الفهرس 
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Abstract
Part1: A total number of 50 smoked Herring samples and 10 samples of smoked Salmon samples were randomly collected from different markets in Alexandria Governorate, Egypt. Collected samples were separately wrapped in sterile polyethylene bags and transported to the laboratory without any delay in time to be examined for chemical and microbiological examination
1- Chemical evaluation:
1.1. pH evaluation:
The mean values of pH of smoked fish samples (Herring- Salmon) were 5.95±0.02 with a minimum value of 5.60 to a maximum value of 6.28 for smoked Herring samples and 5.98±0.06 with a minimum value of 5.65 to a maximum value of 6.20 for smoked Salmon samples, respectively. There was no significant difference for mean values at (p˂ 0.01).
1.2. Total Volatile Nitrogen (TVB-N) evaluation:
The mean values of TVB-N (mg/100g) of smoked fish samples (Herring- Salmon) were13.82±0.0.43 with a minimum value of 9.40 to a maximum value of 19.15 for smoked Herring samples and 16.80±0.68 with a minimum value of 13.56 to a maximum value of 19.20 for smoked Salmon samples, respectively. There was a significant difference for mean values at (p˂ 0.01).
1.3. Thiobarbituric acid evaluation (TBA):
The mean values of TBA (mg/kg) of smoked fish samples (Herring- Salmon) were 0.15±0.02 with a minimum value of 0.08 to a maximum value of 0.85 for smoked Herring samples and 0.30±0.04 with a minimum value of 0.10 to a maximum value of 0.51 for smoked Salmon samples, respectively. There was no significant difference for mean values at (p˂ 0.01).
1.4. Free fatty acids (FFA) evaluation:
The mean values of FFA (mg/100g) of smoked fish samples (Herring- Salmon) were 1.12±0.07 with a minimum value of 0.30 to a maximum value of 2.00 for smoked Herring samples and 1.23±0.15 with a minimum value of 0.50 to a maximum value of 1.70 for smoked Salmon samples, respectively .There was no significant difference for mean values at (p˂ 0.01).
1.5. Trimethylamine (TMA) evaluation:
The mean values of TMA (mg/100g) of smoked fish samples (Herring- Salmon) were 0.58±0.02 with a minimum value of 0.30 to a maximum value of 0.90 for smoked Herring samples and 3.98±0.24 with a minimum value of 2.50 to a maximum value of 4.80 for smoked Salmon samples, respectively. There was a significant difference for mean values at (p˂ 0.01).
2- Microbiological assesment:
2.1. Aerobic bacterial count:
The mean values of aerobic bacterial count of smoked fish samples (Herring- Salmon) were 7.38X105± 1.19X104 with a minimum value of 3.5X105 to a maximum value of 1.15X106 for smoked Herring samples and 2.04X105±9.27X103 with a minimum value of 1.8X105 to a maximum value of 2.3x105 for smoked Salmon samples, respectively.
2.2. Total Enterobacteriaceae count:
The mean values of Enterobacteriaceae count of smoked fish samples (Herring- Salmon) were 6.90X103±1.32X103 with a minimum value of 2.30X103 to a maximum value of 4.50X104 for smoked Herring samples and 6.50X103±1.16X103 with a minimum value of 2.80X103 to a maximum value of 2.00x104 for smoked Salmon samples, respectively.
2.3. Coliforms count:
The mean values of coliforms count of smoked fish samples (Herring- Salmon) were 6.87X103±1.28X103 with a minimum value of 2.50X103 to a maximum value of 1.16X104 for smoked Herring samples and 1.87X103±2.72X102 with a minimum value of 1.20X103 to a maximum value of 2.80X103 for smoked Salmon samples, respectively.
On the other hand, E.coli O157H7 could not be detected from any of examined smoked Herring and/or Salmon samples.
2.4. Yeast and mold count:
The mean values of yeast and mold count of smoked fish samples (Herring- Salmon) were 1.98X105±2.80X104 with a minimum value of 3.00X104 to a maximum value of 3.30X105 for smoked Herring samples and 2.00X104±2.05X103 with a minimum value of 4.00X102 to a maximum value of 7.80X104 for smoked Salmon samples, respectively.
2.5. Proteolytic count:
The mean values of proteolytic count of smoked fish samples (Herring- Salmon) were 1.28X104±2.10X102 with a minimum value of 1.00X104 to a maximum value of 4.00X104 for smoked Herring samples and 1.73X104±5.12X103 with a minimum value of 6.00X103 to a maximum value of 3.00X104 for smoked Salmon samples, respectively.
Part 2:
Firstly, whole fish samples were infected with a dose at range 105 of Vibrio parahaemolyticus with different numbers as 5X105±0.86X105, 5.2X105±0.77X105, 5.3X105±0.80X105 and 5.7X105±0.78X105 for control samples, 1% treated samples, 2% treated samples and 3 % treated samples, respectively.
After that we observed the Vibrio count at specific periods as the counts for the first 6 hours were 5.8X105±0.89X105, 6.4X105±0.92X105, 5.4X105±0.93X105 and 5.9X105±0.09X105 with a difference percent in relation to initial dose +16%, +23%, +2% and +3% for control samples, 1% treated samples, 2% treated samples and 3 % treated samples, respectively.
After 12 hours vibrio counts were 3.4X105±1.39X105, 5.38X105±0.91X105, 5.1X105±1.02X105 and4.92X105±0.76X105 with a difference percent in relation to initial dose -32%, +3%, - 4% and – 14% for control samples, 1% treated samples, 2% treated samples and 3 % treated samples, respectively.
After 24 hours vibrio counts were 5.6X105±1.03X105, 4.3X105±0.77X105, 3.1X105±0.58X105 and 1.22X105±0.50X105 with a difference percent in relation to initial dose +12%, - 18%, - 42% and -21% for control samples, 1% treated samples, 2% treated samples and 3 % treated samples, respectively.
After 3 days vibrio counts were 12.8X105±1.56X105, 3X105±0.77X105, 2.4X105±0.51X105 and 3.5X104±1.3X104 with a difference percent in relation to initial dose +56%, -43 %, - 55% and – 93.86% for control samples, 1% treated samples, 2% treated samples and 3 % treated samples, respectively.
Then after 6 days vibrio counts were 9.08X105±5.02X105, 1.75X105±0.26X105, 7X104±0.7X104 and 1.8X103±0.63X103 with a difference percent in relation to initial dose +81%, - 66%, - 87% and -99.8% for control samples, 1% treated samples, 2% treated samples and 3 % treated samples, respectively.
Finally after 9 days of storage vibrio counts were 13.1X105±7.68X105, 9.4X104±0.30X104, 5X104±0.7X104 and 2.3X102±0.53X102 with a difference percent in relation to initial dose +62%, - 82%, - 91% and – 99.96% for control samples, 1% treated samples, 2% treated samples and 3 % treated samples, respectively.
According to the previous results, we observed that the counts of 1% treated samples and 2% treated samples were very near, but the 3 % treated samples were the best result and the best effect.
Finally, the present study deducted that Moringa oleifera is a good effective preservative substance against many microbes especially Vibrio species.