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

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

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

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