1,720,996 research outputs found
Pediococcus spp.: caratterizzazione fenotipica, tecnologica e genotipica
Full text linkLo scopo di questa sperimentazione è stato quello di esplorare alcuni aspetti specifici legati ai batteri appartenenti al genere Pediococcus, al fine di un potenziale utilizzo tecnologico. Il progetto ha previsto un’indagine attraverso l’impiego di metodi tradizionali e molecolari sulla presenza di la Pediococcus spp. isolati da differenti alimenti fermentati con lo scopo di identificarli e caratterizzarl
Valutazione della resistenza a sanificanti utilizzati nell’industria alimentare in Staphylococcus aureus
No full textThe new trends in food production
lead to an increased need for efficient
sanitary practices and consequently
a more frequent use of chemical
disinfection. In this study 10
Staphylococcus aureus strains were tested
for resistance and adaptation responses
towards Quaternary Ammonium
Compounds (QAC). Minimum
Inhibitory Concentration (MIC)
determinations were performed in
order to evaluate the strains resistance
to each sanitizer. One strain showed
high resistance to QACs. Increasing
disinfecting concentration resulted
in the adaptation of Staphylococcus
aureus. The final MICs, however,
did not exceed the concentrations
used in working solutions in the food
processing plants. Most antimicrobials
were observed to cause crossadaptation
to other disinfectants.
Results obtained in this study may be
valuable when designing a rotation
of disinfectants in food processing
plants, since very little information is
available on how the rotation should
be performed and which disinfectants
to use
SANITIZERS SENSITIVITY OF LISTERIA MONOCYTOGENES BIOFILMS GROWN UNDER STATIC AND DYNAMIC CONDITIONS
No full textMicrobial biofilm: Bio-forming ability in Staphylococcus aureus in the dairy industry
No full textS. aureus is a major cause of contamination in milk and dairy products, representing a problem for the safety of the consumer. The ability to form biofilms, a pathogenic factor present in S. aureus, has been studied in a limited way in mastitic and food isolates. The purpose of this study was to investigate the ability to form biofilms and the peracetic acid resistance of dairy S. aureus isolates. The biofilm-forming ability was found to be widespread in S. aureus, and this trait may in part explain the presence and persistence of S. aureus in the dairy industry. The biofilm of S. aureus have been shown to be quite tolerant to peracetic acid, which highlights the need, in the development of a cleaning protocol, to keep in consideration the spread of microbial forms capable of forming biofilms in the dairy industry
Effect of environmental factors on biofilm formation by Pseudomonas spp. of dairy origin
No full text
Evaluation of amino acid-decarboxylative microbiota throughout the ripening of an Italian PDO cheese produced using different manufacturing practices
No full textAim: To investigate the presence of biogenic amines (BAs) in Montasio cheese
produced by using different cheese manufacturing practices.
Methods and Results: Three batches of Montasio cheese were made in the following
way: batch A using raw milk and natural milk culture, batch B with
thermized milk and natural milk culture and batch C with thermized milk and
natural milk culture added of a commercial starter culture. During 120 days of
ripening analyses were performed for microbial counts and BA content; indeed,
the potential to produce BAs was screened in lactic acid bacteria and Enterobacteriaceae
isolates. At the end of ripening, the total BA contents of cheeses
from batches A, B and C were 166Æ3, 207Æ3 and 29Æ8 mg kg)1, respectively.
Amino acid decarboxylase activity was widespread among isolates.
Conclusions: The BA content of Montasio cheese from the three batches was
below the threshold proposed as potentially toxic. The highest BA content was
found in cheese produced using thermized milk and natural milk culture;
therefore, the thermal treatment of milk was not enough by itself to reduce the
counts of decarboxylase-positive bacteria in cheese. The use of selected starters
guaranteed a low BA content in Montasio cheese.
Significance and Impact of the Study: The study of the effects of some technological
processes on the incidence of decarboxylative microbiota in ‘protected
denomination of origin’ cheeses could provide useful information on the hygienic
risk related to their production
Crescita di Staphylococcus aureus, Escherichia coli e Listeria monocytogenes in formaggi a latte crudo
No full textNei formaggi a latte crudo la qualità microbiologica del latte, le tecniche di lavorazione e l’igiene di produzione rivestono un ruolo essenziale nel prevenire e/o arrestare la crescita dei microrganismi potenzialmente patogeni. Scopo di questo lavoro è stato quello di valutare l’efficacia delle pratiche di stoccaggio del latte e di caseificazione nel controllo di Staphylococcus aureus, Listeria monocytogenes ed Escherichia coli. I risultati delle prove di stoccaggio evidenziano come le temperature testate (da 8 a 12 C) permettano di arrestare la crescita di S. aureus ma non quella di L. monocytogenes e di E. coli, la cui carica aumenta dopo 24 ore a 10 e 12 C. Le pratiche effettuate durante la caseificazione (sosta del latte in caldaia, aggiunta di lattoinnesto e lisozima, cottura a 45 C) non creano le condizioni per la moltiplicazione dei patogeni, ma non causano nemmeno un abbattimento della loro carica. E’ quindi di fondamentale importanza la qualità igienico-sanitaria della materia prima e la temperatura di stoccaggio del latte prima della lavorazione, al fine di consentire l’utilizzo di pratiche casearie artigianali che permettano l’ottenimento di prodotti sicuri, oltre che di elevata qualità organolettica
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