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Abdelhai et al., J Food Nutr Disor 2015, 4:2
http://dx.doi.org/10.4172/2324-9323.1000167
Journal of Food &
Nutritional Disorders
Research Article
A SCITECHNOL JOURNAL
Some Chemical and
Microbiological Characteristics of
Shawerma Meat Product
Mandour H. Abdelhai1*, Abdel Moneim E. Sulieman2 and El Rakha
B. Babiker3
1Department
of Food Science and Technology, Faculty of Engineering and
Technology, University of Gezira, Wad-Medani, Sudan
2Department
of Biology, Faculty of Science, University of Hail, Hail Kingdom of
Saudi Arabia
3Food
Research Centre, Agricultural Research Corporation, Shambat, Sudan
*Corresponing
author: Department of Food Science and Technology, Faculty of
Engineering and Technology, University of Gezira, Wad-Medani, Sudan, Tel:
966538081679; E-mail: [email protected]
Rec date: Nov 13, 2014 Acc date: Apr 02, 2015 Pub date: Apr 06, 2015
Abstract
This study aimed to determine the chemical and
microbiological quality characteristics of Shawerma meat
product which is consumed largely as snack food in many
Arabic countries including Sudan. Fifteen samples of
Shawerma were collected from various sites in Wad Madani
(central Sudan). These sites included, AlsugAlkabeer (A),
AlsugAlsageer (B) and AlsugAlshabi (C). In addition, control
samples of Shawerma were prepared at the laboratory using
the most common method followed in Wad Madani. The results
indicated that there were notable differences in most of the
chemical components of raw and cooked Shawerma. The pH
value of the various Shawerma samples falls between 4.8 ± 0.1
and 5.4 ± 0.05. However, the protein content of raw Shawerma
(19.25 ± 0.9 to 23 ± 0.41%) was lower than that of cooked
Shawerma (22.75 ± to 28 ± 0.9%). The fat content in raw
Shawerma ranged between 3.44 ± 0.32 and 6 ± 0.1%, while in
cooked Shawerma, it ranged between 4.76 ± to 10 ± 0.15%.
The concentration of Fe, Na, and K were higher in cooked
Shawerma samples than in raw Shawerma samples. On other
hand, the microbiological analysis revealed that the product
contained high levels of total viable count, coliforms, yeast and
mould, and Staphylococcus spp., in addition, E.coli and
salmonella were detected in most of the raw and cooked
Shawerma.
Meat is highly perishable, because it is high in protein and moisture
and semi-neutral in pH which makes it an ideal medium for bacterial
growth [2].
Meat and meat products can make a valuable contribution to the
diets in developing countries since many diets in these countries are
based on cereals or root crops. It has less nutritional importance in
industrialized countries where a wide variety of foods of all kinds is
available.
The importance of meat in the diet is as a concentrated source of
protein which is not only of high biological value but its amino acid
composition complements that of cereal and other vegetable proteins
[3].
Fresh meats from food animals and birds contain a large group of
potential spoilage
bacteria that include species of Pseudomonas, Acinetobacter,
Moraxella, Shewanella, Alcaligenes, Escherichia, Enterobacter,
Serratia, Hafnia, Proteus, Brochothrix, Micrococcus, Enterococcus,
Lactobacillus, Leuconostoc, Carnobacterium, and Clostridium, as well
as yeasts and molds [4]. The kind and amount of spoilage of meat
depend upon the availability of nutrients, presence of oxygen,
temperature of storage, pH, the storage time of the product, and the
generation time of the spoilage microorganisms under a given
environment [5].
Shawerma is also not an indigenous food of the Sudan, it started
entering in the 1980s from the Turk region. The Shawerma in Turkish
language means meat slices and meat barbecue. Shawarma is an Arabic
meat preparation, where lamb, chicken, turkey, beef, veal, or mixed
meats are placed on a spit (commonly a vertical spit in restaurants),
and may be grilled for as long as a day. Shavings are cut off the block
of meat for serving, and the remainder of the block of meat is kept
heated on the rotating spit. Nowadays, it is one of the most popular
foods, and consumed in large amounts in Sudan. However, the raw
shawerma is highly perishable, because it is high in protein and
moisture and semi-neutral in pH which make it an ideal medium for
bacterial growth [7]. Objective of the present study was to evaluate the
chemical composition and microbiological characteristics of
Shawerma meat product.
Materials and Methods
Collection of samples
Keywords:
Shawerma;
Microbiological tests
Meat;
Protein;
Macro-mineral;
Introduction
Meat and meat products are one of the main components of the
human diet. Meat is supplying the human body with proteins easily
digestible proteins and contains diverse nutrients like iron. Due to the
increasing sensitivity of consumers the requirements regarding the
quality of meat and meat products are constantly growing [1].
There are two major aspects of meat quality, nutritional quality
which is objective and "eating" quality as perceived by the consumer flavour, juiciness, tenderness and colour - which is highly subjective.
Fifteen processed Shawera samples were collected immediately after
processing in sterilized containers from different markets at Wad
Madani, central Sudan [8] samples from each market, these markets
included: Aldepaga (A), AlsugAlkabeer (B), AlsugAlsageer (C),
AlsugAlshabi (D) and the industrial area (E). In addition, raw Shawera
was prepared at laboratory level (L) using raw beef purchased from the
local butcher at Wad Madani local market. The samples were
transported under aseptic conditions to the Meat Technology
Laboratory of the Department of Food Science and Technology,
University of Gezira.
Preparation of Shawerma at the laboratory
The common traditional method was followed in preparation of
Shawerma Figure 1 at the laboratory early in the morning as follows:
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Citation:
Abdelhai MH, Sulieman AME, Babiker ERB (2015) Some Chemical and Microbiological Characteristics of Shawerma Meat Product. J Food Nutr
Disor 4:2.
doi: http://dx.doi.org/10.4172/2324-9323.1000167
The beef meat (1 kg) was cut and kept at a refrigerator for
overnight. The ingredients (butter peanut, eggs, sauce, oil, nutmeg,
garlic, Chinese and cassia pepper) were mixed together to produce
liquid recipe. Then the beef meat was mixed with the liquid recipe and
put in stick in Shawerma machine at 110°C. The stick turns over itself
near the fire.
hours [7,10]. The counts were presented as colony forming units per
gram (cfu/g).
The coliforms count was determined by plating one ml of sample
onto Mac Conkey Agar media. The plates were incubated at 37ºC for
48 hours and the counts were presented as colony forming unites per
gram (cfu/g). Plates showing positive coliform were subjected to the
confirmed test using Brilliant green bile lactose broth in test tubes with
Durham tubes. The test tubes were then incubated at 44ºC for 48
hours. Each confirmed positive tube was subcultured into E.C. broth
medium and then incubated at 44.5ºC for 24 hours. Tubes showing
any amount of gas production were considered to be positive.
For determination of staphylococcus count, 0.1 ml was plated onto
Baird Parker Agar medium and the inoculum was distributed evenly
using sterile glass rod. The plates were then incubated at 37ºC for 24
-48 hours and the counts were presented as colony forming units per
gram (cfu/g).
Figure 1: Preparation of Shawerma
Proximate chemical composition
The contents of moisture, protein, fat, crude fibre and ash were
determined according to the AOAC [8] method for samples consisting
of raw and cooked Shawerma as well as the laboratory made
Shawerma (LMS). The carbohydrate content in various samples was
determined by subtracting the sum of moisture, protein, ash, crude
fiber and fat content from 100 and the pH of the various samples was
measured using (pH -meter 7020).
Macro-minerals determination
Potassium (K) and sodium (Na) concentrations were accomplished
by means of flame photometer model (Corning 400 flam photometer),
and iron (Fe) by Spectrophotometer (Spectrumlab 22 PC). These
minerals were determined according to the AOAC [9] method.
Microbiological analysis
Serial dilutions were prepared for the various microbiological
analyses as follows:
Thirty grams from each sample was shaken thoroughly with 270 ml
sterile distilled water to give 10-1 dilution. A set of 6 tubes containing
9 ml sterile distilled water was prepared and 1ml of the suspension was
transferred to the first tube of the dilution series. This was repeated up
to the dilution 10-7.
For the determination of total viable count, one ml aliquots from
suitable dilutions were transferred aseptically into sterile Petri dishes.
To each dilution 10-15 ml of melted and cooled (42ºC) plate count
agar were added. Inoculums was mixed well with the medium and
allowed to solidify. The plates were then incubated in an incubator at
37ºC for 24-48 hours.
For the determination of yeast and mould count, from suitable
dilutions 0.1ml samples was aseptically surface plated onto potato
dextrose agar medium (PDA) with 40 ppm chloramphenicol added to
inhibit bacterial growth. The plates were incubated at 25ºC-28ºC for 48
Volume 4 • Issue 2 • 1000167
For salmonella detection, 10 grams of sample were weighted
aseptically and mixed well with 100 ml sterile nutrient broth. This was
incubated at 37ºC for 24 hours. Then 10 ml were drawn aseptically and
added to 100 ml selenite broth. The broth was incubated at 37ºC for 24
hours. Then with a loopful streaking was done on dried Bismuth
sulphite agar plates. The plates were then incubated at 37ºC for 72
hours. Black metallic sheen discrete colonies indicated the presence of
salmonella. A confirmatory test was carried out by taking a discrete
black sheen colony and sub culturing it in a Triple sugar iron agar
tubes. Production of a black colour at the bottom of the tube confirms
the presence of salmonella.
Results and Discussion
Composition of Shawerma samples
Tables 1 and 2 show the chemical composition of Shawerma
samples collected from various areas as well as Laboratory Made
Shawerma (LMS), respectively. The pH value falls between 4.8 ± 0.1
and 5.4 ± 0.05. The process of broken down of glycogen to lactic acid
in the muscle meat after slaughtering serves an important function in
establishing acidity (low pH) in the meat. The typical taste and flavour
of meat is only achieved after sufficient drop in pH down to 5.8 to 5.4.
The pH is also important for the storage life of meat. From the
processing view point, meat with pH 5.6-6.0 is better for products
where good water binding is required (e.g. frankfurters, cooked ham),
as meat with higher pH has a higher water binding capacity. In
products which lose water during fabrication and ripening, meat with
a lower pH (5.6–5.2) is preferred as it has a lower water binding
capacity [11].
The moisture content of Shawerma samples was in the range
between 72.37 ± 0.21 and 69.24 ± 0.51% in raw Shawerrma, and
ranged between 68.02 ± 0.28 and 55.72 ± 0.29% in cooked Shawerma.
This difference in moisture content may be due to the differences in
cooking procedures. It has been reported that water content can be
decreased in many meat products as a result of processing. During
these processes, care must be taken to protect the nutritional and
organoleptic (taste, smell, texture and appearance) properties of the
meat. Lawrie [12] reported a range of 56-72% %, while Palear et al.
[13] reported a value of 70% water in meat.
The ash content ranged between 0.97 ± 0.04 and 3.67 ± 0.1%). This
relative increase in ash content in comparison of that of fresh meat
• Page 2 of 5 •
Citation:
Abdelhai MH, Sulieman AME, Babiker ERB (2015) Some Chemical and Microbiological Characteristics of Shawerma Meat Product. J Food Nutr
Disor 4:2.
doi: http://dx.doi.org/10.4172/2324-9323.1000167
may be due to the ingredients used in Shawerma recipe. Hassan [14]
revealed a value of 0.96% ash in fresh beef, due to cooking method,
cooking temperature as well as the amount of ingredients added.
The protein content of raw Shawerma (19.25 ± 0.9 to 23 ± 0.41%)
was lower than that of cooked Shawerma (22.75 ± to 28 ± 0.9%). It has
been reported that the nutritional value of meat is essentially related to
the content of high quality protein. High quality proteins are
characterized by the content of essential amino acids which cannot be
synthesized by our body but must be supplied through our food. In
this respect the food prepared from meat has an advantage over those
of plant origin. Lawrie, [12] reported a range of 56-72%, while Palear
et al. [13] reported a value of 19% protein in meat. However, Hassan
[14] reported a value of 21.2% of protein in raw beef. The variation of
protein content could be attributed to the type of meat and the
additives used.
The fat content in raw Shawerma ranged between 3.44 ± 0.32 and 6
± 0.1%, while in cooked Shawerma ranged between 4.76 ± to 10 ±
0.15% Lawrie [12] reported a range of 5-34% %, while Palear et al.[13]
reported a value of 5% fat in meat. Fat is an important energy source
Site
A
because of the amount of energy produced can be doubled from that
generated by proteins and carbohydrates. Fat in meat is generally in
triglycerides form. The composition of triglycerides significantly
determines meat tenderness and roughness. Fatty acid composition in
each species is different and it is also has different effect on fat
properies in each species. Total saturated fatty acids in sheep, cattle
and pigs respectively 53%, 45% and 40%, while the unsaturated fatty
acids respectively were 47%, 55% and 60% [7].
The concentration of Fe, Na, and K were higher in cooked
Shawerma samples than in raw Shawerma samples, because of the high
moisture content in raw sample than the cooked samples. Lawrie [12]
found that Fe in (meat and meat products) raw and cooked was (2.3
and 3.9 mg/100ml), respectively. It has been reported that meat is an
excellent source of the minerals iron, zinc, and phosphorus. It also
contains a number of essential trace minerals, including copper,
molybdenum, nickel, selenium, chromium, and fluorine. The Table
provides a comparison of the vitamin and mineral content of different
types of meat [15].
B
C
Raw
Cooked
Raw
Cooked
Raw
Cooked
pH
4.8 ± 0.1
5.4 ± 0.05
5.0 ± 0.05
5.3 ± 0.1
5.0 ± 0.1
5.4 ± 0.5
Moisture (%)
71.02 ± 0.76
62.13 ± 0.5
69.24 ± 0.51
55.72 ± 0.29
72.37 ± 0.21
68.02 ± 0.28
Ash (%)
0.97 ± 0.4
0.98 ± 0.3
2.84 ± 0.4
3.67 ± 0.1
2.9 ± 0.4
1.34 ± 0.1
Protein (%)
20.7 ± 0.2
26.0 ± 0.45
23.0 ± 0.41
28.0 ± 0.9
20.7 ± 0.25
24.15 ± 0.1
Fat (%)
6.0 ± 0.1
9.0 ± 0.5
3.34 ± 0.32
10.0 ± 0.15
3.44 ± 0.32
5.17 ± 0.4
Crude Fiber (%)
0.52 ± 0.3
0.49 ± 0.4
0.67 ± 0.04
0.41 ± 0.01
0.20 ± 0.3
0.81 ± 0.6
Carbohydrate (%)
0.79 ± 0.3
1.4 ± 0.97
0.91 ± 0.78
2.22 ± 0.91
0.39 ± 0.83
0.51 ± 0.24
Fe (mg/100g)
1.9
1.36
1.9
1.8
1.6
1.8
Na (mg/100g)
59
53
46
57
45
52.5
K (mg/100g)
142
120
71
73
99
107
Table 1: Chemical composition of Shawerma samples collected from different areas
Microbiological characteristics of Shawerma
Table 3 shows the microbiological characteristics of Shawerma
samples collected from different areas, while the microbiological
characteristics of the laboratory made Shawerma (LMS) are shown in
Table 4. The lowest bacterial count in raw Shawerma samples was
detected in sample B (AlsugAlsageer) which was 2.6x105cfu/g, while
the highest was found in sample A (AlsugAlkabeer) which was
5.5x106cfu/g. However, the LMS sample showed a total bacterial count
of 9.4x104cfu/g. The microbial food additives most properly contribute
to the final total bacterial count. In the cooked samples the lowest total
bacterial count was found in sample B (3.6x103cfu/g), while the
highest was found in sample A sample (7.7x104cfu/g). However, the
total bacterial count in LMS found to be 4.5x102cfu/g. Musa [16]
reported an average aerobic plate count of 1.2x106cfu/g in fresh beef
before processing whereas, during processing the average was
9.4x105cfu/g, 1.1x107cfu/g and 2.6x108cfu/g for minced meat, sausage
and beef burger, respectively, and after processing the average reached
Volume 4 • Issue 2 • 1000167
6.4x106, 8.2x107 and 7.9x108 cfu/g for meat balls, sausage and beef
burger, respectively. Arafat [17] reported that the total viable bacterial
count in fresh meat ranged from 4.78x104 to 3.39x105cfu/g. The
contaminations of meat originate from external sources during
slaughtering bleeding, handling, skinning and cutting. Additional
contamination took place in the retails markets during handling,
chopping bocks, and from sawdust and containers [10].
Parameter
Raw
Cooked
pH
pH
5.3 ± 0.02
Moisture%
Moisture%
58.46 ± 0.29
Ash%
Ash%
3.07 ± 0.1
Protein%
Protein%
22.75 ± 0.9
Fat%
Fat%
4.76 ± 0.15
• Page 3 of 5 •
Citation:
Abdelhai MH, Sulieman AME, Babiker ERB (2015) Some Chemical and Microbiological Characteristics of Shawerma Meat Product. J Food Nutr
Disor 4:2.
doi: http://dx.doi.org/10.4172/2324-9323.1000167
Fiber%
Fiber%
0.58 ± 0.01
Carbohydrate%
Carbohydrate%
10.39 + 0.06
Na mg/100g
Na mg/100g
42
K mg/100g
K mg/100g
92
Fe mg/100g
Fe mg/100g
2.8
In raw Shawerma the highest coliform level was found in sample A
(3.5x106cfu/g), while the lowest was found in sample C (1.0x105cfu/g).
However, the LMS contained 5.0x104cfu/g coliforms. In cooked
Shawerma the highest was found in sample A (2.5x103cfu/g), however,
they were not detected in sample B and the LMS. All the raw and
cooked shawerma samples are positive for coliform showed the
presence of E. coli. The detection of E. coli after cooking makes the
product has evidence for human contamination.). Most of the
coliforms on meat probably originate from contamination on the hide
of the animal. This contamination could be of enteric origin but may
also come from soil and vegetation. Ayres (1979) [21]. State that the
most probable number for E. coli should not exceed (10-102 cfu/g).
Table 2: Chemical composition of Laboratory Made Shawerma (LMS)
In raw Shawerma, the lowest yeast and moulds count was found in
sample C (AlsugAlshabi) to be 2.6x103cfu/g, while the highest was
found in sample A (2.1x104cfu/g), and the LMS contained
8.4x103cfu/g. In cooked Shawerma the lowest yeast and mould count
was found in sample B, while the highest was found in sample A and
sample C contained 2.0x102cfu/g, however, the raw LMS contained
3.4x10 cfu/g. Moulds are abundant in the human environment. It has
been reported that moulds often contaminate vegetable and animal
products, becoming a source of diseases in man and slaughter animals
[18]. The conditions of the environment in the manufacturing rooms,
stores, refrigerators and shops are very suitable for the development of
moulds inside the products, but more frequently on the surface of
various sorts of meat and meat products [19]. Generally, the spoilage
of food caused by bacteria, yeasts, and moulds is a complex process
that is determined by different factors such as the food and the
environmental conditions, and if these conditions are suitable for all
three groups, then bacteria will often grow more quickly than yeasts
and yeasts will grow more quickly than moulds [20].
Site
Staphylococcus spp. was only detected in sample B (raw and
cooked) and in the raw LMS. However, it was eliminated in the cooked
sample of the LMS. The SSMO [22] standard requires the absence of
salmonella in meat products. Results presented in this study was
different from area to another, this differences was probably due to
different factors associated with different locations. During handling,
the contaminations came from knives, saws, cleavers, slices, grinders,
choppers, scales, sawdust, and containers, as well as form the market.
The detection of harmful microorganisms in some of Shawerma
product will create health risk to the consumers; it seems that the
temperature used is not sufficient to destroy those microbial groups.
Other factors of contamination could be the method of cooking and/or
the mishandling of the raw meat and the final products. It has been
reported that the lower the pH, the less favorable conditions for the
growth of harmful bacteria. Meat of animals, which had depleted their
glycogen reserves before slaughtering will not have a sufficient fall in
pH and will be highly prone to bacterial deterioration.
A
B
C
Raw
Cooked
Raw
Cooked
Raw
Cooked
Total viable bacteria count
(cfu/g)
Total viable bacteria count
(cfu/g)
Total viable bacteria count
(cfu/g)
Total viable bacteria count
(cfu/g)
3.6x103
3.6x103
6.9x103
Total yeast
(cfu/g)
Total yeast
(cfu/g)
Total yeast
(cfu/g)
Total yeast
(cfu/g)
2.2x10
2.2x10
2.0x102
&
mould
&
mould
&
mould
&
mould
Coliform (cfu/g)
Coliform (cfu/g)
Coliform (cfu/g)
Coliform (cfu/g)
Nil
Nil
2.5x102
E. coli
E. coli
E. coli
E. coli
-ve
-ve
+ve
1.5x102
1.5x102
Nil
-ve
-ve
-ve
Staphylococcs
Staphylococcs
Staphylococcs
Staphylococcs
spp. (cfu/g)
spp. (cfu/g)
spp. (cfu/g)
spp. (cfu/g)
Salmonella
Salmonella
Salmonella
Salmonella
Table 3: Microbiological characteristics of Shawerma samples collected from different areas
Parameter
Total viable
count (cfu/g)
Total yeast & mould
Coli form
(cfu/g)
(cfu/g)
E. coli
Staphylococcs
Salmonella
Spp.
(cfu/og)
Raw
9.4x104
9.4x104
5.0x104
+ve
1.5x106
+ve
Cooked
4.5x102
4.5x102
Nil
-ve
Nil
-ve
Table 4: Microbiological characteristics of laboratory made Shawerma (LMS).
Volume 4 • Issue 2 • 1000167
• Page 4 of 5 •
Citation:
Abdelhai MH, Sulieman AME, Babiker ERB (2015) Some Chemical and Microbiological Characteristics of Shawerma Meat Product. J Food Nutr
Disor 4:2.
doi: http://dx.doi.org/10.4172/2324-9323.1000167
Conclusion
8.
Raw meat used for the processing of Shawerma is a low quality
meat. Shawerma showed poor microbiological quality since the load in
many cases exceed the allowed standard level. The cooking
temperature (heat treatment) to which Shawerma products is exposed
is not sufficient to eliminate harmful microorganisms such as E. coli.
High quality meat has to be used to process meat products.
9.
Shawerma should be cooked properly so as to eliminate spoilage
and pathogenic microorganisms. Different part of Shawerma machine
should to be cleaned thoroughly using detergents and hot water. The
consumption of these products may lead to serious health risks. -The
local government should be prohibiting ceiling this type of food at
Wadmedani town. Further study is needed to highlight the problem
associated with meat handling, preparation, cooked and distribution
and its influence on the final product quality in Sudan.
Acknowledgements
Our sincere gratitude to the members of the Department of Food
Science and Technology, Faculty of Engineering and Technology,
University of Gezira for their assistance during this study.
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