MICROBIOLOGICAL INVESTIGATIONS ON SOME OF THE COMMERCIAL FROZEN MEAT IN İZMIR 1

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1 Turkish Electronic Journal of Biotechnology Special Issue, p:1823, 2002 Biotechnology Association MICROBIOLOGICAL INVESTIGATIONS ON SOME OF THE COMMERCIAL FROZEN MEAT IN İZMIR 1 KARABOZ, İsmail and DİNÇER, Belma Ege University, Science Faculty, Biology Department, Basic and Industrial Microbiology Section, Bornovaİzmir Turkey. Summary In this study, we investigated 35 frozen meat which commercially marketed in İzmir. We analyzed Staphylococcus aureus and Salmonella in this products and in addition that for determination of microbiological quality, amount of total mesophilic aerobic bacteria, pshycrophilic bacteria, mould and yeast, total coliform and fecal streptococcus has been achieved. It has been determined that the total number of mesophilic aerobic bacteria was between 4.4x x10 6 cfu/g, the total number of psychrophilic bacteria was between 5.1x x10 6, the total number of mould and yeast was between 7.0x x10 4 cfu/g, the total number of coliform was between 4.0x10 2 > cfu/g, the total number of fecal streptococcus was between 2.9x10 3 cfu/g and staphylococci was between 1.0x x10 4 cfu/g. 28 Salmonella spp. were isolated from the commercial frozen meat samples. Introduction Fresh meat productions are marketed after having been cooled freshly or having been frozen in a particular way. In both situations the meats need to be marketed without getting sour and been corrupted and without any change in the quality and appropriate packaging. Today, the fresh meat products are been marketed either as freshly cooled or as preserved for a while after having been frozen. The preservation process of the meat frozen is considered to be too simple in our country. Meat manufacturer think they know what to do and therefore neglect this issue. Hence, it is a must to give the necessary information about how frozen and preserved meat must be transformed, processed, marketed and consumed (1). Researches claim that the number of aerobic bacteria is a good criterion in determining the hygienic quality of meat (2). The amount of coliform bacteria in meat is important and it should not exceed certain values. This microorganisms are very good indicators concerning whether the food has been processed in hygienic conditions (1). Coagulase positive Staphylococcus aureus is a bacteria that can be dangerous particularly in meat and meat products and that is important in terms of food poisoning. 1 This work was funded by E. U Research Fund (Project No: ) 18

2 It has been emphasized in the standards and in the bylaw that Salmonella type bacteria is not to exist in food. The Salmonella bacteria isolated from the meat can be emphasized to be spread by the animals whose intestine, fertilizer skin are cut and because of the equipment used in cutting and the unhygienic and careless working (2). When meat is frozen the number of the microorganisms decreases. However, yeast and mould can reproduce at 5 o C but the reproduction stops at 10 o C. The wet surfaces occurring when meat is dissolved after it is frozen creates suitable conditions for bacteria to reproduce and increases the potential to get spoiled. Materials and Methods Materials 35 various frozen meat samples investigated in this study were collected from different markets in İzmir and transferred in sterile food bags and analyzed in the same day so that the product in ice bath won t melt. Methods After 25 g frozen meat sample had been weighed in sterile petri dishes for the counting of staphylococci, yeastmould, pshycrophilic bacteria, fecal streptococcus, total coliform and viable organisms in all experiments, they were homogenized in a blender containing sterile dilution under the aseptic conditions. The other decimal solutions were prepared from 10 1 dilutions prepared in the described way above. For the search of Salmonella 25 g frozen meat sample was prepared to be analyzed by being put in 225 ml sterile buffered water. Plate Count Agar (PCA) medium was used to determine the total bacteria number. Colony counting was carried out after the 48hour incubation at 37 o C set, by pour plate method(3). The same method used in counting total bacteria number as in pshycrophilic bacteria counting was followed except that incubation was applied at 5 o C for 7 days. Brilliant Green Lactose Bile Broth was prepared to count the total coliform bacteria and the countings were carried out through the EMS technique. For counting the yeastmould inoculations were done in a yeastmould medium containing chloramphenicol using pour plate method. The counting was carried out after the plates were incubated at 25 ± 1 o C for 35 days (TS, 6560). Glucose Azide Broth was prepared for the counting of fecal streptococcus and probable fecal streptococ number was calculated with the MPN method being used (4). In counting the Staphylococci Baird Parker Agar medium was used and the typical colonies were counted. Afterwards, to prove this some tests such as gram reaction, catalase, coagulase and KOH were applied to the typical colonies (5). In the search of Salmonella, Selenith Sisitine Broth and Bismute Sulphite Agar were used and the typical Salmonella colonies were defined. To prove this gram reaction, oxidase, gelatinase, H 2 S, urease, lactose, maltose movement and IMVIC tests were applied to this typical colonies (TS, 3446). 19

3 Results and Discussion The total mesophilic and pshycrophilic aerobic bacteria counting results obtained from 35 samples collected from some frozen meat products marketed in İzmir were given in Table1. The 80% of 35 frozen meatballs investigated according to the Turkish Standards were found to be suitable to the standards whereas the 20% weren t. All of the 35 meatball samples investigated according to ICMSF were found to be suitable to be consumed in respect of mesophilic aerobic bacteria. When similar investigations in other countries are considered, the total living organism number was found to be averagely 10 6 /g in an investigation carried out in South America in order to determine the total living organism number in 115 frozen beef and in some the number of organisms reach to 10 9 /g (6). Khalafalla et al. (1993) suggested that the total bacteria number of frozen minced meat prepared at homes was found out to be 4x10 4 8x10 6 each g while the one prepared at butchers 4x10 5 6x10 7 /g. As understood from the findings, the microbial intensity in the frozen minced meat samples prepared after having been minced at butchers was discovered to be more (7). 40 % of 35 samples investigated according to the Turkish Standards were suitable to the standards in terms of pshycrophilic bacteria whereas 60 % were not. As understood from the results in this study it was seen that the counting of total pshycrophilic bacteria is higher than that of the mesophilic aerobic bacteria. That the counting of pshycrophilic bacteria is an indicator that the rules of hygiene and sanitation were violated during the time when the food was prepared, processed and frozen. The total number of yeast and mould of 35 samples collected from among some frozen meat products ready to be consumed in İzmir is given in the Table1. Only one (2.9 %) of the 35 samples investigated was suitable to the standards whereas 34 (97.1 %) weren t when the evaluation is done on the basis of Turkish Standards. When similar studies in the world are compared Chong and Lan (1984) could not determined any mould each g but they found yeast number 1.5 x x10 7 (averagely 1.6x10 6 ) each g in the frozen beef samples (8). Reddy et al. (1990) determined that in the buffalo meat kept frozen for three months they found the yeast number 85 each g and mould number 5900 each g at the end of the first month. At the second month they found yeast number 4300 each g while yeast number 220 each g. In this study at the third month of the storage duration they could not find any mould and yeast. In our study yeast and mould found commonly is an indicator of insufficient processing. The importance of coliform goup counting for frozen food is not as geat as in water and milk. On the other hand this organisms are influenced from freezing and long term storing. In evaluating the microbiological quality of food and in controlling whether sanitation has been done properly; E. coli, enterococci and fecal streptococcus are used as indicator microorganisms (10). Only one (2.9 %) of 35 samples investigated according to the ICMSF (1978) was suitable to the standards whereas 34 (97.1 %) were not. In the study we carried out that total coliform number and the results of fecal streptococcus counting were found high is an indicator that there was insufficient sanitation caution in the plant and/or that the product was left exposed to the conditions in which unwanted microorganisms can be reproduced. Vanderline et al. (1998) found coliform number less than 2 each g in 523 samples (66.2 %) and 210 each g 143 samples (18.1 %) and each g in 174 samples (9.4 %) and more than 1000 each g 20

4 in 15 samples (1.9 %) in 790 pieces of beef imported from Australia packed as big pieces and frozen as boneless (11). Table1. mesophilic and pshycrophilic aerobic bacteria, total yeast and mould, total coliform, fecal streptococcus, Staphylococcus and Salmonella results found in 35 samples of the frozen meat products which were marketing in İzmir Fecal Stafilococcus Salmonella Sample Sample Mezophilic Aerobic Bacteria Pshycrophilic Bacteria Yeast Mould Coliform Streptococcus ı 1 Tekirdağ 1.4x x x x x x , x x x x x x x x x x x x x x İnegöl 5.1x x x x x x x x x x x x x x x x x x x x Adana 3,6x x x x x x x x x x x x x x x x x x x Coctail 1.0x x x x x x x x x x x x x x x x x x x x Shish 1.5x x x x x x x x x x x x x x x x x x x x x x Burger 6.1x x x x x

5 27 2.7x x x x x x x x x x x x x x x Home 6.4x x x x x x x x x x x x x x x x x x x10 3 The Salmonella and Staphylococci results of 35 samples collected from some frozen meat products ready to be consumed in İzmir are shown in the Table1. Pathogen Staphylococcus reproduction was found in only one of 35 samples (2.9 %) and nonpathogen Staphylococci reproduction in 34 (97.1 %) the pathogen Staphylococcus aureus reproduction in this one sample is the indicator of contamination resulted from the working stuff and their hands in processing. 22 samples of 35 samples (62.9 %) investigated according to the standards in the notification of Turkish Food Codex Meat Products issued in the numbered and 10 February 2000 dated official newspaper by Republic of Ministry of Agriculture and Rural Affairs were suitable to the given standards whereas 13 samples ( 37.1 %) were not. When compared with those of 1978 ICMSF, 27 of the samples (77.2 %) were not suitable to the standards whereas 8 of the samples (22,8 %) were. When similar studies in the world are considered Khalafalla et al. (1993) found Streptococcus number averagely 10 3 each g in the frozen minced meat prepared in the house whereas averagely 8x10 3 each g in those prepared at butchers (7). Chong and Lan (1984) found coagulase ()Streptococcus in one sample of 10 frozen beef samples (8). It is necessary that Salmonella, belonging to the pathogen bacteria group and causing diseases such as typhoid, paratyphoid and food poisoning not be found in food. Suspicious Salmonella spp. was found in 28 of 35 samples (80 %) investigated. Vanderlinde et al. (1998) found Salmonella spp. in 3 (0.38 %) of 787 big pieces of frozen and packed beef samples, which were exported from Australia (11). Chong and Lan (1984) found no Salmonella in 10 frozen beef sample in the microbiologic analysis they did (8). In the study we carried out it was determined that some frozen meat products investigated are of great risk in terms of Salmonella. 22

6 References 1. Gökalp, II. Y., Kaya, M. ve Zorba, Ö., 1977, Et Ürünleri İşleme Mühendisliği, 2.baskı, Atatürk Üniv. Yayın No: 786; Atatürk Üniv. Yayın No: 320; Atatürk Üniv. Ders Kitapları Serisi No: 70; Atatürk Üniv. Ziraat Fakültesi Ofset Tesisi, Erzurum, 561 s. 2. Gökalp, H. Y., Yetim, H. ve Kaya, M., 1987, Ticari Kuruluşlarda Dondurularak Muhafaza Edilen Tavuk Etlerinin Kokuşma Düzeyleri ve Bakteriyolojik Durumları Üzerine Bir Araştırma, Et ve Balık Endüstrisi Dergisi, 8(51): 1322s. 3. ICMSF (The International Commission on Microbiological Spesifications for Food), 1978, Microorganism in Foods,, 2 nd Edition, Universty of Toronto press, Canada, 213p. 4. Harrigan, W. F. and Mc Cance, M. E.,1976, Laboratory Methods in Food and Dairy Microbiology Academic Press. Inc. London, LTD., 10101p. 5. Kloss, W. E., Schleifer, K. and Götz, F., 1984, The Genus Staphylococcus aureus. The Bergey s Manuel of the Systematic Bacteriology 8 th. The Wilkins Comb., Baltimore, Vol: III, Chapter 63, p. 6. Göktan, D., 1990, Gıdaların Mikrobiyal Ekolojisi, Cilt I: Mikrobiyolojisi, Ege Üniv. Müh. Fak. Yayınları No: 21, Ege Üniv. Basımevi, İzmir, 292s. 7. Khalafalla, F., Gergıs, A. F. and ElSherif, A., 1993, Effect of Freezing and Mincing Technique on Microbial Load of Minced Meat, Die Nahrung, 37(5): p. 8. Chong, C. E. and Lan, Y.Q., 1984, Microbiological Quality of Fresh Chilled and Frozen Meat, Mardi Res. Bull, 12,3: p. 9. Reddy, P. M., Jatcar, V. D. and Damodar, N., 1990, A Study on Certain Quantitive and Qualitytative Characteristics of Buffalo Meat, IndianVeterinary Journal, 67(8): p. 10. Peterson, A. C. and Gunderson, M. F., 1981, The Freezing Preservation of Foods, Vol:II, Tressleri D.K., Van Arsdel, W. B. and Compley, M.J. (Eds), 3 rd Printing, The Avi Publishing Company, Inc., Westport, Connecticut, 397p. 11. Vanderlinde, P. B., Shay, B. and Murray, J., 1998, Microbiological Quality of Australian Beef Carcass Meat and Frozen Protection, 61(4): p. 23

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