melted cheese and butter cream; 1 sample of cheese and spread). Specific colonies of
Listeria monocytogenes were not founding samples of milk and pasteurized cream. The
facts were steady and reliable, therefore, these indicators can be used in evaluating the
safety of milk and dairy products. In addition, it should be noted that the method is
economic, simple in execution, but its results give specific quality indicators in terms
of color and size of Listeria monocytogenes colonies.
A method wepropose is a qualitative technique of improving the horizontal
method of Listeria monocytogenes detection in milk and dairy products along with
other methods of determining dairy products safety (determination of the total number
of microorganisms) and determining the bacteria of intestinal stick group, salmonella
and staphylococci) [5, 10, 15, 17].
The advantage of this method among existing qualitative techniques is
determining the safety of milk and dairy products on the basis of reliable coloring and
size indicators of Listeria monocytogenes colonies.
The basis of Salmonella detection method in milk and dairy products is
developing a strategy of improving the horizontal method of Salmonella detection in
milk and dairy products by changing the quantity of research suspension, which is
prepared in the ratio of 1:5 (samples of milk and dairy products in the amount of 10−11
cm
3
(d) and 50−55 cm
3
of preview concentration medium (buffered peptone water),
and further incubation of received suspension for 16±2 hours at the temperature of
35±1 °C and subsequent selective concentration. The received culture in the quantity
of 0.06 − 0.07 cm
3
is transferred into test tube that contains 5.0−5.1 cm
3
RV medium
(chloride of malachite medium of green Rappaport-Vassiliadis) and 5−6 cm
3
of this
culture are also put in a flask containing 50−51 cm
3
of selenidecystine medium. These
two sawing mediums are kept in the thermostat at the temperature of 41±1 °C for about
23±1 hours and at the temperature of 35±1 °C for about 23±1 hours. After that the
culture received with the help of two mediums is inoculated with the help of electronic
circuit on the surface of Petri cup in the quantity of 2.0−2,5 cm
3
, which contains a solid
selective medium (carbolic acid red brilliant green agar-agar). Then we exposure it at
the temperature of 35±1 °C for 23±2 hours to get isolated typical Salmonella colony of
red color in terms of changing the medium from pink to red color.
The results of our research identified the isolated typical colonies of red color
Salmonella in 23±2 hours at the temperature of 35±1 °C in the following samples of
milk and dairy products: 7 samples of raw milk; 4 samples of cream and butter; 3
samples of melted cheese; 2 samples of curd and cheese and 1 sample of pasteurized
milk. The peculiar red Salmonella colonies were not detected in pasteurized cream.
The obtained results were steady and reliable, so these figures can be used in
evaluating the safety of milk and dairy products. In addition, it should be noted that the
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