Mikrobiologische Qualität von Fleischerzeugnissen aus ökologischer Produktion

Gegenwärtig gibt es keine repräsentativen Daten zur mikrobiologischen Sicherheit und Qualität von Ökofleischerzeugnissen wie streichfähiger Rohwurst und vorverpackter Aufschnittware wie Brühwurst und Kochschinken, die im Einzelhandel mit Mindesthaltbarkeiten von 15-30 Tagen angeboten werden. Aufgrund des zunehmenden Marktanteils von Ökofleischerzeugnissen und weitreichender Abweichungen bei der Fleischerzeugung und –verarbeitung, mit teilweisem oder völligem Verzicht auf Nitrit und andere „chemische“ Zusatzstoffe, war es erforderlich, diese Wissenslücke zu füllen. Von Oktober 2002 - Oktober 2003 untersuchten wir Erzeugnisse, die wir zum einen direkt von sechs kooperierenden Herstellern mit deutschlandweiter Vermarktung und zum anderen aus dem Naturkosthandel bezogen. Die Ergebnisse wurden mit aktuellen Befunden der amtlichen Lebensmittelüberwachung verglichen. Es zeigte sich, dass Ökofleischerzeugnisse, die nach den Richtlinen anerkannter Verbände wie Demeter und Bioland hergestellt werden, kein erhöhtes Gesundheitsrisiko im Vergleich zu konventionellen Produkten aufweisen. Proben von streichfähiger Rohwurst enthielten weder Salmonellen noch enterohämorrhagische Escherichia coli. Keimzahlen von Listeria monocytogenes waren immer < 10 KBE/g, d.h. innerhalb der tolerierten Grenzen. Enterobacteriaceae sowie Koagulase-positive Staphylokokken wurden bis auf wenige Ausnahmen in gesundheitlich unbedenklichen Keimzahlen gefunden. Isolierte Enterokokken zeigten keine klinisch relevanten Antibiotikaresistenzen. Die Aufschnittwaren enthielten in keinem Fall, weder „frisch“ noch nach Ablauf des Haltbarkeitsdatums, mehr als 100 KBE/g Listeria monocytogenes. Die Keimzahlen der Milchsäurebakterien und Enterobacteriaceae waren ähnlich wie bei konventionellen Produkten. Es werden Vorschläge gemacht, wie die mikrobiologische Qualität der Erzeugnisse weiter verbessert werden kann

Phenotypic and genetic comparison of a plant-internalized and an animal-isolated salmonella choleraesuis strain

Contamination of fresh produce with human pathogens poses an important risk for con-sumers, especially after raw consumption. Moreover, if microorganisms are internalized, no re-moval by means of further hygienic measures would be possible. Human pathogenic bacteria identified in these food items are mostly of human or animal origin and an adaptation to this new niche and particularly for internalization would be presumed. This study compares a plant-internalized and an animal-borne Salmonella enterica subsp. enterica serovar Choleraesuis aiming at the identification of adaptation of the plant-internalized strain to its original environment. For this purpose, a phenotypical characterization by means of growth curves under conditions resembling the indige-nous environment from the plant-internalized strain and further analyses using Pulsed-field gel electrophoresis and Matrix-assisted laser desorption ionization time of flight spectrometry were as-sessed. Furthermore, comparative genomic analyses by means of single nucleotide polymorphisms and identification of present/absent genes were performed. Although some phenotypical and genetic differences could be found, no signs of a specific adaptation for colonization and internaliza-tion in plants could be clearly identified. This could suggest that any Salmonella strain could directly settle in this niche without any evolutionary process being necessary. Further comparative analysis including internalized strains would be necessary to assess this question. However, these kinds of strains are not easily available. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Mycotoxin occurrence in commodities, feeds and feed ingredients sourced in the Middle East and Africa

Between February and October 2009, 324 grain, feed and feed commodity samples were sourced directly at animal farms or feed production sites in Middle East and Africa and tested for the presence of A- and B-trichothecenes, zearalenone, fumonisins, aflatoxins and ochratoxin A, or for selected groups of mycotoxins only. Samples were analyzed after clean-up by immunoaffinity or solid-phase extraction followed by HPLC with derivatization where appropriate and fluorescence, UV or mass spectrometric detection. The percentage of positive samples of B-trichothecenes ranged from 0 to 87% of tested samples. The prevalence of fumonisins in the different countries was >50% in most cases. Zearalenone was present in tested commodities from all countries except three. The presence of aflatoxin in analyzed samples varied from 0 to 94%. Ochratoxin A was present in 67% of samples in Sudan and in 100% of Nigerian samples. No A-trichothecenes were found in this survey

Penicillium verrucosum occurrence and Ochratoxin A contents in organically cultivated grain with special reference to ancient wheat types and drying practice

This study addresses the relationship between the ochratoxigenic strains of Penicillium verrucosum and ochratoxin A (OTA) contents in organically cultivated grain. It included 37 combined, non-dried grain samples from farmers with no drying facilities as well as 19 non-dried and 22 dried samples from six farms with on-farm drying facilities (Case studies 1-6). The study focused on the ancient wheat type spelt but also included samples of wheat, rye, barley, oats, triticale, emmer, and einkorn. All 78 samples were analysed for moisture content (MC) and occurrence of P. verrucosum. The latter was assessed by plating non-disinfected kernels on DYSG agar and counting those contaminated by the fungus. Fiftyfive samples were analysed for OTA. Most of the combine harvested samples (82%) were contaminated with P. verrucosum prior to drying. This was ascribed to difficult harvest conditions and many samples of spelt, which was significantly more contaminated by P. verrucosum than oats, wheat and barley. Though not statistically significant, the results also indicated that spelt was more contaminated than rye, which is usually regarded the most sensitive small grain cereal. No correlation was found between number of kernels contaminated by P. verrucosum and OTA content. Despite many non-dried samples being contaminated by P. verrucosum, only two exceeded the EU maximum limit for grain (5 ng OTA g-1), both being spring spelt with 18 and 92 ng g-1, respectively. The problems were most likely correlated to a late harvest and high MC of the grain. The case studies showed exceedings of the maximum limit in a batch of dried oats and spring wheat, respectively, probably to be explained by insufficient drying of late harvested grain with high MC. Furthermore, our results clearly indicate that OTA is not produced in significant amounts in samples with MCs below 17%. All dried samples with MCs above 18% exceeded the 5 ng OTA g-1 limit in grain. However, no correlation between MC and the amount of OTA produced was found

Observation of T-2 Toxin and HT-2 Toxin Glucosides from Fusarium sporotrichioides by Liquid Chromatography Coupled to Tandem Mass Spectrometry (LC-MS/MS)

The trichothecenes produced by solid and liquid cultures of Fusarium sporotrichioides were evaluated with high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Along with the expected T-2 toxin HT-2 toxin and neosolaniol, two additional compounds were detected, which had ions 162 m/z higher than those in the mass spectra of T-2 toxin or HT-2 toxin. Fragmentation behavior of these two compounds was similar to that of T-2 toxin and HT-2 toxin. Based on LC-MS/MS behavior, it is proposed that the two compounds are T-2 toxin 3-O-glucoside and HT-2 toxin 3-O-glucoside. Production of the two glucosides was measured in kernels from wheat and oat inoculated with F. sporotrichiodes, as well as in cultures grown in liquid media and on cracked corn or rice. Production of glucosides in wheat and oats suggest that they may also be present in naturally contaminated cereals

Overcoming cross-cultural group work tensions: mixed student perspectives on the role of social relationships

As universities worldwide rapidly internationalise, higher education classrooms have become unique spaces for collaboration between students from different countries. One common way to encourage collaboration between diverse peers is through group work. However, previous research has highlighted that cross-cultural group work can be challenging and has hinted at potential social tensions. To understand this notion better, we have used robust quantitative tools in this study to select 20 participants from a larger classroom of 860 students to take part in an in-depth qualitative interview about cross-cultural group work experiences. Participant views on social tensions in cross-cultural group work were elicited using a unique mediating artefact method to encourage reflection and in-depth discussion. In our analysis of emergent interview themes, we compared student perspectives on the role of social relationships in group work by their academic performance level. Our findings indicated that all students interviewed desired the opportunity to form social relationships with their group work members, but their motivations for doing so varied widely by academic performance level

Generación de energía solar fotovoltaica en grandes superficies cubiertas de la ciudad de Paraná, Entre Ríos

El objetivo de este trabajo fue determinar la generación de energía eléctrica a través de plantas solares fotovoltaicas diseñadas sobre superficies cubiertas del parque industrial de la ciudad de Paraná. A partir de un relevamiento y selección de industrias con superficie cubierta mayor a 500 m² se identifican diferentes escenarios según la forma, inclinación y orientación de las cubiertas. A través del modelado de los escenarios con el software PVSyst se obtuvieron resultados de la productividad final (YF) e influencia de la radiación sobre cada situación. Sobre un total de 113.142 m² se obtiene una generación de 22.014 MWh al año, con pérdidas del 10,7% en comparación con un diseño óptimo. Se concluye que en el área de estudio se debe comenzar a diseñar edificios con orientación y geometría óptima para incorporar sistemas fotovoltaicos y maximizar la producción de energía limpia y reducir el impacto ambiental.The objective of this work was focused to determine the generation of electric energy through photovoltaic solar plants, which were assumed to be installed on covered surfaces of the industrial park of Paraná city. From a survey and selection of industries with a surface area of more than 500 m², different scenarios were identified according to the shape, inclination and orientation of the decks. Through modeling of these scenarios with the PVSyst software the results of the final yield (YF) and the influence of the radiation on each situation were obtained. Of a total of 113,142 m², a generation of 22,014 MWh per year was obtained, with losses of 10.7% compared to an optimum design. It is concluded that in the study area, the design of buildings with optimum orientation and geometry to incorporate photovoltaic systems should be started in order to maximize the production of clean energy and reduce the environmental impact.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Mental Health of Parents and Life Satisfaction of Children: A Within-Family Analysis of Intergenerational Transmission of Well-Being

This paper addresses the extent to which there is an intergenerational transmission of mental health and subjective well-being within families. Specifically it asks whether parents’ own mental distress influences their child’s life satisfaction, and vice versa. Whilst the evidence on daily contagion of stress and strain between members of the same family is substantial, the evidence on the transmission between parental distress and children’s well-being over a longer period of time is sparse. We tested this idea by examining the within-family transmission of mental distress from parent to child’s life satisfaction, and vice versa, using rich longitudinal data on 1,175 British youths. Results show that parental distress at year t-1 is an important determinant of child’s life satisfaction in the current year. This is true for boys and girls, although boys do not appear to be affected by maternal distress levels. The results also indicated that the child’s own life satisfaction is related with their father’s distress levels in the following year, regardless of the gender of the child. Finally, we examined whether the underlying transmission correlation is due to shared social environment, empathic reactions, or transmission via parent-child interaction

Generación de energía solar fotovoltaica en grandes superficies cubiertas de la ciudad de Paraná, Entre Ríos

El objetivo de este trabajo fue determinar la generación de energía eléctrica a través de plantas solares fotovoltaicas diseñadas sobre superficies cubiertas del parque industrial de la ciudad de Paraná. A partir de un relevamiento y selección de industrias con superficie cubierta mayor a 500 m² se identifican diferentes escenarios según la forma, inclinación y orientación de las cubiertas. A través del modelado de los escenarios con el software PVSyst se obtuvieron resultados de la productividad final (YF) e influencia de la radiación sobre cada situación. Sobre un total de 113.142 m² se obtiene una generación de 22.014 MWh al año, con pérdidas del 10,7% en comparación con un diseño óptimo. Se concluye que en el área de estudio se debe comenzar a diseñar edificios con orientación y geometría óptima para incorporar sistemas fotovoltaicos y maximizar la producción de energía limpia y reducir el impacto ambiental.The objective of this work was focused to determine the generation of electric energy through photovoltaic solar plants, which were assumed to be installed on covered surfaces of the industrial park of Paraná city. From a survey and selection of industries with a surface area of more than 500 m², different scenarios were identified according to the shape, inclination and orientation of the decks. Through modeling of these scenarios with the PVSyst software the results of the final yield (YF) and the influence of the radiation on each situation were obtained. Of a total of 113,142 m², a generation of 22,014 MWh per year was obtained, with losses of 10.7% compared to an optimum design. It is concluded that in the study area, the design of buildings with optimum orientation and geometry to incorporate photovoltaic systems should be started in order to maximize the production of clean energy and reduce the environmental impact.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES