You are here

Analysis of the insemination of the mesophilic and psychrotrophic microflora of frozen fish

The article presents the results of research on the dehiscence of frozen fish with mesophilic and psychrotrophic microflora. Physico-chemical and organoleptic changes which appear in fish during refrigeration are connected with the life of the psychotropic group of microflora, which is more active than mesophilic. Fish are a nutrient medium for the development of microorganisms of all groups, due to its high nutritional and biological value, so the fish are perishable food products, the conditions and terms of their storage require appropriate temperature regimes to stop the development of microorganisms. The aim of the work was carrying out a comparative analysis of insemination of frozen fish with mesophilic and psychrotrophic microflora to make an amend to standards according to microbiological criteria.

The microbial number in frozen fish samples  was estimated with the temperature of (30 ± 1) ºС incubation of crops for 72 hours (mesophilic microflora) and incubation for 10 days (psychrotrophic microflora) with the temperature (6.5 ± 0.5) ºC.

It was identified that there were taken the samples from frozen fish with a quantity of mesophilic bacteria to 102 CFU/g, 1.4-1.8 times (p <0.05) more psychotropic microorganisms. The researched samples with the number of mesophilic microorganisms from 103 to 104 CFU/g were contaminated with psychotropic microflora, which in 1.7-6.8 times (p <0.05) exceeded the content of the mesophilic microflora. With such amount of mesophilic microorganisms, on average of up to 25% of samples, this had a content of psychotrophs of more than 105 CFU/g of fish. According to the content of mesophilic bacteria the samples of frozen fish, which were mathed to a certain norm of 5 × 104 CFU/g, basically in the number of psychrotrophic microflora did not correspond to this indicator, and exceeded it 2 times or more.

In the cold period of the year, 63.6 ± 2.1% of frozen fish samples were mesophilic bacteria containing less than 101 CFU/g. 
At the same time, samples with such content mesophilic bacteria in the warm period of the year was 9.0%, or 7.0 times
(p <0.05) less.  In addition, in the cold period of the year, only 9.0% of samples were detected, which, according to the content of mesophilic bacteria exceeded the maximum allowable level.  At the same time, during the warm period, the number of samples with an excess of mesophilic bacteria content was 27.3 ± 0.3%. Practically the same pattern was observed regarding the insemination of the psychrotrophic microflora in these periods of the year, which was characterized by the fact that in the warm period of the year, frozen fish contains a large number of psychrotrophic microorganisms. Consequently, the results of studies on the amount of microflora in the warm period of the year established 3,0 times (p <0,05) more samples of frozen fish, which, according to the content of mesophilic bacteria, exceeded the maximum permissible level compared with the cold period of the year.

It was established that samples of frozen fish containing mesophilic microorganisms less than 101 CFU/g were most unevenly contaminated with psychrotrophic microflora.  Among these samples, only 30.1 ± 1.4% were with the number of psychrotrophic microflora less than 101 CFU/g, at the same time, 60.0 ± 0.5% of the samples were contaminated with a
psychrotrophic microflora of 101 to 105 CFU/g and 10,  0 ± 0.2% over 105 CFU/g.  In the study of frozen fish samples with the number of mesophilic bacteria from 101 to 102 CFU/g revealed a coincidence in the content of psychrotrophs in only 16,7 ± 0,3% of samples, and 33,3 ± 0,3% of fish samples were with the content of psychrotrophic microflora from  102 to 103 CFU/g and 103 to 104 CFU/g and 16.7 ± 0.3% were contaminated with psychrotrophy more than 104 CFU/g. It was established that samples of frozen fish containing mesophilic microorganisms less than 101 CFU/g were most unevenly contaminated with psychrotrophic microflora.  Among these samples, only 30.1 ± 1.4% were with the number of psychrotrophic microflora less than 101 CFU/g, at the same time, 60.0 ± 0.5% of the samples were contaminated with a psychrotrophic microflora of 101 to 105 CFU/g and 10,  0 ± 0.2% over 105 CFU/g.  In the study of frozen fish samples with the number of mesophilic bacteria from 101 to 102 CFU/g revealed a coincidence in the content of psychrotrophs in only 16,7 ± 0,3%
of samples, and 33,3 ± 0,3% of fish samples were with the content of psychrotrophic microflora from  102 to 103 CFU/g and 103 to 104 CFU/g and 16.7 ± 0.3% were contaminated with psychrotrophy more than 104 CFU/g.

It was found that that the psychrotrophic microflora of frozen fish is quantitatively predominantly content of mesophilic bacteria several orders of magnitude. During the warm period of the year, more samples of frozen fish were detected in 3,0 times (p <0,05), which, according to the content of mesophilic bacteria, exceeded the maximum permissible level in comparison in the cold period of the year.  It was found that 92,6 ± 2,5% of frozen fish samples were in compliance with the requirements of DSTU 4868: 2007. The fish is frozen. At the same time, during the fish evaluation, the contents of the psychrotrophic microflora showed that samples exceeding 5 × 104 CFU/g was in 2.6 times (p <0.05) more than the mesophilic bacteria content.

In future the generic and species composition of the psychrotrophic microflora of frozen fish will be studied and the fish evaluating criteria according to the psychrotrophs in order to make corrections according to the microbiological criteria.

Key words: frozen fish, psychrotrophic microflora, mesophilic bacteria, contamination, microbial number.

 

1. Mohammed Saud, Al-J., & Fahad Mohammed, Al-J. (2011). Study the Chemical, Physical Changes and Microbial Growth as Quality Measurement of Fish. Annual Research & Review in Biology. Vol. 4, Issue 9, pp. 1406–1420.

2. Berkel, B.M., Boogaard, B.V., & Heijnen, C. (2004). Preservation of fish and meat. Agromisa Foundation, Wageningen, The Netherlands. Vol. 8, pp. 78–80.

3. Usydus, Z., Szlinder-Richert, J., Polak-Juszczak, L., Kanderska, J., Adamczyk, M., & Malesa-Ciecwierz, M. (2008). Food of marine origin: between benefits and potential risks. Food Chemistry. Vol. 111, pp. 556–563.

4. Pacheco-Aguilar, R., Lugo-Sanchez, M.E., Robles-Burgueno, M.R. (2000). Postmortem biochemical characteristic of Monterey sardine muscle stored at 0°C. Journal of  Food Science. Vol. 65, pp. 40–47.

5. Rey, M.S., García-Soto, B., Fuertes-Gamundi, J.R., Aubourg, S., Barros-Velázquez, J. (2012). Effect of a natural organic acid-icing system on the microbiological quality of commercially relevant chilled fish species. LWT, Food Science and Technology. Vol. 46, pp. 217–223.

6. Akinbowale, O. L., Peng, H., Barton, M. D. (2006). Antimicrobial resistance in bacteria isolated from aquaculture sources in Australia. Journal of Applied Microbiology. Vol. 100, Issue 5, pp. 1103–1113. 

7. Mikš-Krajnik, M., Yoon, Y. J., Ukuku, D. O., Yuk, H. G. (2016). Volatile chemical spoilage indexes of raw Atlantic salmon (Salmo salar) stored under aerobic condition in relation to microbiological and sensory shelf lives. Food Microbiology. Vol. 53, pp. 182–191. Available at:http://doi.org/10.1016/j.fm.2015.10.001. PMid:26678146.

8. Velu, S., Bakar, A. F., Mahyudin, N. A., Saari, N., Zaman, M. Z. (2013). Effect of modified atmosphere packaging on microbial flora changes in fishery products. International Food Research Journal.  Vol.  20, Issue 1, pp. 17–26.

9. Riba samorozhena. Technіtschnі umowi [Frozen fish. Specifications]. (2007). HOST 4868:2007 from 01th January 2008. Kyiv National Standard of Ukraine.

10. Mulic, R., Giljanovic, S., Ropac, D., & Katalinic, V. (2004). Some epidemiologic characteristics of foodborne intoxications in Croatia during the 1992–2001 period. Acta Medica Croatica. Vol. 58, pp. 421–427.

11. Liston, J. Fish and shellfish and their products. In International Commission on Microbiological Specifications for Foods – ICMSF (Ed.). (1980). Microbial ecology of food. Vol. 2, pp. 567–605.

12. Zambuchini, B., Fiorini, D., Verdenelli, M.C., Orpianesi, C. (2008). Inhibition of microbiological activity during sole (Solea solea L.) chilled storage by applying ellagic and ascorbic acids. Food Science and Technology. Vol. 41, pp. 1733–1738.

13. Jeon, Y. J., Kamil, J. Y., Shahidi, F. (2002). Chitosan as an edible invisible film for quality preservation of herring and Atlantic cod. Journal of Agricultural and Food Chemistry. Vol.  50, Issue 18, pp. 5167–5178. Available at:http://dx.doi.org/10.1021/jf011693l

14. Broekaert, K., Heyndrickx, M., Herman, L., Devlieghere, F., & Vlaemynck, G. (2011). Seafood quality analysis: Molecular identification of dominant microbiota after ice storage on several general growth media. Food Microbiology. Vol. 28, Issue 6, pp. 1162–1169. Available at:http://dx.doi.org/10.1016/j.fm.2011.03.009

15. Ercolini, D., Russo, F., Nasi, A., Ferranti, P., Villani F. (2009). Mesophilic and Psychrotrophic Bacteria from Meat and Their Spoilage Potential In Vitro and in Beef. Applied and environmental microbiology. Vol. 75, pp. 1990–2001.

16. Salata, W.S., Kuchtin, M.D. (2017). Mіkrovlora ocholodzhenoi і primorozhenoi jalowitschini sa cholodil'nogo sberіgannja [Microflora of cooled and frozen beef for cooling storage]. Kharkiv : Zbirnyk naukovykh prats Kharkivskoi derzhavnoi zooveterynarnoi akademii [Collection of scientific works of the Kharkov State Zoo Veterinary Academy. RV HDZVA]. Part 2, Issue 34, pp. 332–336.

17. Hassan, M. A., Shaltout, F. A., Maarouf, A. A., & El-Shafey, W. S. (2015). Psychrotrophic bacteria in frozen fish with special reference to pseudomonas species. Benha Veterinary Medical Journal. Vol. 27, Issue 1, pp. 78–83.

18. Popelka, P., Jevinova, P., Marcinčák, S. (2016). Microbiological and chemical quality of fresh and frozen whole trout and trout fillets. Potravinarstvo. Scientific Journal for Food Industry. Vol. 10, Issue 1, pp. 431–436. doi:10.5219/599.

 19. Popelka, P., Nagy, J., Pipová, M., Marcinčák, S., Lenhardt, L. (2014). Comparison of chemical, microbiological and histological changes in fresh, frozen and double frozen rainbow trout (Oncorhynchus mykiss). Acta Vet. Brno. Vol.  83, pp. 157–161. Available at:https://doi.org/10.2754/avb201483020157

20. Morita, R. Y. (1975). Psychrotrophilic bacteria. Bacteriol. Rev., Vol. 39, pp. 189–190.

21. Rezaei, M., Hosseini, S. F. (2008). Quality assessment of farmed rainbow trout (Oncorhynchus mykiss) during chilled storage. Journal of Food Sciences. Vol. 73, Issue 6, pp. 27–32.

22.  Ninan, G., Zynudheen, A.A, Joseph, J. (2011). Effect of Chilling on Microbiological, Biochemical and Sensory Attributes of Whole Aquacultured Rainbow Trout (Oncorhynchus mykiss Walbaum, 1792). Journal of Aquaculture Research and Development. Vol. 5, Issue 2, 5 p.   Available at:http://dx.doi.org/10.4172/2155-9546.S5-001

23. Mikrobiolohiia kharchovykh produktiv ta kormiv dlia tvaryn. Hotuvannia doslidnykh prob, vykhidnoi suspenzii ta desiatykratnykh rozveden dlia mikrobiolohichnoho doslidzhennia. Chastyna 3. Spetsialni pravyla hotuvannia ryby ta rybnykh produktiv [Microbiology of food and animal feeding stuffs. Preparation of test samples, initial suspension and decimal dilutions for microbiological examination – Part 3: Specific rules for the preparation of fish and fishery products]. (2014). HOST 6887-3:2014 from 01th May 2015. Kyiv National Standard of Ukraine.

AttachmentSize
PDF icon malimon_1_2019.pdf5.35 MB