The purpose of this study was to investigate the thermal resistance of acid adapted and non-adapted stationary phase Escherichia coli O157:H7, Salmonella enterica Typhimurium and Listeria monocytogenes in pomegranate juice. In addition, the performance of generic E. coli was evaluated as an indicator. Non-adapted stationary phase cells were grown by incubating inoculated tryptic soy broth without glucose (TSB-NG) at 36±1°C for 18±2 hours. Tryptic soy broth with 1% glucose (10 g/l; TSBG) was used for acid adaptation. All media used for L. monocytogenes was supplemented with 0.6% yeast extract. After washing the cells with peptone, 5 ml of pasteurized pomegranate juice was added onto the pellet to obtain inoculated juice with a initial concentration of 107-1010 log CFU/ml. Inoculated pomegranate juice was sealed into the microcapillary tubes. Microtubes were heat treated in waterbaths at 50, 52 and 54±1°C by immersing at pre-determined time intervals. Survived populations were counted on tryptic soy agar (TSA). S. Typhimurium had the lowest thermal resistance in pomegranate juice. At 50°C, E. coli O157:H7 was the most resistant, whereas L. monocytogenes was more thermally tolerant at 52 and 54°C. Acid adaptation decreased the thermal resistance of E. coli O157:H7, but increased the heat resistance of L. monocytogenes at all tested temperatures significantly. Thermal tolerance of S. Typhimurium increased only at 50°C. The most resistant microorganism was non-adapted generic E. coli at 50 and 52°C; acid-adapted L. monocytogenes had the most thermal tolerance at 54°C. Thermal inactivation of microorganisms in pomegranate juice could be tested at lower temperatures compare to other fruit juices. This may be due to the natural antimicrobial effect and more acidic content of pomegranate juice.

In this study, the microbial profiles of external top surfaces of beverage cans sold in Izmir markets, and the survival of E. coli on the top surfaces of cans were investigated through the storage period of 0, 10, 20 and 30 days at 4 and 25°C. Total aerobic mesophilic bacteria (TAMB), coliforms and E.coli counts of 100 cans without protective cover and 20 cans with protective cover were examined. The numbers of TAMB on the cans without protective cover were in the range of 0.43-2.20×103 cfu/cm2. Lower bacteria counts in the range of

Seafood poisoning due to mussels contaminated with pathogens is an important health issue all over the world. Increasing attention and efforts are made to improve the last product quality of mussels and to save consumers from food poisoning. In this study, the depuration process of black mussels (Mytilus galloprovincialis) which have a high consumption rate and located in coastal waters of Turkey was tried to improve using Chloramine-T and superoxide disinfectants. For this purpose, mussels contaminated with Escherichia coli were subjected to depuration for 6 hours in the presence of 20 mg / L of two disinfectants. In the study, It was determined that E. coli numbers in the mussels of disinfectant groups with an initial bacterial load of 4.4 Log cfu / g, decreased to 3.70 and 3.86 Log cfu / g, respectively and the depuration was faster than the control group (4.05 Log cfu / g). As a result, it has been concluded that the use of food-suitable disinfectants in deposition waters can be used for faster and more effective purification. However, considering the possibility of chemicals leaving residues in mussels, detailed studies should be carried out.

Bu çalışmada zencefil (Zingiber officinale), sarımsak (Allium sativum L.) ve nane (Mentha piperita L.) tıbbi ve aromatik bitkilerinden farklı çözücüler kullanılarak hazırlanan ekstraktların çoklu antibiyotik dirençli Escherichia coli suşları üzerine in vitro antimikrobiyal aktivitesi belirlenmiştir. Zencefil, sarımsak ve nane ekstraktlarının hazırlanmasında çözücü olarak etanol, metanol, aseton ve saf su kullanılmıştır. Çözücülerin ekstraksiyon verimi belirlendikten sonra hazırlanan ekstraktların in vitro antimikrobiyal aktivitesi altı farklı çoklu antibiyotik dirençli E. coli suşu (EC1-6) kullanılarak disk difüzyon yöntemiyle belirlenmiştir. Çözücü olarak su veya metanol kullanılan nane ekstraksiyonundan elde edilen ekstraksiyon verimi, aseton ve etanolden daha yüksek bulunmuştur (P<0,001). Benzer şekilde, zencefil ve sarımsak örneklerinden su kullanılarak alınan ekstraksiyon verimi diğer çözücülerden daha yüksek olmuştur (sırasıyla P=0,013 ve P<0,001). Zencefil etanol ve metanol ekstraktlarının E. coli EC2 ve EC4 suşlarına karşı antimikrobiyal aktivite gösterdiği (sırasıyla P=0,020 ve P=0,026), buna karşın diğer E. coli suşları üzerine zencefil ekstraktlarının herhangi bir etkisi olmadığı (P>0,05) belirlenmiştir. Benzer şekilde, sarımsak etanol ve metanol ekstraktlarının E. coli EC2 suşu dışındaki tüm E. coli suşlarına antibakteriyel etki gösterdiği belirlenmiştir (P<0,05). Bununla birlikte, farklı çözücüler kullanılarak hazırlanan nane ekstraktlarının hiçbir E. coli suşuna karşı antimikrobiyal aktivitesi tespit edilmemiştir. Çalışmanın sonuçları, zencefil etanol veya metanol ekstraktlarının, sarımsak etanol ekstraktlarının çalışılan E. coli suşlarına karşı antimikrobiyal ajan olarak kullanılabileceğini göstermiştir.