الفهرس 
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Abstract
Food safety, particularly in relation to its microbiological quality, has become a major issue worldwide. Food-associated disease caused by food-poisoning bacteria has a huge economic and human consequence. Food preservation prevents deteriorative reaction, extending the shelf life and assuring its safety. The uses of chemical preservatives have harmful effects in long term application. So the use of next generation of food preservation materials derived from natural plants with antimicrobial activity instead of chemical preservatives are many advantages.
The results of the experiments which were conducted could be summarized as follows:
One hundred and ninety (190) raw material and swab samples were investigated for their load of spoilage and pathogenic bacteria. Which included 40 raw material samples ( 10 sesame, 10 tomato fruits, 10 coca, 10 strawberry) , 60 production line steps samples (10 sesame after wash with tap water,10 sesame after heat treatment, 10 tomato fruits after wash with tap water, 10 tomato juice after heat treatment, 10 strawberry fruits after wash with tap water, 10 straw berry fruits after heat treatment) and 90 cotton swaps samples from production line and worker ( 10 sesame production line, 20 worker swap from sesame production line, 10 tomato production line, 20 worker swab from tomato production line, 10 jam production line. 20 worker swab from jam production line).
The total aerobic bacterial count of raw material samples showed that, the contamination positive samples ranged from 100% to 20% according to the type of raw material samples. Higher incidence percentage was observed in sesame and cocoa contained the lowest incidence percentage.
As well as, the highest contamination samples with E. coli; were observed in sesame with percentages 100%. While, cocoa samples exhibited lower contamination percentages.
Salmonella spp was found in low level contamination of raw material samples. where is contamination percentage ranged from 100%, 60%, 0% and 70% according to the type of raw material samples of sesame, tomato, cocoa and strawberry respectively, where cocoa samples exhibited lowest contamination level with S. typhimruium.
On the other hand, the obtained results showed that, the raw material samples were contaminated with Gram positive bacteria, Staph. aureus.
The higher contamination percentage samples were obtained for sesame with incidence percentages 100%, tomato incidence percentages were 100%.strawberry incidence percentages were 100%. While cocoa contained the lowest contamination level with 0%.
The obtained total aerobic bacterial count of production line steps samples showed that, the contamination positive samples ranged from 100% to 40% according to the type of production line steps samples. Higher average log no. was observed in Sesame after wash with tap water (STW), and Jam after heat treatment (JH) contained the lowest average log no.
As well as, the highest contamination samples with E. coli; were observed in Sesame after wash with tap water (STW) with average log no. 7.07 cfu/g. While, Jam after heat treatment (JH) samples exhibited lower contamination average log no.
The average log no., of E. coli were 2.69,2.65 and 2.47 cfu/g according to the type of surface cotton swap samples
Salmonella spp was found in low level contamination of production line steps samples. where is contamination percentage ranged from 100%,40%, 60%, 20%,50% and 0% according to the type of production line steps samples of sesame after wash with tap water, sesame after heat treatment, tomato after wash with tap water, tomato after heat treatment, strawberry after wash with tap water and strawberry after heat treatment samples respectively.
On the other hand, the obtained results showed that, the production line steps samples were contaminated with Gram positive bacteria, Staph. aureus. The higher contamination percentage samples were obtained for sesame after wash with tap tomato after wash with tap water strawberry after wash with tap water with incidence percentages 100%. While tomato after heat treatment strawberry after heat treatment contained the lowest contamination level with 0%.
The obtained total bacterial count ranged from 3.3 cfu/ml to 3.17 cfu/ml according to the type of surface cotton swab samples. Surface swaps from sesame production line the highest record of total bacterial count while, Surface swab from jam production line contained the lowest ones. And the average log no., of total bacterial count ranged from 1.95 cfu/ml to 1.47 according to type of worker cotton swap samples worker swab from sesame production line the highest record of total bacterial count while, worker swab from jam production line contained the lowest ones..
The average log no., of E. coli were 2.69 and 2.47 cfu/g according to the type of surface cotton swap samples and the average log no., of E. coli were 1.27 and 1.11 cfu/g according to the type of worker cotton swap samples.
Salmonella spp; Results cannot detected in all cotton swap samples as a surface swaps from production line samples or worker swaps from production line samples.
On the other hand, the obtained results showed that, the cotton swap samples were contaminated with Gram positive bacteria, Staph. aureus. The contamination percentages were 80%, 50%, 40%, 40%, 30% and 40% of Surface swaps from sesame production line, Surface swaps from tomato production line, Surface swaps from jam production line, worker swaps from sesame production line, worker swaps from tomato production line and worker swaps from jam production line samples respectively.
The isolated bacteria were identified according to morphological and biochemical tests and then the identification were confirmed by MICROBACT system.
The total isolates of E.coli (87) isolates with (30),(36)and (21) isolates in raw material, production steps and cotton swaps samples respectively.Staph. aureaus (86) isolates with (30),(32)and (28) isolates in raw material, production steps and cotton swaps samples respectively. Salmonella (50) isolates with (23) and (27) isolates in raw material and production steps and samples respectively.
In this study most of the tested plants extracts showed antibacterial activities against Gram positive and Gram negative tested foodborne bacteria. 2 plants extracts had tested for antibacterial activities ( Olea europaea and Bauhinia variegate)
The olive aqueous leaf extracts showed good inhibitory effects on pathogenic bacteria with average diameter and standard error of inhibition zones, 17.33±0.83, 19.45±0.54 and 13.6±0.83 for E.coli, S.arueus and Salmonella respectively.
On the other hand pathogenic bacteria was 100% resistance to the bauhinia aqueous extract (Bauhinia variegate) with no inhibition zone.
The ethanol olive leaf extracts showed good inhibitory effects on pathogenic bacteria with average diameter and standard error of inhibition zones, 21.2±0.36, 24±0.34 and 19.85±0.56 for E.coli, S.arueus and S. typhimruium respectively.
Also the ethanol bauhinia leaf extracts showed good inhibitory effects on pathogenic bacteria with average diameter and standard error of inhibition zones, 19.2±0.85, 22.65±0.61 and 18.33±0.46 for E.coli, S.arueus and S. typhimruium respectively.
The (MIC) is defined as the lowest concentration of a drug/compound that will inhibit the visible growth of an organism in vitro after overnight incubation. Based on the previous our results most tested foodborne bacteria were sensitive in low concentrations of olive aqueous leaf extracts.
In the presence of aqueousl extract of Olea europaea at lowest concentration 50 mg/ ml got the highest inhibition for Salmonella and Staphylococcus arueus. While E.coli required more milligram 60 mg/ml of aqueous extract for highest inhibition.
The results showed the (MICs) values of ethanol extract of Olea europaea the growth of tested foodborne associated bacteria.
In the presence of ethanol extract of Olea europaea at lowest concentration 30 mg/ ml and 50 mg/ml got the highest inhibition for Staphylococcus arueus and Salmonella respectively. While E.coli required more milligram 60 mg/ml of ethanol extract for highest inhibition.