Универзитет у Београду, Факултет ветеринарске медицине
Abstract
Osnovni princip pakovanja hrane je sledeći – izbegavanje kontaminacije, odlaganje kvara,
pojedine enzimske reakcije koje pospešuju mekoću proizvoda, smanjenje gubitka na masi i
osiguranje zadržavanja organoleptičkih svojstava namirnice. Savremen potrošač traži hranu
visokog kvaliteta koja je zadržala senzorske karakteristike sirovine od koje je proizvedena, i da
je u isto vreme bezbedna po zdravlje.
Sposobnost listerija da rastu pri temperaturi hlađenja, da su rasprostranjene u prirodi i da
preživljavaju dugo vremena u nepovoljnim uslovima doprineli su saznanju da je ova bakterija
sve značajniji patogen koji se prenosi hranom na ljude.
Osnovni cilj u okviru ove doktorske disertacije je bio da se ispita uticaj pakovanja i uslova
čuvanja na rast različitih serotipova Listeria monocytogenes (različitog porekla) u laboratorijski
kontaminiranim uzorcima dimljene pastrmke. Jedan od ciljeva ovog istraživanja je da se ispita
uticaj pakovanja dimljene ribe (pastrmke) u vakuum i modifikovanoj atmosferi na održivost i
odabrane parametre kvaliteta. Pored toga, ispitivano je i prisustvo drugih patogena (Salmonella
spp., koagulaza pozitivne stafilokoke, sulfitoredukujuće klostridije) kod hladno dimljene
pakovane pastrmke. Izvršeno je ispitivanje promene ukupnog broja bakterija, promene broja
mlečno-kiselinskih bakterija, kao i broja Listeria monocytogenes u uzorcima hladno dimljene
pastrmke pakovane u vakuum i modifikovanoj atmosferi i skladištene pri temperaturi 3°C,
odnosno pri 8°C.
U toku 35 dana skladištenja pri 3°C, odnosno 8°C, ukupan broj aerobnih mezofilnih bakterija
rastao je u zavisnosti od ispitivane grupe do 14. odnosno 28. dana, da bi 35.dana bio na nivou
broja bakterija nultog dana ispitivanja ili manji. Prosečan ukupan broj bakterija u uzorcima
hladno dimljene pastrmke pakovane u vakuum, odnosno u modifikovanoj atmosferi bio je tokom
ispitivanja manji u uzorcima koji su skladišteni pri nižim temperaturama. Način pakovanja
(vakuum, modifikovana atmosfera) i skladištenje pri istim temperaturnim uslovima (3°C ili 8°C)
u većini slučajeva ne utiče značajno na razlike u ukupnom broju aerobnih mezofilnih bakterija...The main principle for food packing is the following: avoiding contamination, staleness delay,
some enzyme reactions that increase softness of the product, reduce loss of mass, and to
ensure the preservation of organoleptic aspects of food. The modern consumer is searching
for the high quality food, which retains the sensory features and nutritional value of the raw
material it was made of and also to be health safe.
The ability of listeria to grow at cooler temperatures, to be wide-spread in nature and to
survive for a long time in unfavorable conditions, have all contributed to the knowledge that
this bacterium is becoming an increasingly significant pathogen that is transferable to people
from food.
The main objective of this PhD thesis is to explore the impact of packaging and storage
conditions on the growth of various serotypes of Listeria monocytogenes (of different origin)
in laboratory contaminated samples of smoked trout. One of the objectives of this research is
to examine the impact of vacuum packing of smoked fish (trout) and modified atmosphere on
maintainability and protection of quality parameters. The presence of other pathogens
(Salmonella spp., coagulase positive Staphylococci, sulphite-reducing Clostridia) in cold
smoked packed trout was also investigated. The research was conducted regarding the change
of the total number of bacteria, and the change of the number of lactic acid bacteria, as well as
the number of Listeria monocytogenes in samples of cold smoked trout vacuum packed, under
modified atmosphere and stored at the temperatures of 3°C and 8°C, respectively.
During 35 days of storage at the temperatures of 3°C and 8°C, respectively, the total
number of bacteria was increasing until day 14 and day 28 subject to a group, only to be at the
level of number of bacteria on day 0 or less. The average total number of bacteria in samples
of cold vacuumed smoked trout, or at modified atmosphere was less during the research in
samples that were stored at lower temperatures..
