الفهرس 
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Abstract
One hundred Ras cheese samples were collected from supermarkets, street vendors and different localities ah Alexandria Governorates. The obtained samples were collected as sold to the public and transferred as soon as possible to the laboratory to be examined mycologically and to detect incidence and concentration of mycotoxins in both surface and core, respectively.
The second part of the study was measuring the antifungal effect of Ethanolic Extracted Propolis when applied by spraying on the surface of manufactured Ras cheese blocks.
7.1. Compositional quality evaluation of Ras cheese samples:
7.1.1. Acidity percent:
The acidity percent of examined Ras cheese samples ranged between 0.6 and 4.05 with a mean value of 1.59 ± 0.51. There is no regulation regarding the acidity percent of Ras cheese.
7.1.2. Salt content:
The salt content in the surface of examined Ras cheese samples was varied between 4.14 and 5.06 g/100gm with a mean value of 4.5±0.08. While, the salt content in the core of examined samples was varied between 4.07 and 4.85 g/100gm with a mean value of 4.47±0.078. No regulations concerning the amount of added salts to Ras cheese.
7.2. Mycological evaluation of examined Ras cheese samples:
7.2.1. Yeast count:
The incidence percent of contaminated ras cheese samples with yeasts were 54% and 70% with a mean count of 7.5× 106 ± 1.1× 106 and 5.8× 10⁴± 1.04× 10⁴ for surface and core, respectively.
According to ES(1007-5/20015): which stipulated that Ras cheese should not contain more than 100 cfu/g of yeast. All positive samples were not complied with the established limit.
7.2.2. Mould count:
The incidence rate of contaminated Ras cheese samples with mould were 59% and 56% with total moulds count ranging between 2.0×10⁴ to 3.0×106 with a mean count of 4.9 × 105 ± 0.83 × 105 cfu and 1.0×10³ to 1.03×105 with a mean count of 6.33 × 10³ ± 1.9 × 10³ cfu for surface and core, respectively.
According to Es: (1007-5/2005) which stipulated that Ras cheese should not contain more than 10cfu/g of mould. All positive samples were not complied with established limit for mould.
7.2.3. Isolated moulds from the examined dairy products:
The frequency of distribution of mould isolated from examined Ras cheese for surface and core samples were Absidia cormbifera 0 (0%) and 2 (1.25%), Acremoium spp. 1 ( 0.6%) and 0 ( 0%), Alternaria alternate spp. 7( 4.29% ) and 5 ( 3.12%), Aspergilus niger 27 (16.5% ) and 26 (16.25%), A. flavus 13 (7.97% ) and 17 (10.6%), A. fumigatus 0 ( 0%) and 5 (3.12%), A. ochraceus 6 (3.68%) and 1 (0.62%), A. candidus 5 (3.06) and 1 (0.62%), A. terreus 1 (0.6%) and 0 (0%), A. nodulans 1 (0.6%) and 0 (0%), Chatmeom spp. 3 ( 1.84%) and 0 (0%), Cladosporium 30 (18.4%) and 24 (15%), Geotricum candidum 1 (0.62%) and 2 (1.25%), Mucor spp 9 ( 5.5%) and 15 (9.37%), Paeciliomyces 2 (1.22% ) and 2 (1.25%), Penicillium spp 53 (32.5%) and 58 ( 36.25%), Rhizopus spp 4 (2.45%) and 2(1.25%), respectively.
7.3. Determination of aflatoxin residues in the examined pooled Ras cheese samples:
The results showed that AFM1 could be detected in both cuts ranging between 0.197 to 2.355 ppb and from 0.171 to 0.309 ppb with an incidence of 41.66 % and 16.6% for surface and core, respectively. Also, AFM2 has been detected in the surface of pooled Ras cheese samples ranging between 0.284 to 1.007 ppb with an incidence of 25% but has not been detected in the core of pooled samples. AFB1, AFB2, AFG1and AFG2 residues in surface of pooled samples ranged between 0.047 to 0.926; 0.060 to 0.542; 0.135 to 0.289 and 0.071 ppm, with an incidence of 33.3%, 25%, 16.6 % and 8.3 %respectively. While, AFB1, AFB2, AFG1and AFG2 residues in the core of pooled cheese were ranging between 0.218 to 0.767; 0.149 to 0.325; 0.066 to 0.110 ppb and G2 was not detected in the core samples and the incidence percent were 33.3%, 16.6%, 16.6% and 0%, respectively. Ochratoxin A has been detected ranging between 0.693 to 1.508 ppb and only detected in the group number 9 of core with a concentration of 0.118 ppm. The incidence percent were 16.6% and 8.33% for surface and core, respectively.
7.4. Antifungal effect of Ethanolic Extracted propolis on manufactured Ras cheese blocks:
Ethanolic extracted propolis had no significant inhibitory effect on growth and multiplication of yeasts even the highest EEP concentration (750 ppm) did not show any inhibitory effect on yeast.In contrast, EEP has a slight inhibitory effect on total mould count of Ras cheese block treated with 250 ppm concentration which decreased from 0.1×104 ± 0.05× 104 to 6×103 ± 0.03× 103. While, the 500 ppm EEP showed inhibitory effect on total mould count till the 30th day after treatment reaching to a total mould count 0.15×104 ± 0.02×104 and then the resistance of mould has been severely declined and a clear fungicidal effect has been obvious. Also, the highest concentration of EEP (750 ppm) showed a strong fungicidal effect on the total mould count since the 45th day after treatment . Control block showed an increasing mould count started from day one till the 60th day.
The isolated mould species from cheese blocks before treatment were Penicillium spp, Geotricum, Cladsporium, A. niger and mucor. In 250 ppm EEP treated block the isolated mould species in 15th , 30th and 45th days of ripening were Penicillium, Cladosporium, Alternaria and A. fumigatus. While at 60th day the only detected species were Penicillium and A. fumigatus. For higher concentration treated blocks with 500 and 750 ppm EEP the only isolated mould species throughout the first 30 days of ripening were Penicillium species only and then all mould count has been eradicated.