Observations on quasi-uniform products

AbstractWe prove that any product of quotient maps in the category of quasi-uniform spaces and quasi-uniformly continuous maps is a quotient map. We also show that a quasi-uniformly continuous map from a product of quasi-uniform spaces into a quasi-pseudometric T0-space depends on countably many coordinates.Furthermore we characterize those quasi-uniformities that are unique in their quasi-proximity class and prove that this property is preserved under arbitrary products in the category of quasi-uniform spaces

Relevance of microbial finished product testing in food safety management

Management of microbiological food safety is largely based on good design of processes, products and procedures. Finished product testing may be considered as a control measure at the end of the production process. However, testing gives only very limited information on the safety status of a food. If a hazardous organism is found it means something, but absence in a limited number of samples is no guarantee of safety of a whole production batch. Finished product testing is often too little and too late. Therefore most attention should be focussed on management and control of the hazards in a more pro-active way by implementing an effective food safety management system. For verification activities in a food safety management system, finished product testing may however be useful. For three cases studies; canned food, chocolate and cooked ham, the relevance of testing both of finished products and the production environment is discussed. Since the level of control of different processes can be largely different it is beneficial if the frequency of sampling of finished products and production environments would be related to the associated human health risk, which can be assessed on the basis of risk assessment and epidemiological data. Keywords: Sampling; Verification; Microbiological food safet

Consumer habits and their impact on the food safety of cooked chilled foods: results of a survey in Belgium

The consumer exposure to pathogenic microorganisms due to consumption of cooked chilled foods is influenced by the industrial production process and consumer behaviour. A consumer survey was organised to assess the consumption frequency, storage time, reheating practices and perception of and respect for the product’s ‘use by’ date. Of the 874 respondents, over three quarters (77.5%, n=677) had consumed at least one REPFED over the last year. Consumption frequency was the highest between the ages of 18 and 30. Nine out of ten consumers were able to give an acceptable estimate of the shelf life of cooked chilled foods (e.g. less than four weeks). By contrast, only half of the consumers (53.3%) fully respected the ‘use by’ date as indicated on the packaging, the remaining consumers consider a margin of 3 days or more to be acceptable. In addition only half of the consumers fully complied with the reheating instructions on the label. To determine the distribution of the time a cooked chilled food spends in a consumer fridge, the consumers were asked how frequently they bought these products and how they stored them. This information was used to construct a Time to Consumption (TTC) distribution. This TTC demonstrated that approx. 20% of the products was consumed on the day of purchase; about half (52.9%) were consumed within two days of purchase, 75.5% within four days and over 90% during the first week. Furthermore, the data shows that frequent consumers are likely to store the products for shorter times. These short storage times are likely to reduce the exposure to psychrotrophic microorganisms present in cooked chilled foods

RiskBenefit4EU project – a strategy for risk-benefit assessment of foods in Portugal

O balanço entre os riscos e benefícios para a saúde resultante do consumo de alimentos é um importante contributo para apoiar a definição de políticas de saúde e a promoção da literacia dos consumidores. No âmbito do projeto RiskBenefit4EU, financiado pela European Food Safety Authority e coordenado pelo Departamento de Alimentação e Nutrição do Instituto Nacional de Saúde Doutor Ricardo Jorge, o presente trabalho pretende descrever a estratégia implementada para a capacitação das equipas portuguesas em avaliação de risco-benefício de alimentos (RBA). Concretizada pelos parceiros do Institut National de la Recherche Agronomique e da Technical University of Denmark, a capacitação consiste em três atividades principais: 1) Formação teórica, focando os conceitos-chave para a avaliação de RBA; 2) Formação prática, aplicando os conceitos adquiridos e as metodologias transmitidas a um estudo de caso; e 3) Missões científicas, de curta duração, para formação avançada em domínios específicos da avaliação de RBA. No que diz respeito à formação prática, e com o objetivo de consolidar os conhecimentos adquiridos em avaliação de RBA, está previsto o desenvolvimento de um estudo de caso português sobre alimentos à base de cereais habitualmente consumidos por crianças. A estratégia de capacitação seguida neste projeto servirá de modelo para outras equipas e países, contribuindo para a disseminação de uma cultura de avaliação de RBA nas vertentes toxicológica, microbiológica e nutricional a nível internacional.The balance of risks and health benefits from food consumption constitutes a crucial topic to consumer literacy and health policy-makers. Through the RiskBenefit4EU project, funded by the European Food Safety Authority, and coordinated by the Food and Nutrition Department of Portuguese National Institute of Health Dr. Ricardo Jorge, the present work intends to identify the applied strategy to capacitate the Portuguese teams for the development and implementation of risk-benefit assessment (RBA) in food. The training of the Portuguese team is being accomplished by the French National Institute for Agricultural Research and the Technical University of Denmark members, through three main capacity building activities: 1) Theoretical training, focusing on the key concepts for RBA; 2) Practical training, applying the concepts acquired and the methodologies transmitted to a concrete case study; and 3) Short-term scientific missions for advanced training in specific areas of RBA. In order to complete the training of the Portuguese teams and consolidate the knowledge acquired in RBA, a Portuguese case study on cereal-based foods usually consumed by children is planned. The training strategy followed in this project will contribute as a model of capacity building for disseminating a culture of risk-benefit assessment in the toxicological, microbiological and nutritional aspects at the international level.Trabalho desenvolvido no âmbito do projeto “RiskBenefit4EU – Partnering to strengthen the risk-benefit assessment within EU using a holistic approach” financiado pela EFSA Partnering Grants (Grant Agreement Number A/EFSA/AFSCO/2017/01 – GA02).info:eu-repo/semantics/publishedVersio

Risk-Benefit Assessment of Cereal-Based Foods Consumed by Portuguese Children Aged 6 to 36 Months-A Case Study under the RiskBenefit4EU Project

This article belongs to the Section Pediatric Nutrition.Cereal-based foods, including breakfast (BC) and infant cereals (IC), are among the first solid foods introduced to infants. BC and IC are sources of macro and micronutrients that have bene ficial effects on health, but can also be sources of harmful chemical and microbiological contaminants and nutrients that may lead to adverse health effects at high consumption levels. This study was performed under the RiskBenefit4EU project with the aim of assessing the health impact associated with consumption of BC and IC by Portuguese children under 35 months. Adverse effects associated with the presence of aflatoxins, Bacillus cereus, sodium and free sugars were assessed against the benefits of fiber intake. We applied a risk–benefit assessment approach, and quantified the health impact of changes in consumption of BC and IC from current to various alternative consumption scenarios. Health impact was assessed in terms of disability-adjusted life years. Results showed that moving from the current consumption scenario to considered alternative scenarios results in a gain of healthy life years. Portuguese children can benefit from exchanging intake of IC to BC, if the BC consumed has an adequate nutritional profile in terms of fiber, sodium and free sugars, with levels of aflatoxins reduced as much as possible.This research was funded by European Food Safety Authority (EFSA) (Grant Agreement Number–GA/EFSA/AFSCO/2017/01–GA02) (The authors declare that this manuscript reflects only the authors’ view and EFSA is not responsible for any use that may be made of the information it contains.). R.A., P.A. and C.M. also thanks FCT/MCTES for the financial support to CESAM (UIDP/50017/2020 + UIDB/50017/2020), through national funds. R.A. was supported by FCT Individual CEEC 2018 Assistant Researcher Grant CEECIND/01570/2018.info:eu-repo/semantics/publishedVersio

Tyrosine-610 in the receptor kinase BAK1 does not play a major role in brassinosteroid signaling or innate immunity

The plasma membrane-localized BRI1-ASSOCIATED KINASE1 (BAK1) functions as a co-receptor with several receptor kinases including the brassinosteroid (BR) receptor BRASSINOSTEROID-INSENSITIVE 1 (BRI1), which is involved in growth, and the receptors for bacterial flagellin and EF-Tu, FLAGELLIN-SENSING 2 (FLS2) and EF-TU RECEPTOR (EFR), respectively, which are involved in immunity. BAK1 is a dual specific protein kinase that can autophosphorylate on serine, threonine and tyrosine residues. It was previously reported that phosphorylation of Tyr-610 in the carboxy-terminal domain of BAK1 is required for its function in BR signaling and immunity. However, the functional role of Tyr-610 in vivo has recently come under scrutiny. Therefore, we have generated new BAK1(Y610F) transgenic plants for functional studies. We first produced transgenic Arabidopsis expressing BAK1 (Y610F)-Flag in the homozygous bak1-4 bkk1-1 double null background. In a complementary approach, we expressed untagged BAK1 and BAK1(Y610F) in the bak1-4 null mutant. Both BAK1(Y610F) transgenic lines had no obvious growth phenotype compared to wild-type BAK1 expressed in the same background. In addition, the BAK1(Y610F)-Flag plants responded similarly to plants expressing BAK1-Flag in terms of brassinolide (BL) inhibition of root elongation, and there were only minor changes in gene expression between the two transgenic lines as monitored by microarray analysis and real-time PCR. In terms of plant immunity, there were no significant differences between plants expressing BAK1(Y610F)-Flag and BAK1-Flag in the growth of the non-pathogenic hrpA mutant of Pseudomonas syringae pv. tomato DC3000. Furthermore, untagged BAK1(Y610F) transgenic plants were as responsive as plants expressing BAK1 (in the bak1-4 background) and wild-type Col-0 plants towards treatment with the EF-Tu- and flagellin-derived peptide epitopes elf18- and flg22, respectively, as measured by reactive oxygen species (ROS) production, mitogen-activated protein kinase (MAPK) activation, and seedling growth inhibition. Together, these new results demonstrate that Tyr-610 does not play a role in either BR or immune signaling

Cardinal parameter meta-regression models describing Listeria monocytogenes growth in broth

Since Listeria monocytogenes has a high case-fatality rate, substantial research has been devoted to estimate its growth rate under different conditions of temperature, pH and water activity (aw). In this study, published findings on L. monocytogenes growth in broth were extracted and unified by constructing meta-regression models based on cardinal models for (i) temperature (CM[T]), (ii) temperature and pH (CM[T][pH]), and (iii) temperature, pH and aw (CM[T][pH][aw]). After assessing all the sources retrieved between 1988 until 2017, forty-nine primary studies were considered appropriate for inclusion. Apart from the modelling variables, study characteristics such as: type of broth (BHI, TSB, TPB), reading method (colony-forming-units, CFU; or binary-dilution optical density methods, OD), inoculum concentration and strain serotype, were also extracted. Meta-regressions based on CM[T] and CM[T][pH] were fitted on subsets of the 2009 growth rate measures and revealed that type of broth and reading method significantly modulated the cardinal parameter estimates. In the most parsimonious CM[T][pH][aw] meta-regression model, whereby the variability due to type of broth was extracted in a nested random-effects structure, the optimum growth rate ?opt of L. monocytogenes was found to be lower when measured as CFU (0.947 h-1; SE=0.094 h-1) than when measured as OD (1.289 h-1; SE=0.092 h-1). Such a model produced the following cardinal estimates: Tmin=-1.273°C (SE=0.179 °C), Topt=37.26°C (SE=0.688 °C), Tmax=45.12°C (SE=0.013 °C), pHmin=4.303 (SE=0.014), pHopt=7.085 (SE=0.080), pHmax=9.483 (SE=0.080), aw min=0.894 (SE=0.002) and aw opt=0.995 (SE=0.001). Integrating the outcomes from numerous L. monocytogenes growth experiments, this meta-analysis has estimated pooled cardinal parameters that can be used as reference values in quantitative risk assessment studies.Foundation for Food Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020). U. Gonzales-Barron acknowledges the national funding by FCT, P.I., through the Institutional Scientific Employment Program contractinfo:eu-repo/semantics/publishedVersio

Avaliação de risco-benefício associado à alimentação: um instrumento para uma melhor política alimentar e de saúde na Europa

O RiskBenefit4EU (GP/EFSA/AFSCO/2017/01 - GA02) é um projeto europeu, financiado pela EFSA, que visa fortalecer a capacidade de avaliação de risco-benefício associado à alimentação na União Europeia (UE), aplicando uma abordagem holística. Este projeto resulta de uma parceria entre instituições de investigação & desenvolvimento e académicas, das áreas da saúde, alimentação e nutrição, e autoridades nacionais de segurança alimentar, de Portugal (país coordenador), Dinamarca e França.info:eu-repo/semantics/publishedVersio