الفهرس 
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Abstract
This work was carried out to evaluate the chemical and microbiological composition of milk and some dairy products including (yoghurt, Kareish cheese, Baramili cheese, Ras cheese and Requefort cheese) were collected randomly from different markets in assiut city.Egypt. They include 10 samples from each product in ice tank and kept in refrigerator for analysis, in addation to isolation and identification of fungi and detection of their mycotoxins. All samples were statisticaly analyzed for ANOVA and the correlation factor between all resulted parameters values.
5.1 chemical quality of milk and dairy products:
The chemical quality of cow’s milk, buffalo milk, yogurt, Kariesh cheese, Baramelli cheese, Requefort cheese, and Ras cheese were evaluated and the results of the analysis were as follows:
5.1.1 Acidity:
The acidity content was 0.133, 0.180, 0.731, 0.440, 0.48, 0.740, and 0.84 calculated as a percentage of lactic acid for cow’s milk, buffalo milk, yogurt, Kareish cheese, Baramelli cheese, Requfort cheese and Ras cheese, respectively.
5.1.2 Fat percentage:
The fat content was 3.908, 6.572, 3.66, 2, 21.67, 32.33, and 31.67% for cow’s milk, buffalo milk, yogurt, Kareish cheese, Baramelli cheese, Requfort cheese and Ras cheese, respectively.
5.1.3 Total Nitrogen (TN):
The percentages of total nitrogen averages were as follows: 0.48, 0.56, 0.77, 2.42, 2.11, 3.50, and 3.42% for cow’s milk, buffalo milk, yogurt, Kareish cheese, Baramelli cheese, Requfort cheese and Ras cheese, respectively.
5.1.4 Soluable Nitrogen (SN):
The SN content was 0.305, 0.418, 0.0215, 0.35, 0.015, 1.25 and 0.41 for cow’s milk, buffalo milk, yogurt, Kareish cheese, Baramelli cheese, Requfort cheese and Ras cheese, respectively.
5.1.5 Salt Precentage:
The mean values of the percentage of salt in the products are 0.231, 0.200, 0.2068, 2.912, 5.445, 4.340, and 5.09741% for cow’s milk, buffalo milk, yogurt, Kareish cheese, Baramelli cheese, Requfort cheese and Ras cheese, respectively.
5.1.6 Ash Precentage:
The Ash content was 0.681, 0.691, 0.799, 2.84, 7.22, 4.08, and 6.63% for cow’s milk, buffalo milk, yogurt, Kareish cheese, Baramelli cheese, Requfort cheese and Ras cheese, respectively.
5.2 Microbiological quality of milk and dairy products:
5.2.1 Total Bacterial Counts (T.B.C):
The mean total bacteria count log for cow’s milk, buffalo milk, yogurt, Kareish cheese, Baramelli cheese, Requfort cheese and Ras cheese were 7.09 log10 , 7.17 log10, 7.25 log10
,7.08 log10, 7.10 log10, 6.39 log10, 6.57 log10, cfu/ ml or gm.
5.2.2 Total Molds and Yeasts Counts:
The average of yeasts and fungi count log for cow’s milk, buffalo’s milk, yogurt, Kareish cheese, Baramelli cheese, Requfort cheese and Ras cheese were 5.51 log10, 5.52 log10, 5.38 log10, 4.48 log10, 4.58 log10, 5.14 log10, 4.53 log10 cfu/ ml or gm.
5.2.3 Detection of Coliform Bacteria
The coliform bacteria was found in 75% of the total cow’s milk samples, 100% of buffalo’s milk samples and 20% of of yogurt samples .Regrading cheese, coliform bacteria was not found in all samples of Requefort, Kareish and Baramili cheese while it was found in about 66.66% of Ras cheese samples.
5.3 Isolation and Identification of Fungi from milk and dairy products:
Two types of media were used in this study (Shabex dextrose agar for the count of fungi and Yeast Malt extract media) for the number, isolation and identification of yeasts and fungi in all the products that were used in the study:
First, cow’s milk
The count of fungi was 3050 cfu/ml of milk using of Czapek̕s dextrose
media of
agar, and four species belonging to three genera of fungi were isolated from four samples of cow’s milk collected from different dairy markets :
Cladosporium cladosporioides, Aspergillus terreus, Aspergillus niger, Absidia cylindrospora
The total count of fungi and yeasts using the media of Yeast Malt Extract agar was 9150 cfu / ml of milk, and six species belonging to five genera of fungi were isolated :
Absidia cylindrospora, Aspergillus flavus, Aspergillus terreus, Cladosporium cladosporioides, Fusarium oxysporum, Mucar hiemalis.
Second, buffalo’s milk:
The total count of fungi was 5100 cfu/ml of milk using Czapek’s dextrose agar media. Five species belonging to three genera of fungi were isolated from six samples of buffalo’s milk from different dairy shops:
Absidia corymbifera, Aspergillus flavus, Aspergillus niger, Aspergillus Ochraceus,
Cladosporium cladosporioides
the total count of fungi and yeasts using the media of Yeast Malt Extract Agar media was 14,900 cfu/ml of milk, and five species belonging to three genera of fungi were isolated
Cladosporium cladosporioides, Aspergillus terreus, Aspergillus niger, Penicillum roqueforti, Aspergillus flavus.
Third, Yoghurt
The total count of fungi was 6000 cfu/ g of yogurt using Czapek’s dextrose agar media. Six species belonging to four genera of fungi were also isolated from 10 samples of yogurt from different dairy stores, namely:
Aspergillus flavus var. Colaris ,Aspergillus niger, Aspergillus
.fumigatus, Cochliobolus lunatus, Geotrichum candidum, Rhizopus arrhizus.
the total count of fungi and yeasts using the media of Yeast Malt Extract agar was 22,125 cfu/ g of yogurt, and eight species belonging to five genera of fungi were isolated:
Aspergillu flavus, Aspergillus niger, Aspergillus fumigatus, Aspergillus terreus, Cochliobolus lumatus, Geotrichum candidum, Penicillum chrysogenum, Rhizopus arrhizus.
Fourthly, Ras cheese:
The total count of fungi was 2800 cfu/ g of cheese using Czapek’s dextrose agar media. Five species belonging to four genera of fungi were also isolated from three samples of Ras cheese from different dairy shops, namely:
Alternaria chlamydospora, Aspergillus Niger, Aspergillus Fumigatus, Eurotium repens,
Rhizopus stolonifer
the total count of fungi and yeasts in Yeast Mall Extract Agar media 1850 cfu/ g of cheese, and four species belonging to the two genera of fungi were isolated, namely:
Aspergillus fumigatus, Aspergillus niger, Aspergillus tamari, Rhizopus stolonifer
Fifthly, Requefort cheese
The total count of fungi was 1350 cfu/ g cheese using Czapek’s dextrose agar media. Four species belonging to three genera of fungi were also isolated from three samples of Requefort cheese from different dairy stores, namely:
Aspergillus niger, Aspergillus parasiticus, Penicillum requeforti, Rhizopus stolonifer
the total count of fungi and yeasts on Yeast Malt Extract agar media was 1350 cfu/ g of cheese, and four species belonging to three genera of fungi were isolated, namely:
Aspergillus niger, Fusarium solani, Penicillum roqueforti, Rhizopus stolonifer.
Sixth, Kareish cheese
The total count of fungi was 1000 cfu / g of cheese using the media of Czapek’s Dextrose Agar, as well as three species belonging to the two genera of fungi were isolated from three samples of Kareish cheese from different dairy shops :
Aspergillus niger, Aspergillus flavus, Eurotium chevalieri
the total count of fungi and yeasts on media of Malt-Extract Agar was 920 cfu/g of cheese, and two belonging to two species of fungi were isolated.
Aspergillus flavus, Eurotium chevalieri.
Seventh, Baramili cheese
The total ciunt of fungi was 450 cfu/ g of cheese using Czapek’s dextrose agar media. Two species belonging to a genus of fungi were also isolated from three samples of Barameli cheese from different dairy shops:
Aspergillus flavus, Aspergillus niger
the total count of fungi and yeasts on the malt extract agar media generated 2,400 cfu/ g of cheese, and two species of fungi belonging to two genera were isolated:
Aspergillus flavus, Eurotium amstelodami
5.4 Detection and Identification of mycotoxins from milk and dairy products:
Twenty- four of isolate of Aspergillus flavus group were isolated from milk and dairy products were tested for aflatoxins production (B1, B2, G1, G2). Out of 18 Aspergillus flavus Link isolate 14 showed positive aflatoxins production and four isolates were free from aflatoxins. Aspergillus Flavus var. columnaris Raper and Fennell recovered from
brand samples, Aspergillus parasiticus Speare recovered from Roquefort cheese, and
Aspergillus tamarii Kita isolated from ras cheese cleared positive aflatoxins production.
that 38 isolate of different Aspergillus sp. groups isolated from different dairy sources on potato dextrose agar (PDA) and yeast malt extract medium (YME) at 28±1oC were tested for aflatoxins production (B1, B2, G1, G2). Out of 24 Aspergillus niger van Tieghem, Out of 5 Aspergillus terreus Thom, Aspergillus ochraceus Wilhelm, Out of 8 Aspergillus fumigatus Fresenius and 31 isolate of different fungal groups.
Fungi represrnt one of the important sources of contamination in milk and it’s products, and a major concern for industrials and scientistis that are looking for efficient solutions to prevent or limits fungal spoilage in milk and it̕s products so This study recommended to :
Control of the chemical quality of milk and its products and be sure that they stander products.
Control of the microbiological quality of milk and dairy products by prevent different microbial contamination such as fungi.
Prevent fungi reach to milk and dairy products by using antimycotoxins .
To prevent fungi contamination, some methods can be used:(i) preventation methods include air filtration, hygiene pradices, and deoutamination systems, (ii) contral methods include temperature control, inadivation tretments and modified atmosphere packaging. (iii) bioprotective cultures, it refers to increase in food safty and extenition shelf- life using natural, or added microbiota or antimicrobial compounds.