Thesis (Ph.D.) - Cairo University - Faculty of Veterinary Medicine - Department of Food Hygiene and Control

This study was performed to investigate the chemical and microbiological quality of some traditionally produced dairy products (Ras, Domiati, Karish cheeses and Mish) 200 random samples (50 each) were examined. The mean values of moisture, salt and acidity % for Ras cheese were (30.3, 3.30 and 0.65), respectively, while (56.44, 6.63 and 0.68) for Domiati cheese, (77, 0.95 and 0.63) for Karish cheese and (85.70, 7.56, 0.50) for Mish samples, respectively. Mean counts of total bacteria, presumptive coliform, staphylococci, yeast and mold were (2{u00D7}10⁸, 3{u00D7}10⁵, 1{u00D7}10⁶, 3{u00D7}10⁵ and 7{u00D7}10³) for Ras cheese, (3{u00D7}10⁶ 5{u00D7}10, 4{u00D7}10⁵, 1{u00D7}10⁵ and 4{u00D7}10³) for Domiati cheese, (9{u00D7}10⁶, 5{u00D7}10, 3{u00D7}10³, 8{u00D7}10⁵ and 7{u00D7}10²) for Karish cheese and (1{u00D7}10⁷, 5{u00D7}10², 1{u00D7}10⁵, 5{u00D7}10⁵ and 3{u00D7}10⁴) for Mish samples, respectively. There was a significant correlation coefficient between chemical parameters and the examined microorganisms. Some potentially pathogenic microorganisms were isolated as Escherichia coli that serologically identified as O125, O18 and O114, as well as the virulence genes fimH and iss were detected by molecular examination. Enterotoxigenic Staphylococcus aureus strains producing enterotoxin (B, D and E) were also detected. Therefore, strict hygienic measures should be applied during manufacture, handing and distribution of traditional products. On the other side of the study, synbiotic Karish cheese was produced as a trial for improving such cheese type

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