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Campylobacter-associated gastroenteritis remains an important cause of morbidity worldwide, and some evidence suggests that poultry is an important source of this foodborne infection in humans. This study was conducted to analyze the prevalence and genetic background of resistance of 149 Campylobacter jejuni and 54 Campylobacter coli strains isolated from broiler chicken carcasses and from stool samples of infected children in Poland from 2003 through 2005. Nearly all isolates were susceptible to macrolides and aminoglycosides. The highest resistance in both human and chicken strains was observed for ciprofloxacin (more than 40%), followed by ampicillin (13 to 21%), and tetracycline (8 to 29%). Resistance to ampicillin and tetracycline rose significantly between 2003 and 2005. Slight differences in resistance between human and chicken isolates indicate that although chicken meat is not the only source of Campylobacter infection in our population, it can be involved in the transmission of drug-resistant Campylobacter strains to humans.

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The aim of this study was to develop models based on Linear Discriminant Analysis (LDA), Classi cation and Regression Trees (C&RT), and Arti cial Neural Network (ANN) for the prediction of the botanical origin of honeys using their physicochemical parameters as well as their antioxidative and thermal properties. Also Principal Component Analysis (PCA) and Cluster Analysis (CA) were performed as initial steps of data mining. The datasets consisted of 72 honey samples (false acacia, rape, buckwheat, honeydew, linden, nectar-honeydew and multi oral) obtained from different regions of Poland and collected between April 2014 and November 2016. Ash content, pH, free acidity, colorimetric coordinates in the CIELAB space (L*, a*, b*, h*, C*), total phenolics content, antioxidant activity, and glass transition temperatures (T g) of the honey samples were determined. The rst four principal components accounted for about 85% of the total variance. PC1 was highly correlated with colour intensity, the hue angle (h*), and total phenolics content, whereas PC2 was dominated by chroma (C*) value and glass transition temperatures (T g). The CA dendrogram displays two clusters: one with light coloured honey samples and second with dark coloured honey samples. On the basis of the LDA analysis, the colour parameters possessed the highest discrimination power according to the botanical origin of honey samples. The models based on ANN and C&RT algorithms were characterized by 100% accuracy. Study results demonstrate that the chemometric approach enables high-accuracy classi cation of honeys according to their botanical origin.

The aim of this study was to examine the thermal denaturation properties of proteins from fresh and frozen pond mussels Anodonta woodiana by differential scanning calorimetry (DSC). The A. woodiana (Lea, 1834) mussels were collected from the bottom of a lake located in West Poland. Three parts of the mussel: adductor muscle (AM), foot muscle (FO) and part of internal organs (IO), were taken for analysis. The DSC technique was used to characterize the stability of the protein system, and SDS-PAGE was applied for the separation and identification of proteins. Thermal analysis in all parts of the mussel revealed two main endothermic transitions: the first at 60-61°C and the second at 69-70°C. Denaturation transition occurred in the temperature range from 42 to 76°C. The highest enthalpy of denaturation was observed for FO and was 15.75 J g -1 (per 1 g of protein) and 14.01 J g -1 for AM. The lower-temperature peak, related to myosin and paramyosin, accounted for approximately 70-80 % of the total area of transition. Electrophoretic analysis (SDS-PAGE) confirmed that the paramyosin, with a mass of approx. 98-107 kDa, constituted the largest percentage, i.e., 24 % in AM and 17 % in IO and FO. Two other main myofibrillar proteins were also present in significant amounts: myosin with a molecular mass of 230-245 kDa (12-14 %) and actin with a mass of 47 kDa (18-20 %). In this study, the effect of freezing on protein stability was also investigated. The results of DSC analyses revealed that the process of freezing did not have a significant influence on the first and second peak temperature. Significant differences in enthalpy between fresh and frozen samples were observed only for AM, for which the total enthalpy (DH) decreased by 33 %. This study provided insight into the biochemistry of A. woodiana meat and offers an area of scientific novelty. Recognizing quality properties of meat tissue from freshwater Chinese pond mussels collected from selected water ecosystems seems to be important with respect to the potential possibility of using it for feed, pet food or even in food products.