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Evaluation of Antimicrobial Effects of Gouda Cheese Wax

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ABSTRACT
Background and objectives: Gouda Cheese is regarded as a high quality and one
of the most popular cheeses in the world. The defining characteristics of Gouda cheese are its
yellow color, great aroma and taste of caramel sweetness. The cheese should be well chilled
before waxing, to get better seal. The seal is very important to prevent contamination with
molds and putrefactive bacteria. Cheese wax is made from paraffin with additional
microcrystalline to make pliable for better seal. The aim of this study was to investigate
antibacterial effects of Gouda cheese wax.
Methods: Gouda cheese wax samples were collected from four different
manufacturers in Iran. The total count of coliforms, Escherichia coli, Salmonella, coagulase-
positive Staphylococcus and mold and yeast on the samples was determined. The
antimicrobial activities of Gouda cheese wax against E. coli, S. aureus, Saccharomyces
cerevisiae, Aspergillus brazilissis and Salmonella enterica were investigated by determining
minimum bactericidal concentration and minimum inhibitory concentration.
Results: The results indicated that all Gouda cheese wax samples were prepared in
accordance with the national standards. In addition, the examined wax samples had no
antimicrobial properties against the tested microorganisms.
Conclusions: The wax used in production of Gouda cheese in Iran has no
antimicrobial properties.
Keywords: Escherichia coli , Cheese , Salmonella .
DOI: 10.29252/mlj.15.1.18
Evaluation of Antimicrobial Effects of Gouda Cheese Wax
Received: 2019/12/07
Revised: 2020/10/10
Accepted: 2020/10/14
This work is licensed under a Creative
Commons Attribution 4.0 License.
Mojtaba Mohammadzadeh Vazifeh
(PhD)Department of Microbiology and
Microbial Biotechnology, Faculty of Life
Sciences and Biotechnology, Shahid
Beheshti University, Tehran, Iran
Seyed Masoud Hosseini
(PhD)Department of Microbiology and
Microbial Biotechnology, Faculty of Life
Sciences and Biotechnology, Shahid
Beheshti University, Tehran, Iran
Ali Mohammadi
Department of Microbiology, Faculty of
Biological Sciences, Alzahra University,
Tehran, Iran
Mahdi Jahanfar
(PhD)Department of Microbiology and
Microbial Biotechnology, Faculty of Life
Sciences and Biotechnology, Shahid
Beheshti University, Tehran, Iran
Hadi Maleki
(PhD)Department of Microbiology and
Microbial Biotechnology, Faculty of Life
Sciences and Biotechnology, Shahid
Beheshti University, Tehran, Iran
Corresponding author: Seyed Masoud
Hosseini
Tel: +982129905913
Email: Ma_Hosseini@SBU.AC.IR
Address: Department of Microbiology and
Microbial Biotechnology, Faculty of Life
Sciences and Biotechnology, Shahid
Original Article
MATERIALS AND METHODS
Samples of Gouda cheese wax were collected
from four Iranian dairy manufacturers between
April and June 2018. Table 1 shows the
specifications of the collected samples.
Culture media including violet red bile lactose
agar, mannitol salt agar, lauryl sulfate broth,
SS agar and yeast extract glucose
chloramphenicol agar were purchased from
Merck Co. (Germany) to culture coliforms, S.
aureus, E. coli, Salmonella and mold and
yeast, respectively (12). The standard strains
E. coli ATCC 19118, S. aureus ATCC 6538,
Saccharomyces cerevisiae PTCC 5074,
Aspergillus brasiliensis and Salmonella
enterica PTCC 1709 were obtained from the
Ibresco Co. (Iran).
According to the Codex C-5; 2013 and
Institute of Standards and Industrial Research
of Iran (ISIRI) 9013, all collected samples
were examined for microbial enumeration of
coliforms, E. coli, Salmonella and coagulase-
positive Staphylococcus based on ISO 4832,
ISO 11866-1, ISO 6785, ISO 68883 and ISO
6611, respectively (4, 5, 12-19).
The MIC of Gouda cheese wax against the
tested microorganisms was determined using
the broth microdilution method. First, serial
dilutions were prepared from the wax in
microbial growth media. The tested
microorganisms were added to the wax
dilutions and incubated for growth. The
examined wax was serially diluted in sterile
purified water. Next, 5 ml of each wax dilution
were added to 5 ml of concentrated media.
Two media control tubes were prepared by
mixing 5 ml sterile purified water with 5 ml of
2× media )14, 15).
All tubes were inoculated with 0.05 ml of the
test microorganisms and were incubated at 37
± 2 ˚C for 16-20 hours. Finally, absorption at
620 nm was read by a spectrophotometer
(UNIQO UV2100, USA) to determine
bacterial growth.
The MBC was determined as the lowest
concentration of cheese wax required to kill
the tested microorganisms (20, 21). After
determining the MIC, the microorganisms
were cultured on a culture medium of Muller's
Hilton-Agar sterile, and the plates were placed
in a 35 ˚C incubator for 16 to 18 hours.
INTRODUCTION
Gouda cheese is one of the most popular
cheeses worldwide (1, 2). This semi-hard to
hard cheese was first introduced in the
Netherlands and was prepared from
pasteurized cow’s milk. Aged Gouda cheese
have a strong flavor with a sharp yet sweet
taste at the same time. Various microbial and
chemical changes occur in the preparation of
Gouda cheese. At the final stage of production,
it is waxed with paraffin-based ingredients and
then dried (1, 2). Production of this cheese
include milk pasteurization, coagulation,
cutting the curds, releasing the whey,
moulding of cheese, brining, coating and
maturing and storing (3-5).
There are International and National Standards
on Gouda cheese that define the sensory,
microbial, chemical, physical and packaging
properties of this product. These standards also
determine the microbial limitations for
coliforms, Escherichia coli, Salmonella,
coagulase-positive Staphylococcus, mold and
yeast (4, 5).
According to Centers for Disease Control and
Prevention in the US, a total of 113 outbreaks
caused by cheese consumption were reported
during 19982015, resulting in 2418 illnesses,
291 hospitalizations and 18 deaths (6).
Gouda cheese wax is obtained from petroleum
derivatives. This type of wax can be recovered
and used in a wide range of desirable
applications. Paraffin and microcrystalline are
widely used in the food industry because of
their neutral properties. Paraffin with
microcrystalline are used in packaging of
various hard and semi-hard cheeses, such as
Edam cheese and Gouda cheese. Edible
paraffin and microcrystalline waxes are used
to provide strength and waterproof properties
(7-9). The function of the coating is to protect
the cheese from microbial contamination while
allowing moisture to evaporate. This coating is
semi-permeable, which allows cheese to
breathe and continue the maturation process
(10).
Research plays an important role in increasing
the longevity and improving the quality and
safety of cheese products (11). The aim of this
study was to evaluate antimicrobial effect of
Gouda cheese wax and to determine the
microbial contamination of Gouda cheese with
and without wax.
19/ Mohammadzadeh Vazifeh and colleagues
Medical Laboratory Journal, Mar-Apr, 2021; Vol 15: No 2
the microorganisms. In other words, the
collected samples of Gouda cheese wax had no
inhibitory effect on E. coli, S. aureus, S.
cerevisiae, A. brasiliensis and S. enterica.
DISCUSSION
Cheese is vulnerable to microbiological
deterioration throughout storage, distribution,
processing and ripening due to its high water
extensive microorganism development at
cheese surface, which considerably reduces the
RESULTS
All wax samples collected from Gouda cheese
met the required standards (Table 2).
The results showed that of the tested cheese
wax samples had no effects on the growth of
The results showed that of the tested cheese
wax samples had no effects on the growth of
the microorganisms. In other words, the
collected samples of Gouda cheese wax had no
inhibitory effect on E. coli, S. aureus, S.
cerevisiae, A. brasiliensis and S. enterica.
A
B
C
D
15
15
15
15
Table 1- Technical specifications of the collected Gouda cheese wax samples
ISO: International organization for standardization
HACCP: Hazard Analysis Critical Control Point
Gouda cheese wax samples
Total coliforms (Cfu/g)
E. coli
in one gram
Coagulase-positive
Staphylococcus
in one
gram
Mold and Yeast (Cfu/g)
Salmonella
in 25 grams
Manufacturer A
1
10>
Negative
Negative
0.3×102
Negative
2
10>
Negative
Negative
0.2×102
Negative
3
10>
Negative
Negative
0.4×102
Negative
4
10>
Negative
Negative
0.6×102
Negative
5
10>
Negative
Negative
0.5×102
Negative
Manufacturer B
1
10>
Negative
Negative
0.1×102
Negative
2
10>
Negative
Negative
0.1×102
Negative
3
10>
Negative
Negative
0.3×102
Negative
4
10>
Negative
Negative
0.3×102
Negative
5
10>
Negative
Negative
0.5×102
Negative
Manufacturer C
1
10>
Negative
Negative
0.1×102
Negative
2
10>
Negative
Negative
0.1×102
Negative
3
10>
Negative
Negative
0.3×102
Negative
4
10>
Negative
Negative
0.4×102
Negative
5
10>
Negative
Negative
0.1×102
Negative
Manufacturer D
1
10>
Negative
Negative
0.7×102
Negative
2
10>
Negative
Negative
0.4×102
Negative
3
10>
Negative
Negative
0.1×102
Negative
4
10>
Negative
Negative
0.1×102
Negative
5
10>
Negative
Negative
0.2×102
Negative
Table 2- The results of contamination of wax of Gouda cheese samples
20/ Evolution of Antimicrobial. . .
Medical Laboratory Journal, Mar-Apr, 2021; Vol 15: No 2
(27). Haniyah et al. reported that eight weeks
of ripening Gouda cheese with a composite
edible film containing modified lysozyme can
effectively inhibit microbial growth both at the
surface and inside Gouda cheese (28).
Saravani et al. prepared an inhibitory edible
coating for Gouda cheese based on whey
protein containing lactoperoxidase and Bunium
persicum essential oil in order to control post-
pasteurization contamination. Their results
showed that the Bunium persicum essential oil
in combination with lactoperoxidase system
can be applied as natural antimicrobial agents
for extending the shelf life of washed and
ripened Gouda cheese (26). Generally, wax
can protect cheese against contamination and
inappropriate physical conditions to some
extent but cannot remove contaminations once
the cheese become contaminated. Therefore, it
is recommended that dairy manufacturers use
active wax or wax with antibacterial capacity
in production of cheese (27, 28).
CONCLUSION
The Gouda cheese wax samples collected from
Iran have no antimicrobial properties. It is
recommended to use Gouda cheese coating
with antimicrobial properties to minimize the
risk of contamination and spread of
microorganisms.
ACKNOWLEDGEMENTS
None.
CONFLICT OF INTEREST
The authors declare no conflict of interest.
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microorganisms. Maintaining hygienic
conditions during ripening and storage plays a
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coating used for preventing contamination,
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Waxing cheese is a simple method to protect
hard cheese from airborne bacteria, unwanted
mold and excessive drying. This process is
generally applied on semi-hard and hard
cheeses. Hard cheese wax is a food-grade,
paraffin-based wax. We found that wax
samples from Gouda cheese had no inhibitory
effect on potential pathogens in Gouda cheese,
which is in agreement with two previous
studies (11, 23).
Coating is a traditional method of maintaining
the quality of cheese during shelf life. Cheese
can be contaminated with various
microorganisms during initial preparation,
processing, packaging and storage. Thus, it
can be concluded that antimicrobial
compounds can improve cheese quality and
shelf life (6, 26).
Our findings indicated that wax had no role in
the prevention of microbial contamination of
Gouda cheese. Some studies have investigated
production of wax with antimicrobial
properties. For instance, Taherkhani et al. used
Kermanian Black Cuminin extract in Gouda
cheese wax to induce antimicrobial properties
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How to Cite:
Mohammadzadeh Vazifeh M, Hosseini SM, Mohammadi A, Jahanfar M, Maleki H[Evolution of Antimicrobial Effects of Gouda
Cheese Wax ]. mljgoums. 2021; 15(2): 18-22 DOI: 10.29252/mlj.15.2.18
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This study describes the diffusion of NaCl and water in Gouda cheese during brining and ripening. Furthermore, we established water activity as a function of the NaCl-in-moisture content in Gouda cheese during ripening. We determined NaCl content, water content, and water activity in block-type Gouda cheeses that were brined for 3.8 d and foil-ripened for a period of 26 wk, and in wheel-type Gouda cheeses that were brined for 0.33, 2.1, or 8.9 d and subsequently nature-ripened for a period of 26 wk. The calculated diffusion coefficients of NaCl during brining were 3.6·10(-10) m(2)s(-1) in the block-type Gouda cheeses and 3.5·10(-10) m(2)s(-1) in the wheel-type Gouda cheeses. Immediately after brining, gradients of NaCl and water were observed throughout both types of cheese. During ripening, these gradients disappeared, except for the water gradient in nature-ripened cheeses. An empirical model was derived for Gouda cheese, in which water activity is expressed as a function of the NaCl-in-moisture content, as established for different brining times, locations and ripening times. Moreover, the effect of reduced water activity on inhibition of growth of Listeria monocytogenes in Gouda cheese was calculated. In addition to the presence of lactate and a pH of 5.2 to 5.3, the reduced water activity as seen in Gouda cheese can substantially contribute to inhibition of microbial growth and even to inactivation when cheeses are brined and ripened for extended times and subjected to nature-ripening.
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