BACTERIOLOGICAL STUDY ON RABBIT MEAT

BACTERIOLOGICAL STUDY ON RABBIT MEAT

Elsaid A.Eldaly ;Rasha M. El-Bayomi ; Abdallah F.A. Mahmoud and Rania H.M.A.Shata

Department of Food control, Faculty of Veterinary Medicine, Zagazig University, Egypt

Key Words:Enterobacteriaceae, Pseudomonas, Psychrotrophic, Rabbit meat.

ABSTRACT

Rabbit meat is increasingly valued for its nutritional characteristics; it is a lean meat with a low fat, cholesterol content and of less saturated fatty acids than any other meats. Rabbit meat is thought to be a safe product since it has not been involved in outbreaks of foodborne disease. Despite this fact; rabbit can carry food-poisoning organisms derived from multiple sources. These pathogens can result in many cases of food poisoning. Therefore, the present study was conducted to evaluate the bacteriological quality of rabbit meat in MitGhamr City, Dakahlia Governorate, through determination of Enterobacteriaceae, pseudomonas, and psychrotrophic count. The obtained results revealed that the Enterobacteriaceae counts in the fresh thigh and back meat samples were ranged from 3 to 5 and 4.23 to 5.53 log10cfu/g with mean values of 3.98 ± 0.103 and 4.79 ± 0.094 log10cfu/g respectively, Pseudomonas counts in the fresh thigh and back meat samples were ranged from 4.70 to 7.46 and 5 to 7.38 log10cfu/g with mean values of 5.90 ± 0.134and 5.98 ± 0.124 log10cfu/g respectively, and the Psychrotrophes counts in the fresh thigh and back meat samples were ranged from 4.08 to 7.20 and 4.70 to 6.95 log10cfu/g with mean values of 5.67 ±   0.154 and 6.10 ± 0.101 log10cfu/g respectively.

INTRODUCTION

Rabbit is thought to be an ideal meat-producing animal for having short life cycle, short pregnancy period, gestation interval and it is very productive with high feed conversion rate. Also it is characterized by a relatively low cost of production and less space needed for breeding (Lebaset al. 1997). Moreover, rabbit skin has an economic value for fur production and it is one of the most important experimental animals. Rabbits are unique among food animals. Their reproduction cycle is short, their growth rate is fast and their fertility rate is high. They are easy to transport and do not cost too much transportation. Rabbits produce white meat that is fine grained, high in protein, low in cholesterol and fat, and rich in vitamins and minerals (DalleZotte, 2002).Rabbit meat is juicy, delicious of high nutritive value along withthe production of fur, hair, and leather .According toDalleZotte  2002, amount of water (g), protein(g), lipid(g), energy(kj), cholesterol(mg),sodium(mg),vit B 12(mg) in 100 g of rabbit meat are 70.8, 21.3, 6.8, 618, 45, 37–47, and 8.7–11.9 subsequently.Rabbit meat is thought to be the healthiest most nutritious meat known to mankind. If you are a health conscious, a weight watcher and like to build muscles, rabbit meat can certainly help to optimize your diet.it is often recommended by nutritionists over other meat types. Theincorporation of rabbit meat in human diet would promote human health as it is a lean meat rich in protein of high biological value with high level of unsaturated fat, phosphorous, vitamin B and low content of cholesterol, sodium (Hernández and Gondret2006).

rabbit meat is thought to be a safe product since it  has not been involved in outbreaks of foodborne disease ( DalleZotte, 2002).Despite this fact, rabbit can carry food-poisoning organisms derived from multiple sources (skin, gut contents, feces, workers ,abattoir environment,  cutting and packaging processes, and handling at the retail level). And subsequently spoilage will occur as a result of microbial action (Hulot and Ouhayoun, 1999).There are two dominant sources of bacteria causing foodborne diseases in meat. The living animal carries pathogenic bacteria, while the processing environment harbors them(Badr, 2004).At the point of arrival at slaughter house, rabbits have considerable amount of microorganisms associated with them. Micro biota present on carcass surfaces may arise from the rabbit itself, especially from the fur or skin, the feet, the digestive tract and fecal contamination. Moreover, carcasses can be contaminated throughout the whole process from transport, slaughter till processing. The degree of carcass contamination depends on the cleanliness of incoming rabbit, the slaughter plant structural design (ex. the separation between clean and dirty areas), the slaughter technology, the sanitation and disinfection system, and hygiene (e.x. personnel hygiene) (Zweifelet al. (2014).Each processing step from animal slaughtering till consumption will add microbes to the primary bacterial count and subsequently lower the keeping quality of meat. In a healthy living rabbit, muscles are sterile. However, many microbes harbor the digestive tract, lungs, skin, etc. Throughout slaughtering and evisceration, contamination of muscle tissue with a variable number of microorganisms can occur due to an increase in microbial count coming from the gastrointestinal tract (Rougeret al. (2017).

Psychrotrophic bacteria develop on meat products at chill temperatures. They belong to microbial genera of both gram positive, such as lactic acid bacteria, and gram-negative bacteria, such as Pseudomonas spp. and Enterobacteriaceae(Ercoliniet al., 2009). Pseudomonas species are the major causative spoilage bacteria in meat, primarily due to their metabolic versatility and ability to produce extracellular proteases and lipases cause oxidation, color change, off‐flavor, slimy form and animal tissues degradation (Doulgeraki et al. 2012).  The undesirable Presence of enterobacteriaceae in meat is used as an indicator of fecal contamination and poor hygiene during processing and storage. Its appearance within the meat of slaughtered rabbits may be due to the fact that the external part of animals and lower gastrointestinal tract harbor massive numbers of bacteria which accidently may be relocated to the surface of meat during evisceration and dressing (Görner and Valík (2004).

Keeping the above view, the present study was planned to evaluate the bacteriological quality of rabbit meat in MitGhamr City, Dakahlia Governorate.

MATERIALS AND METHOD

Collection of samples:

A total of fifty healthy domestic rabbits (10 weeks of age, around 2 kg live weight) were collected from Dakahlia Governorate and slaughtered manually under hygienic conditions. Meat samples were taken from the thigh and back. All samples were transferred under complete a septicconditionsto Food Control lab for,bacteriological examination.

Preparation of samples:

According toAPHA (2001).

Determination of total psychrotrophic count:

On standard plate count agar (Oxiod CM325) according to APHA (2002)

Determination of Pseudomonas count:

On Pseudomonas Agar Base (CM 559; Oxoid) supplemented with cetrimide, fucidin, and cephaloridine (CFC) supplements according to Roberts and Greenwood (2003).

Determination of Enterobacteriaceae count:

On violet red bile glucose agar (VRBG) agar according to ISO21528-2 (2004).

Statistical analysis

One way analysis of variance (ANOVA) was done by using the statistical package for social sciences (SPSS-14; Chicago, IL, USA). Statistical significance was evaluated using tukey-kramer honestly significant difference tests with p < 0.05.

RESULTS

Results illustrated in Table (1,2,3) revealed that the Enterobacteriaceae counts in the fresh thigh and back meat samples were ranged from 3 to 5 and 4.23 to 5.53 log10cfu/g with mean values of 3.98 ± 0.103 and 4.79 ± 0.094 log10cfu/g respectively, Pseudomonas counts in the fresh thigh and back meat samples were ranged from 4.70 to 7.46 and 5 to 7.38 log10cfu/g with mean values of 5.90 ± 0.134and 5.98 ± 0.124 log10cfu/g respectively, and the Psychrotrophes counts in the fresh thigh and back meat samples were ranged from 4.08 to 7.20 and 4.70 to 6.95 log10cfu/g with mean values of 5.67 ±   0.154 and 6.10 ± 0.101 log10cfu/g respectively.

Table (1): Statistical analytical results of Enterobacteriaceae count in thigh and back muscles of the examined rabbit samples (log₁₀ CFU/g)

Table (2): Statistical analytical results of Pseudomonas count in thigh and back muscles of the examined rabbit samples (log₁₀ CFU/g)

Table (3): Statistical analytical results of Psychrotrophic count in thigh and back muscles of the examined rabbit samples (log₁₀ CFU/g)

CFU/g: Colony forming unit per gram

No: Number of examined samples (50 of each sample)

S.E: Standard error of mean

Means are not significantly different (p > 0.05)

DISCUSSION

Enterobacteriaceaein meat is used as an indicator of fecal contamination and poor hygiene during processing and storage.Lower results were obtained by Khalafalla (1993) who mentioned that the Enterobacteriaceae count of the freshly slaughtered rabbits was 6 x 10²   ±  10 ² organisms per gram, Rodriguez - Calleja et al. (2005) who found that the Initial values (log cfu/g) of Enterobacteriaceae was 0.49   ± 0.45,Soultos et al. (2009) who mentioned that Enterobacteriaceae count was  (1.3 ± 0.38 log cfu/cm2 ), Pereira and Malfeito-Ferreira (2015)  who reported that mean value ± standard deviation (log CFU g-1) of  Enterobacteriaceae was 1.18± 1.35,Cwiková and Pytel (2017) who recorded that the Enterobacteriaceae count in samples from butcher shops, domestic slaughtered carcasses, and  in frozen ones were 2.91 log CFU.g-1 , 1.47 log CFU.g-1  , 1.36 log CFU.g-1 respectively, and Cullere et al . (2018) who found that enterobacteriaceae count (CFU Log10) of LTL muscle at day 1 of shelf-life of Pannon White rabbits (Hungary) fed on a diet containing 3% sunflower oil or another  diet having 3% linseed oil were 0.70 for both.

Pseudomonas spp., are used as general indicators of processing hygiene, storage conditions and spoilage in meat industries. It is an important meat spoilage indicator as nitrogenous compounds, including primary, secondary, tertiary amines and others, are released. Lower results were obtained by Khalafalla(1993) who mentioned that the Pseudomonas count of the freshly slaughtered rabbits was 3 x 10²  ±   10² organisms per gram , Rodriguez - Callejaet al. (2005) who found that the Initial values (log cfu/g) of Pseudomonas was 3.39 ± 1.12,Soultoset al. (2009) who mentioned that Pseudomonas count was  (3.6 ± 0.40 log cfu/cm2), Pereira and Malfeito-Ferreira  (2015)  who reported that Mean value ± standard deviation (log CFU g-1) of  Pseudomonas was 2.68 ± 0.85, who counted Pseudomonas numbers (log CFU/g) in rabbit thighs at day 0 and found The average values was 1.03±0.38,  and Cullereet al . (2018) who found that Pseudomonas count (CFU Log10) of LTL muscle at day 1 of shelf-life of Pannon White rabbits (Hungary) fed on a diet containing 3% sunflower oil or another  diet having 3% linseed oil were 3.00  and 1.70 respectively.

Psychrotrophic bacteria are capable of surviving in extremely cold environment. They provide an estimation of the shelf life of meat. Significance differences were detected between the examined samples (P ˂ 0.05). The variation in counts may be attributed to improper handling and poor sanitation level during the processing steps and storage. Such results were nearly similar to those reported by Rodriguez - Callejaet al. (2005) who found that the initial values (log cfu/g) of psychrotrophic bacteria was 4.81 ± 0.81, Cwiková and Pytel (2017) who recorded that the psychrotrophic count in samples from butcher shops were 4.98 log CFU.g-1.  However, Lower results were obtained by Pereira and Malfeito-Ferreira  (2015)  whoreported that Mean value ± standard deviation (log CFU g-1) of  psychrotrophic was 3.63 ± 0.86, and Cwiková and Pytel (2017) who recorded that  psychrotrophic count in samples from home slaughtered rabbits were 2.52 log CFU.g-1.

The variation in the count may be attributed to the difference in hygienic level during slaughtering, processing, packaging and transportation which may include secondary contamination of carcasses originating from air, used tools, containers, from animal skin and fur and from packaging materials, containers.

REFERENCES

APHA (2001): American Public Health Association:Compendium of methods for the microbiological examination of foods (4th Ed.). APHA technical committee on microbiological methods for foods. Washington, D.C., USA.

APHA (2002): American Public Health Association:Methods for the microbiological examination of foods. 4th Ed., Technical Committee on Microbiological Methods for Foods. Washington, D.C., USA.

Badr, H. M. (2004). Use of irradiation to control foodborne pathogens and extend the refrigerated market life of rabbit meat. Meat Science, 67(4): 541-548

Cullere, M. ;A.DalleZotte ;G.Tasoniero ;V.Giaccone ;Z.Szendrő ;M. SzínandZ. Matics (2018). Effect of diet and packaging system on the microbial status, pH, color and sensory traits of rabbit meat evaluated during chilled storage. Meat Science, 141: 36-43.‏

Cwiková, O.andR. Pytel (2017).Evaluation of rabbit meat microbiota from the viewpoint of marketing method. Potravinárstvo: Slovak Journal of Food Sciences, 11(1): 391-397.

DalleZotte, A. (2002).Perception of rabbit meat quality and major factors influencing the rabbit carcass and meat quality. Livestock Production Science, 75(1): 11-32.

Doulgeraki, A.I.; D.Ercolini ; F. Villani and G.J.E. Nychas(2012): Spoilage microbiota associated to the storage of raw meat in different conditions. Int. J. Food Microbiol., 157: 130– 141.

Ercolini, D.; F.Russo; N. Antonella; P. Ferranti and F. Villani (2009): Mesophilic and Psychrotrophic Bacteria from Meat and Their Spoilage Potential In Vitro and in Beef. Appl Environ Microbiol., 75(7): 1990–2001.

Görner, F. and L. Valík(2004).Applied food microbiology.(Aplikovanámikrobiológiapoživatín). Bratislava, Slovakia :Malé Centrum, PPA. 528 p. ISBN 80-967064-9-7.

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Hulot, F.andJ. Ouhayoun (1999).Muscular pH and related traits in rabbits: a review. In World Rabbit Science (Vol. 7, No. 1).World Rabbit Science.ICTA.UPV.

ISO21528-2 (2004): Microbiology of food and animal feeding stuffs. Horizontal method for the detection and enumeration of Enterobacteriacae,  part 2: colony count method. Enumeration. EN ISO, Geneva.

Khalafalla, F. A. (1993). Microbiological status of rabbit carcases in Egypt. ZeitschriftfürLebensmittel-Untersuchung und Forschung, 196(3): 233-235.

Lebas, F. ;P.Coudert ; R.Rouvier andH. De Rochambeau (1997). The Rabbit: husbandry, health, and production. Rome: Food and Agriculture organization of the United Nations.

Pereira, M.andM. Malfeito-Ferreira (2015).A simple method to evaluate the shelf life of refrigerated rabbit meat. Food control, 49, 70-74.

Roberts, D. and M. Greenwood (2003): Practical food microbiology. 3rd edition. Blackwell Publishing Ltd, UK. 273-274.

Rodríguez-Calleja, J.M. ;M.L.García-López ; J.A. Santos andA. Otero (2005).Development of the aerobic spoilage flora of chilled rabbit meat. Meat Science, 70(2): 389-394.

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دراسة بکتیریولوجیة عن لحوم الارانب

السعید الدالی ، رشا محمد البیومی ، عبدالله فکری عبدالله محمود ،

 رانیا محمد أحمد شطا

قسم مراقبة الاغذیة – کلیة الطب البیطری – جامعة الزقازیق

تتسم لحوم الأرانب بأنها ذات قیمة غذائیة عالیة ؛ حیث أنها غنیة بالأحماض الدهنیةالغیرالمشبعة،الفوسفور, والبروتینات عالیة القیمة التی تتمیزبمحتوى عال من الأحماض الأمینیة الأساسیة. علاوة على ذلک فان لحوم الأرانب تشکل  مصدر هامللمعادن والفیتامینات خاصة فیتامین ب، فیتامین ب 12. وجدیر بالذکر، فان لحوم الأرانب لا تحتوى على حمض الیوریک. 

یُعتقد أن لحم الأرانب هو أکثر اللحوم الصحیة المعروفة للبشریة وغالبا ما ینصح به خبراء التغذیة.بالمقارنة مع أنواع اللحوم الأخرى ، تحتوی لحوم الأرانب على کمیة أقل من الأحماض الدهنیة المشبعة والدهون (6.8 جم / 100 جرام من اللحوم الطازجة) ، والسعرات الحراریة (618 کیلو جول / 100 جرام من اللحوم الطازجة) وأدنى مستوی من الکولیسترول  (53 مغ / 100 جرام من اللحوم الطازجة) و الصودیوم کما أنه یحتوى على  10 أضعاف کمیة البوتاسیوم الموجودة باللحوم الأخرى و أیضا نسبة جیدة من أومیغا 3: أومیغا 6 (5.9) . وبالتالی ، فلحوم الأرانب مناسبة للغایة لمرضى القلب ، وارتفاع ضغط الدم ، والنظام الغذائی للمسنین ، والوجبات الغذائیة منخفضة الصودیوم ، والوجبات الغذائیة المخصصة لخفض الوزن ، إلخ.

تتعرض الأرانب أثناء ذبحها وتجهیزها ونقلها للتلوث بمختلف المیکروبات التی تؤدی إلی فسادها  وبعض التغیرات الکیمیائیة  کتحلل البروتین والتزنخ مما یشکل خطرا علی  سلامة منتجات الأرانب وصحة الإنسان  لذلک إتجهت أنظار العالم إلی تحسین الإنتاج الحیوانى ووصول لحومها إلی المستهلک فی حالة جیدة وخالیة من المیکروبات للحصول علی منتج عالی الجودة.

أجریت هذه الدراسة على خمسین من الأرانب المنزلیة  التى تم تجمیعها من محافظة الدقهلیة وذبحها یدویًا فی ظروف صحیة. تم أخذ عینات اللحم من عضلات الفخذ والظهر. تم فحص العینات المجمعة  بکتریولوجیًا.

وکشفت النتائج التی تم الحصول علیها على أن تعداد البکتیریاالمعویة فی عینات الفخذ والظهر الطازجة تراوحت بین 3 إلى 5 , 4.23 إلى 5.53مع متوسط ​​قیم 3.99 ± 0.103 , 4.79 ± 0.094على التوالی.

فى حین کان تعدادالسیدوموناسفی عیناتالفخذ والظهر الطازجة 4.70 إلى 7.46 , من 5 إلى 7.38مع متوسط ​​قیم 5.90 ± 0.134 , 5.98 ± 0.124على التوالی.

تراوحت أعداد البکتیریا المحبة للبرودة فی عینات الفخذ والظهر الطازجة من 4.08 إلى 7.20 , 4.70 إلى 6.95مع متوسط ​​قیم 5.67 ± 0.154 , 6.10 ± 0.101على التوالی.