الفهرس | Only 14 pages are availabe for public view |
Abstract The present study was done on 150 samples (raw milk, ice-cream and yogurt (50 of each)) which randomly collected from different shops and supermarkets in Mansoura city, Dakahlia Governorate, Egypt. Our result revealed that the prevalence of Listeria species in milk, yogurt and ice-cream. The results showed that Listeria species in milk was 36% as L. monocytogenes isolated from7 samples (14%), L. innocua from 3 samples (6%) and other Listeria species from 8 samples (16%). In yogurt Listeria species was isolated from 3 samples (6%) where L. innocua was isolated from 1 sample (2%) and other Listeria species were from 2 samples (4%) while no L. monocytogenes was isolated from yogurt. In ice-cream Listeria species were isolated from 4 samples (8%) where L.monocytogenes isolated from 1 sample (2%) and other Listeria species from 3 samples (6%) while no L. innocua was detected from ice-cream. L.innocua strain isolated from food has been subjected to whole genome sequencing and then the sequence types (STs) for these isolates were determined by identification of the specific seven genes were selected and subjected to multilocus sequence type (MLST) and result showed ST 1085. Using of plant extract has been recommended as food preservatives to avoid side effects of chemical preservatives in food industry. Clove, thyme and pomegranate peel extracts have been used in this study. Antimicrobial activity has been done for plant extracts and sensory evaluation was done on white soft cheese process. The concentration of plant extract recommended by panelists in sensory evaluation was 2.5%. The reduction rate of plant extracts implanted in white soft cheese was high reached to 98% and 99% for both Listeria monocytogenes and Listeria innocua. |