الفهرس 
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Abstract
Twenty samples including 2 (brands A & B) of locally produced processed cheese, (each of 10 samples) were collected at the day of production from 2 different factories (A & B) and were stored under room temperature (25 - 30°C) and chilling temperature (5 -8°C) untill the end of the expiration date which was written out side the package (6 months). The samples were examined organoleptically, chemically and microbiologically at the day of production, then monthly till the deteriorative changes were detected organoletically.
The mean overall score (20, overall score points) value of organoleptic evaluation of fresh brand A processed cheese samples was 16.05, while the mean overall score value of brand B fresh samples was 15.05. The mean overall score values of organoleptic evaluation of both brands A & B during storage at room temperature were 13.05 & 13.05 (at 1st month) 11.65 & 10.00 (at the 2nd month), 9.08 & 7.75 (at 3rd month) and 6.50 & 5.30 (at the 4th month) of storage, respectivley. During storage at chilling temperature, the mean overall score values of organoleptic evaluation of brand A processed cheese samples
after 1st, 2nd, -rd, 4th and 5th month of storage were : 13.90, 12.85, 11.45, 8.35 and 5.85, respectively. While the mean overall score values of organoleptic evaluation of brand B samples during storage at 5 - 8°C were : 14.15, 11.95, 9.75 and 7.00 after 1st, 2nd, 3rd
and 4th month of storage, respectively. The mean pH value of (brand A) processed cheese samples obtained at the day of manufacture was 5.59 but in case of (brand B) fresh samples was 5.79. The mean pH values of (brand A) samples during storage at 25 -30°C were 5.65, 5.73, 5.78 and 5.88 after 1st, 2nd, 3rd and 4th month of storage, respectively.
While the mean pH values of (brand A) samples during storage at 5-8°C were 5.60, 5.67, 5.76, 5.83 and 5.91 after 1st, 2nd, 31d, 4th and 5th month of storage respectively.
In case of (brand B) processed cheese samples, the mean pH values during storage at both room and chilling temperatures were : 5 . 87 & 5.80, 5.92 & 5.84, 6.04 & 5.95 and 6.08 & 5.99 after 1st, rd, 3rd and 4th month of storage, respectively. The mean values of TVN for both (brands A & B) processed cheese obtained at the day of manufacture were 7.10 and 9.10, respectively. The mean values of TVN for both (brands A & B) during storage at 25 - 30°C were : 12.30 & 15.60 (after 1st month), 16.90 & 22.10 (after 2nd month), 25.00 & 30.60 (after 3rd month) and 33.20 & 37.60 after 4th month of storage, respectively.
The mean values of TVN during storage at chilling temperature for (brand A) & (brand B) were : 10.00 & 12.80; 13.80 & 17.70; 20.70& 24.80 and 27.20 & 32.10 after 1st, 2nd, 3rd and 4th month of storage, respectively. While, after the 5th month of storage (brand A) processed cheese samples, the mean TVN value was 32.50.
The mean value of TBA of fresh processed cheese samples for (brand A) was 0.025, while for (brand B) was 0.055. At room temperature, the mean value of TBA of (brand A) processed cheese samples were : 0.093, 0.135, 0.249 and 0.372 while, the mean value of TBA for (brand B) samples were : 0.115, 0.192, 0.297 and 0.390 after 0, 2nd, 3rd and 4th month of storage, respectively. The mean values of TBA during storage at 5-8°C for (brand A) samples after 1st, 2nd, -rd, 4th and 5th months of storage were : 0.077, 0.116, 0.210, 0.290 and 0.357 respectively. During storage the (brand B) at 5-8°C, the mean TBA values were 0.098, 0.157, 0.249 and 0.347 after 1st, 2nd, 3rd & 4th months’ of storage
respectively. The mean values of TVFA of fresh samples of (brand A) and (brand B) were 20.00 & 25.70, respectively. The mean value of TVFA for (brand A) processed cheese samples during storage at room and chilling temperatures after 1st, 2nd, 3rd and 4th month of storage were : 47.10 & 37.40; 64.40 & 55.30; 91.70 & 78.10
and 118.30 & 100.10, respectively. After 5 months of storage, the mean value of TVFA for (brand A) was 128.00. After 1st, 2nd 3rd and 4th a 4 month of storage at 25 - 30°C the mean values of TVFA for (brand B) were : 55.30, 77.40, 111.40 and 133.70 respectively, while during storage at 5-8°C, the mean values of TVFA of the same brand and same period of examination were : 46.00, 65.20, 97.40 and 118.60, respectively.
The mean values of APC of processed cheese samples obtained at the day of manufacture for (brand A & B) were 3.24 x 103 cfu/g and 3.05 x 103 cfu/g, respectively.
The mean values of APC for (brand A) samples during storage at room temperature were 1.43 x 104 cfu/g (after 1St month), 3.05 x 105 cfu/g (after 2nd, month), 7.68 x 105 cfu/g (after 3rd month) and 3.44 x 107 cfu after 4th months of storage, while for (brand B) samples, the mean values of APC were : 1.11 x 105, 2.10 x 106, 1.37 x 107 and 1.88 x 108 cfu/g after
1st, 2nd, 3rd and 4th months of storage, respectively. During storage at chilling temperature, the mean values of APC of (brand A) samples after 1st, 2nd, -rd,
3 4th and 5th month of storage were 1.03 x 104, 1.39 x 105, 3.21 x 105, 7.83 x 106 and 2.36 x 107 cfu/g, respectively. The mean values of APC for (brand B) processed cheese samples were : 1.04 x 105, 5.80 x 105, 3.63 x 106 and 3.47 x 107 cfu/g,
respectivley after 1st, 2nd, 3rd — and 4th month of storage at chilling temperature. For fresh samples of processed cheese (brand A), the mean value of thermophilic bacteria was 5.72 x 102 cfu/g while for (brand B) was 6.29 x 103 cfu/g. The mean values of thermophilic bacteria for (brand A) processed cheese samples during storage at room temperature were : 2.78 x 103, 7.28 x 104, 8.52 x 104 and 2.38 x 106 cfu/g after 1St, 2nd, 3rd and 4th months
of storage respectively. The mean values of thermophilic bacteria for (brand A) samples during storage at chilling temperature were 7.72 x 102, 2.88 x 104, 6.89 x 104, 3.50 x 105 and 1.13 x 107 cfu/g after 1st, 2nd, ,rd, t 4h- and 5th months of storage, respectively.
While, for (brand B), the mean values of thermophilic bacteria during storage at (25 -30°C) after 1st, 2nd , and 4th months of storage were: 6.17 x 104, 1.52 x 105, 1.27 x 106 and 3.54 x 106 cfu/g, respectively. After 1st, 2nd, 3rd and 4th months of storage at (5-8°C), the mean values of thermophilic bacteria for (brand B) processed cheese samples were 4.24 x 104, 7.05 x 104, 6.03 x 105 and 3.35 x 106 cfu/g, respectively. The mean values of aerobic spore formers bacteria for (brand A) & (brand B) processed cheese samples obtained at the day of manufacture were 8.50 x 102 & 5.11 x 103 cfu/g, respectively.
During storage at 25 - 30°C, the mean value of aerobic spore -formers bacteira for both brands (A & B) processed cheese samples were 1.42 x 103 & 2.47 x 104 cfu/g (after 1st month), 2.00 x 104 & 4.14 x 105 The mean values of total mycotic count of (brand A) processed cheese samples during storage at chilling temperature were 1.88 x 102, 6.83 x 103, 4.48 x 104, 2.68 x 105 cfu/g and 7.38 x 106 after 1st, 2nd, 3rd, 4th and 5th month of storage, respectivley. At chilling temperature, the mean values of total mycotic counts for (brand B) processed cheese samples were 8.73 x 103, 1.73 x 104, 2.66 2nd, — X 104 and 3.77 x 105 cfu/g after 1st, 2 3rd and 4th months of storage, respectively.
The analysis of variance (F-test) for chemical and microbial characters of the examined processed cheese samples of the two brands at zero time and during storage at different temperatures and times were adopted and showed that in most cases there were significant differences between the investigated parameters.