of digital and IT technologies will make this problem insignificant in the nearest future. Then the CFD will become an indispensable element in the design of equipment and technological lines in the food industry.

Decontamination of Spores on Model Stainless-Steel Surface by Using Foams Based on Alkyl Polyglucosides

In the food industry, the surfaces of processing equipment are considered to be major factors in the risk of food contamination. The cleaning process of solid surfaces is essential, but it requires a significant amount of water and chemicals. Herein, we report the use of foam flows based on alkyl polyglucosides (APGs) to remove spores of Bacillus subtilis on stainless-steel surfaces as the model-contaminated surface. Sodium dodecyl sulfate (SDS) was also studied as an anionic surfactant. Foams were characterized during flows by measuring the foam stability and the bubble size. The efficiency of spores' removal was assessed by enumerations. We showed that foams based on APGs could remove efficiently the spores from the surfaces, but slightly less than foams based on SDS due to an effect of SDS itself on spores removal. The destabilization of the foams at the end of the process and the recovery of surfactant solutions were also evaluated by using filtration. Following a life cycle assessment (LCA) approach, we evaluated the impact of the foam flow on the global environmental footprint of the process. We showed significant environmental impact benefits with a reduction in water and energy consumption for foam cleaning. APGs are a good choice as surfactants as they decrease further the environmental impacts.

Dry surface biofilms in the food processing industry: An overview on surface characteristics, adhesion and biofilm formation, detection of biofilms, and dry sanitization methods

Bacterial biofilm formation in low moisture food processing (LMF) plants is related to matters of food safety, production efficiency, economic loss, and reduced consumer trust. Dry surfaces may appear dry to the naked eye, however, it is common to find a coverage of thin liquid films and microdroplets, known as microscopic surface wetness (MSW). The MSW may favor dry surface biofilm (DSB) formation. DSB formation is similar in other industries, it occurs through the processes of adhesion, production of extracellular polymeric substances, development of microcolonies and maturation, it is mediated by a quorum sensing (QS) system and is followed by dispersal, leading to disaggregation. Species that survive on dry surfaces develop tolerance to different stresses. DSB are recalcitrant and contribute to higher resistance to sanitation, becoming potential sources of contamination, related to the spoilage of processed products and foodborne disease outbreaks. In LMF industries, sanitization is performed using physical methods without the presence of water. Although alternative dry sanitizing methods can be efficiently used, additional studies are still required to develop and assess the effect of emerging technologies, and to propose possible combinations with traditional methods to enhance their effects on the sanitization process. Overall, more information about the different technologies can help to find the most appropriate method/s, contributing to the development of new sanitization protocols. Thus, this review aimed to identify the main characteristics and challenges of biofilm management in low moisture food industries, and summarizes the mechanisms of action of different dry sanitizing methods (alcohol, hot air, UV-C light, pulsed light, gaseous ozone, and cold plasma) and their effects on microbial metabolism.

Impact of industrial effluents on the environment and human health and their remediation using MOFs-based hybrid membrane filtration techniques

The hazardous risk posed by industrial effluent discharge into the ecosystem has raised a plethora of environmental issues, public health, and safety concerns. The effluents from industries such as tanning, leather, petrochemicals, pharmaceuticals, and textiles are create significant stress on the aquatic ecosystem, which induces significant toxicity, involved in endocrine disruptions, and inhibits reproductive functions. Therefore, this review presented an overall abridgment of the effects of these effluents and their ability to synergize with modern pollutants such as pharmaceuticals, cosmetic chemicals, nanoparticles, and heavy metals. We further emphasize the metal organic framework (MOF) based membrane filtration approach for remediation of industrial effluents in comparison to the traditional remediation process. The MOF based-hybrid membrane filters provide higher reusability, better adsorption, and superior removal rates through the implication of nanotechnology, while the traditional remediation process offers poorer filtration rates and stability.

Evaluation of the Hygienic Quality of the Gastronomic Offer of a Coastal Tourist Destination: A Study in San Pablo, Ecuador

In Ecuador, the San Pablo commune is one of the main tourist destinations in the Ecuadorian coastal region, recognized for its scenic landscapes and its gastronomy based on fish and seafood. The objective of this study is to evaluate the hygienic quality of the food offered in this location. Hence, five local restaurants were audited for compliance to good manufacturing practices (GMP), considering requirements for personnel, raw materials, facilities, equipment and utensils, quality assurance and storage conditions. Concurrently, four groups of ready-to-serve foods were sampled: rice, fish, natural juice, and raw salads to analyze total coliforms, Staphylococcus aureus, Escherichia coli, and Salmonella spp. The results confirmed the absence of Staphylococcus aureus, Escherichia coli, and Salmonella spp. However, values outside the norm for total coliforms were quantified in three food groups. There was an average compliance of 66.46 ± 16.67% regarding GMP with no significant difference in compliance between the six groups of requirements. These results indicate that work is needed to improve GMP, increase the hygienic quality of food and enhance the gastronomy offered in San Pablo.

Combined Effect of Temperature and Relative Humidity on the Survival of Salmonella Isolates on Stainless Steel Coupons

The survival on stainless steel of ten Salmonella isolates from food factory, clinical and veterinary sources was investigated. Stainless steel coupons inoculated with Salmonella were dried and stored at a range of temperatures and relative humidity (RH) levels representing factory conditions. Viability was determined from 1 to 22 days. Survival curves obtained for most isolates and storage conditions displayed exponential inactivation described by a log-linear model. Survival was affected by environmental temperatures and RH with decimal reduction times (DRTs) ranging from <1 day to 18 days. At 25 °C/15% RH, all isolates survived at levels of 10³ to 10⁵ cfu for >22 days. Furthermore, temperatures and RH independently influenced survival on stainless steel; increasing temperatures between 10 °C and 37 °C and increasing RH levels from 30–70% both decreased the DRT values. Survival curves displaying a shoulder followed by exponential death were obtained for three isolates at 10 °C/70% RH. Inactivation kinetics for these were described by modified Weibull models, suggesting that cumulative injury occurs before cellular inactivation. This study highlights the need to control temperature and RH to limit microbial persistence in the food manufacturing environment, particularly during the factory shut-down period for cleaning when higher temperature/humidity levels could be introduced.

Bactericidal efficacy of slightly acidic electrolyzed water (SAEW) against Listeria monocytogenes planktonic cells and biofilm on food-contact surfaces

In the present study, the bactericidal efficacy of slightly acidic electrolyzed water (SAEW) against L. monocytogenes planktonic cells and biofilm on food-contact surfaces including stainless steel and glass was systematically evaluated. The results showed that SAEW (pH of 5.09 and available chlorine concentration (ACC) of 60.33 mg/L) could kill L. monocytogenes on food-contact surfaces completely in 30 s, whose disinfection efficacy is equal to that of NaClO solutions (pH of 9.23 and ACC of 253.53 mg/L). The results showed that long exposure time and high ACC contributed to the enhancement of the disinfection efficacy of SAEW on L. monocytogenes on food-contact surfaces. Moreover, the log reduction of SAEW treatment presented an increasing tendency within the prolonging of treatment time when SAEW was used to remove the L. monocytogenes biofilm formed on stainless steel and glass surfaces, which suggested that SAEW could remove L. monocytogenes biofilm effectively and its disinfection efficacy is equal to (in case of stainless steel) or higher than (in case of glass) that of high ACC of NaClO solutions. In addition, the results of the crystal violet staining and scanning electron microscopy (SEM) also demonstrated that SAEW treatment could remove the L. monocytogenes biofilm on food-contact surfaces.

Potential of Flow Cytometric Approaches for Rapid Microbial Detection and Characterization in the Food Industry-A Review

As microbial contamination is persistent within the food and bioindustries and foodborne infections are still a significant cause of death, the detection, monitoring, and characterization of pathogens and spoilage microorganisms are of great importance. However, the current methods do not meet all relevant criteria. They either show (i) inadequate sensitivity, rapidity, and effectiveness; (ii) a high workload and time requirement; or (iii) difficulties in differentiating between viable and non-viable cells. Flow cytometry (FCM) represents an approach to overcome such limitations. Thus, this comprehensive literature review focuses on the potential of FCM and fluorescence in situ hybridization (FISH) for food and bioindustry applications. First, the principles of FCM and FISH and basic staining methods are discussed, and critical areas for microbial contamination, including abiotic and biotic surfaces, water, and air, are characterized. State-of-the-art non-specific FCM and specific FISH approaches are described, and their limitations are highlighted. One such limitation is the use of toxic and mutagenic fluorochromes and probes. Alternative staining and hybridization approaches are presented, along with other strategies to overcome the current challenges. Further research needs are outlined in order to make FCM and FISH even more suitable monitoring and detection tools for food quality and safety and environmental and clinical approaches.

Promising strategies to control persistent enemies: Some new technologies to combat biofilm in the food industry-A review

Biofilm is an advanced form of protection that allows bacterial cells to withstand adverse environmental conditions. The complex structure of biofilm results from genetic-related mechanisms besides other factors such as bacterial morphology or substratum properties. Inhibition of biofilm formation of harmful bacteria (spoilage and pathogenic bacteria) is a critical task in the food industry because of the enhanced resistance of biofilm bacteria to stress, such as cleaning and disinfection methods traditionally used in food processing plants, and the increased food safety risks threatening consumer health caused by recurrent contamination and rapid deterioration of food by biofilm cells. Therefore, it is urgent to find methods and strategies for effectively combating bacterial biofilm formation and eradicating mature biofilms. Innovative and promising approaches to control bacteria and their biofilms are emerging. These new approaches range from methods based on natural ingredients to the use of nanoparticles. This literature review aims to describe the efficacy of these strategies and provide an overview of recent promising biofilm control technologies in the food processing sector.

Isolation and Characterization of Bacteriophage ZCSE6 against Salmonella spp.: Phage Application in Milk

Food safety is very important in the food industry as most pathogenic bacteria can cause food-borne diseases and negatively affect public health. In the milk industry, contamination with Salmonella has always been a challenge, but the risks have dramatically increased as almost all bacteria now show resistance to a wide range of commercial antibiotics. This study aimed to isolate a bacteriophage to be used as a bactericidal agent against Salmonella in milk and dairy products. Here, phage ZCSE6 has been isolated from raw milk sample sand molecularly and chemically characterized. At different multiplicities of infection (MOIs) of 0.1, 0.01, and 0.001, the phage–Salmonella interaction was studied for 6 h at 37 °C and 24 h at 8 °C. In addition, ZCSE6 was tested against Salmonella contamination in milk to examine its lytic activity for 3 h at 37 °C. The results showed that ZCSE6 has a small genome size (<48.5 kbp) and belongs to the Siphovirus family. Phage ZCSE6 revealed a high thermal and pH stability at various conditions that mimic milk manufacturing and supply chain conditions. It also demonstrated a significant reduction in Salmonella concentration in media at various MOIs, with higher bacterial eradication at higher MOI. Moreover, it significantly reduced Salmonella growth (MOI 1) in milk, manifesting a 1000-fold decrease in bacteria concentration following 3 h incubation at 37 °C. The results highlighted the strong ability of ZCSE6 to kill Salmonella and control its growth in milk. Thus, ZCSE6 is recommended as a biocontrol agent in milk to limit bacterial growth and increase the milk shelf-life.

Influence of the design of fresh-cut food washing tanks on the growth kinetics of Pseudomonas fluorescens biofilms

Mitigation of cross-contamination of fresh-cut food products at the washing step was studied by investigating how the vat design would affect the biofilm contamination surfaces. Hygienic design features such as no horizontal surfaces and only open angles exceeding 100° were proposed. The flow organization (velocity streamlines, wall shear stresses, and dynamics of the flow) was identified by means of computational fluid dynamics (CFD) calculation. Pseudomonas fluorescens PF1 biofilm growth kinetics were then mapped. The change in some geometrical features induced a better flow organization reducing “dead zones”. This significantly changed the biofilm growth kinetics, delaying the detection of biofilms from 20 hr to 24 hr. Critical areas such as welds, corners, and interfaces appeared far less prone to strong bacterial development. This would mean milder or less chemicals required at the washing step and faster and easier cleaning.

•

Pseudomonas fluorescens biofilm growth kinetics strongly related to the vat design

•

Improved design lead to 24hr lag time before the biofilm exponential growth phase

•

Corners, welds, and wetting front areas contamination could be largely mitigated

Molecular dynamics model for the antibactericity of textured surfaces

An original model has been developed for the initial stage of bacterial adhesion on textured surfaces. Based on molecular dynamics, the model describes contact between individual bacterial cells in a planktonic state and a surface, accounting for both the mechanical properties of the cells and the physico-chemical mechanisms governing interaction with the substrate. Feasibility of the model is assessed via comparison with experimental results of bacterial growth on stainless steel substrates textured with ultrashort laser pulses. Simulations are performed for two different bacterial species, Staphylococcus aureus and Escherichia coli, on two distinct surface types characterised by elongated ripples and isolated nanopillars, respectively. Calculated results are in agreement with experiment outcomes and highlight the role of mechanical stresses within the cell wall due to deformation upon interaction with the substrate, creating unfavourable conditions for bacteria during the initial phases of adhesion. Furthermore, the flexibility of the model provides insight into the intricate interplay between topography and the physico-chemical properties of the substrate, pointing to a unified picture of the mechanisms underlying bacterial affinity to a textured surface.

Need for a balance between short food supply chains and integrated food processing sectors: COVID-19 takeaways from India

India is an agrarian country with a long history of traditional food processing practices and Short food supply chains (SFSC). However, last few decades saw a huge investment and steady increase in large scale integrated food processing units to combat globalization, food security and India’s export demands. Recent outbreak of COVID-19 has manifested the drawbacks in the existing production and supply chain system with a wide range of issues and enforces the need for a more balanced approach. This scenario can be commonly observed in many other agrarian developing nations. This article discusses various issues concerning the existing integrated food processing sectors such as high energy consumption, greenhouse gas emissions and food insecurity during disasters and pandemic outbreaks. Moreover, we emphasise a more sustainable approach with a better balance and understanding between SFSC and integrated food processing. A potential solution in this scenario would be, rejuvenating SFSC and traditional food processing approaches along with integrated food processing units. An approach of this kind, opens up new possibilities for a next generation process-supply system.

Nonthermal plasma-activated water: A comprehensive review of this new tool for enhanced food safety and quality

Nonthermal plasma (NTP) is an advanced technology that has gained extensive attention because of its capacity for decontaminating food from both biological and chemical sources. Plasma-activated water (PAW), a product of NTP's reaction with water containing a rich diversity of highly reactive oxygen species (ROS) and reactive nitrogen species (RNS), is now being considered as the primary reactive chemical component in food decontamination. Despite exciting developments in this field recently, at present there is no comprehensive review specifically focusing on the comprehensive effects of PAW on food safety and quality. Although PAW applications in biological decontamination have been extensively evaluated, a complete analysis of the most recent developments in PAW technology (e.g., PAW combined with other treatments, and PAW applications in chemical degradation and as curing agents) is nevertheless lacking. Therefore, this review focuses on PAW applications for enhanced food safety (both biological and chemical safeties) according to the latest studies. Further, the subsequent effects on food quality (chemical, physical, and sensory properties) are discussed in detail. In addition, several recent trends of PAW developments, such as curing agents, thawing media, preservation of aquatic products, and the synergistic effects of PAW in combination with other traditional treatments, are also presented. Finally, this review outlines several limitations presented by PAW treatment, suggesting several future research directions and challenges that may hinder the translation of these technologies into real-life applications.

The sps Genes Encode an Original Legionaminic Acid Pathway Required for Crust Assembly in Bacillus subtilis

The crust is the outermost spore layer of most Bacillus strains devoid of an exosporium. This outermost layer, composed of both proteins and carbohydrates, plays a major role in the adhesion and spreading of spores into the environment. Recent studies have identified several crust proteins and have provided insights about their organization at the spore surface. However, although carbohydrates are known to participate in adhesion, little is known about their composition, structure, and localization. In this study, we showed that the spore surface of Bacillus subtilis is covered with legionaminic acid (Leg), a nine-carbon backbone nonulosonic acid known to decorate the flagellin of the human pathogens Helicobacter pylori and Campylobacter jejuni We demonstrated that the spsC, spsD, spsE, spsG, and spsM genes of Bacillus subtilis are required for Leg biosynthesis during sporulation, while the spsF gene is required for Leg transfer from the mother cell to the surface of the forespore. We also characterized the activity of SpsM and highlighted an original Leg biosynthesis pathway in B. subtilis Finally, we demonstrated that Leg is required for the assembly of the crust around the spores, and we showed that in the absence of Leg, spores were more adherent to stainless steel probably because of their reduced hydrophilicity and charge.IMPORTANCE Bacillus species are a major economic and food safety concern of the food industry because of their food spoilage-causing capability and persistence. Their persistence is mainly due to their ability to form highly resistant spores adhering to the surfaces of industrial equipment. Spores of the Bacillus subtilis group are surrounded by the crust, a superficial layer which plays a key role in their adhesion properties. However, knowledge of the composition and structure of this layer remains incomplete. Here, for the first time, we identified a nonulosonic acid (Leg) at the surfaces of bacterial spores (B. subtilis). We uncovered a novel Leg biosynthesis pathway, and we demonstrated that Leg is required for proper crust assembly. This work contributes to the description of the structure and composition of Bacillus spores which has been under way for decades, and it provides keys to understanding the importance of carbohydrates in Bacillus adhesion and persistence in the food industry.

Hydrophobicity of abiotic surfaces governs droplets deposition and evaporation patterns

Surface contamination with droplets containing bacteria is of concern in the food industry and other environments where hygiene control is essential. Deposition patterns after the drying of contaminated droplets is affected by numerous parameters. The present study evaluated the rate of evaporation and the shape of deposition patterns after the drying of water droplets on a panel of materials with different surface properties (topography, hydrophobicity). The influence of the particle properties (in this study 1 μm-microspheres and two bacterial spores) was also investigated. Polystyrene microspheres were hydrophobic, while Bacillus spores were hydrophilic or hydrophobic, and surrounded by different surface features. In contrast to material topography, hydrophobicity was shown to deeply affect droplet evaporation, with the formation of small, thick deposits with microspheres or hydrophilic spores. Among the particle properties, the spore morphology (size and round/ovoid shape) did not clearly affect the deposition pattern. Conversely, hydrophobic spores aggregated to form clusters, which quickly settled on the materials and either failed to migrate, or only migrated to a slight extent on the surface, resulting in a steady distribution of spores or spore clusters over the whole contaminated area. Adherent bacteria or spores are known to be highly resistant to many stressful environmental conditions. In view of all the quite different patterns obtained following drying of spore-containing droplets, it seems likely that some of these would entail enhanced resistance to hygienic processes.

Antimicrobial Coatings for Food Contact Surfaces: Legal Framework, Mechanical Properties, and Potential Applications

Food contact surfaces (FCS) in food processing facilities may become contaminated with a number of unwanted microorganisms, such as Listeria monocytogenes, Escherichia coli O157:H7, and Staphylococcus aureus. To reduce contamination and the spread of disease, these surfaces may be treated with sanitizers or have active antimicrobial components adhered to them. Although significant efforts have been devoted to the development of coatings that improve the antimicrobial effectiveness of FCS, other important coating considerations, such as hardness, adhesion to a substrate, and migration of the antimicrobial substance into the food matrix, have largely been disregarded to the detriment of their translation into practical application. To address this gap, this review examines the mechanical properties of antimicrobial coatings (AMC) applied to FCS and their interplay with their antimicrobial properties within the framework of relevant regulatory constraints that would apply if these were used in real-world applications. This review also explores the various assessment techniques for examining these properties, the effects of the deposition methods on coating properties, and the potential applications of such coatings for FCS. Overall, this review attempts to provide a holistic perspective. Evaluation of the current literature urges a compromise between antimicrobial effectiveness and mechanical stability in order to adhere to various regulatory frameworks as the next step toward improving the industrial feasibility of AMC for FCS applications.

Evaluation of the hydrophobic properties of latex microspheres and Bacillus spores. Influence of the particle size on the data obtained by the MATH method (microbial adhesion to hydrocarbons)

The current experimental study investigates the influence of latex microsphere particles' size on the assessment of their hydrophilic/hydrophobic character, using the method known as "Microbial Adhesion to Hydrocarbons" (MATH). Since bacteria surfaces often change according to the environment in which they find themselves, most of the experiments here were carried out using the calibrated latex microspheres Polybeads® and Yellow-green Fluoresbrite® (Polyscience) microspheres with diameters between 0.2 μm and 4.5 μm. All the beads had a density of ˜1.05 g/cm³. The first set of experiments was performed to adapt the procedure for measurements of water contact angles to microsphere lawns. It was found that all the microspheres tested were hydrophobic, when using a water contact angle of around 110-118°. However, wide differences were observed using the MATH method. The smaller microspheres (0.2 μm, 0.5 μm +/- 0.75 μm) exhibited a poor affinity to hexadecane, even after long contact times, suggesting a hydrophilic character. In contrast, larger microspheres quickly adhered to hexadecane, which is consistent with the values obtained for the water contact angles observed. These results suggest that, at least where hydrophobic particles are concerned, the MATH method is not suitable for the assessment of the hydrophobic character of particles with diameters of less than 1.0 μm. We lastly investigated whether the data obtained for Bacillus spores could also be affected by spore size. The hydrophobicity of spores of eight Bacillus strains was analysed by both MATH and contact angle. Some discrepancies were observed between both methods but could not be related their size (length or width).

Development of a Brazilian Food Truck Risk Assessment Instrument

This study aimed to develop and validate a checklist instrument as a first step for the risk assessment of the hygienic-sanitary practices and conditions of food trucks. We invited sixteen experienced experts in the food safety field to take part in the process. The checklist was designed based on the Codex Alimentarius, Brazilian resolutions Collegiate Board Resolution 216, Brazilian Collegiate Board Resolution 275, Brazilian Federal District Law no. 5.627 and Brazilian Federal District Normative Instruction 11. The preliminary version of the checklist—composed of 29 items (nine sections)—was evaluated by 13 experts. They evaluated the items regarding their importance (content validation) and clarity (semantic evaluation) by the Delphi technique. The criteria for the approval of the content validation (Likert scale from 1 to 5) and semantic evaluation (Likert scale from 0 to 5) processes were as follows: a minimum of 75% agreement among the experts (W-values ≥ 0.75) and a mean grade ≥ 4. We performed the complete validation process in three rounds. The final version of the assessment instrument comprised 39 items, following suggestions from experts to add or subdivide some questions. The checklist can be used to conduct inspections of food trucks by health surveillance auditors, of food truck vendors’ decision-making processes and also as a diagnostic tool. The application of this checklist will allow the effective risk assessment of the hygienic-sanitary practices and conditions in food trucks and potentially ensure consumers’ access to safe street food.

The Sources of Chemical Contaminants in Food and Their Health Implications

Food contamination is a matter of serious concern, as the high concentration of chemicals present in the edibles poses serious health risks. Protecting the public from the degrees of the harmfulness of contaminated foods has become a daunting task. This article highlights the causes, types, and health implications of chemical contamination in food. The food contamination could be due to naturally occurring contaminants in the environment or artificially introduced by the human. The phases of food processing, packaging, transportation, and storage are also significant contributors to food contamination. The implications of these chemical contaminants on human health are grave, ranging from mild gastroenteritis to fatal cases of hepatic, renal, and neurological syndromes. Although, the government regulates such chemicals in the eatables by prescribing minimum limits that are safe for human consumption yet measures still need to be taken to curb food contamination entirely. Therefore, a variety of food needs to be inspected and measured for the presence of chemical contaminants. The preventative measures pertaining about the food contaminants problems are pointed out and discussed.