1,720,961 research outputs found
VALUTAZIONE DELL’EFFETTO DEL CONGELAMENTO SULLA CONTAMINAZIONE MICROBIOLOGICA DI MATRICI ALIMENTARI
No full textFood safety and the protection of Public Health are the main
objectives of the European Community Regulations. Within
this framework, the low-temperature preservation (-18°C)
of the samples to be analysed needs special attention in
order to eventually obtain accurate analytical results. The
objective of the present research has been to evaluate the
variation of the analytical results during the processes of
freezing and thawing in various typologies of food according
to their physical state and to the time of frozen storage. The
result showed that in minced meat, some microbial species
are less sensitive to freezing storage. In fact the count of
Enterobacteriaceae, Escherichia coli and L. monocytogenes
remained within the range of uncertainty of measurement
until, respectively, the 3rd, 31st and 90th day of preservation
(66% of the samples). In all other cases, freezing leads to an
undervaluation of the analytic results which would lose its
value in terms of accuracy and food safety, for example in
the case of assessment in relation to batches and production
stock
Caratterizzazione microbiologica del “Sushi”
No full textIn the last decade some alternative food models
have progressively spread in response to the
growing interest of consumers in novelty
and change. It is within this context that the
consumption of typical Japanese dishes based on
raw fish takes place (Sushi and Sashimi). Due to
the presence of raw fish as a basic feature, the
consumption of sushi requires a greater guarantee
of hygienic-sanitary safety, especially when there
is a risk of not using high-quality ingredients. The
aim of the present study is to make a hygienic
and sanitary evaluation of ‘Sushi’ by verifying the
current safety and procedure criteria, especially
in relation to the thermic treatment stages, to
the microbial contamination and to the way the
latter can vary according to the different product
typologies
Valutazione della biocontaminazione nel processo produttivo delle lavanderie industriali
No full text
Qualità microbiologica del processo di produzione di vegetali di i gamma
No full textIn the present work has been featured in over a year, the microbiological quality of the production plants of the first range through the study of health and hygiene requirements of certain types of leafy vegetables (lettuce), machined surfaces, and irrigation water. We proceeded to search for Enterobacteriaceae, E. coli, yeast and molds, Salmonella spp., Listeria monocytogenes, total mesophilic counts. With regard to irrigation waters investigations have focused on the research of E. coli, enterococci, sulphite reducing Clostridia, Pseudomonas aeruginosa, total bacterial count at 22 ° C and 36 ° C. The average values in lettuces at different stages of processing with regard to the CMT were equal to 9×106 cfu / g, Enterobacteriaceae 7×104 cfu / g, Yeasts 9×102 cfu / g, Molds 1.6 ×104 cfu / g. All samples were negative for Salmonella spp and Listeria monocytogenes and E. coli. These values when compared with those of Regulation 1441 regarding herbal products are ready-to-eat (RTE) meet the criteria of acceptability. Particular attention should be directed towards hygiene of surfaces such as alveolar containers and the quality of the water used for irrigation
Hygiene and health risks associated with the consumption of edible lamellibranch molluscs
No full textEdible lamellibranch molluscs are frequently the cause of very serious outbreaks of food poisoning. Microbiological suitability for human consumption, according to EC Reg. n. 1441/2007, is only based on two faecal bacteriological contamination parameters (. Escherichia coli and Salmonella) and does not consider other microorganisms which are naturally present within the marine environment and are potentially pathogenic such as those belonging to the genus Vibrio. In this study, a total of 540 samples of edible lamellibranch molluscs (mussels, clams and oysters) bred in Sardinia were analyzed for E. coli and Salmonella, according to EC Reg n. 1441/2005, and for the presence of Vibrios of major public health interest. Environmental parameters (seawater temperature and salinity) were also recorded. The 40% (. n=. 216) of samples were positive for Vibrio while the levels of E. coli were above the legal European limit only in 6.4% of samples. A correlation between the presence of micro-organisms of faecal origin and potentially harmful Vibrios to human health was not observed. Vibrio alginolyticus was the most common in 68% of isolated species, followed by Vibrio parahaemolyticus in 22.6%, Vibrio cholerae in 6% and Vibrio vulnificus in 1.1%. Virulence gene (. trh sequence) was present in 1.6% of the V. parahaemolyticus-positive samples. The V. cholerae, V. vulnificus and V. alginolyticus strains detected were non toxigenic. The absence of genes encoding major virulence factors in the studied strains does not exclude the possibility of exposure to pathogenic strains. This study indicates the potential health risk associated with the presence of pathogenic Vibrios in edible lamellibranch molluscs bred in Sardinia, where shellfish production is very important to the local economy. alginolyticus was predominant (68%). parahaemolyticus, V. vulnificus and V. cholerae showed frequencies of isolation of 22.6%, 6% and 1.1% respectively. parahaemolyticus tested positive for virulence gene (trh)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
