See discussions, stats, and author profiles for this publication at: https://www.researchgate.

net/publication/283885435

Effect of moisture content on the quality of processed cheese spread

Article · January 2009

CITATIONS READS

11 625

1 author:

Magdy Mohamed Ismail

Agricultural Research Center, Egypt
100 PUBLICATIONS 335 CITATIONS

SEE PROFILE

Some of the authors of this publication are also working on these related projects:

‫ ﺗﺒﺴﻴﻂ اﻟﻌﻠﻮم اﻟﺰراﻋﻴﺔ‬Simplification of Agricultural Sciences View project

Jameed View project

All content following this page was uploaded by Magdy Mohamed Ismail on 16 November 2015.

The user has requested enhancement of the downloaded file.

Egyptian J. Dairy Sci., 37: 255-262, 2009

Effect of moisture content on the quality of processed cheese spread

BY
Hamad M. N. * and M. M., Ismail **

*Food science and Dairy Department, Faculty of Agriculture "Qena", South Vally
University.
** Dairy Technology Department, Animal Production Research Institute, Agricultural
Research Center.

ABSTRACT
The objective of this research was to determine the effect of increasing
water amount added to the ingredients on microbial and organoleptic properties
of processed cheese spread. Six treatments of cheese were made by adding 25, 26,
27, 28, 29 and 30 % water to the ingredients. Resultant cheese was stored for 3
months at 5-10°C or at 25-30°C. Increasing amount of water added to the blend
of processed cheese spread increased the pH values of resultant cheese while
decreased total viable bacterial count (TVBC) and sporeformes bacteria
numbers. Storage of processed cheese spread at 25-30°C decreased pH values
and increased TVBC and sporeformes bacteria numbers of cheese more than
that stored at 5-10°C. No significant differences (p> 0.001) were observed in
sensory scores of different treatments. From the results of feasibility study it
could appear that increasing the concentration of water added to the blend of
processed cheese spread raised the net profit.
Key ward: processed cheese spread- water- palm oil- Ras cheese.

Introduction
Processed cheese is a generic term used to describe 3 separate categories of
cheese. These categories are pasteurized processed cheese (PC), pasteurized
processed cheese food (PCF), and pasteurized processed cheese spread (PCS)
(Code of Federal Regulations, 2003). According to the Code of Federal
Regulations (2003), these 3 categories differ on the basis of the requirements for
minimum fat content on DM basis and the maximum allowed moisture content
as well as the quantity and the number of optional ingredients that can be used.
A typical processed cheese formulation contains substantial amounts of salt and
water, and it may be possible to replace the salt and water with salt whey. In
Egypt processed cheese is one of the most popular varieties of cheese,
particularly, among the children due to its palatability, high nutritive value and
spread ability. The ingredients used in processed cheese manufacture different
from plan to other but they usually consists from aged cheese such as Ras cheese
, Young cheese or Quark cheese, butter oil (anhydrous) , palm oil , skim milk
powder and emulsifying salts.
On the other hand, salt whey, unlike sweet whey, cannot be conveniently
processed because of its high salinity level (Sanderson et al., 1996). Moreover, it
has a high biological oxygen demand and chemical oxygen demand, which make
its disposal a problem (Zayed and Winter, 1995). One possible alternative for

1
salt whey is to use it as an ingredient in processed cheese as it is or after
filtration. The use of whey retentate in processed cheese spread has several
technological, nutritional and economical advantages. Form the economical
point of view, the use of the cheap whey retentate to replace the expensive cheese
would reduce the cost of production of this product, and in the mean time, offer
a feasible way for the utilization of whey retentate. The high biological value of
whey proteins would improve the nutritional value of processed cheese spread
containing whey retentate. The addition of whey proteins in processed cheese
spread can also modify the functional properties of the product for variable uses.
Yield of cheese is very important factor for cheese producers, increasing of
this yield means more profits and little costs, so that the objective of this study
was to evaluate the feasibility of increasing yield of processed cheese
manufacture using whey retentate by adding water to cheese ingredients and
determine any influences on the chemical, microbial and sensory properties of
the resulting processed cheese.

Materials and Methods

Materials:
Quark cheese used in the ingredient blends was prepared from skim milk
concentrates by ultrafiltration, so added 10% palm oil, so homogenization at 50
bar, so added citric acid and rennet at pH 5.2. Old Ras cheese (6-10 months) was
obtained from private Ras cheese production laboratory in Domiatt
Governorate. Precooked cheese was the residual of previous processed cheese
blend. The chemical composition of quark, old Ras cheese and precooked cheese
was indicated in Table (1). The emulsifying salts used were No emulsifier
(consists of sodium diphosphate, sodium polyphosphate and sodium
orthophosphate) and S9 emulsifier (consists of sodium diphosphate, sodium
polyphosphate and sodium triphosphate) which obtained from Benckiser
Knapsaek Gmb H, Lodenburg, Germany. Other ingredients were butter oil
(imported from France by Flecgard, S.A., Importer, Arab Trading Company),
palm oil (Misr Oil and Soap Company, Zagazig Factory) , skim milk powder
(low heat) (imported from USA by Egyptian Company for Trad , Industry "
Zahran") and potassium sorbate and nisin ( Pharmacentical Company, Pfizer).
Methods:
Preparation of whey retentate:
Ras cheese whey was pasteurized to 72°C/15 sec., then ultrafiltered at 45°C using
the ultrafiltration unit (Carbo-Sep unit type 25 151, France). The whey retentate
was heated at 60°C/15 sec., cooled to 45°C followed by homogenization using a
one stage homogenizer (Rannie, Copenhagen, Denmark) at 50 kg/ cm2. The
prepared ultrafiltrated whey retentate had 36% TS.

Table 1. Chemical composition of ingredients used in processed cheese making

Ingredients pH TS % Fat % Protein Salt %
%
Quark 5.20 31.50 11.50 13.20 0.22
Ras cheese 4.90 70.00 35.00 30.14 2.90
Precooked cheese 5.75 49.50 26.50 - 2.70
Whey 6.02 8.76 0.10 3.44 0.22
Whey retentate 5.75 36.00 2.10 28.75 1.00

2
Manufacture of processed cheese spread:
The manufacture of processed cheese spread was carried out as described
by Meyer (1973). The detailed ingredients blends and formulations for six cheese
treatments are indicated in Table (2). From pervious study (Hamad 1997), we
added whey retentate to the blend of processed cheese by 7.5% and different
amounts of water were used as mentioned in Table (2). Processed cheese was
made as follows:
Ras cheese was cut into small-pieces with a sharp knife. The pieces were fed
into electric mincer to convert them into finally minced cheese. Each formulation
of blends (except nisin) was placed in a 40 kg processing kettle (Kustner, SA
Geneva – 22H 210 986), closed and heated by direct steam injection at pressure
of 3-5 kg/cm2 under continuous stirring, at a temperature of 90-94°C for 10
minutes, and the melted cheese was maintained at such temperature for 3
minutes and then nisin was added. The resultant processed cheese spread of all
treatments were filled in 160 g glasses and stored for 3 months at 5-10°C
(refrigerator) or at 25-30°C (room temperature). The processed cheese were
chemically, microbiologically and organoleptically analyzed while fresh at zero
time and then after 1, 2, and 3 months of storage.

Table 2. Processed cheese formulation

Ingredients Control Treatments
% (A) B C D E F
Quark 25.0 25.0 25.0 25.0 25.0 25.0
Whey retentate 7.5 7.5 7.5 7.5 7.5 7.5
Ras cheese 12.5 12.5 12.5 12.5 12.5 12.5
Palm oil 8.5 8.5 8.5 8.5 8.5 8.5
Butter oil 8.5 8.5 8.5 8.5 8.5 8.5
Skim milk powder 5.0 5.0 5.0 5.0 5.0 5.0
Precooked cheese 5.0 5.0 5.0 5.0 5.0 5.0
Emulsifying salts 3.0 3.0 3.0 3.0 3.0 3.0
Added water 25.0 26.0 27.0 28.0 29.0 30.0
Total 100 101 102 103 104 105
Preservatives 0.1% potassium sorbate + 12.5 ppm nisin

Cheese analyses:
Quark, Ras cheese, precooked cheese, whey and whey retentate samples were
analyzed for total solids (TS), fat and total protein contents according to Ling
(1963). The pH values were estimated using a pH meter type CG 710. Cheese was
analyzed pH according to Ling (1963). Salt contents of ingredients were
estimated using Volhard method according to Richardson (1985). Cheese
samples were analyzed for total viable bacterial count (TVBC); colifom bacteria;
staphylococci; moulds and yeast counts according to the methods described by
the American Public Health Association (1992). The cheese samples were scored
for outer appearance (20 points), inner appearance (40 points) and flavour (40
points) by ten panelists according to Meyer (1973). The obtained results were
statistically analyzed using a software package (SAS, 1991) based on analysis of
variance. When F-test was significant, least significant difference (LSD) was
calculated according to Duncan (1955) for the comparison between means. The
data were presented, in the Tables, as the mean (± standard deviation) of 3
replicate experiments.

3
 Results and Discussion
pH values of Processed cheese spread:
Tanaka et al. (1986) conducted a definitive study to evaluate factors
important in the microbiological stability of pasteurized process cheese spreads.
Important factors included pH, moisture content, sodium chloride content, and
type and quantity of melting salts. In general, the relationship among these
factors is that, as pH and moisture content decrease and sodium chloride and
melting salt concentrations increase, the product becomes more inhibitory with
respect to microbial activity.
pH values of the fresh processed cheese spread and during storage period
are given in Table (3). An increase in water concentrations added to the cheese
ingredients caused a proportional increase in the final pH values of the cheese.
This may be due to dilution of ingredients acidity (especially old Ras cheese) by
added water. Gradual decrease in pH values was noticed in both cheese stored at
7 and 25°C for three months. However, great decrease occurred in cheese stored
at 25°C so these cheese treatments had the lowest pH values at the end of storage
time. The observed differences in cheese pH between treatments stored at
refrigerator and others stored at room temperature may be related to a
difference in bacterial growth and enzymatic activation rates in both cheese
treatments which happened slowly in cold storage cheese.
Changes in pH depend on change in lactose, protein and fat in cheese during
storage. Lactose plays an important role in this respect. Similar results were
reported by Emara (1984), El-Neshawy et al.,(1987), Farahat et al., (1993), Omar
(1994) and Hamad (1997).
Microbiological quality of processed cheese spread:
Total viable bacterial count (TVBC) and sporeformes bacteria numbers of
processed cheese spread were different with significant (p> 0.001) effects of both
adding water and storage temperature and their interaction (Tables 4 and 7).
The TVBC and sporeformes bacteria contents decreased with an increase in the
level of water added to the blends of cheese. At the end of storage time at 5-10°C,
treatment F (30% water) had the lowest TVBC (1.82 x103) whereas treatment C
(27% water) possessed the lowest number of sporeformes bacteria (1.50 x103). It
could also be appeared that TVBC and sporeformes bacteria numbers were
lower in cheese treatments stored at 5-10°C than that of stored at 25-30°C, which
is mainly due to the retarding effect of low temperature upon the growth and
activity of these bacteria. During storage period there was significantly (p<
0.001) increase in the TVBC and sporeformes bacteria numbers in all processed
cheese spread samples. The maximum growth of TVBC for treatments stored at
5-10°C or 25-30°C was achieved at the end of second month of storage period
and then it decreased, sporeformes bacteria numbers in all treatments stored at
25-30°C had the same trend while they reached to the highest levels at the end of
storage period after three months in cheese treatments stored at 5-10°C. In spite
of treatment A (control) had the highest TVBC and sporeformes bacteria
numbers but the rates of increasing in these microbial groups throughout the
different examined periods were higher in other treatments as compared with
treatment A. The increasing rates of TVBC from beginning and end of storage
period at 5-10°C were 13.69, 13.75, 14.29, 18.06, 19.61 and 21.33% for
treatments A, B, C, D, E and F respectively.

4
 Table 3. The pH values of processed cheese as affected by increasing water
concentrations in formulations
Treatments Storage time pH
(month) Storage temperature °C
7±2 25±3
A 0 5.90 5.90
(25% water) 1 5.82 5.85
2 5.65 5.68
3 5.57 5.68
B 0 5.93 5.93
(26% water) 1 5.88 5.90
2 5.69 5.81
3 5.60 5.80
C 0 5.95 5.95
(27% water) 1 5.90 5.91
2 5.76 5.80
3 5.62 5.78
D 0 5.96 5.96
(28% water) 1 5.88 5.91
2 5.69 5.77
3 5.59 5.75
E 0 6.00 6.00
(29% water) 1 5.87 5.90
2 5.65 5.85
3 5.58 5.80
F 0 6.00 6.00
(30% water) 1 5.88 5.91
2 5.65 5.87
3 5.59 5.80

Coliform bacteria, molds and yeast and Staphylococcus aureus were not
detected in all treatments of fresh processed cheese and during storage period
due to good hygienic condition during manufacturing and storage period.
Processed cheese spread sensory properties:
No significant differences (p> 0.001) were observed in sensory scores of
different treatments (Tables 5 and 7). It is obvious that the total score gained by
the examined cheese, generally, decreased by advancing the storage period. Such
decrease, however, was more noticeable when storage was carried out at higher
than at lower temperature. Outer and inner appearances were perceived to be
similar in the control (treatment A) and other treatments of processed cheeses.
Overall flavour scores were slightly higher for processed cheese made using 29
and 30% water (treatments E and F) than those made using 25, 26, 27 and 28%
water (treatments A, B, C and D respectively). However, samples E and F
obtained the same higher scores than the rest samples but the most panelists
preferred sample E than F. From the results of sensory evaluation, it seems that
adding 29% water to blend of processed cheese spread improves sensory
properties of the resultant cheese by improving flavour.

5
 Table 4. Effect of adding water to ingredients and storage temperature on some
microbial groups of processed cheese spread
Treatments Storage TVBC Coliform Spore- Moulds  Staph.
3
time (x10 ) bacteria forms Yeast aureus
(month) (x102) bacteria (x102) (x102)
(x103)
Storage temperature °C
7±2 25±3 7±2 25±3 7±2 25±3 7±2 25±3 7±2 25±3
A 0 1.68 1.68 - - 1.10 1.10 - - - -
(25% 1 1.50 3.70 - - 1.30 2.30 - - - -
water) 2 2.35 6.00 - - 1.43 4.80 - - - -
3 1.91 5.15 - - 1.56 3.30 - - - -
B 0 1.60 1.60 - - 0.99 0.99 - - - -
(26% 1 1.49 2.53 - - 0.84 2.00 - - - -
water) 2 2.00 6.00 - - 1.33 4.10 - - - -
3 1.82 5.00 - - 1.52 2.99 - - - -
C 0 1.61 1.61 - - 1.01 1.01 - - - -
(27% 1 1.50 2.71 - - 1.07 2.00 - - - -
water) 2 1.95 6.00 - - 1.28 3.83 - - - -
3 1.84 5.10 - - 1.50 2.99 - - - -
D 0 1.55 1.55 - - 1.00 1.00 - - - -
(28% 1 1.50 2.18 - - 1.10 1.85 - - - -
water) 2 1.99 6.01 - - 1.31 4.23 - - - -
3 1.83 5.11 - - 1.56 3.01 - - - -
E 0 1.53 1.53 - - 1.00 1.00 - - - -
(29% 1 1.40 2.58 - - 1.15 1.99 - - - -
water) 2 1.98 6.00 - - 1.35 4.00 - - - -
3 1.83 5.00 - - 1.55 3.01 - - - -
F 0 1.50 1.50 - - 0.98 0.98 - - - -
(30% 1 1.38 2.63 - - 1.20 1.89 - - - -
water) 2 2.10 5.90 - - 1.50 4.10 - - - -
3 1.82 5.00 - - 1.67 3.00 - - - -

Feasibility study:
Tables (6a and b) show the simple economic analysis for increasing amount
of water in processed cheese spread manufacture. The costs of the ingredients
used in the examined blend and the total price as well as the net profit are
illustrated in the mentioned tables. It could appear that increasing the
concentration of water added to the blend of processed cheese spread raised the
yield and net profit.
Conclusions
Levels of added water when increased in the blend have a direct impact on
chemical and microbial characteristics of process cheese spread. This study
indicates that adding 29% water to blend of processed cheese spread improves
sensory properties of the resultant cheese by improving flavour. Also, increasing
amount of water added to ingredients in processed cheese spread increase yield
and so reduce costs and raised net profit.

6
Table (5): Sensory scores of processed cheese spread.
Treatments Storage Outer Inner Flavour Total
time Appearance Appearance (40) (100)
(month) (20) (40)
Storage temperature °C
7±2 25±3 7±2 25±3 7±2 25±3 7±2 25±3
A 0 18 18 37 37 37 37 92 92
(25% 1 18 18 36 37 37 35 91 90
water) 2 17 17 36 35 36 35 89 87
3 17 16 36 35 35 34 88 85
B 0 18 18 37 37 37 37 92 92
(26% 1 18 18 37 37 37 35 91 90
water) 2 17 17 36 36 36 35 89 88
3 17 16 36 35 35 35 88 86
C 0 18 18 38 38 37 37 93 93
(27% 1 18 18 37 37 37 36 92 91
water) 2 17 17 36 36 36 36 89 89
3 17 16 36 34 35 35 88 87
D 0 18 18 38 38 38 38 94 94
(28% 1 18 18 37 37 37 37 92 92
water) 2 17 18 36 36 36 36 89 90
3 17 17 36 34 35 36 88 87
E 0 18 18 38 38 39 39 95 95
(29% 1 18 18 37 38 37 37 93 93
water) 2 17 18 37 37 37 37 91 92
3 17 17 36 35 36 36 89 88
F 0 18 18 38 38 39 39 95 95
(30% 1 18 18 37 38 37 37 93 93
water) 2 17 18 37 37 37 37 91 92
3 17 17 36 35 36 36 89 88

7
 Table 6a. Economical studies on processed cheese spread
Ingredients Price The amount of Price of total
(Kg.) ingredient used in amount of
(L.E.) making 100kg cheese ingredient
(kg)
Quark cheese 8.00 25 200.00
Whey Retentate 5.00 7.5 37.50
Ras cheese 20.00 12.5 250.00
Skim milk powder 26.00 5.0 130.00
Precooked cheese 10.00 5.0 50.00
Palm oil 5.00 8.5 42.50
Butter oil 18.00 8.5 153.00
Emulsifying salt 14.00 3.0 35.00
0.1 % Potassium sorbate 40.00 100g 4.00
12.5 PPm (Nicin)/ kg cheese 3000 12.5ppm 3.75
Total Price of 100kg cheese -- -- 905.75 L.E.

Table 6b. Economical studies on processed cheese spread

Treatments Yield Cost of Production (100kg cheese) Cheese Gain Gain
(kg) Ingredients Processing Total Price(100kg)* L.E %
38 % (L.E.)
A 100.00 905.75 344.18 1249.93 1875.00 625.07 33.33
B 100.80 905.75 344.18 1249.93 1890.00 640.07 33.86
C 101.25 905.75 344.18 1249.93 1898.44 648.51 34.16
E 102.75 905.75 344.18 1249.93 1926.56 676.63 35.12
F 103.50 905.75 344.18 1249.93 1940.63 690.70 35.59
D 104.00 905.75 344.18 1249.93 1950.00 700.07 35.90
* Cheese Price = 18.75 (price of 1 kg cheese) x yield.

Table 7. Statistical analysis of processed cheese spread treatments

Analysis Effect of cheese treatments
Storage at 7±2 °C Storage at 25±3 °C
A B C D E F A B C D E F
pH 5.78cd 5.86ab 5.86ab 5.84abc 5.89a 5.90a 5.76d 5.78cd 5.81bcd 5.78cd 5.78cd 5.78cd
TVBC 1.86e 1.75f 1.73f 1.71f 1.68f 1.72f 4.13a 3.83bc 3.86bc 3.89b 3.78cd 3.72cd
abc d d cd bcd ab abc d a cd
SBN* 1.35 1.17 1.20 1.24 1.27 1.41 1.35 1.17 1.42 1.24 1.27bcd 1.44a
a a a a a a a a a a
Oapp** 17.62 17.75 17.50 17.50 17.50 17.25 17.25 17.25 17.25 17.75 17.75a 17.75a
a a a a a a a a a a
Iapp*** 36.25 36.25 36.75 37.75 37.25 37.25 36.00 36.25 36.25 36.25 37.00a 37.00a
abc abc abc abc ab a c bc abc ab
Flavor 36.25 36.25 36.25 36.50 37.00 37.25 35.25 35.50 36.00 36.75 37.00ab 37.25a
Effect of storage time (month)
0 1 2 3
pH 5.96a 5.88b 5.74c 5.69d
TVBC 1.58d 2.09c 4.08a 3.47b
d c b
SBN* 1.05 1.16 1.40 1.57a
a a a
Oapp** 18.00 18.00 17.25 16.79a
a a b
Iapp*** 37.67 37.17 36.25 35.33c
a b b
Flavor 37.67 36.58 36.17 35.33c
*SBN :sporeformes bacteria numbers; **Oapp :Outer appearances; *** Iapp: Inner
appearances
For each effect the different letters in the means the multiple comparison are different from each. Letters a
is the highest means followed by b, c …..etc.

8
 References
American Public Health Association (1992): Standard Methods for the Examination of
Dairy Products. Amer. Publ. Health Assoc. Inc.12th ed., New York, USA.
Code of Federal Regulations. (2003): Section 133.169 US Dept. Health Human Services,
Washington, DC.
Duncan, D. B. (1955).Multiple Range and Multiple F-test.Biometrics,11:1– 42.
El-Neshawy,A.A., Abdel-Baky,A.A., Farahat,S.M. and El-Desoki, M.E. (1987): Cheese
curd slurry in the manufacture of processed cheese spread. Egyptian J. Dairy
Sci.,15: 287-297.
Emara,H.M. (1984) : Effact of storage period on properties of processed cheese. M.Sc.
Thesis, . Zagazig Univ.
Farahat, S.M., Abdel-Baky,A.A., Aly, M.E. and Hana,U.B.B. (1993): The use of palm oil
in the manufacture of processed cheese spread. Zagazig J.Agric. Res., 20 (2A).
Hamad,M.N.(1997): Studies on the application of whey retentate produced by
ultrafiltration in process cheese manufacture. M.Sc. Thesis, . Mansoura Univ.
Ling, E. R. (1963). A text - book of Dairy Chemistry. Vol. 2, Practical, 3rd ed., Champan
and Hall, London, England.
Meyer,A. (1973): Processed Cheese Manufacture. Food Trade Press, Ltd, London.
Omar.M.A.M. (1994): A study on processed cheese. M.Sc. Thesis, . Al-Azhar Univ.
Richardson, G.H.(1985): Standard Methods of the Examination of Daity Products. 15th
ed. American Public Health Assocition. Washington, DC.
Sanderson, W. B., Brady, A. P., Whitehead, G. F., Oldham, I. J., and Brockwell, I. P.
inventors. (1996): Recycling salt solution in cheese processing and apparatus
therefore. Murray Goulburn Co-Operative Co. Limited, Australia, assignee. US
Pat. No. 5,73,237.
SAS (1991). SAS User’s guide: statistics. SAS Inst, Inc, Cary, NC.
Tanaka N., Traisman, E., Plantilnga, P., Finn, L., Flom, W., Meske, L. and Guggisberg,
J. (1986): Evaluation of factors involved in antibotulinal properties of
pasteurized process cheese spreads. J. Food Prot. 49526.
Zayed, G., and Winter,J. (1995): Batch and continuous production of lactic acid from
salt whey using free and immobilized cultures of lactobacilli. Appl. Microbiol.
Biotechnol. 44:362–366.

‫تقييم زيادة تصافي مفرودات الجبن المطبوخ بزيادة كمية الماء المضاف‬
.‫للمكونات‬
‫م ة م ةص‬ ‫تممد اسة ممث تمميادة نس م ال اء م ث ة م ة ض م إ ي ممو ات ا م د ا ممةباةد ة ب م ع ة ل مم‬
‫م ث اتم امد امع ا مةباةد‬ ‫ة تد بسث ب ة دتةببدمث ب ة سءمدث ب تفم هو مذة ة نم امع ة بم ع دم صمنت‬
‫ ب تد ت زسع ة ب ع ة ن تج دل‬.‫ ا ي و خ لث ة ب ع‬% 03 ‫ ب‬52 ،52 ،52 ،52 ،52 ‫بإض هث‬ ‫ةبعة ل‬
‫ ب تشدة ة ن م ج ي م أن نسم ال م دمث ة م ة ضم إ ي مو‬.‫م‬°03-52 ‫م ب‬°03 -2 ‫اسجث ةةسل‬ ‫اماث شه س‬
‫ات ا م د ا ممةباةد ة ب م ع ة ل م أاد ي ممو نس م ال تف م هو ة ب م ع ب ممدد ة مة د ة هدممدسبجدنو ب ي ممو ةا م‬
‫اس ى ة ب ع اع ة ال ة ف ث ة ت دث ب ة د ع ب ة ن ةبجدع ة ت و ب ة ن ةبجدع ة ذة ب هو ة م ب ة تمد ة ت مو‬
‫م اسجمث‬ ‫ ممذ ك تشمدة ة ن م ج ي مو أن ت مزسع ا مةباةد ة بم ع ة ل م‬.‫ت ةس ب ة ت ةس ة ت اث بمةةادد‬
‫دد ة ة د ة هددسبجدنو ب ة ن ةبجدع ة ت و هو دع أاى ي و نسم ال اس م ى‬ ‫م أاى ي و ةا‬° 03-52 ‫ةةسل‬
‫ب ة تمد ة ت مو ت ةسم ب ة ت ةسم ة ت امث‬ ‫ة ب ع اع ة ةا ة ف ث ة ت دث ب ة د ع ب ة ن ةبجدع ة ذة ب هو ة‬
‫ أسض م ل ممد سم ممف ةخ مه م د اتن سممث بةضممسث هممو‬.‫م‬° 2-2 ‫بممةةادد ار ساممث ب م ب ع ة ممزن م اسجممث ممةةسل‬
‫ ب اع ا دث أخمةى همين ا م ج اسة مث ة بمدبى تشمدة ي مو أن‬.‫ث‬ ‫اسج د ة رددد ة سءو ا بدع ة ت امد ة‬
‫ة ضم إ ت ام د ا مةباةد ة بم ع ة ل م أاد ي مو نسم ال همو صم هو سبم مذة ة نم امع‬ ‫نس ال اءب ة‬
.‫ة ب ع‬

View publication stats