BSE: Risk, Uncertainty, and Policy Change

The authors discuss how, in our risk society, a range of potential risks and uncertainties are associated with new technologies and new diseases, such as BSE. These risks bring with them worries about human health, while the ability to assess and manage new health scares is an essential skill for government and related industries

Acrylamide formation in potato products

End of Project ReportAcrylamide, a substance classified as a potential carcinogen, occurs in heated starchy foods at concentrations many times in excess of levels permitted in drinking water. Early surveys indicated that levels of acrylamide in potato products such as French fries and potato crisps were the highest of the foodstuffs investigated. The present project addressed this issue by determining levels of acrylamide precursors (asparagine and reducing sugars) in raw potatoes and levels of acrylamide in (i) potato products from different storage regimes, (ii) spot-sampled potatoes purchased from a local supermarket, (iii) samples that received pre-treatments and were fried at different temperatures and (iv) French fries reheated in different ovens.A risk assessment of the estimated acrylamide intake from potato products for various cohorts of the Irish population was also conducted

Development of active, nanoparticle, antimicrobial technologies for muscle-based packaging applications

Fresh and processed muscle-based foods are highly perishable food products and packaging plays a crucial role in providing containment so that the full effect of preservation can be achieved through the provision of shelf-life extension. Conventional packaging materials and systems have served the industry well, however, greater demands are being placed upon industrial packaging formats owing to the movement of muscle-based products to increasingly distant markets, as well as increased customer demands for longer product shelf-life and storage capability. Consequently, conventional packaging materials and systems will have to evolve to meet these challenges. This review presents some of the new strategies that have been developed by employing novel nanotechnological concepts which have demonstrated some promise in significantly extending the shelf-life of muscle-based foods by providing commercially-applicable, antimicrobially-active, smart packaging solutions. The primary focus of this paper is applied to subject aspects, such as; material chemistries employed, forming methods utilised, interactions of the packaging functionalities including nanomaterials employed with polymer substrates and how such materials ultimately affect microbes. In order that such materials become industrially feasible, it is important that safe, stable and commercially-viable packaging materials are shown to be producible and effective in order to gain public acceptance, legislative approval and industrial adoption

Kinetic desorption models for the release of nanosilver from an experimental nanosilver coating on polystyrene food packaging

To predict the kinetic desorption of silver from an experimental nanosilver coated polystyrene food packaging material into food simulants (0, 1, 2 and 3% acetic acid (HAc) in distilled water (dH2O)) at 4 temperatures (10, 20, 40 and 70 °C), 5 sorption models were examined for their performance. A pseudo-second order kinetic sorption model was found to provide the best prediction of an unseen desorption validation dataset with R2 = 0.90 and RMSE = 3.21. Poor predictions were witnessed for desorption at 70 °C, potentially due to re-adsorption of the silver back onto the polystyrene substrate, as shown in the kinetic migration experiments. Similarly, the temperature dependence of the desorption rate constant was satisfactorily described using the Arrhenius equation with the exception of the 70 °C scenario. The use of sorption models identified scenarios that may limit human exposure to nanosilver migrating from this experimental nanocoating, i.e. low temperature applications. Industrial relevance: The use of antimicrobial packaging has the potential to reduce food spoilage and risk from pathogenic microorganisms while reducing food waste by extending the shelf life of food products. Coating of antimicrobial silver nanoparticles (AgNPs) to polymer surfaces is a highly advantageous technology as microbial contamination predominantly occurs on the surface of fresh and processed food products. However, uncertainty related to the potential release of nanoparticles from food packaging materials, subsequent potential human exposure and toxicology is a barrier to the uptake of these novel materials. In the European Union, where the safety assessment of these materials is stringent, mathematical models used to predict the worst case migration of nanoparticles from food packaging materials have supported the acceptance of some nanomaterials for use in food packaging. The performance of a number of desorption models was evaluated to predict the release of AgNPs from AgNP coated polystyrene. The model identified factors that influenced migration and possible industrial applications for the developed material to minimise human exposure. The study highlights the potential benefits of using predictive models to assess migration of NPs from polymers into food simulants instead of time consuming and expensive migration studies

Ranking hazards pertaining to human health concerns from land application of anaerobic digestate

peer-reviewedAnaerobic digestion (AD) has been identified as one of the cleanest producers of green energy. AD typically uses organic materials as feedstock and, through a series of biological processes, produces methane. Farmyard manure and slurry (FYM&S) are important AD feedstock and are typically mixed with agricultural waste, grass and/or food wastes. The feedstock may contain many different pathogens which can survive the AD process and hence also possibly be present in the final digestate. In this study, a semi-quantitative screening tool was developed to rank pathogens of potential health concern emerging from AD digestate. A scoring system was used to categorise likely inactivation during AD, hazard pathways and finally, severity as determined from reported human mortality rates, number of global human-deaths and infections per 100,000 populations. Five different conditions including mesophilic and thermophilic AD and three different pasteurisation conditions were assessed in terms of specific pathogen inactivation. In addition, a number of scenarios were assessed to consider foodborne incidence data from Ireland and Europe and to investigate the impact of raw FYM&S application (without AD and pasteurisation). A sensitivity analysis revealed that the score for the mortality rate (S3) was the most sensitive parameter (rank coefficient 0.49) to influence the final score S; followed by thermal inactivation score (S1, 0.25) and potential contamination pathways (S2, 0.16). Across all the scenarios considered, the screening tool prioritised Cryptosporidium parvum, Salmonella spp., norovirus, Streptococcus pyogenes, enteropathogenic E. coli (EPEC), Mycobacterium spp., Salmonella typhi (followed by S. paratyphi), Clostridium spp., Listeria monocytogenes and Campylobacter coli as the highest-ranking pathogens of human health concern resulting from AD digestate in Ireland. This tool prioritises potentially harmful pathogens which can emerge from AD digestate and highlights where regulation and intervention may be required

A Bayesian inference approach to quantify average pathogen loads in farmyard manure and slurry using open-source Irish datasets

peer-reviewedFarm-to-fork quantitative microbial risk assessments (QMRA) typically start with a preliminary estimate of initial concentration (Cinitial) of microorganism loading at farm level, consisting of an initial estimate of prevalence (P) and the resulting pathogen levels in animal faeces. An average estimation of the initial concentration of pathogens can be achieved by combining P estimates in animal populations and the levels of pathogens in colonised animals' faeces and resulting cumulative levels in herd farmyard manure and slurry (FYM&S). In the present study, 14 years of data were collated and assessed using a Bayesian inference loop to assess the likely P of pathogens. In this regard, historical and current survey data exists on P estimates for a number of pathogens, including Cryptosporidium parvum, Mycobacterium avium subspecies paratuberculosis (MAP), Salmonella spp., Clostridium spp., Campylobacter spp., pathogenic E. coli, and Listeria monocytogenes in several species (cattle, pigs, and sheep) in Ireland. The results revealed that Cryptosporidium spp. has potentially the highest mean P (Pmean) (25.93%), followed by MAP (15.68%) and Campylobacter spp. (8.80%) for cattle. The Pmean of E. coli is highest (7.42%) in pigs, while the Pmean of Clostridium spp. in sheep was estimated to be 7.94%. Cinitial for Cryptosporidium spp., MAP., Salmonella spp., Clostridium spp., and Campylobacter spp. in cattle faeces were derived with an average of 2.69, 4.38, 4.24, 3.46, and 3.84 log10 MPN g −1, respectively. Average Cinitial of Cryptosporidium spp., Salmonella spp., Clostridium spp., and E. coli in pig slurry was estimated as 1.27, 3.12, 3.02, and 4.48 log10 MPN g −1, respectively. It was only possible to calculate the average Cinitial of Listeria monocytogenes in sheep manure as 1.86 log10 MPN g −1. This study creates a basis for future farm-to-fork risk assessment models to base initial pathogen loading values for animal faeces and enhance risk assessment efforts

Urease and Nitrification Inhibitors—As Mitigation Tools for Greenhouse Gas Emissions in Sustainable Dairy Systems: A Review

peer-reviewedCurrently, nitrogen fertilizers are utilized to meet 48% of the total global food demand. The demand for nitrogen fertilizers is expected to grow as global populations continue to rise. The use of nitrogen fertilizers is associated with many negative environmental impacts and is a key source of greenhouse and harmful gas emissions. In recent years, urease and nitrification inhibitors have emerged as mitigation tools that are presently utilized in agriculture to prevent nitrogen losses and reduce greenhouse and harmful gas emissions that are associated with the use of nitrogen-based fertilizers. Both classes of inhibitor work by different mechanisms and have different physiochemical properties. Consequently, each class must be evaluated on its own merits. Although there are many benefits associated with the use of these inhibitors, little is known about their potential to enter the food chain, an event that may pose challenges to food safety. This phenomenon was highlighted when the nitrification inhibitor dicyandiamide was found as a residual contaminant in milk products in 2013. This comprehensive review aims to discuss the uses of inhibitor technologies in agriculture and their possible impacts on dairy product safety and quality, highlighting areas of concern with regards to the introduction of these inhibitor technologies into the dairy supply chain. Furthermore, this review discusses the benefits and challenges of inhibitor usage with a focus on EU regulations, as well as associated health concerns, chemical behavior, and analytical detection methods for these compounds within milk and environmental matrices.Department of Agriculture, Food and the Marine, Irelan

Anaerobic digestion of agricultural manure and biomass – Critical indicators of risk and knowledge gaps

peer-reviewedAnaerobic digestion (AD) has been identified as a potential green technology to treat food and municipal waste, agricultural residues, including farmyard manure and slurry (FYM&S), to produce biogas. FYM&S and digestate can act as soil conditioners and provide valuable nutrients to plants; however, it may also contain harmful pathogens. This study looks at the critical indicators in determining the microbial inactivation potential of AD and the possible implications for human and environmental health of spreading the resulting digestate on agricultural land. In addition, available strategies for risk assessment in the context of EU and Irish legislation are assessed. Storage time and process parameters (including temperature, pH, organic loading rate, hydraulic retention time), feedstock recipe (carbon-nitrogen ratio) to the AD plant (both mesophilic and thermophilic) were all assessed to significantly influence pathogen inactivation. However, complete inactivation of all pathogens is unlikely. There are limited studies evaluating risks from FYM&S as a feedstock in AD and the spreading of resulting digestate. The lack of process standardisation and varying feedstocks between AD farms means risk must be evaluated on a case by case basis and calls for a more unified risk assessment methodology. In addition, there is a need for the enhancement of AD farm-based modelling techniques and datasets to help in advancing knowledge in this area.Department of Agriculture, Food and the Marin

Quantitative microbial risk assessment associated with ready-to-eat salads following the application of farmyard manure and slurry or anaerobic digestate to arable lands

peer-reviewedFarmyard manure and slurry (FYM&S) and anaerobic digestate are potentially valuable soil conditioners providing important nutrients for plant development and growth. However, these organic fertilisers may pose a microbial health risk to humans. A quantitative microbial risk assessment (QMRA) model was developed to investigate the potential human exposure to pathogens following the application of FYM&S and digestate to agricultural land. The farm-to-fork probabilistic model investigated the fate of microbial indicators (total coliforms and enterococci) and foodborne pathogens in the soil with potential contamination of ready-to-eat salads (RTEs) at the point of human consumption. The processes examined included pathogen inactivation during mesophilic anaerobic digestion (M-AD), post-AD pasteurisation, storage, dilution while spreading, decay in soil, post-harvest washing processes, and finally, the potential growth of the pathogen during refrigeration/storage at the retail level in the Irish context. The QMRA highlighted a very low annual probability of risk (Pannual) due to Clostridium perfringens, norovirus, and Salmonella Newport across all scenarios. Mycobacterium avium may result in a very high mean Pannual for the application of raw FYM&S, while Cryptosporidium parvum and pathogenic E. coli showed high Pannual, and Listeria monocytogenes displayed moderate Pannual for raw FYM&S application. The use of AD reduces this risk; however, pasteurisation reduces the Pannual to an even greater extent posing a very low risk. An overall sensitivity analysis revealed that mesophilic-AD's inactivation effect is the most sensitive parameter of the QMRA, followed by storage and the decay on the field (all negatively correlated to risk estimate). The information generated from this model can help to inform guidelines for policymakers on the maximum permissible indicator or pathogen contamination levels in the digestate. The QMRA can also provide the AD industry with a safety assessment of pathogenic organisms resulting from the digestion of FYM&S

FOODSIM'2008, 5th international conference on simulation on modelling in the food and bio-industry.

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