Bacteriological Profile Of Frozen Broiler Chickens

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49

BACTERIOLOGICAL PROFILE OF FROZEN BROILER CHICKENS H. A. Abdel-Rahman1, M.A. Yassein1, A.M. Ahmed1, H. Hayashidani2 and A. E. Elhelaly1* 1. Dept. Food Hygiene and Control, Fac. Vet. Med., Suez Canal Univ., Ismailai, Egypt. 2. Dept. Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan

ABSTRACT A total of 122 (67 imported and 55 locally processed) frozen broiler chicken samples in a form of whole carcasses, wings, legs and breast pieces were purchased from different retail outlets at Tokyo area, Japan, for bacteriological assessment. The means of total aerobic counts (TAC), S. aureus counts and MPN of coliforms in the imported and locally processed broiler chicken meat were (4.10±0.91 and 4.77±0.22), (2.03±0.10 and 2.27±0.13) and (1.94±0.14 and 2.46±0.16) log CFU/g, respectively, with average values in all the examined samples of 4.43±0.55, 2.13±0.11 and 2.20±0.15 log CFU/g. The counts in the locally processed chicken meat were found to be significantly higher than that in the imported ones. Frozen broiler chicken meat was proved to show lower profiles of microbiological contamination than the fresh ones, moreover, the imported broiler meats to Japan were proved to be of low microbial profile in comparison to the locally produced ones. The study reinforces the importance of hygienic measures adopted during production, retailing and handling of chicken meat as well as the importance of freezing as a method of preservation. INTRODUCTION Poultry meat is an important human food item due to its contribution in solving the problem of animal protein shortage and it contains

high amount of protein, many vitamins and minerals (Mountney, 1966). ---------------------------------------------* Corresponding author. Mailing address: Department of Food Hygiene and Control, Faculty of Vet. Medicine, Suez Canal University, Ismailia, Egypt. E-mail: [email protected], [email protected]

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Abdel-Rahman et al.,

Broiler chicken meat and its products are liable to contamination with various kinds of spoilage microorganisms from different sources (Mehlman and Romero, 1982). Such contamination may render the chicken meat unsafe to consumer or impair its quality. Aerobic plate count is a commonly recommended microbiological method for estimating the food shelf life. Coliforms and Enterococci are commonly predominant in the fecal matters and used as indicators for potential fecal contamination of foods. E. coli and S. aureus could be used as indicators for the contamination of broiler by pathogens (ICMSF, 1986). Few researches were conducted to evaluate the bacteriological conditions of the frozen chicken carcasses, unlike the fresh ones.

Therefore, the present study was designed to evaluate some bacteriological quality parameters of the frozen broiler chickens sold at Japanese markets. MATERIALS & METHODS 1. Sample collection: A total of 122 imported and locally processed frozen broiler samples were purchased at Tokyo area, Japan. Samples classification is shown in Table (1). Samples were immediately transferred in an ice box container to the Laboratory of Veterinary Hygiene, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology for bacteriological evaluation.

Table (1): Classification of the collected broiler chicken meat samples. Sample type

Imported

Locally processed

Total

Whole carcass

40

21

61

Wing

7

11

18

Leg

11

11

22

Breast

9

12

21

Total

67

55

122

2. Preparation of samples: Broiler samples were left packaged in fridge for thawing, at 4ºC for

18 and 12 hours for whole carcasses and parts, respectively as method recommended by FDA (2001). 25±0.5 grams composite meat sample with its

SCVMJ, XIII (1) 2008 covering skin layer were aseptically excised and transferred into stomacher bag containing 225 ml sterile 0.1 % (w/v) buffered peptone water (BPW) whereas homogenized using a Stomacher 400 Lab Blender (Seward Medical, London, UK) for 2 minutes to obtain the original homogenate fluid of a dilution rate; (10-1). From the original homogenate, tenth fold serial dilutions of up to 10-5 were then prepared. 3. Microbiological analysis: A. Total Aerobic Counts (TAC): It was carried out according to APHA (1992) using surface spreading method where 0.2 ml aliquots of the sample homogenate, at selected dilutions, were spread onto duplicate sterile plates of prepared and well dried Standard Plate Count agar (Nissui) and incubated at 35°C for 48 hr. Colonies between “25-250” were counted and the total aerobic colony counts were then expressed as log CFU/ gram. B. Staphylococcus aureus counts: Carried out according to Kitai et al. (2005) by transferring and even spreading of 0.2 ml from the prepared tenth-fold serial dilutions of each sample onto Mannitol salt agar (Nissui)

51 supplemented with 3 % fresh egg yolk emulsion and incubation at 37°C for 48 hours. Characteristic colonies of yellow color surrounded by yellow zone with egg-yolk factor positive were calculated and recorded as presumptive countable S. aureus count log CFU/g of chicken meat. Counts less than 50 CFU/g were uncountable. 1~5 colonies were picked up and purified on another Mannitol salt agar plate for morphological and biochemical confirmation by Gram staining and biochemical tests. C. Most Probable Number (MPN) of Coliforms: The most precise type of the MPN series is used in this study according to Kokubo (2004), which depend upon using the 5:5:5 series of tubes using ES Coliblue broth medium (EIKEN) which after inoculation by the sample dilutions, were incubated at 37 oC for 24 h. To confirm presumptive results, a loopful from the positive broth tubes was streaked on Levine's Eosine Methylene Blue (EMB) agar (Nissui) and incubated at 37oC for 24 hours. Mucoid and atypical colonies were confirmed as coliform organisms and green shiny colonies were confirmed as E. coli colonies.

52

Abdel-Rahman et al.,

RESULTS: Table (1): Mean counts (log CFU/g) of the examined microorganisms in the imported and locally processed samples. Product origin

S. aureus count

Coliform MPN

4.10±0.91

2.03±0.10a

1.94±0.14a

67

4.77±0.22b**

2.27±0.13b**

2.46±0.16b*

122

4.43±0.55

2.13±0.11

2.20±0.15

Samples No.

TAC

Imported

55

Locally processed Total

a

- Mean counts with the different letters are significantly different. - (*) indicate significant differences (P≤ 0.05). - (**) indicate highly significant differences (P≤ 0.01). Table (2): The mean counts (log CFU/g) in different sample types of imported chicken meat. Samples

Samples No.

TAC

S. aureus count

MPN Coliforms

Whole

40

3.78 ± 0.126

2.09 ± 0.061

2.17 ± 0.089

Wing

7

5.07 ± 0.120

1.93 ± 0.153

1.90 ± 0.206

Leg

11

3.75 ± 0.118

2.15 ± 0.064

1.81 ± 0.067

Breast

9

3.80 ± 0.067

1.94 ± 0.113

1.90 ± 0.180

Total

67

4.10 ± 0.907

2.03 ± 0.10

1.94 ± 0.14

Table (3): The mean counts (log CFU/g) in different sample types of locally processed chicken meat. Samples

Samples No.

TAC

S. aureus count

MPN Coliforms

Whole

21

5.18 ± 0.128

2.20 ±0.093

4.51 ± 0.105

Wing

11

4.51 ± 0.190

2.12 ± 0.089

4.21 ± 0.170

Leg

11

5.07 ± 0.320

2.35 ± 0.184

4.62 ± 0.174

Breast

12

4.31 ± 0.313

2.40 ± 0.143

4.49 ± 0.206

Total

55

4.77± 0.22

2.27 ± 0.13

4.46 ± 0.16

SCVMJ, XIII (1) 2008

53

5.40

Imported

5.20

Local

5.00 4.80

TAC (log CFU/g)

4.60 4.40 4.20 4.00 3.80 3.60 3.40

a

3.20

b**

a

a

a

b**

a

b*

3.00 Whole

Wing

Sample type

2.90

Leg

Breast

2.90

Imported 2.70

Count (log CFU/g)

Count (log CFU/g)

2.50 2.30 2.10 1.90 1.70

Imported 2.70

Local

a

a

a

a

a

b**

a

a

1.50

Local

2.50 2.30 2.10 1.90 1.70

a

a

a

b*

a

b**

a

b*

1.50

Whole

Wing

Leg

Breast

Sam ple type

Whole

Wing

Leg

Sam ple type

Breast

Figure (1): Statistical analytical results of the TAC (a), S. aureus counts (b) and MPN of Coliforms (C) (log/g) in different sample types of the examined chicken meat. - Column pairs with the same letters are not significantly different. - Column pairs with the different letters are significantly different. - (*) indicate significant differences (P≤ 0.05). - (**) indicate highly significant differences (P≤ 0.01).

54

Abdel-Rahman et al.,

Table (4): Frequency distribution results in the examined chicken meat. Interval (log CFU/g)

TAC Imported

Local

Interval S. aureus count (log CFU/g) Imported Local

F

%

F

%

F

< 1.7

0

0.0

0

0.0

1.7 ~ 6

67

100 46 83.6

>6

0

0.0

9

16.4

>2

Total

67

100 55

100

Total

< 1.7

%

F

Interval (log CFU/g)

%

100

55 100

Local

%

F

%

<2

35

52.2

12

21.8

≥2 ~ 3

29

43.3

28

50.9

>3

3

4.5

15

27.3

Total

67

100

55

89

19 28.4 20 36.4 67

Imported F

34 50.8 18 32.7

1.7 ~ 2 14 20.9 17 30.9

MPN Coliforms

Table (5): Mean counts of the TAC, S. aureus counts and MPN of Coliforms (log/g) in different sample types of the examined chicken meat.

TAC

S. aureus count

MPN Coliforms

Samples Imported

Local

Imported

Local

Imported

Local

Whole

3.78 ± 0.126 5.18 ± 0.128 2.09 ± 0.061 2.20 ±0.093 2.17 ± 0.089 2.51 ± 0.105

Wing

5.07 ± 0.120 4.51 ± 0.190 1.93 ± 0.153 2.12 ± 0.089 1.90 ± 0.206 2.21 ± 0.170

Leg

3.75 ± 0.118 5.07 ± 0.320 2.15 ± 0.064 2.35 ± 0.184 1.81 ± 0.067 2.62 ± 0.174

Breast

3.80 ± 0.067 4.31 ± 0.313 1.94 ± 0.113 2.40 ± 0.143 1.90 ± 0.180 2.49 ± 0.206

Total

4.10 ± 0.907 4.77 ± 0.221

2.03 ± 0.10

2.27 ± 0.13

3.94 ± 0.14

4.46 ± 0.16

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55

90.0 80.0 70.0

81.0

81.8

Imported Local

72.7

65.0

67.3

60.0

49.3

50.0

%

42.9

40.0 30.0

18.2

20.0

22.225.0

10.0 0.0 Whole

Wing

Leg

Breast

Total

Sample type

Figure (2): Prevalence of countable S. aureus in imported and locally processed samples.

DISCUSSION Spoilage bacteria are suggested as potential indicators of food quality. These indicator bacteria including coliforms, E. coli and S. aureus are part of the normal intestinal flora of poultry which could be spread among the processed carcasses even under good processing practices (FAO/WHO, 1979). TAC is accepted to be the most important microbial group associated with raw food as indicator for wholesomeness. The mean counts of TAC,

S. aureus counts and MPN of Coliform counts shown in Table (1) revealed that all of the means in the locally processed samples were higher than that in the imported ones at different degrees of significance. At the level of sample types, there was an evidence of higher counts of the examined organisms in the locally processed samples than the imported ones at different degrees of significance (Tables, 2 &3 and Figure 1) especially in cases of

56 chicken parts than whole carcass samples (Table, 5). This contamination may be considered as indicator for the degree of sanitation during handling, processing, packaging and transportation or during storage and retailing in supermarkets. The higher counts of TAC, S. aureus counts and MPN of Coliforms in the examined locally processed chicken meat than that found in the imported may be attributed to the better hygienic standards under which the imported chickens are produced or due to the inhibitory effect of freezing because of longer freeze storage periods (2~6 months) in the imported chicken than the locally processed ones (1 day ~ 3 months). This theory compiles with Lambert et al., (1991), Roberts et al., (1998), Yammamoto and Harris, (2001) and Gill (2002), who stated that, the number of viable bacteria tends to decline with prolonged frozen storage where, during frozen storage some viable bacteria are killed, while others may only sublethally damaged and can recover when thawing. These differences in counts may also reflect the dissimilarity in the slaughtering and processing procedures between imported and locally processed. Relatively higher counts than that found in this study were recorded by Abu-Ruwaida

Abdel-Rahman et al., et al. (1994), Altalhi and Albashan (2004) and Ahmed and Dalia (2005). The standards stipulated by the guidelines of PHLS (2000) stated that the TAC and S. aureus in raw chickens should not exceed 6 and 2 log CFU/g, respectively. According to these standards, and regarding the frequency distribution results of TAC shown in Table 4, 100 % of the examined imported chickens were within this limit while 83.6 % of the locally processed were within this limit and 16.4 % are higher than that acceptable limit. Regarding the frequency distribution results of the S. aureus in raw chickens (Table, 4) and according to these standards, 28.4 % and 36.4 % of the imported and locally processed chickens, respectively, were higher than that limit. The food should be regarded as unwholesome when it has a large number of microorganisms, even if they were not known to be pathogens and they had not altered the meat character (Elliot and Michener, 1961). The prevalence rates of S. aureus found in this study are shown in Figure (2) which revealed that, countable S. aureus were prevalent in the examined imported and locally processed samples at levels of 49.3 % and 67.3 %. Other recorded rates were by other authors are variable; 43.1 % (Manso et at., 1987), 40–75 % (El-

SCVMJ, XIII (1) 2008 Leithy & Rashad, 1989), 71 % (Mead et al., 1993), 23.4%–39.5% (Vorster et al., 1994), 35 to 92.7 % (Waldroup, 1996), 0 to 23 % (Abd El-Monem and Saad, 1999) and 71.4 % to 85.7 % (Ahmed and Dalia, 2005). Similar results in Japan were reported by Kitai et al. (2005) who isolated S. aureus from 65.8 % of the chicken samples. Reported counts by other authors are also very variable; 2.3–3 log CFU/g (Mead et al., 1993), 4.1 log CFU/g (Abu-Ruwaida et al., 1994) and 0~3 log CFU/cm2 (Anonymous, 1996). These variations may be attributed to the variations in sample size, stage of production sampled, hygienic measures applied and methodology used as well as the country where the samples collected. The presence of S. aureus in foods commonly indicates contamination that may be directly introduced into the food by workers from skin, hair and hands that contain S. aureus, or by sneezing or coughing (Jay, 1986). The frequency distributions of MPN of coliforms in the imported and locally processed chickens illustrated in Table (4) revealed that the highest frequency distribution (52.3 %) in the examined imported samples lied within the range of “< 2 log CFU/g”, while, in locally processed samples (50.9 %) lied within the range of “≥2 ~ 3 log CFU/g”. Generally, these

57 relatively low Coliform counts in the examined frozen samples were relatively lower than that reported by Álvarez-Astorga et al. (2002); 3.56 log CFU/g. Other authors reported lower counts than the results recorded in this study; 2.7–3.8 log CFU/g (Mead et al., 1993), 4.1–4.9 log CFU/g (Abu-Ruwaida et al., 1994), 2.98 log CFU/cm2 (Izat et al., 1989) and 3.13 log CFU/cm2 (Fliss et al., 1991). These variations may be also attributed to variation in the sample types (carcass or portions, fresh or frozen) of chicken meat, the methodology used and the place where samples collected. The Presence of Coliforms in the food points at the unsatisfactory sanitary conditions of slaughtering and processing in the plants as they are indicative of fecal pollution either from workers and/or poultry (Cruickshank et al., 1970). From the obtained results it can be concluded that, frozen broiler chicken meat, both imported to Japan and locally processed showed variations in their bacteriological profiles regarding the TAC, S. aureus counts and Coliform counts, where the imported broiler revealed lower microbial level than the locally produced ones. These variations may reflect the differences in the standards of hygiene

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Sultan Qaboos University, J. Scientific Research, 9(2): 51-64. The examined microorga- Al-Mohizea, I.S.; Mashhadi, A.S.; nisms were proved to survive freezing Fawwal, A. and Al-Shalhat, A. but in lower counts than that pre- (1994): Microbiological and shelf life viously recorded in fresh chicken meat. assessment of chilled eviscerated Based on these results, consumers and whole chicken broilers in Saudi producers should follow safety guid- Arabia. Br. Poult. Sci., 35(4): 519-526. elines and hygienic measures in han- Álvarez-Astorga, M.; Capita, R.; dling and preparation of it. The pres- Alonso-Calleja, C.; Moreno, B. and ent study indicates also that proper García-Fernández, M.C. (2002): Microbiological quality of retail chifreezing of chicken meat can significantly reduce the risk of spoilage cken by-products in Spain. Meat Science, 62: 45–50. bacteria. APHA; American Public Health REFERENCES: Association (1992): Compendium of ExaAbu-Ruwaida, A.S.; Sawaya, W.N.; Methods for the Microbiological rd Dashti, B.H.; Murard, M. and Al- mination of Foods, 3 ed. APHA, Othman, H.A. (1994): Microbio- Washington, DC, USA. logical quality of broilers during Anonymous (1996): Nationwide broprocessing in a modern commercial iler chicken microbiological baseline slaughterhouse in Kuwait. J. Food data collection program. USDA-FSIS. Cruickshank, R.; Duguid, J.P.; Prot., 57: 887-892. Ahmed, A.M. and Dalia, M.H. Marmion, B.P. and Swain, R.H.A. th (2005): Indicators and pathogenic (1970): Medical Microbiology. 11 bacteria on freshly processed broilers Ed., Churchill, Livingstone, Edinbfrom the poultry abattoir and shops. urgh, London and New York. 2nd International Scientific Confer- Elliott, R. P. and Michener, H. D. (1961): Microbiological Standards and ence, Qena & Luxor, Egypt. Abd El-Monem, Kh.M. and Saad, Handling Codes for Chilled and FroS.M. (1999): Contamination of zen Foods. A Review. App. Env. dressed broilers with enterotoxigenic Micr., 9(5): 452-468. Staphylococcus aureus during proc- El-Leithy, M.A. and Rashad, F.M. essing. Vet. Med. J., Giza, 47(1): 1-10. (1989): Bacteriological studies on Altalhi, A. and Albashan, M. (2004): ground meat and its products. Archiv Bacteriological study of frozen meat für Lebensmittelhygiene, 40: 49. in Taif governorate in Saudi Arabia. adopted during handling, processing and freeze storage from farm to table.

SCVMJ, XIII (1) 2008 FAO/WHO (1979): Microbiological Criteria for Foods. Report of a Joint FAO/WHO Working Group on Microbiological Criteria for Foods, WHO, Geneva. FDA (2001): U.S. Food and Drug Administration Bacteriological Analytical Manual, 8th Ed., Revision A, 1998. Chapter 1, Available [online] at: http://vm.cfsan.fda.gov/~ebam/bamtoc.html. Fliss, L.; Simard, R.E. and Ettriki, A. (1991): Microbiological quality of different fresh meat species in Tuniian slaughterhouses and markets. J. Food Prot., 54: 773. Gill, C.O. (2002): Microbial Control with Cold Temperatures. In: V.K. Juneja and Sofos, J.N., Control of Foodborne Microorganisms. Marcel Dekker, Inc. New York. ICMSF (1986): Microorganisms in Foods 2. Sampling for microbiological analysis: Principles and Specific Applications. 2nd ed., International Commission on Microbiological Specifications for Foods. Blackwell Scientific Publications, Oxford. Izat, A.L.; Colberg, M.; Adams, M.H.; Reiber, M.A. and Waldroup, P.W. (1989): Production and processing studies to reduce the incidence of Salmonellae on commercial Broilers. J. Food Prot., 52: 670-673. Jay, J. (1986): Staphylococcal Gastroenteritis. In Modern Food Micro-

59 biology (3rd ed.), Van Nostrand Reinhold, New York. Kitai, S.; Shimizu, A.; Kawano, J.; Sato, E.; Nakano, C.; Kitagawa, H.; Fujio, K.; Matsumura, K.; Yasuda, R. and Inamoto, T. (2005): Prevalence and characterization of Staphylococcus aureus and enterotoxigenic S. aureus in retail raw chicken meat throughout Japan. J Vet. Med. Sci., 67(3): 269-274. Kokubo, Y. (2004): Coliform, fecal coliform and Escherichia coli, P129145. In Terao, M. (ed.): Standard Methods for food Hygiene, Volume of Microbiology. Japan Food Hygiene Association, Tokyo, Japan. Lambert, A.D.; Smith, J.P. and Dodds, K.L. (1991): Shelf life extension and microbiological safety of meat-A review. Food Micr., 8: 267297. Manso, R.; Pérez, M.L.; Delgado, M.J.; González, B.; Fernández-Cuesta, D.; León, M.P. and Moreno, E. (1987): Bacteriological study of refrigerated chicken carcasses. Alimentaria, 185: 11. Mead, G.C.; Hudson, W.R. and Hinton, M.H. (1993): Microbiological survey of five poultry processing plants in the UK. Br. Poult. Sci., 34(3): 497-503. Mehlman, I.J. and Romero, A. (1982): Enteropathogenic Escherichia coli methods for recovery from foods. Food Tech., 36(3): 73.

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‫‪Abdel-Rahman et al.,‬‬ ‫‪Vorster, S.M.; Greebe, R.P. and‬‬ ‫‪Nortje, G.L. (1994): Incidence of Sta‬‬‫‪phylococcus aureus and Escherichia‬‬ ‫‪coli in ground beef, broilers and pro‬‬‫‪cessed meat in Pretoria, South Africa.‬‬ ‫‪Journal of Food Protection, 57(4):‬‬ ‫‪305-310.‬‬ ‫‪Waldroup, A. L. (1996): Contamin‬‬‫‪ation of raw poultry with pathogens.‬‬ ‫‪World’s Poult. Sci. J., 52: 7–25.‬‬ ‫‪Yammamoto, S.A. and Harris, L.J.‬‬ ‫‪(2001): The effects of freezing and‬‬ ‫‪thawing on the survival of Escherichia‬‬ ‫‪coli O157:H7 in apple juice. Intern‬‬‫‪ational Journal of Food Microbiology,‬‬ ‫‪67: 89–96.‬‬

‫‪Mountney, G.J. (1966): Poultry Pro‬‬‫‪ducts Technology. AVI, Westport,‬‬ ‫‪Connecticut.‬‬ ‫‪PHLS (2000): Guidelines for the‬‬ ‫‪microbiological quality of some ready‬‬‫‪to-eat foods sampled at the point of‬‬ ‫‪sale. Comm. Dis. and Public Health,‬‬ ‫‪3(3): 163-167.‬‬ ‫‪Roberts, T.A., Pitt, J.I., Farkas, J.‬‬ ‫‪and Grau, F.H. (eds.) (1998): Micro‬‬‫‪organisms in Foods 6: Microbial‬‬ ‫‪ecology of food commodities. Inter‬‬‫‪national Commission on Microbiol‬‬‫‪ogical Specifications for Foods. Blac‬‬‫‪kie Academic & Professional, London.‬‬

‫اﻟﻤﻠﺨﺺ اﻟﻌﺮﺑﻰ‬ ‫اﻟﺼﻮرة اﻟﺒﻜﺘﻴﺮﻳﻮﻟﻮﺟﻴﺔ ﻟﺪﺟﺎج اﻟﺘﺴﻤﻴﻦ اﻟﻤﺠﻤﺪ‬ ‫ﺣﺴﻨﻰ ﻋﺒﺪاﻟﻠﻄﻴﻒ ﻋﺒﺪ اﻟﺮﺣﻤﻦ و ﻣﻜﺮم أﺣﻤﺪ ﻳﺲ و ﻋﻠﻰ ﻣﻌﻮض أﺣﻤﺪ و هﻴﺪﻳﻜﻰ هﻴﺎﺷﻴﺪاﻧﻰ‬ ‫وﻋﺒﺪاﻟﻌﻈﻴﻢ اﻟﺴﻴﺪ اﻟﻬﻼﻟﻰ‬ ‫ﻗﺴﻢ اﻟﺮﻗﺎﺑﺔ اﻟﺼﺤﻴﺔ ﻋﻠﻰ اﻷﻏﺬﻳﺔ ‪ .‬آﻠﻴﺔ اﻟﻄﺐ اﻟﺒﻴﻄﺮى‪ .‬ﺟﺎﻣﻌﺔ ﻗﻨﺎة اﻟﺴﻮﻳﺲ ‪ .‬اﻷﺳﻤﺎﻋﻴﻠﻴﺔ‪ .‬ﻣﺼﺮ‬ ‫ﻗﺴﻢ اﻟﻄﺐ اﻟﺒﻴﻄﺮى ‪ .‬آﻠﻴﺔ اﻟﺰراﻋﺔ ‪ .‬ﺟﺎﻣﻌﺔ ﻃﻮآﻴﻮ ﻟﻠﺰراﻋﺔ واﻟﺘﻜﻨﻮﻟﻮﺟﻴﺎ‪ .‬ﻃﻮآﻴﻮ‪ .‬اﻟﻴﺎﺑﺎن‬ ‫أﺟــﺮﻳﺖ هــﺬﻩ اﻟﺪراﺳـــﺔ ﻋﻠـــﻰ ﻋـــﺪد ‪ ١٢٢‬ﻋﻴﻨﺔ ﻋﺸﻮاﺋﻴﺔ ﻣﻦ ﻟﺤﻮم ذﺑﺎﺋﺢ دﺟﺎج اﻟﺘﺴﻤﻴﻦ‬ ‫اﻟﻤﺠﻤﺪة ) ‪ ٦٧‬ﻣﺴﺘﻮردة و‪ ٥٥‬ﻣﻨﺘﺠﺔ ﻣﺤﻠﻴﺎ( ﻣﻦ ﻣﺨﺘﻠﻒ اﻟﻘﻄﻌﻴﺎت )أﺟﻨﺤﺔ ‪ ،‬أرﺟﻞ ‪ ،‬ﺻﺪور ‪ ،‬ذﺑﺎﺋﺢ‬ ‫آﺎﻣﻠﺔ( وذﻟﻚ ﻟﻔﺤﺺ ﺑﻌﺾ اﻟﺨﻮاص اﻟﺒﻜﺘﻴﺮﻳﻮﻟﻮﺟﻴﺔ ﻓﻲ ﻟﺤﻮم ﺑﺪارى اﻟﺘﺴﻤﻴﻦ ﺑﺄﺳﻮاق ﻣﻨﻄﻘﺔ ﻃﻮآﻴﻮ‬ ‫ﺑﺎﻟﻴﺎﺑﺎن‪ .‬أوﺿﺤﺖ اﻟﻨﺘﺎﺋﺞ ﻓﻲ هﺬﻩ اﻟﺪراﺳﺔ أن ﻣﺘﻮﺳﻂ اﻟﻌﺪ اﻟﻜﻠﻰ ﻟﻠﻤﻴﻜﺮوﺑﺎت اﻟﻬﻮاﺋﻴﺔ و ﻣﻴﻜﺮوﺑﺎت‬ ‫اﻟﻤﻜﻮر اﻟﻌﻨﻘﻮدى اﻟﺬهﺒﻰ و ﻣﺘﻮﺳﻂ اﻟﻌﺪد اﻷآﺜﺮ اﺣﺘﻤﺎﻻ) ‪ ( MPN‬ﻟﻠﻤﻴﻜﺮوﺑﺎت اﻟﻘﻮﻟﻮﻧﻴﺔ ﻓﻲ ﻋﻴﻨﺎت‬ ‫اﻟﺪﺟﺎج اﻟﻤﺠﻤﺪ اﻟﻤﺴﺘﻮرد واﻟﻤﻨﺘﺞ ﻣﺤﻠﻴﺎ هﻰ ‪ :‬ﻟﻮﻏﺎرﻳﺘﻢ )ﻟﻮ( )‪ ٤٫١‬و ‪ (٤٫٧٧‬و )‪ ٢٫٠٣‬و ‪ (٢٫٢٧‬و‬ ‫)‪ ١٫٩٤‬و ‪ (٢٫٤٦‬ﺧﻠﻴﺔ ﺑﻜﺘﻴﺮﻳﺔ‪ /‬ﺟﻢ ﻋﻠﻰ اﻟﺘﻮاﻟﻰ ﺑﻤﺘﻮﺳﻂ ﻋﺎم ﻟﻮ ) ‪ ٤٫٤٣‬و ‪ ٢٫١٣‬و ‪ (٢٫٢٠‬ﻋﻠﻰ‬ ‫ﻣﺴﺘﻮى ﺟﻤﻴﻊ اﻟﻌﻴﻨﺎت اﻟﻤﺨﺘﺒﺮة‪ .‬وﻗﺪ ﺗﺒﻴﻦ أن ﻧﺘﺎﺋﺞ اﻟﻌﺪ اﻟﺒﻜﺘﻴﺮى ﻓﻰ ﻋﻴﻨﺎت اﻟﺪﺟﺎج اﻟﻤﻨﺘﺞ ﻣﺤﻠﻴﺎ آﺎﻧﺖ‬ ‫اﻋﻠﻰ ﻣﻨﻬﺎ ﻓﻰ اﻟﻌﻴﻨﺎت اﻟﻤﺴﺘﻮردة‪ .‬وﻗﺪ أﺛﺒﺘﺖ اﻟﻨﺘﺎﺋﺞ أن اﻟﻌﺪ اﻟﺒﻜﺘﻴﺮى ﻟﻠﺪﺟﺎج اﻟﻤﺠﻤﺪ اﻗﻞ ﻣﻨﻬﺎ ﻓﻰ اﻟﻨﺘﺎﺋﺞ‬ ‫اﻟﻤﺴﺠﻠﺔ ﻓﻰ اﻟﺪﺟﺎج اﻟﻄﺎزج وهﻮ ﻣﺎ أآﺪ ﻋﻠﻰ اهﻤﻴﺔ اﻟﺘﺠﻤﻴﺪ آﻮﺳﻴﻠﺔ ﺣﻔﻆ ﻟﻠﺤﻮم اﻟﺪﺟﺎج‪ .‬وأآﺪت ﻧﺘﺎﺋﺞ هﺬﻩ‬ ‫اﻟﺪراﺳﺔ أﻳﻀﺎ ﻋﻠﻰ أهﻤﻴﺔ اﻹﺟﺮاءات اﻟﺼﺤﻴﺔ اﻟﻮاﺟﺐ ﻣﺮاﻋﺎﺗﻬﺎ ﻓﻲ ﻣﺠﺎزر و ﻣﺼﺎﻧﻊ إﻧﺘﺎج ﻟﺤﻮم‬ ‫اﻟﺪواﺟﻦ ﺑﺎﻹﺿﺎﻓﺔ إﻟﻰ اﻟﺘﺨﺰﻳﻦ اﻟﺠﻴﺪ واﻟﺘﻌﺎﻣﻞ ﺑﻄﺮﻳﻘﺔ ﺻﺤﻴﺔ ﻣﻊ ﻟﺤﻮم اﻟﺪﺟﺎج اﻟﻤﺠﻤﺪة ﻟﺘﺠﻨﺐ ﻣﺨﺎﻃﺮ‬ ‫ﺗﻌﺮﺿﻬﺎ ﻟﻠﺘﻠﻮث ﺑﺎﻟﺒﻜﺘﻴﺮﻳﺎ اﻟﻤﻤﺮﺿﺔ أو ﺗﻠﻚ اﻟﻤﺴﺒﺒﺔ ﻟﻔﺴﺎد اﻷﻏﺬﻳﺔ‪.‬‬