Production, Properties and Applications of Materials-based Nano-Enzymes

Chitosan is a modified, natural biopolymer derived by deacetylation of chitin, a major component of the shells of crustacean. Recently, chitosan has received increased attention for its commercial applications in the biomedical, food, and chemical industries. Use of chitosan in food industry is readily seen due to its several distinctive biological activities and functional properties. The antimicrobial activity and film-forming property of chitosan make it a potential source of food preservative or coating material of natural origin. This review focuses on the applications of chitosan for improvement of quality and shelf life of various foods from agriculture, poultry, and seafood origin.

References

The editorial collects a brief summary of the topics discussed in the articles that are published in Emerging Microbial Concerns in Food Safety and New ControlMeasures. We hope that readers of this special issue will find some information of interest in order to expand their knowledge in this field and to increase their level of attention on matters here reported.

Objective. The objective of the study is to determine the levels of food security (individual, household, community, national and global) and to identify the factors that affect food security at each level. Methods. The study used general scientific methods and research techniques: theoretical generalization and comparison (to summarize the definitions of each level of food security), analysis and synthesis (to identify the characteristic factors of influence at each level of food security), deduction-induction (to substantiate each level of food security). Results. It has been determined that the allocation of levels (individual, household, community, national and global) within the theory of food security is based on the definition of food availability, quality and safety. The main factors that affect food security at each level are identified. At the individual level: physical access to food, dietary diversity, social and economic determinants of food access, the broader context of food systems and policies; at the household level: access to adequate food, stability, affordability, nutritional adequacy, utilization, cultural acceptability, sustainability; at the community level: access to food, food availability, food quality, food system sustainability, social justice, food production, emergency reserves, and food security. Improving food security requires concerted efforts at all levels. Global initiatives must be supported by national policies that take into account local circumstances and needs. It is also important to provide support at the individual level through increased income, education and access to social services. A comprehensive approach that combines these measures can significantly improve food security and ensure a healthy future for all people.

ε-poly-L-lysine (ε-PL) is a cationic polypeptide. As a natural antibacterial peptide, it has attracted much attention in the food, biomedical, and chemical industries because of its wide antibacterial spectrum and safety. Use of ε-PL in the food industry is common, due to its biological activity and functional properties. This paper focuses on the physiochemical properties, safety, antibacterial activity, antibacterial mechanism of action, and applications of ε-PL in improving the quality and shelf life of various foods. Practical applications As green consumerism is becoming more popular, there is a growing demand for natural preservatives. This work provides basic theories and methods for the application of ε-PL in food preservation. This paper gives scientific guidelines for consumers and producers of agricultural products. Thus, it may promote the utilization of ε-PL in the food industry and reduce the use of chemical preservatives.

Biosafety risk assessment of nanoparticles: Evidence from food case studies.

Microbial food spoilage and foodborne disease are the main challenges in the food industry regarding food shelf life. Current preservation methods are frequently associated with changes in organoleptic characteristics and loss of nutrients. For this reason, bacteriophage offers an alternative natural method as a biocontrol agent that can reduce bacterial contamination in food without altering the organoleptic properties. This study was conducted to isolate and characterize bacteriophage from soil to control food spoilage bacteria, such as Bacillus cereus and Bacillus subtilis, and foodborne pathogenic bacteria, such as enterotoxigenic Escherichia coli (ETEC) and enterohemorrhagic E. coli (EHEC). Isolation was done by agar overlay assay method, and phages BC-S1, BS-S2, ETEC-S3, and EHEC-S4 were recovered. The host range of all isolated phages tended to be narrow and had high specificity towards the specific bacteria. The phage efficiency were measured where ETEC-S3 showed no effectivity against B. cereus and EHEC-S4 showed low efficiency against Enteropathogenic E. coli (EPEC). Morphology analysis was conducted for phage BC-S1 and ETEC-S3 with Transmission Electron Microscopy (TEM), and it is shown to belong to the Caudovirales order. Phages BC-S1 and BS-S2 significantly reduced the host bacteria when applied to the cooked rice and pasteurized milk samples with miMOI of 0.1. While phage ETEC-S3 at miMOI of 0.001 and phage EHEC-S4 at miMOI of 1 also showed a significant reduction when applied to chicken meat and lettuce samples at storage temperatures of 4 °C and 28 °C. The highest bacterial reduction of 100% was shown by phage BC-S1 on pasteurized milk samples and reduction up to 96.06% by phage ETEC-S3 on chicken meat samples at 28 °C incubation.

Nanotechnology offers the food industry a number of new approaches for improving the quality, shelf life, safety, and healthiness of foods. Nevertheless, there is concern from consumers, regulatory agencies, and the food industry about potential adverse effects (toxicity) associated with the application of nanotechnology in foods. In particular, there is concern about the direct incorporation of engineered nanoparticles into foods, such as those used as delivery systems for colors, flavors, preservatives, nutrients, and nutraceuticals, or those used to modify the optical, rheological, or flow properties of foods or food packaging. This review article summarizes the application of both inorganic (silver, iron oxide, titanium dioxide, silicon dioxide, and zinc oxide) and organic (lipid, protein, and carbohydrate) nanoparticles in foods, highlights the most important nanoparticle characteristics that influence their behavior, discusses the importance of food matrix and gastrointestinal tract effects on nanoparticle properties, emphasizes potential toxicity mechanisms of different food-grade nanoparticles, and stresses important areas where research is still needed. The authors note that nanoparticles are already present in many natural and processed foods, and that new kinds of nanoparticles may be utilized as functional ingredients by the food industry in the future. Many of these nanoparticles are unlikely to have adverse affects on human health, but there is evidence that some of them could have harmful effects and that future studies are required.

Chapter 40 - Nanoscience and nanotechnology advances in food industry

Food Science and TechnologyVolume 36, Issue 4 p. 42-45 SpotlightFree Access Networking to reduce microbial risk in foods First published: 01 December 2022 https://doi.org/10.1002/fsat.3604_11.xAboutSectionsPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Matthew Gilmour and Maria Traka of the Quadram Institute introduce the new UK Food Safety Research Network, which is aiming to Improve the safety of UK foods by harnessing expertise across the food chain in collaborative research and training activities. The challenging ecology of foodborne microbes Preventing microbial pathogens from entering the food chain is challenging due to the multitude of environmental and agricultural niches in which they thrive. Pathogens like Salmonella and Listeria are expert at being carried in and adapting to farm and food production settings, leading to contamination of diverse meat and plant-based foods. The challenges to control these microbes are only becoming more complex as food production systems and consumer preferences evolve and global factors, such as climate change, impact the ecology of food systems. The UK is strongly committed to food safety, with food manufacturers focusing on ensuring foods are healthy and safe for their customers. There are many programmes in place that regulate how food is produced and monitor for hazards that might contaminate foods; some initiatives come from government and some from the food industry itself. However, we also know from UK research that it is common for people to visit their GP with food-associated illness and that about a quarter of the UK population have diarrhoea each year1. The causes of food-associated illness are not always determined; of the estimated £9bn annual cost to the UK of these illnesses, £6bn are from unknown causes. Therefore, some microbial hazards are not only challenging to prevent from entering the food chain, but also to detect in foods and food settings. In studies that examined these cases more closely, the cause was often a microbial pathogen that had been carried over into food from the environment or from livestock or even from people. A solution to these food safety challenges is to catalyse collaborative research between scientific experts, the food industry and food policy partners to robustly consider and act upon new opportunities to make food safer. Applying science as a collaborative network In association with the Biotechnology and Biological Sciences Research Council of UK Research & Innovation (BBSRC-UKRI) and the Food Standards Agency (FSA), the Quadram Institute in Norwich established the new UK Food Safety Research Network (FSRN)2 in April 2022. Acting as a hub for scientific innovation and collaborative research that addresses complex challenges, the Network is creating a community from amongst representatives of the food industry, government departments and academia and developing a shared vision and plan for research that can improve the safety of foods now and in the future. The specific remit of the Network is to address microbial risks in the food chain; as the Network was created it became increasingly clear that more than just ‘microbiology’ was going to be in scope. Interviews with Network members and stakeholders during our establishment stages highlighted that there is a ‘new edge’ to biological research in foods based on new technologies and the dynamic economic and environmental sustainability drivers that are currently shaping food system transformations and which transcend traditional biological questions on food hygiene. At this edge, it is possible to pursue research and training that benefits the food system by collectively harnessing interdisciplinary expertise for cutting-edge technologies, rich food system data and theory, and an existing understanding of social and economic factors. The goal of the UK's FSRN is to take a multi-stakeholder approach to apply science to the food safety challenges prioritised within this community. The focus will be areas where collaborative research or training can build new capacity or knowledge that benefits food safety. Within the Network, policy and industry sectors are now coming together with scientific researchers via: exercises that define food safety problems, funded collaborative research projects and food safety training fora. It is important that the FSRN develops successful pathways to curate new relationships between academic researchers and food stakeholders, who are directly facing and motivated to address the evolving risks and challenges in the food system. We have learned that many in the food industry recognise the need for research and developmental activities that address food safety challenges. However, for some producers (often small and medium sized enterprises) there is little bandwidth beyond the operational challenges of their business to participate in such research. The FSRN is providing a platform for food industry members and academic researchers to make these connections and expedite adoption of effective food safety solutions by directly supporting and resourcing co-designed collaborative projects. Building a community to identify ‘problems worth solving’ that increase the safety of UK foods To scope the key food safety risks that would have a meaningful impact on UK foods if pursued in collaborative projects, we are engaging with members of our community of experts that represent primary food producers, food retailers and food sector trade associations. In a series of one-on-one interviews, we documented members’ experiences and perspectives about what they considered to be the contemporary, emerging and perceived food safety challenges that, if addressed, would bring value to their products and for which they could foresee a route to impact within the food system. Scientific perspectives on food safety risks and challenges were simultaneously sought from stakeholders from across scientific disciplines representing the environment, animals and human health. These included veterinarians, virologists, data scientists and social scientists. Perspectives were also sought from: government institutes, knowledge transfer networks and professional bodies specialising in food system studies, policy and training. It is from this multi-disciplinary and multi-sector community that an ability to address complex food safety issues emerges. A broad view of the issues affecting food safety The food system comprises many social, environmental and political factors that together can affect the foods that are produced and those that are sought by consumers. In our initial problem definition interviews, many of these ‘macro’ factors were repeatedly cited by stakeholders as conceivably having a significant consequence to food safety and shelf life because changes to how foods are produced and stored can impact the ecology of any microbes present. Amongst these extensive and overlapping macro factors, there are multiple points in the food chain at which food safety challenges can emerge and then endure as microbial risks, even those not easily identifiable as risks at the outset. For example, new economic pressures, such as those introduced by COVID-19 and Brexit, that affect supply and distribution networks introduce changes to the sourcing and availability of food ingredients; as food ingredients change so do the standards used to produce them, potentially impacting both the microbial composition and safety profile of individual ingredients. Likewise, economic pressures have resulted in other market shifts, such as the availability of CO2 supplies and operational costs related to the energy crisis. Supplies of CO2 have a direct impact on the ability to introduce modified atmosphere packaging (MAP), which is a preservative that inhibits both pathogenic and spoilage microbes. If food storage temperatures are increased to save on energy costs (e.g. during refrigeration), then basic microbial control measures that are currently effective will be compromised and could lead to altered microbial risk profiles. Food storage conditions were also highlighted from an environmental perspective. As our climate changes so does the ability to maintain optimal storage temperatures in some settings. In addition, global impacts to the environment and agriculture have increasingly led to changes in water, carbon and temperature cycles with direct effects on microbial ecology, e.g. microbial profiles in irrigation waters. As microbial composition changes in this critical agricultural resource, it was easy for our interviewees to conceive how the overall risk of pathogen transmission during primary plant and livestock production could increase. Further ‘upstream’ in the food chain, our stakeholders commonly felt that changes in consumer preference and regulation of food categories sold in retail settings could also conceivably impact food safety. For example, the demand for new plant-based foods means food producers are developing product lines that use new ingredients (e.g. alternative proteins, micro-and macro-algae), new culturing technologies, or new processing techniques, while the overall knowledge of microbial risks for food safety and shelf life of these new categories may be lagging behind their arrival on retail shelves. Furthermore, consumers are also seeking food packaging that reduces plastic use; this requires the introduction of new materials or new methods of packaging (e.g. vacuum packing versus MAP). In addition, governments are regulating for reduced contents of salt, sugar and fat. Each of these changes potentially shifts the ecology and risk of microbes present on foods. Factors impacting food safety and microbial contamination more locally within particular food production settings were also discussed during our stakeholder interviews. For example, cleaning and hygiene is a cornerstone of food safety yet the effectiveness of some disinfection and sanitising agents is uncertain and there can be engineering issues associated with food contact surfaces that make them challenging to clean or maintain at controlled temperatures. Stakeholders also cited that there are knowledge gaps on microbial risks in food product categories or gaps in the ability to implement best food safety practices conceivably exacerbated by labour shortages, which aligns with global economic and political pressures. All of these challenges represent an opportunity for research and for the identification of new knowledge to inform interventions or policies that could improve the safety of food. They also provide a view on emerging food safety risks that require participation from a multitude of stakeholders and scientific disciplines if they are to be appropriately studied and effectively addressed. Brokering project partnerships around priority areas of applied food safety research Following our broad scoping of food safety challenges, the next key activity of the FSRN was to coordinate distribution of resources that supported both innovation and collaboration. We understood that many in our community had not directly participated in collaborative research activities previously, and that for some, Network support would be needed to broker partnerships and develop project plans that could draw on collective insights, data and technologies from across the Network. We also understood that some members were already tuned into food safety research around microbial risk and were ready to act with their partners. In August 2022, we opened the FSRN's first call for proposals. Using a streamlined application process, project applications could be submitted that were either ‘ready to fund and ready to act’ or were ‘expressions of interest’ for projects that needed further time to develop. As a guide to all applicants we publicised three prioritised areas as a framework for collaborative projects based on the earlier stakeholder feedback (Figure 1). Figure 1Open in figure viewerPowerPoint The Food Safety Research Network's priority areas. As a guide to all applicants we publicised three prioritised areas as a framework for collaborative projects based on the earlier stakeholder feedback. Firstly, to address known microbial risks, we sought new evidence for interventions that reduce pathogens, such as Salmonella, Campylobacter or Listeria, which continue to be problematic in some foods and food production settings. Secondly, to increase our understanding of the perceived microbial risk in new food categories and production systems, we sought studies on alternative proteins and new plant-based foods. Lastly, to improve the safety of ready-to-eat (RTE) foods, we sought to develop new ways to apply food safety knowledge and new tools to address this established high-risk food category. As an outcome of our first call for proposals, the successful ‘ready to act’ projects included activities that will develop and assess applications of bacteriophage for control of Salmonella and Listeria contamination in settings such as aquaculture and raw pet food production. Our prioritised area of research on novel foods was represented in a project that will profile the microbial communities of crickets (Acheta domesticus) and assess the production systems for this alternative protein, while other projects will test the efficacy of novel biocide combinations and develop new diagnostic technologies that will support pathogen environmental monitoring programmes. Fried crickets For the ‘expression of interest’ stream we received proposals from industry Network members from across the food chain, ranging from animal producers and primary producers to trade associations; we also received proposals from government departments with mandates outside the food chain. From the successful proposals we are facilitating planning with the applicants, other stakeholders and funders to develop these ideas towards large collaborative projects; further information will be forthcoming from the FSRN on these opportunities and the fora (such as stakeholder workshops) that will be used to progress them. Examples of the areas that were prioritised for additional collaborative work include: conducting focal studies on pathogen transmission in livestock production and the spill-over of microbes into meat-based foods; establishing and promoting fit-for-purpose best practices that improve the safety and shelf life of RTE foods; advancing bacteriophage applications to provide evidence to move beyond existing regulatory barriers; understanding the food safety implications of climate change; filling a gap in certification and guidance on food safety for primary producers; facilitating the availability of microbial testing data amongst partners to enhance trend analyses and overall horizon scanning on microbial risks; developing new methods for investigating foodborne viruses (e.g. norovirus; hepatitis E). As project applications and expressions of interest were received during our call for proposals, we realised that not only can the Network provide partners with essential financial resources to conduct collaborative studies, but also a legitimate entry point to communicate ideas and identify partners. Thus, the FSRN has established a framework for collaborative processes where members become mutually aware of food safety networking and research opportunities. Further, there is also the opportunity to connect with other UK food system network programmes, such as the Transforming UK Food Systems Strategic Partnership Fund3, FSA's PATH-SAFE4 and Innovate UK's KTN Food5, to amplify food safety objectives across multiple partners. Mobilising food safety knowledge Paraphrasing from our stakeholder interviews, key findings from industry were that ‘we need simple tools to interpret test results and their implication for food safety’ and that ‘what we don't need is an expensive list of microbes that we don't know what to do with’. These were powerful sentiments and we understand that for some food industry members their capacity to take new action and adopt scientific advancements supporting their food safety aims can be limited due to accessibility and practicality of scientific information or technologies. As such, the ultimate goal of the FSRN is to bring forward Network discoveries that are game changing by working directly with food producers and other food industry members in a manner that is continually informed by their perspectives and ensures their active involvement in piloting or demonstration of new technologies or knowledge. We have also identified that not all knowledge that should be acted upon needs to be new knowledge. Stakeholders asked that FSRN members exploit existing studies, platforms and experiences within the Network's collaborative projects and promote their accessibility. This would create opportunities to upcycle existing data sets that have value for contemporary food safety challenges but which have not been broadly applied by scientific or stakeholder communities. This would also create long-term impact and value from previously funded research. Further, the FSRN plans to publicly promote and extend the impactful methods and knowledge developed in our collaborative research programmes. We will host a series of training events and sponsor the exchange of scientists and food industry employees between Network member sites. A goal is for our programmes to actively support skills development around food safety and interoperability between Network partners. These include professional groups, such as veterinarians and environmental health officers, and our partners in the food industry, who all have key roles in enhancing the safety of UK foods. Matthew W. Gilmour and Maria H. Traka, UK Food Safety Research Network, Quadram Institute Bioscience, Norwich, UK email foodsafetynetwork@quadram.ac.uk web quadram.ac.uk/food-safety-research-network/ References 1 Food Standards Agency. 2020. Foodborne disease estimates for the United Kingdom in 2018. Available from: https://www.food.gov.uk/research/foodborne-disease/foodborne-disease-estimates-for-the-united-kingdom-in-2018 2 Quadram Institute. 2020. Food safety research network. Available from: https://quadram.ac.uk/food-safety-research-network/ 3 Global Food Security. 2022. Transforming UK food systems SPF. Available from: https://www.foodsecurity.ac.uk/research/foodsystems-spf/ 4 Food Standards Agency. 2022. Pathogen surveillance in agriculture, food and environment programme. Available from: https://www.food.gov.uk/our-work/pathogen-surveillance-in-agriculture-food-and-environment-programme 5Innovate UK, KTN. 2022. Food. Available from: https://ktn-uk.org/agrifood/food/ Volume36, Issue4December 2022Pages 42-45 FiguresReferencesRelatedInformation

Nanoemulsion system is a colloidal system made up of kinetically stable minute droplets. They overcome the drawbacks related to the conventional emulsion system. The structure and composition of nanoemulsion can be moulded to effectively control and deliver bioactive and nutraceutical compounds. There are a number of potential applications found for the effective delivery of functional foods, nutraceuticals, coloring, flavoring and antimicrobial agents in food industry. These systems can be exploited to develop biodegradable packaging and coating films for the enhancement of the functional and nutritional value along with enhancing the quality, bioavailability and shelf life of the functional foods. This chapter focuses on the history of emulsion system and nutraceutical and functional foods, preparation techniques of nanoemulsions, components of nanoemulsion system, encapsulation of nutraceuticals, flavoring, coloring agents and packaging materials, application of nanoemulsion in food and nutraceutical industry and the current and future prospects of the topic.

Serving up graduates

Chapter 6 - Shelf Life and Sensory Quality of Foods and Beverages

The Economics of Enteric Infections: Human Foodborne Disease Costs

Listeria monocytogenes biofilms present a significant challenge in the food industry. This study explores the impact of different acidic conditions of culture media and food matrices on the development and removal of biofilms developed on stainless steel surfaces by wild-type (WT) L. monocytogenes strains as well as in two mutant derivatives, ΔsigB and ΔagrA, that have defects in the general stress response and quorum sensing, respectively. Additionally, the study investigates the efficacy of nanoencapsulated carvacrol as an antimicrobial against L. monocytogenes biofilms developed in Tryptic Soy Broth (TSB) culture media acidified to different pH conditions (3.5, 4.5, 5.5, 6.5), and in food substrates (apple juice, strained yogurt, vegetable soup, semi-skimmed milk) having the same pH levels. No biofilm formation was observed for all L. monocytogenes strains at pH levels of 3.5 and 4.5 in both culture media and food substrates. However, at pH 5.5 and 6.5, increased biofilm levels were observed in both the culture media and food substrates, with the WT strain showing significantly higher biofilm formation (3.04–6.05 log CFU cm−2) than the mutant strains (2.30–5.48 log CFU cm−2). For both applications, the nanoencapsulated carvacrol demonstrated more potent antimicrobial activity against biofilms developed at pH 5.5 with 2.23 to 3.61 log reductions, compared to 1.58–2.95 log reductions at pH 6.5, with mutants being more vulnerable in acidic environments. In food substrates, nanoencapsulated carvacrol induced lower log reductions (1.58–2.90) than the ones in TSB (2.02–3.61). These findings provide valuable insights into the impact of different acidic conditions on the development of L. monocytogenes biofilms on stainless steel surfaces and the potential application of nanoencapsulated carvacrol as a biofilm control agent in food processing environments.