الفهرس 
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Abstract
One hundred random samples of kareish cheese,Ras cheese, Plain yoghurt and Cooking butter.(25 of each)were collected from markets and dairy shops from different localities at El-Behera governorates .The collected samples were obtained on their containers as sold to the public or in sterile cup and were dispatched directly to the laboratory with minimum of delay in an icebox where prepared and examined. All samples, were transferred aseptically in a sterile polyethylene bag . and were subjected to sensory (organoleptic) examination then divided into two sub samples . The first sub sample was used for chemical examination while the second one was subjected to mycological examinations to ensure that the samples were apparently fit for human consumption.
The results can be summarized as follows:
I. Sensory criteria :
All samples were examined organoleptically before being subjected to chemical and mycological examination to ensure that the collected samples were apparently fit for consumption and the results can be summarized as follows:
-The number of Kareish cheese samples with no criticisms were 2 (8%), 4 (16%), 7 (28%) and 22 (88%) for flavour, body and texture, colour and appearance and salty criticisms, respectively.
-The number of Ras cheese samples with no criticisms were 5 (20%), 7 (28%), 10 (40%) and 23 (92%) for flavour, body and texture, colour and appearance and salty criticisms, respectively.
-The number of Plain yoghrut samples with no criticisms were 8 (32%), 7 (28%) and 8 (32%) for flavour, body and texture and appearance criticisms, respectively.
-The number of Cooking butter samples with no criticisms were 5 (20%), 4 (16%) , 13 (52%) , 2 (8%) and zero for flavour, body and texture and colour and appearance salt and package criticisms, respectively.
II. Chemical and sanitary examination:
a. Kareish cheese : The mean values for acidity percent, pH value, sodium chloride, moisture and fat to dry matter percent were 1.82 ± 0.068 ; 4.43 ± 0.099 ; 3.19 ± 0.15 . ; 66.69 ± 0.37 . and 8.87 ± 0.25, respectively .
b.Ras cheese: The mean values for acidity percent ; pH value, sodium chloride, moisture and fat to dry matter percent were 1.76 ± 0.06 ; 4.96 ± 0.066,. 2.35± 0.036. ; 32.23 ± 0.45 . ; 47.79 ± 0.17., respectively .
c.Plain yoghurt : The mean value of acidity percent , pH value were of 1.42 ± 0.04 and 4.73 ± 0.08. respectively,
d. Cooking butter: The mean value of acidity percent , PH value, sodium chloride, moisture and fat to dry matter percent were 0.18 ± 0.01 ; 5.21 ± 0.05. ; 0.46 ± 0.04 . ; 18.22 ± 0.90 and 79.40 ± 0.67. respectively,
III. Mycological examination:
a.Kareish cheese: The mean value of yeast count in examined Kareish cheese samples was2.57 x 104 ± 2.11 x103. While, the mean value of mould count was 1.9 x 104 ± 5.08 x 103 The most commonly yeasts isolated from examined Kareish cheese samples were Candida albicans 10 (35.71%) , Candida famata 3 (10.74%), Candida krusei 4 (14.28%) Candida tropicalis 5 (17.85%) , Cryptococcus neoformans 2 (7.14%), Rhodotorula 2 (7.14%) and Saccharomyces cerevisiae 2 (7.14%) .While the most commonly moulds that could be isolated from the examined Kareish cheese samples were Alternaria alternaria 1 (2.43%), Aspergillus flavus 11 (26.82%) , Aspergillus niger 10 (24.39%) , Aspergillus ochracious 2 (4.87%), Geotricum candidum 3 ( 7.4.%) , Penicillium brevicompactum 1 ( 2.43%) , Penicillium chysogenum 1 ( 2.43%) , Penicillium citrinum 1 (2.43%) , Penicillium roquefortii 2 (4.87%) , Penicillium rubrum 2 ( 4.87%) , Rhizopus species 1 (2.43%) and Mucor species 6 (14.63%).
b.Ras cheese: The mean value of yeast count in examined Ras cheese samples was 2.34 x 104 ± 3.3 x103. While, the mean value of mould count was 8.25 x 103 ± 9.39 x 102. The most commonly yeasts isolated from examined Ras cheese samples were Candida famata 7 (25.0%), Candida kefyr 5 (17.85%), Candida rugosa 5 (17.85%) ,Candida tropicalis 4 (14.28%) , Cryptococcus neoformans 2 (7.14%). , Rhodotorula rubra 2 (7.14%) and Saccharomyces baillii 2 (7.14%). . While the most commonly moulds that could be isolated from the examined Ras cheese samples were identified as ِAspergillus flavus 16 (42.10%) , Aspergillus niger 10 (26.34%) , Aspergillus ochracious 3 (7.89%) , Mucor species 3 (7.89%), Penicillium citrinum 2 (5.26), Penicillium roquefortii 2 (5.26%) , Penicillium rubrum 1 ( 2.63%) ,Penicillium viridicatum 1 (2.63%) .
c. Plain yoghurt: The mean value of yeast count in examined yoghurt samples was 6.38 x 104 ± 9.06 x103. While, the mean value of mould count was 9.26 x 103 ± 1.98 x 103 . .-The most commonly yeasts isolated from examined Plain yoghurt samples were Candida albicans 12 (29.26%), Candida parapsillosis 8 (19.51%) ,Candida tropicalis 11 (26.82%) , , Cryptococcus neoformans 1 (2.47%). Rhodotorula glutinis 6 (14.63%) and Saccharomyces cerevisiae 3 (7.31%). While the most commonly moulds that could be isolated from the examined Plain yoghurt samples were identified as ِAspergillus flavus 9 (32.14%) , Aspergillus niger 6 (21.42%) , Aspergillus ochracious 1 (3.57%) , Geotricum candidum 3(10.71), Mucor species 4 (14.53%), Penicillium brevicompactum 1 (3.57%) , Penicillium roquefortii 2 (7.14%) , Penicillium rubrum 2 ( 7.14%).
d.Cooking butter: The mean value of yeast count in examined Cooking butter samples was 6.6 x 103 ± 1.16 x103 . While, the mean value of mould count was 3.46 x 103 ± 5.05 x 102. The most commonly yeasts isolated from examined Cooking butter samples were Candida albicans 4 (36.37%) ,Candida kefyr 1 (9.09%) , Candida parapsillosis 3 (27.27%) , Candida lipolytica 1 (9.09%) and Saccharomyces cerevisiae 2 (18.18%). While the most commonly moulds that could be isolated from the examined Cooking butter samples were identified as Aspergillus flavus 7 (26.94%), ِAspergillus niger 12 (46.15%), Mucor species 4 (15.38%), Penicillium chrysogenum 2 (7.69%) and Penicillium rubrum 1 ( 3.84%).
ΙV. Screeing of Aspergillus flavus and Aspergillus ochraceus for aflatoxin M1 , G1 and Ochratoxin A production :
-7 out of 11 strains of Aspergillus flavus (63.64%) isolated from Kareish cheese samples were proved tobe toxigenic strains (aflatoxin-producers). While 2 out of 2 strainsof Aspergillus ochraceus (100%) were proved tobe toxigenic strains (Ochratoxin-producers).
-6 out of 16 strains of Aspergillus flavus (37.50%) isolated from Ras cheese samples were proved tobe toxigenic strains (aflatoxin-producers). While 3 out of 3 strainsof Aspergillus ochraceus (100%) were proved to be toxigenic strains (Ochratoxin-producers).
-6 out of 9 strains of Aspergillus flavus (66.67%) isolated from Plain yoghurt samples were proved tobe toxigenic strains (aflatoxin-producers). While 1 out of 1 strainsof Aspergillus ochraceus (100%) were proved tobe toxigenic strains (Ochratoxin-producers).
-5 out of 7 strains of Aspergillus flavus (71.43%) isolated from Cooking butter samples were proved tobe toxigenic strains (aflatoxin-producers). While there is no isolation of Aspergillus ochraceus in cooking butter samples .
-Number of toxigenic strains of Aspergillus flavus and Aspergillus ochraceus isolated from Kareish cheese , Ras cheese, Plain yoghurt and Cooking butter samples were: 7 (63.64%) and 2 (100%) , 6 (37.50%) and 3 (100%) , 6 (66.67%) and 1 (100%), and 5 (71.43%) and zero%. respectively,
-The respective mean values of aflatoxin M1, aflatoxin G1 and ochratoxin A (ppb) produced by Aspergillus flavus and Aspergillus ochraceus were: 12.86 ± 2.64, 9.43 ± 2.16 and 7.50 ± 2.50 for Kareish cheese samples., 23.50 ± 2.69, 17.00 ± 1.86 and 11.67 ± 1.67 for Ras cheese samples., 12. 50 ± 2.50 , 8.50 ± 2.64 and 10 for Plain yoghurt samples. And 15.00 ± 2.24 , 11. 60 ± 3.61 and zero for Cooking butter. respectively,
-The significance and public health importance of the isolated organisims were discussed and the suggestive control measures for improving the criteria and sanitary conditions of Kareish cheese, Ras cheese, Plain yoghurt and Cooking butter were discussed.