This investigation was conducted at the laboratory of Food Science
Department, Faculty of Agriculture, University of Damascus to determine the
effectiveness and the impact of using microwave radiations to reduce or
eliminate Salmonella typhi in co
ntaminated milk and in white cheese
manufactured by traditional method made of contaminated milk.
Results showed that the duration of 60 sec. was enough to eliminate the
S.typhi from milk heated up to 90₀ C and the best treatment was when exposing
cutting cheese for a period of 240 sec, and the temperature reached 85 ?C and
for a period of 300 sec with a temperature reached 100₀C. Presence of water
helped raising the temperature of the cuttings to be equivalent to the hot water
temperature, (100₀C) and to eliminate greatly bacteria S.typhi in cutting cheese.
It was concluded that the use of microwave radiation was safety to destroy
S.typhi in milk and white cheese.
This investigation was done in the laboratories of Faculty of Agriculture –
Damascus University Department of Food Sciences. The aim of this research
was to study the inhibition effect of the growth of Lactic acid bacteria used as
starter, on the
growth of S. typhi O9 bacteria. We used for this study a pure
strains of Salmonella typhi O9 and Lactic acid bacteria (Streptococcus
thermophilus and Lactobacillus bulgaricus). The effect of Lactic acid bacteria on
the number of S. typhi O9 was studied in 37 ◦C and 4◦C. The Lactic acid bacteria
were inoculeted in milk for the yoghurt manufacturing. The number of S. typhi
O9 decreased gradually with time. This decrease number of this bacteria was
more clear when both Str. thermophilus and Lb. bulgaricus were used as a
mixted starter, Lb. bulgaricus then when was used a single starter, or when Str.
thermophilus was used a alone. The S.typhi O9 disappear
