الفهرس 
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Abstract
Present work studied mycological status of some different dairy product serving in student hostel at Faculty of Veterinary Medicine, Alexandria University. Therefore, One hundred and fifty samples of some dairy products serving to student hostel at faculty of Veterinary Medicine including processed cheese, Soft cheese and yoghurt (50 samples of each) collected in plastic bags and transported as soon as possible to laboratory for isolation and identification of yeasts and moulds. In addition, determination AFB1 level in Aspergillus flavus isolated from different products as well as determination level of AFM1 in these products.
The obtained results summarized in the following items.
7.1. Incidence of yeast and mould in cheese samples:
Incidence of yeast in processed and soft cheese were 10 and 34 % with mean values of 1.02×103±5.3×102 and 3.03×104±1.2×104 cfu/g, respectively.
Frequency distribution of different yeast species isolated from examined processed and soft cheese samples were Candida albicans (50 and 25%), Candida parapsillosis (30 and 30%), Candida Tropicalis (10 and 10%) and Rhodotorula species (10 and 35%), respectively.
Incidence of mould in processed and soft cheese were 18 and 26%, with mean value of 6.65×102±2.3×102 and 1.5×104±0.5×104 cfu/g, respectively.
Frequency distribution of mould species isolated from examined processed were Aspergillus flavus 9.1%, Aspergillus Niger 9.1%, Aspergillus fumigatus 9.1%, Aspergillus versicolor 63.6% and Acremonium species 9.1%. Meanwhile, Frequency distribution of mould species isolated from soft cheese were Aspergillus flavus 9.5%, Aspergillus Niger 9.5%, Aspergillus versicolor 19%, Cladosporium species 19%, Mucor species 4.8%, Penicillium species 28.6%, Paecilomyces species 4.8% and Rhizopus species 4.8%.
According to Egyptian Standards (2005), which stated that cheese samples should not contain more than 400 and 10 cells/g of yeast and moulds, there are 6 and 16% of examined processed cheese sample, were not complied with established limits for yeast and mould. In addition, there are 30 and 26% of examined soft cheese were not complied with established limits for yeast and mould
7.2. Incidence of yeast and mould in yoghurt samples:
Incidence of yeast in examined yoghurt samples were 40 % with mean values of 5.6×104±1.6×104 cfu/g.
Frequency distribution of yeast species isolated from examined yoghurt samples were Candida albicans 11.1%, Candida parapsillosis 22.2%, Candida tropicalis 2.7%, Geotrichum species 5.6%, Rhodotorula species 41.7%, and Saccharomyces species 16.7%.
Incidence of mould in examined yoghurt samples were 28 % with mean values of 1.5 ×104±0.44×104 cfu/g.
Frequency distribution of mould species isolated from examined yoghurt samples were Aspergillus flavus 14.3%, Aspergillus Niger 3.6%, Aspergillus versicolor 21.4%, Aspergillus terreus 3.6%, Fusarium species 3.6%, Geotrichum species 32.1%, Mucor species 10.7%, Paecilomyces species 3.6% and Rhizopus species 7.1%.
According to Egyptian Standards (2005), which stated that yoghurt samples should not contain more than 400 cells of yeast /g and 10 cells of mould/g, there are 38 and 28% of examined yoghurt samples were not complied with established limits for yeast and mould.
7.3. Aflatoxin M1 in processed, soft cheese and yoghurt:
Aflatoxin M1 could be detected only in examined two yoghurt samples (20%), ranged from 0.01-0.02 ppb with mean value of 0.015 ± 0.003 ppb, all positive samples below the permissible limit. Meanwhile, Aflatoxin M1 could not be detected in processed and soft cheese samples.
Aflatoxin B1 (ppb) could be detected in 7 examined isolated Aspergillus flavus (1 isolate from processed cheese samples, 2 isolate from soft cheese samples and 4 isolate from yoghurt samples) with mean values of 3.137±0.441, 3.811±0.243 and 6.925±0.848 ppb, respectively in examined processed cheese, soft cheese and yoghurt samples.