Bulletin UASVM Agriculture, 66 (2)/2009 Print ISSN 1843-5246; Electronic ISSN 1843-5386
The Study of the Decontamination Efficiency in Meat Processing Units
Gheorghe ŞTEŢCA, Adriana MOREA, Antonia ODAGIU, Dan SALAGEAN, Cristina HEGEDUŞ
Faculty of Agriculture, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, 3 - 5 Mănăştur Street, 400372 Cluj-Napoca, Romania,
e-mail: pedopel@yahoo.com
Abstract. The monitoring and correct execution of the main activities concerning cleaning, washing, decontamination and neutralization of the substances used for decontamination, are activities included within HACCP system at commercial society level. The decontamination was performed using quantitative and qualitative bacteriological tests that controlled the air, surfaces, spaces and used instruments during production process. The highest air microbian contamination degree was recorded in plum removing space. In evisceration and packaging rooms, the micro-organisms belonging to the three genus were randomly emphasized on the investigated surfaces. Thus, the presence of the staphyloccocus was mentioned only on the conveier and floor, the enteroccocus were emphasized on conveier and work table, and colphorms on conveier and floor (evisceration spaces) and conveier and work tables (room of delivering the final products).
Keywords: decontaminaton, efficiency, meat, HACCP INTRODUCTION
It is well known that thde degree of meat and meat products contamination, often reflects the health status of the animals, who supply the raw material.
Between raw material, surfaces, equipments and instruments used by staff who works in the processing unit a permanent and continuous exchage of microorganisms is produced.
At national level, even in European Union, is unanimously admitted that the hygiene and sanitary status of production surfaces from commercial societies with agro - alimentary profile, and animal production farms are directly reflected in quality and salubrity of animal origin products.
In present conditions the improvement and systematic performing the microbiological examination of the work spaces, surfaces, equipmenta and raw material are imposed. These studies will contribute to the continuous improvement of the sanitation measurements that must be put into practice in such situations, using decontamination methods as appropriate possible.
The monitoring and correct execution of the main activities concerning cleaning, washing, decontamination and neutralization of the substances used for decontamination, are activities included within HACCP system at commercial society level.
A salubrity plan is based on the following objectives:
1. The reducing, as possible, at minimum the existant flora and organic substances that cud favourize the microorganisms multiplication.
2. The elimination of the residuals of chemical substances that were used in actions of washing and decontamination.
In almost all cases, the efficiency of decontamination is conditioned by a series of factors and as consequence, after contact time, the evaluation is compulsory. It is performed
using a series correspondent tests of sanitation, by quantitative and qualitative microbiological examinations, which reveal the modality of performing the requested operations.
The objective of te investigation is represented by the establishing of the critical points with high microbial contamination risk in commercial societies and modality of putting into practice the sanitation methods used in the end of the work programme, which could influence the cleaning state (sanitation) of work surfaces, spaces and instruments.
MATERIAL AND METHOD
Materials and work techniques:
- test tubes 16/160mm;
- graduated droppers de 1 mL, 2 mL, 10 mL;
- mycroscopic blades;
- Petri dishes with 9 cm diameter;
- sampling buffers (for performing the decontamination activities; they contain 0.5%
sodium for neutralizing the chlorine and iodine compounds; 0.1% acetate for alcoholic solutions and other substances);
- a square shaped templet with 10 cm side;
- reagents:sodium hydroxide, hydrocloric acide, saline solution, yolk emulsion with potasium supplements;
- culture media: peptoned water, nutritional bullion, nutritional agare and all agare products.
The work technique
The decontamination was performed using quantitative and qualitative bacteriological tests that controlled the air, surfaces, spaces and used instruments during production process.
The control of the air decontamination
The test was performed by exposing the Petri dishes with specific culture media for spes submitted to decontamination. The KOCH sedimentation technique with Petri dishes without cover in different places at variable hights, was applied. The culture media were made up of 2 % agarose or nutritional gel, for aerobe and mezophile bacteria, Sabouraud media, Potated dextrose agar or media with potato extract for mycro-mycetes development.
After 5 – 10 minutes, the dishes were covered and thermostate incubated (37ºC) for 24 – 48 hours, for bacteria and 3 – 4 days at temperature of 25 - 26ºC for mycro-mycetes.
The colonies develped by each dish were counted, and their number was reported to m3 air, using Omeleanski formula:
Exp.: No. of colonies/m3 air = N * 63662/D2 * T,
where: N = the number of colonies by dishă 63662 = Omeleanski constant D = dish diameter
T = exposing time.
The average of the microbial charge of the air before and after decontamination was finnaly calculated. Then both obtained values were reported and the efficiency of
decontamination operation efficiency was estimated, resulting the reducing degree of the microbial charge by volume unity.
This is a relative method, because it does not supply the possibility of pathogen germ identification, entirely.
The control of surfaces decontamination
Concerning the surfaces, the samples were harvested before and after decontamination. In this case, the surfaces were split with a 10 cm side square templete, then the surfaces were wipped with a sterile cotton in three directions, then the cotton was maintained in neutralizing solution for 5 – 6 minutes, then passed to inital test tube with saline solution.
In laboratory, the isolation and identification of Staphylococcus şi Escherichia germs was performed. They are used as microbiologica markers for estimating the decontamination efficiency.
The following determinations were performed:
- coliphorms tests - staphilococus test.
The coliphorm test
Escherichia microorganisms were selected as test germs for the qualitative bacteriological examination, because germs are constantly encountered in humans and animal intestine.
The work technique includes several stages. In the beginning the selective meadia (Levine sau Maconkey) is melted on a water bath, then is colded at 50 - 55ºC and placed on Petri dishes.
The medium area from dishes was inseminated directly with rod destined to sample insemination. The Petri dishes were incubated in termostate placed with head down for 24 – 48 hours. In order to confirm the presence of Escherichia germs in samples, is recommended that from characteristic colonies (from Levine or Maconkey agares) a fragment to be harvested and with it the 2 % nutritional geloese to be inseminated. The reaction is considered positive when Indol is produced in media, and in Durham tubes, gases will be accumulated.
The staphylococus test
The studies with a large spectra of decontamined and antiseptic substances de monstrated the sensibility of the microorganisms known as coliphorms. The have characteristic behaviour against tested products at different concentration.
The work technique is the same as in Coli test, only cultivation media differs, staphyloccoci being well developed in Chapman hyperchlorinated media.
The staphylococus colonies that develop on this selective media have the characteristics of the S type. A correct decontamination may be appreciated if from the Chapman media, colonies characteristic for staphylococi are not developed.
At laboratory level, supplies with new cultura media were delivered, agare (Baird- Parker) mixed with egg yolk and potassium telurite.
It is well known that the surfaces with the greatest decontamination degree are the floors.
The samples were harvested from dry surfaces, and decontamination was considered as satisfactory when at their level Staphylococcus and Escherichia gems were not found.
RESULTS AND DISCUSSIONS
1. The estimation of the decontamination efficiency in units of poultry meat valuation - The poultry meat remains a major problem of food origin dieases, in conditions when it is not appropriate preparated or a new contamination occurres after preparation.
- The composition of the residual microbial flora Compoziţia florei microbiene reziduale şi regimul contaminării carcaselor reflectă fidel condiţiile de igienă a spaţiilor de procesare.
- In condition of using the microbiological markers for estimation the sanitation measures of the germs from Staphylococcus and Escherichia genus, we studied the hygiene state of the surfaces and air in the unit of poultry meat processing and due to the existence of the Enterococcus germs with great resistance to the action of external physical and chemical factors.
- Even they are considered not pathogenous organisms, the big concentration of the enteroccoci in above mentioned products may produce digestive or urinary infections.
- Their presence as germs of enteric nature situated on the surfaces of the technoogical elements from the industry of poultry meat processing, suggest their contamination with faeces.
- The samples were harvested in the end of the work programme, before performing mechanical cleaning and after aplication of decontamined substances, followed by a rinsing.
- The work surfaces with direct contact withthe raw material (tables, equipment, floor and room air) were studied.
2. The efficiency of work area decontamination with sodium hydroxide
- The 3.5% sodium hydroxide was used as decontamination solution,becuse it has a large spevtre of action on bacteria, viruses, micro-mycetes, etc. (Coman et al., 1997).
- After sodium hydroxide decontamination, the repeated surface and instruments washing was performed with much water, because it is well known that the solution may degradate the metals, rubber and other contact surfaces.
- The estimation of the air decontamination efficiency was performed using quantitative microbiological tests, both before and after decontamination, and results are presented in Tab. 1.
Tab. 1 Dthe dynamics of the micro-air-flora from sodium hydroxide decontamined spaces
UFC/m3 air Objective
NTB/m3 air Degree of reducing %
NTM/m3 air Degree of reducing %
I.D. D.D. I.D. D.D.
Poultry slaughter 21500 7960 62.95 79580 14166 82.1
Carcass boiling 92485 39155 57.65 49778 19225 61.30
Plum removing from sarcass 322250 38835 87.96 226879 15051 94.25
Evisceration 17075 6845 59.92 19125 8128 57.49
Package of the final product 17300 7640 55.84 9695 3344 65.51
Legend: UFC = units colonies formating NTB = total bacteria number NTM = total micromycetes number I.D. = before decontamination D.D. = after decontamination
All data presented in table 1 demonstrate that the air microbialcharge is high both befre and after decontamination. No work spaces have values of the microorganism charge within present standards (600 bacteria/m3 and 300 micromycetes/m3 air).
Beforedecontamination, the number of the microorganisms from the slaughter space was of 21,500/ m3 air in bacteria, and for mycetes, it was of 14,166 m3 air.
In the hall of carcass storage, the number of the emphasized germs within the same volume unity, had very big values. Thus, the total number of bacteria from a cube meter of air was of 322,250/ m3 air, by 536 folds higher than admitted maximum limit, and micro-mycetes recorded values up to 226,879 UFC/m3 air.
The highest air microbian contamination degree was recorded in plum removing space (Fig. 1).
Fig. 1. The bacterial charge of the plume removing hall: before and after decontamination
The phenomena may be explained because the rubber covers from the plum removing devices, by continuous mooving, antrenate the air currents and recirculate them withn respective space.
The number of the germs from the air of the work spaces recorded a sharp decrease in evisceration rooms. Thus, in evisceration and packaging rooms, the bacterial charge recorded sensible similar values (17,070 UFC/ m3 air in evisceration hall and 17,295 UFC/ m3 air in package room), while in the number of mico-mycetes from both rooms significant differences appeared (19,124 UFC/ m3 air in evisceration and 9,693 germs/m3 air in packaging space).
These values, even low, did not framed within maximum admitted limits for the number of micro-organisms from a cube meter of air.
After contamination, the number of micro-organisms vehiculated by the air currents recorded a visible diminish, the reduction degree oscillating in bacteria between 55.83 % in room destined tom final products packaging sala and 87.94 % in plum removing space, while the micro-mycetes from one meter cube of air decreased in share of 57.49% in eviceration room and of 94.24 % in plum removing room. The most intense decreasing percent was recorded in the carcass plum removing space (87.94%) for bacteria and 94.24 % for micro- mycetes, without framing within maximum admitted limits.
The results demonstrated that air, as vehiculated element of an important germ quantity, cannot be included in decontamination activity, the NTG/m3 diminishing being in majority the resut of low circulation of air currents and humidity determined by he aerosols that appeared in the moment of application of the decontaminat substance.
Form the work surfaces (conveiers, tables, work equipment), as well as from the floor, the samples were harvested from all five production spaces (slaughter, boiling, plum removing, evisceration and packaging), according to the standardized work technique. The investigation results are presented in Tab. 2.
Tab. 2 The efficiency of surface contamination using the sodium hydroxide
Germe ns
SLAUGHTER CARCASS BOILING CARCASS
PLUM REMOVING EVISCERATION PACKAGING OF FINAL PRODUCT
ID DD ID DD ID DD ID DD ID DD
C S Pd C S Pd C S Pd C S Pd C S Pd C S Pd C S Pd C S Pd C S Pd C S Pd Staphylo-
coccus + + + + + + + - + + + + + + + + + + + + + + - - + + + + - -
Escherichia + + + + + + + + + + + - + + + + + + + + + + - + + + + + + -
Entero-
coccus + + + + + + + + + + + + + + + + + + + + - - + - + + + + - -
Legend: ID = before decontamination DD = after decontamination C = conveier
S = contact surface (tables, equipment) Pd = floor
+ = present culture
- = culture absence
The microbial charge in on the work surfaces of the technological flow elements, almost no record differences between both harvesting moments (before and after decontamination).
The data from the table suggested that before decontamination micro-organisms from Staphylococcus, Enterococcus and Escherichia genus were almost constant in the surfaces in contact with raw material (conveier, work hand, tables, equipment) and floor. An important aspect is represented by the contamination sources with pathogen germs which remains the
same even after 3% sodium hydroxide decontamination. Thus, in rooms where Thus, in rooms where the microbial charge of the air is much over the maximum admitted limits (slaughter, boiling and plum removing) we observe that the germs from Staphylococcus, Enterococcus and Escherichia genus were constantly isolated after decontamination (Fig. 3).
In evisceration and packaging rooms, the micro-organisms belonging to the three genus were randomly emphasized on the investigated surfaces. Thus, the presence of the staphyloccocus was mentioned only on the conveier and floor, the enteroccocus were emphasized on conveier and work table, and colphorms on conveier and floor (evisceration spaces) and conveier and work tables (room of delivering the final products).
In order to emphasize the bacteria on inert supports a more brief test was applied, meaning the hygicult, which consists in fingerprinting of the surfaces Staphylococcus and Escherichia germs. The results will serve as comparation elements with those obtained with clasical work method, aspect that allow us the formation of an overrall immage on their use in units of meat processing.
The Escherichia germs were not emphasized at the level of the surfaces when the testing was performed using the hygiculture.
Fig. 3. The germs from Staphylococcus and Escherichia genus before and after slaughter space decontamination
For the micro-organisms belonging to Staphylococcus genus, between both testes (classic and hygicult) did not exist sigificant differences, when they were performed on samples from floor level (Fig. 4).
REFERENCES
1. Abraham M. K. (1991). Staphylococcus aureus Enterotoxina Isolated From Goat Milk, Israel Journal Veterinary Medicine, vol. 46, p. 89
2. Albert S. (1993). Biotehnologii şi dezvoltare, Editura Tehnică
3. Apostu S. (2003). Managementul unităţilor alimentare, Editura Risoprint, Cluj-Napoca
4. Rotaru O., M. Mihaiu (2003). Igiena veterinară a produselor alimentare, Editura Risoprint, Cluj- Napoca
5. Stănescu V. et. al. (2000). Controlul alimentelor de origine animală, Bucureşti
6. Ştețca Gh. (2008). Igiena unităţilor de industrie alimentară, Editura Risoprint, Cluj-Napoca
7. Ştețca Gh. (2005). Cercetări privind condiţiile de igienă în spaţiile de depozitare a produselor alimentare de origine animală din pieţe şi unităţi de desfacere, Teză de doctorat, USAMV Cluj-Napoca
8. Ştețca Gh., C. Man, C. Laszlo, Gh. Mihai (2004). Cerinţe privind condiţiile de igienă şi de temperatură a produselor de origine animală în pieţe şi magazine de desfacere ale Clujului, Simpozionul „Prospects for the 3
rd Millenium Agriculture”, USAMV Cluj-Napoca
