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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: All articles published in Journal of Food & Nutritional Disorders are the property of SciTechnol and is protected by copyright laws. Copyright © 2015, SciTechnol, All Rights Reserved. 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. References 1. 2. 3. 4. 5. 6. 7. Bender A (1992) Meat and meat products in human nutrition in developing countries. FAO Food Nutr Pap 53: 1-91. Meat Processin Hygiene. FAO Corporate Document Repository. Dilbaghi N, Sharma S (2007) Food spoilage, food infections and intoxications caused by microorganisms and methods for their detection.Food and Industrial Microbiology. James M J (2005) Modern Food Microbiology. IVth Edition. 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J Food Sci SSMO, Sudanese Standardization Metrology Organization, (2001) Sudanese Microbiological Standards for Frobic bacteria in fresh and processed beef B.Sc Master,University of Khartoum Fraizier WC, Westhoff DC (1978) Food Microbiology, 3rd edition, Macgraw. Hill Book Company. • Page 5 of 5 •