=Paper=
{{Paper
|id=Vol-2761/HAICTA_2020_paper86
|storemode=property
|title=Microbiological and Physicochemical Parameters of Beef and Lamb Meat Produced in Slaughterhouses in Northern Greece. Preliminary Results
|pdfUrl=https://ceur-ws.org/Vol-2761/HAICTA_2020_paper86.pdf
|volume=Vol-2761
|authors=Anestis Tsitsos,Vangelis Economou,Eirini Chouliara,Theodoros Kalitsis,Aggeliki Argyriadou,Georgios Arsenos,Ioannis Ambrosiadis
|dblpUrl=https://dblp.org/rec/conf/haicta/TsitsosECKAAA20
}}
==Microbiological and Physicochemical Parameters of Beef and Lamb Meat Produced in Slaughterhouses in Northern Greece. Preliminary Results==
https://ceur-ws.org/Vol-2761/HAICTA_2020_paper86.pdf
Microbiological and Physicochemical Parameters of Beef
and Lamb Meat Produced in Abattoirs in Northern
Greece. Preliminary Results
Anestis Tsitsos1, Vangelis Economou2, Eirini Chouliara3, Theodoros Kalitsis4,
Aggeliki Argyriadou5, Georgios Arsenos6, Ioannis Ambrosiadis7
1
Laboratory of Hygiene of Food of Animal Origin – Veterinary Public Health, School of
Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Greece;
e-mail: tsitanes@vet.auth.gr
2
Laboratory of Hygiene of Food of Animal Origin – Veterinary Public Health, School of
Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki. Greece;
e-mail: boikonom@vet.auth.gr
3
Laboratory of Technology of Food of Animal Origin, School of Veterinary Medicine,
Faculty of Health Sciences, Aristotle University of Thessaloniki, Greece; e-mail:
echoulia@vet.auth.gr
4
Laboratory of Animal Husbandry, School of Veterinary Medicine, Faculty of Health
Sciences, Aristotle University of Thessaloniki, Greece; e-mail: tgkallitsis@vet.auth.gr
5
Laboratory of Animal Husbandry, School of Veterinary Medicine, Faculty of Health
Sciences, Aristotle University of Thessaloniki, Greece; e-mail: argyrian@vet.auth.gr
6
Laboratory of Animal Husbandry, School of Veterinary Medicine, Faculty of Health
Sciences, Aristotle University of Thessaloniki, Greece; e-mail: arsenosg@vet.auth.gr
7
Laboratory of Technology of Food of Animal Origin, School of Veterinary Medicine,
Faculty of Health Sciences, Aristotle University of Thessaloniki, Greece; e-mail:
ambros@vet.auth.gr
Abstract. Meat quality and hygiene are perquisites for the marketing of meat
and meat products. In this research paper the results of the monitoring of meat
quality from abattoirs of Northern Greece are reported. Samples of lamb meat
and beef were collected in order to examine the physicochemical parameters
(pH, moisture, total fat and total proteins) and microbiological quality indicators
(total mesophilic count, total psychrophilic counts and coliform count) of meat
produced in these plants. Concerning beef, the most contaminated area was the
hindquarter, followed by the forequarter and the abdomen. Differences were
observed in the microbiological quality of the lamb carcasses prepared at
different abattoirs, pointing the importance of personalized hygiene measures.
Small deviation was observed in the physicochemical parameters examined,
with lamb meat having a pH of 6.17 (SD=0.24), humidity of 63.2% (SD=4.5%),
total fat 5.4% (SD=4.1%), and total proteins 20.8% (SD=4.5%).
Keywords: meat quality; meat hygiene; lamb meat; mutton; goat; Greece.
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1 Introduction
Meat is an essential part of the human diet. As in most foods, its suitability for
human consumption is determined by its safety and quality. The term "safety" is easily
defined; still, it is not so for the term "quality" which is a rather generic term, prone to
social and time variations. With hygiene a perquisite, it is acceptable that quality is
formed by the consumer preferences, namely its organoleptic characteristics,
nutritional value, and the technological properties of meat (Elmasry et al., 2012). Still,
in order to compare quality of different meat, certain physicochemical parameters have
been introduced as quality markers that are objective still not usually perceived by the
consumer. In Greece, the characterization of meat quality relies mostly in empirical
characteristics, with scarce scientific information concerning objective quality
characteristics (Krystallis et al., 2007). The scope of this research was to assess the
hygiene and quality of beef and sheep meat produced in abattoirs of Northern Greece
by certain hygiene and quality markers.
2 Materials and Methods
The abattoirs under examination are situated in the Prefectures of Thessaly and
Central Macedonia. They are licensed by the European Union for the slaughter of
ruminants and pigs. The abattoirs were visited from October 2019 to June 2020.
Approximately 1 hr after slaughter, the surface of the carcasses was sampled following
the non-destructive swab method. In brief, a sterile swab was soaked in 5 ml of
Minimum Recovery Diluent (MRD, Oxoid) and was used to wipe a 100 cm2 carcass
surface area. The swab was added to the tube containing 5 ml MRD and transported to
the Laboratory of Food Hygiene – Veterinary Public Health in an insulated container
under refrigeration. Within 24 hr, decimal dilutions were performed in MRD
containing tubes. From each dilution, 0.1 ml of the diluent was surface inoculated in
the appropriate media. For the microbiological parameters examined the plates
inoculated were Plate Count agar (Biolab) for Total Mesophilic Viable Count (TMVC)
and Total Psychrophilic Plate Count, and Violet Red Bile agar (Biolab) for coliform
count. The examination of samples for TMVC and coliform count was performed
according to ISO 4833/2005 and ISO 21528-2/2017 with modifications, as proposed
by the Commission Regulation (EC) No. 2073/2005 on microbiological criteria for
foodstuffs. Incubation was performed at 30oC for 72h for TMVC, 10oC for 7 days for
TPVC and 37oC for 24h for coliforms. After incubation, the characteristic colonies
were counted, and the results were recorded. A total of 88 and 166 swab samples were
examined for surface contamination of beef and sheep carcasses respectively.
Samples were also collected by the destructive method from cold carcasses. In brief
a piece weighting approximately 100 g was excised from the thigh region (quadriceps
fermoris) or elsewhere and transported to the laboratory within the same day. The
samples were examined for their pH, water activity, humidity, total fats and total
proteins. Prior to examination the samples were comminuted with a Warring
laboratory blender. For pH examination, 10 g of muscle were dispersed in 40 ml of
distilled water and let to settle. Ph examination was performed with a Hannah Ph211
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pH meter. Water activity was measured with a HygroPalm HP23-AW-A water
Activity Analyzer (Rotronic AG) according to the manufacturer’s instructions.
Humidity was examined with a moisture analyser (Ohaus MB27) according to the
manufacturer’s instructions. Total fat was determined according to the reference
analysis Weibull-Stoldt method, with hydrolysis as the first step and extraction in the
Soxtherm, according to the AOAC method 991.36. Total protein was determined
according to the AOAC Official Method 928.08. A total of 110 beef samples and 37
sheep samples were examined for their physicochemical properties, with 10 and 25 of
them respectively examined for total fat and total proteins.
3 Results and Discussion
An effort was made to monitor the hygiene and quality of lamb and beef produced
in the abattoirs of Northern Greece. For this purpose, a total of 88 and 166 surface
samples were collected from bovine and sheep carcasses, and 110 beef samples and 37
sheep meat samples examined for their physicochemical properties. The
physicochemical analyses results are reported in Table 1 and Table 2. In brief the cold
carcass hindquarter pH was in average 5.69, the diaphragm pH was in average 6.2, the
forequarter pH was in average 5.77 and the liver pH was in average 6.43. The deviation
was small, implying the repeatability of the slaughtering procedure and the uniform
conditions in all animals slaughtered, not permitting different conditions of chilling.
Table 1. PH of the beef muscle from the sites sampled (average in bold, standard deviation in
parentheses and italics).
Carcass part
Hindquarter 5.69 (0.10)
Diaphragm 6.2 (0.15)
Forequarter 5.77 (0.24)
Liver 6.43 (0.04)
Concerning the physicochemical analyses of the hindquarter samples from sheep
cold carcasses, the average value of pH was 6.26, humidity was 63.2%, total fat was
5.4%, and total proteins 20.8 %. Little difference was observed between samples from
different abattoirs concerning the pH of the cold carcass and the humidity. Still there
were differences in the total fat and total proteins of the samples examined that were
not statistically significant as shown by the deviation of the abattoir 2 samples. This
can be attributed to the number of samples examined and the examination of some
older animal carcasses from abattoir 2 since meat from older animals is generally richer
in fat.
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Table 2. Physicochemical analyses of lamb meat (average in bold, standard deviation in
parentheses and italics).
pH Humidity Total fat Total proteins
Abattoir 1 6.26 (0.14) 63.8% (3.0%) 4.0% (1.2%) 19.8% (4.4%)
Abattoir 2 6.07 (0.29) 61.4% (7.7%) 9.9% (6.4%) 24.3% (2.8%)
Total 6.17 (0.24) 63.2% (4.5%) 5.4% (4.1%) 20.8% (4.5%)
Concerning the surface contamination of bovine carcasses, the results are shown in
Table 3 and in Graphs 1 and 2. In hindquarters, the average value of TMVC was 4.83
log10 CFU/cm2, TPVC 2.13 log10 CFU/cm2 and coliform count was 0.86 log10 CFU/cm2.
The abdomen examination results were 1.76 log10 CFU/cm2 for TMVC, 0.83 log10
CFU/cm2 for TPVC, and 0.56 log10 CFU/cm2 coliform count. In forequarter samples
TMVC was 2.48 log10 CFU/cm2, TPVC 1.35 log10 CFU/cm2 and coliform count was
0.68 log10 CFU/cm2 in average. The hindquarter surface was more contaminated than
the forequarter and abdomen surfaces, with the abdomen surfaces being the least
contaminated.
The microbial counts are in average below the limits posed by the he Commission
Regulation (EC) No. 2073/2005 on microbiological criteria for foodstuffs. More
specifically, no batch of carcasses exceeded the average limit posed of 3.5 log10
CFU/cm2. In three cases the surface count was larger than 3.5 log10 CFU/cm2 but below
the upper limit of 5.0 log10 CFU/cm2 of individual samples. According to Paszkiewicz
& Pyz-Łukasik (2012) the total aerobic bacteria count on calf carcasses slaughtered in
Polish abattoirs ranged from 3.5*103 CFU/cm2 up to 7.0*103 CFU/cm2. These results
are larger than the ones reported in our study for abdomen and forequarter areas, but
smaller than the counts observed for hindquarter samples. This can be justified by the
unified analysis of the different carcass surface sampling points. Also, the coliform
counts reported (1.7*10 cfu/cm2) are larger than the ones reported in this paper,
possibly due to better evisceration techniques. Zweifel et al. (2008) have examined the
surface contamination of pigs and cattle slaughtered in small scale Swiss abattoirs.
They report that the mean TMVCs of cattle carcasses ranged from 2.7 to 3.8
log10CFU*cm-2, a value that is smaller than the ones observed in this study. Camargo
et al. (2018) report that the contamination rates in four Brazilian abattoirs were in
average 2.93 ± 0.06 log10CFU*cm-2 for TMVC and 1.81 ± 0.07 log10CFU*cm-2 for total
coliforms, which are comparable to the ones observed in the present study. Still, it
should be noted that comparison of microbial contamination of the carcasses should
not be done with data from countries outside the European Union since in other areas
and more specifically in North America, they are hampered by the application of
decontamination procedures (Koohmaraie et al., 2005). In contrast, Petruzzelli et al.
(2016) report quite lower TMVC counts (1.96 log cfu/cm2) in bovine carcasses from
three small-scale Italian abattoirs.
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Table 3. Microbial counts of different beef carcass areas (average in bold, standard deviation in
parentheses and italics).
Hindquarter Abdomen Forequarter Average
TMVC 4.83 (1.79) 1.76 (0.70) 2.48 (1.21) 3.02 (1.85)
TPVC 2.13 (2.07) 0.83 (0.49) 1.35 (1.23) 1.44 (1.50)
Coliforms 0.86 (0.78) 0.56 (0.16) 0.68 (0.31) 0.66 (0.39)
7 7
6
Total Mesophilic Count Total Psychrophilic
Beef 6 Count
5 5
log CFU/cm2
log CFU/cm2 Beef
4 4
3 3
2 2
1 1
0 0
en
en
er
er
er
er
rt
rt
rt
rt
om
om
ua
ua
ua
ua
bd
bd
eq
eq
dq
dq
A
A
r
r
in
in
Fo
Fo
H
H
Fig. 1. Total mesophilic counts of beef Fig. 2. Total psychrophilic count of beef
carcass areas (n= 36). carcass areas (n= 36).
The microbial counts of the sheep carcasses surface samples from the two abattoirs
under investigation are reported in Table 4. In brief, TMVC was 4.02 log10 CFU/cm2
and 1.91 log10 CFU/cm2, TPVC was 3.47 log10 CFU/cm2 and 2.56 log10 CFU/cm2, and
coliform count was 4.02 log10 CFU/cm2 and 1.91 log10 CFU/cm2 in abattoir 1 samples
and abattoir 2 samples respectively. In Graphs 3, 4 and 5, boxplot graphs of the
microbial counts under investigation have been constructed in order to compare the
contamination of the surfaces in the carcasses produced in these two abattoirs. The
TPVC and coliform counts were comparable, showing no actual differences. Still, the
TMVC variation was larger in abattoir 1 than in abattoir 2, with the median being
larger in abattoir 2 than in abattoir 1; therefore, the production process is judged as
inconsistent in abattoir 1, although in general the efficiency of its procedures could end
up in a less contaminated sheep carcass.
570
Table 4. Microbial counts of lamb hindquarters (log10 CFU/cm2) between the two abattoirs
sampled (average in bold, standard deviation in parentheses and italics).
Abattoir 1 Abattoir 2
(n=44) (n=122)
Total Mesophilic Count 4.02 (1.67) 1.91 (1.30)
Total Psychrophilic Count 3.47 (0.57) 2.56 (0.74)
Coliforms 1.26 (0.98) 1.26 (1.13)
Sierra et al. (1997) have reported larger microbial counts after the washing step of
a sheep abattoir in Ireland. In brief the average microbial counts in four plans
investigated ranged from 4.63 to 4.88 log10 CFU/cm2. The larger counts can be
attributed to the different carcass areas sampled which were the abdomen. This is in
accordance with the observation that the evisceration stage was considered the most
implicated in carcass contamination by Enterobacteriaceae, although no correlation
between the total counts and the Enterobacteriaceae was observed. Milios et al. (2011)
have reported, among other, that TMVC and Enterobacteriaceae counts in a Greek
lamb abattoir were 5.89 and 3.74 log10 CFU/cm2. They have also proposed that steam
decontamination could greatly benefit the overall microbial quality of the sheep
carcass. Røssvol et al. (2018) compared the effects of two evisceration methods on the
hygiene of sheep carcasses, stating that no difference exists between the methods
examined. Petruzzelli et al. (2016) report quite smaller TMVC counts (2.27 log
cfu/cm2) in bovine carcasses from three small-scale Italian abattoirs.
7 Total mesophilic count 7
Total psychrophilic count
6 Lamb 6 Lamb
5 5
Log CFU/cm2
Log CFU/cm2
4 4
3 3
2 2
1 1
0 0
Fig. 3. Comparison of total mesophilic Fig. 4. Comparison of total psychrophilic
counts of lamb hindquarters from abattoir 1 counts of lamb hindquarters from abattoir 1
and 2. and 2.
571
7
Coliforms
6 Lamb
5
Log CFU/cm2
4
3
2
1
0
Figure 5. Comparison of coliform counts of
lamb hindquarters between abattoir 1 and 2.
Acknowledgments. This research has been co-financed by the European Regional
Development Fund of the European Union and Greek national funds through the
Operational Program Competitiveness, Entrepreneurship and Innovation, under the
call RESEARCH – CREATE – INNOVATE (project code: T1EDK-05479).
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