Effects of dry heating on the progression of in vitro digestion of egg white proteins: contribution of multifactorial data analysis

The impact of dry heating on the progression of in vitro digestion of egg white proteins was investigatedthrough application of multiple factor analysis (MFA) to electrophoresis data. Dry heating (from 1 to 10days between 60 and 90 °C) enhanced protein unfolding and aggregation, thus generating differentSDS-PAGE patterns for each sample before digestion. The progression of in vitro digestion was thenmodified according to the degree of protein unfolding and/or aggregation. In vitro digestion tended todecrease the heterogeneity of sample electrophoretic patterns overall but it occurred either at the verybeginning of the gastric stage or throughout the gastric stage or again during the duodenal stage,depending on the heat treatment to which the sample had been subjected. At the end of digestion, threegroups of samples were obtained: all samples dry heated at 60 °C and one sample dry heated for 1 day at70 °C that were more hydrolysed than the control, samples dry heated for more than 2 days at 80 °C or90 °C that were less hydrolysed than the control, and samples dry heated for more than 2 days at 70 °C or1 day at 80 or 90 °C that were as hydrolysed as the control

Occurrence of Bacteria of the Bacillus cereus Group in Conventional Henhouses and in Egg Breaking Factories

Bacteria belonging to the Bacillus cereus group are found in soil, air, dust, water and in many raw and processed foods. Several strains of this group are able to produce toxins in food or in the human intestine that can lead to emesis or diarrhoea, respectively. Their various enzymatic activities are also recognised as causing food spoilage, even at refrigerated temperatures when psychrotrophic strains are involved. Since liquid egg products usually receive mild heat treatments inefficient on spores and they are stored at low temperature, monitoring and control of bacteria belonging to the B. cereus group are of high importance for the sector of egg production. The aim of the present study was to get new insights on the consequences of breeding practices on the occurrence of this type of bacteria on eggshells and in liquid whole egg products. The study consisted in an inquiry about the breeding practices of about sixty farms in parallel with egg collection. Samples of liquid egg products were simultaneously collected in six egg breaking industries. The study was carried out during hot and cold seasons in order to identify a putative relationship between the season and the relative occurrence of mesophilic and psychrotrophic bacteria of the group. All the samples were enriched at 10°C during 5 days and 30°C during 24 h, to favor the growth of psychrotrophic and mesophilic bacteria, respectively. The presence of bacteria belonging to the B. cereus group was then investigated by real-time PCR. Molecular analyses were carried out for the discrimination between psychrotrophic and mesophilic strains in the positive enrichments. Statistical analyses were conducted in order to identify factors favoring contamination at the breeding level. These findings form the starting point for a detailed study on the control of this type of bacteria in the sector of egg production

Reliable ELISAs showing differences between resistant and susceptible lines in hens orally inoculated with Salmonella Enteritidis

Reliable ELISAs were investigated with the aim to select hen lines resistant to Salmonella Enteritidis and producing high levels of antibodies. In the first experiment, the relation between the humoral response and the bacteriological results was assessed on hens from the Y11 resistant line and the L2 susceptible line, orally inoculated with 10$^8$ CFU S. Enteritidis per animal. Anti- lipopolysaccharide (LPS) IgG titres were higher but the liver and spleen were less contaminated in hens from the Y11 line than in hens from the L2 line ($p = 0.013$, 0.031 and 0.026 respectively). In the second experiment, the hens were inoculated orally with $1.7 \times 10^8$ CFU S. Enteritidis per animal in order to select the ELISA methods showing the more significant differences. ELISAs were based on LPS, flagella, LPS from rough (LPS-R) and smooth strains (LPS-S) and detected IgG and IgM antibodies from sera and yolks. No between-line host response variation was observed in the yolk, with LPS-S and R antigens nor with anti-LPS IgM in the sera. Otherwise, significant differences were encountered between hen lines with the ELISAs performed on the sera detecting anti-LPS IgG, anti-flagella IgG or IgM ($p = 0.017$, 0.017 and $p < 0.001$ respectively). When comparing the kinetics of the selected ELISAs, the IgG antibodies against LPS detected between-line variations as early as 1 to 4 weeks pi, whereas with IgG against flagella, the differences were only detected at 1 and 2 weeks pi and with IgM against flagella, the differences were significant at 1, 2, 4 and 8 weeks pi. In conclusion, resistant hen lines producing higher levels of antibodies than the susceptible hen lines may be selected with these ELISAs.Méthodes ELISA permettant de différencier des lignées de poules résistante et sensible à Salmonella Enteritidis inoculées par voie orale. Des méthodes ELISA ont été recherchées pour sélectionner les lignées de poules résistantes à Salmonella Enteritidis produisant des taux élevés d'anticorps. Dans la première expérience, la relation entre la réponse sérologique et les résultats bactériologiques a été évaluée sur les poules des lignées résistante Y11 et sensible L2, inoculées par voie orale avec 10$^8$ UFC S. Enteritidis par animal. Les titres en anticorps IgG anti- lipopolysaccharidiques (LPS) étaient supérieurs mais les foies et rates étaient moins contaminés chez les poules de la lignée Y11 que chez les poules de la lignée L2 ($p = 0.013$, 0.031 et 0.026 respectivement). Dans la seconde expérience, les deux lignées de poules ont été inoculées par voie orale avec $1.7 \times 10^8$ UFC S. Enteritidis par animal afin de sélectionner les méthodes ELISA les plus discriminantes. Les ELISA utilisaient comme antigènes des LPS, flagelles, LPS des souches rough (LPS-R) et smooth (LPS-S), et détectaient des anticorps IgG et IgM dans le sérum et le vitellus. Aucune différence significative n'a été observée à partir du vitellus, ou avec les antigènes LPS-S et R, ainsi qu'avec les IgM anti-LPS dans le sérum. En revanche, les tests ELISA réalisés sur les sérums et basés sur le dépistage des IgG anti-LPS, des IgG ou IgM anti-flagellaires permettent de montrer une différence significative entre les deux lignées ($p = 0.017$, 0.017 et $p < 0.001$ respectivement). La comparaison des cinétiques obtenues avec les tests ELISAs retenus a montré que les IgG anti-LPS permettaient de détecter des différences entre lignées dès 1 semaine jusqu'à 4 semaines après inoculation, alors qu'avec les IgG anti-flagellaires les différences apparaissaient seulement à 1 et 2 semaines, et avec les IgM anti-flagellaires les différences étaient significatives à 1, 2, 4 et 8 semaines après inoculation. En conclusion, les lignées de poules résistantes et produisant des taux d'anticorps plus élevés que les lignées de poules sensibles peuvent être sélectionnées avec ces tests ELISA

Reliable ELISAs showing differences between resistant and susceptible lines in hens orally inoculated with Salmonella Enteritidis

Reliable ELISAs were investigated with the aim to select hen lines resistant to Salmonella Enteritidis and producing high levels of antibodies. In the first experiment, the relation between the humoral response and the bacteriological results was assessed on hens from the Y11 resistant line and the L2 susceptible line, orally inoculated with 10$^8$ CFU S. Enteritidis per animal. Anti- lipopolysaccharide (LPS) IgG titres were higher but the liver and spleen were less contaminated in hens from the Y11 line than in hens from the L2 line ($p = 0.013$, 0.031 and 0.026 respectively). In the second experiment, the hens were inoculated orally with $1.7 \times 10^8$ CFU S. Enteritidis per animal in order to select the ELISA methods showing the more significant differences. ELISAs were based on LPS, flagella, LPS from rough (LPS-R) and smooth strains (LPS-S) and detected IgG and IgM antibodies from sera and yolks. No between-line host response variation was observed in the yolk, with LPS-S and R antigens nor with anti-LPS IgM in the sera. Otherwise, significant differences were encountered between hen lines with the ELISAs performed on the sera detecting anti-LPS IgG, anti-flagella IgG or IgM ($p = 0.017$, 0.017 and $p < 0.001$ respectively). When comparing the kinetics of the selected ELISAs, the IgG antibodies against LPS detected between-line variations as early as 1 to 4 weeks pi, whereas with IgG against flagella, the differences were only detected at 1 and 2 weeks pi and with IgM against flagella, the differences were significant at 1, 2, 4 and 8 weeks pi. In conclusion, resistant hen lines producing higher levels of antibodies than the susceptible hen lines may be selected with these ELISAs.Méthodes ELISA permettant de différencier des lignées de poules résistante et sensible à Salmonella Enteritidis inoculées par voie orale. Des méthodes ELISA ont été recherchées pour sélectionner les lignées de poules résistantes à Salmonella Enteritidis produisant des taux élevés d'anticorps. Dans la première expérience, la relation entre la réponse sérologique et les résultats bactériologiques a été évaluée sur les poules des lignées résistante Y11 et sensible L2, inoculées par voie orale avec 10$^8$ UFC S. Enteritidis par animal. Les titres en anticorps IgG anti- lipopolysaccharidiques (LPS) étaient supérieurs mais les foies et rates étaient moins contaminés chez les poules de la lignée Y11 que chez les poules de la lignée L2 ($p = 0.013$, 0.031 et 0.026 respectivement). Dans la seconde expérience, les deux lignées de poules ont été inoculées par voie orale avec $1.7 \times 10^8$ UFC S. Enteritidis par animal afin de sélectionner les méthodes ELISA les plus discriminantes. Les ELISA utilisaient comme antigènes des LPS, flagelles, LPS des souches rough (LPS-R) et smooth (LPS-S), et détectaient des anticorps IgG et IgM dans le sérum et le vitellus. Aucune différence significative n'a été observée à partir du vitellus, ou avec les antigènes LPS-S et R, ainsi qu'avec les IgM anti-LPS dans le sérum. En revanche, les tests ELISA réalisés sur les sérums et basés sur le dépistage des IgG anti-LPS, des IgG ou IgM anti-flagellaires permettent de montrer une différence significative entre les deux lignées ($p = 0.017$, 0.017 et $p < 0.001$ respectivement). La comparaison des cinétiques obtenues avec les tests ELISAs retenus a montré que les IgG anti-LPS permettaient de détecter des différences entre lignées dès 1 semaine jusqu'à 4 semaines après inoculation, alors qu'avec les IgG anti-flagellaires les différences apparaissaient seulement à 1 et 2 semaines, et avec les IgM anti-flagellaires les différences étaient significatives à 1, 2, 4 et 8 semaines après inoculation. En conclusion, les lignées de poules résistantes et produisant des taux d'anticorps plus élevés que les lignées de poules sensibles peuvent être sélectionnées avec ces tests ELISA

The NIMPH Project

The next generation of telecommunication satellites operating in the Ku and Ka bands consider radio over optical fibre (RoF) technologies as a good candidate for the future flexible payloads. During the last 10 years CNES has supported the evaluation of optical components for spatial requirements. At present, experimental feedback in real environment would accelerate the introduction of RoF technologies for spatial needs. It is in this context that Thales Alenia Space and CNES offered the opportunity to the students of Toulouse University to realize a nanosatellite dedicated to the orbital test of a RoF transmission. This 2 years old ongoing project is entitled: Nanosatellite to Investigate Microwave Photonics (NIMPH)

Pasteurisation of liquid whole egg: Optimal heat treatments in relation to its functional, nutritional and allergenic properties

Pasteurised liquid egg products represent around 70% of total egg products. Pasteurisation, necessary formicrobiological safety, is a unit operation undergone by the totality of liquid whole egg commercialized.The present work aims to investigate the impact of a wide range of pasteurisation rates (among thoseclassically used in industry) on the interfacial properties, in vitro digestibility and antigenicity of wholeegg proteins, in order to optimize the unit operation parameters to ensure all whole egg qualities.Pasteurisation from 4 to 10 min at 60 C improved protein interfacial properties, in vitro digestibility anddecreased ovomucoïd antigenicity but did not significantly change ovotransferrin and lysozyme antigenicity.On the opposite, pasteurisation from 4 to 10 min at 66 C decreased protein in vitro digestibilityand increased drastically ovotransferrin antigenicity. Pasteurisation from 4 to 10 min at 60 C enabled toreach all whole egg properties, but for safety reasons, higher pasteurisation rates at 62 or 64 C are goodcompromises to ensure microbiological safety without excessively damaging the functional properties

Heat treatments applied to egg product have a rather low impact on in vivo allergenicity, despite significant changes in protein digestibility and antigenicity

Egg products represent 15 to 50% of egg consumption in Europe depending on the country. For microbiological safety reasons, thermal treatments are applied to egg products. Liquid egg products are pasteurized for 2 to 6 min around 56°C (egg white) or 68°C (for whole egg and yolk); egg white powders are dry-heated up to several weeks from 60 to 80°C. The effects of these treatments on egg functional properties have been widely studied, but what about egg protein digestibility or allergenicity? The aim of our study was to investigate the effect of a wide range of pasteurization rates (on liquid whole egg) and dry heating rates (on egg white powder) on the in vitro digestibility, antigenicity and allergenicity of egg proteins.Pasteurization of liquid whole egg up to 10 min at 60°C, improved protein in vitro digestibility and decreased ovomucoïd antigenicity. Conversely, pasteurization up to 10 min at 66°C decreased protein in vitro digestibility and lysozyme antigenicity, but increased drastically ovotransferrin antigenicity. However pasteurization (6 min at 66°C) had a limited impact on the prick test (PT) reactivity of most children. Dry heating of egg white powder, from 1 to 10 days at 60°C, improved protein in vitro digestibility and slightly decreased lysozyme antigenicity. But dry heating over 1 day at 80°C or 90°C decreased protein in vitro digestibility and lysozyme antigenicity, while drastically increased ovotransferrin antigenicity. Dry heating of egg white powder up to 7 days at 80°C had a limited impact on egg allergy tested in mice

Technological advances in egg product processing with reference to allergenicity

Egg is a widely used ingredient in many food products all around the world. It is indeed a major source of high quality proteins and essential nutrients and provides many desirable functional attributes such as foaming, emulsifying, gelling, colouring, and flavouring. However, hen’s egg is also one of the most frequent allergenic foods, particularly in childhood, affecting 1.6 to 3.2 % of young children in Europe.Egg products represent 15 to 50% of egg consumption in Europe depending on the country. For microbiological safety reasons, thermal treatments are applied to egg products. Liquid egg products are thus pasteurized for 2 to 6 min between 56°C (for egg white) and 68°C (for whole egg and yolk), whereas egg white powders are dry-heated up to several weeks between 60 and 80°C. The effects of these treatments on egg functional properties have been widely studied; this is not the case for egg protein digestibility or allergenicity. The aim of our study was thus to investigate the effect of a wide range of pasteurization rates (on liquid whole egg) or dry heating rates (on egg white powder) on the in vitro digestibility, antigenicity and allergenicity of egg proteins.Liquid whole egg was pasteurized from 2 to 6 min between 60°C and 66°C, and egg white powder was dry heated from 1 to 10 days between 60°C and 90°C. In vitro digestion of samples was performed using a model that mimics successive gastric and duodenal stages of digestion in the adult human. The degree of hydrolysis was quantified by OPA method at the end of each stage, and the SDS PAGE pattern was followed throughout the in vitro digestion. Ovomucoïd, ovotransferrin and lysozyme antigenicity was tested by inhibition ELISA with specific monoclonal antibodies. Liquid whole egg allergenicity was investigated in 54 egg-allergic children by skin prick testing and IgE-binding pattern to egg proteins was determined by indirect ELISA. Egg white powder allergenicity was tested on mice sensitized and challenged through oral route by measuring plasmatic histamine concentration, specific and total IgE and IgG levels, and cytokine concentration in spleen cell culture supernatants.Pasteurization of liquid whole egg, from 4 to 10 min at 60°C, improved protein in vitro digestibility and decreased ovomucoïd antigenicity, but did not significantly change ovotransferrin and lysozyme antigenicity. Conversely, pasteurization from 4 to 10 min at 66°C decreased protein in vitro digestibility and lysozyme antigenicity, but increased drastically ovotransferrin antigenicity. Pasteurization (6 min at 66°C) had a limited impact on the prick test (PT) reactivity of most children. However, two main classes of patients were obtained from PT diameter variations: for 34 children, pasteurization had no impact on PT reactivity, whereas for 20 children, pasteurization significantly decreased reactivity. A large effect was even found for 4 children who had null PT with pasteurized liquid whole egg. No correlation was found between patterns of IgE-binding to egg proteins and patterns of PT-reactivity as a function of pasteurization.Dry heating of egg white powder, from 1 to 10 days at 60°C, improved protein in vitro digestibility and slightly decreased lysozyme antigenicity. On the other hand, dry heating over 1 day at 80°C or 90°C decreased protein in vitro digestibility and lysozyme antigenicity, but drastically increased ovotransferrin antigenicity. Dry heating of egg white powder up to 7 days at 80°C had a limited impact on egg allergy tested in mice. No significant effect was found on histamine concentration, or specific and total IgE and IgG levels. Only a significant decrease of IL4 cytokine concentration was observed for mice groups fed with dry heated powders.Heat treatments applied to egg products thus have, in most cases, a rather low impact on in vivo allergenicity, despite significant changes in protein digestibility and antigenicity

Women and health professionals’ perspectives on a conditional cash transfer programme to improve pregnancy follow-up: a qualitative analysis of the NAITRE randomised controlled study

Objectives Women of low socioeconomic status have been described as having suboptimal prenatal care, which in turn has been associated with poor pregnancy outcomes. Many types of conditional cash transfer (CCT) programmes have been developed, including programmes to improve prenatal care or smoking cessation during pregnancy, and their effects demonstrated. However, ethical critiques have included paternalism and lack of informed choice. Our objective was to determine if women and healthcare professionals (HPs) shared these concerns.Design Prospective qualitative research.Setting We included economically disadvantaged women, as defined by health insurance data, who participated in the French NAITRE randomised trial assessing a CCT programme during prenatal follow-up to improve pregnancy outcomes. The HP worked in some maternities participating in this trial.Participants 26 women, 14 who received CCT and 12 who did not, mostly unemployed (20/26), and - 7 HPs.Interventions We conducted a multicentre cross-sectional qualitative study among women and HPs who participated in the NAITRE Study to assess their views on CCT. The women were interviewed after childbirth.Results Women did not perceive CCT negatively. They did not mention feeling stigmatised. They described CCT as a significant source of aid for women with limited financial resources. HP described the CCT in less positive terms, for example, expressing concern about discussing cash transfer at their first medical consultation with women. Though they emphasised ethical concerns about the basis of the trial, they recognised the importance of evaluating CCT.Conclusions In France, a high-income country where prenatal follow-up is free, HPs were concerned that the CCT programme would change their relationship with patients and wondered if it was the best use of funding. However, women who received a cash incentive said they did not feel stigmatised and indicated that these payments helped them prepare for their baby’s birth.Trial registration number NCT0240285

Severity of COVID-19 and survival in patients with rheumatic and inflammatory diseases: data from the French RMD COVID-19 cohort of 694 patients

International audienceObjectives: There is little known about the impact of SARS-CoV-2 on patients with inflammatory rheumatic and musculoskeletal diseases (iRMD). We examined epidemiological characteristics associated with severe disease, then with death. We also compared mortality between patients hospitalised for COVID-19 with and without iRMD.Methods: Individuals with suspected iRMD-COVID-19 were included in this French cohort. Logistic regression models adjusted for age and sex were used to estimate adjusted ORs and 95% CIs of severe COVID-19. The most significant clinically relevant factors were analysed by multivariable penalised logistic regression models, using a forward selection method. The death rate of hospitalised patients with iRMD-COVID-19 (moderate-severe) was compared with a subset of patients with non-iRMD-COVID-19 from a French hospital matched for age, sex, and comorbidities.Results: Of 694 adults, 438 (63%) developed mild (not hospitalised), 169 (24%) moderate (hospitalised out of the intensive care unit (ICU) and 87 (13%) severe (patients in ICU/deceased) disease. In multivariable imputed analyses, the variables associated with severe infection were age (OR=1.08, 95% CI: 1.05-1.10), female gender (OR=0.45, 95% CI: 0.25-0.80), body mass index (OR=1.07, 95% CI: 1.02-1.12), hypertension (OR=1.86, 95% CI: 1.01-3.42), and use of corticosteroids (OR=1.97, 95% CI: 1.09-3.54), mycophenolate mofetil (OR=6.6, 95% CI: 1.47-29.62) and rituximab (OR=4.21, 95% CI: 1.61-10.98). Fifty-eight patients died (8% (total) and 23% (hospitalised)). Compared with 175 matched hospitalised patients with non-iRMD-COVID-19, the OR of mortality associated with hospitalised patients with iRMD-COVID-19 was 1.45 (95% CI: 0.87-2.42) (n=175 each group).Conclusions: In the French RMD COVID-19 cohort, as already identified in the general population, older age, male gender, obesity, and hypertension were found to be associated with severe COVID-19. Patients with iRMD on corticosteroids, but not methotrexate, or tumour necrosis factor alpha and interleukin-6 inhibitors, should be considered as more likely to develop severe COVID-19. Unlike common comorbidities such as obesity, and cardiovascular or lung diseases, the risk of death is not significantly increased in patients with iRMD