4.1 Introduction

The Camelidae is included in the genera Camelus (dromedary and Bactrian species), but also includes Lama (guanaco and Ilama), and Vicugna (vicuña and alpaca) (Saadoun and Cabrera 2008). However, the camel is often used broadly to describe all of the aforementioned camel-like animals. The one-humped dromedary (Camelus dromedarius) accounts for over 90% of all camels, while the two-humped Bactrian camel (Camelus bacterium) represents the remainder (Kadim et al. 2008). The approximately 28 million camels in the world have increased in number by about 38% between 2000 and 2014. Within the same period, camel meat production increased by 55% (approximately 250,000 camels slaughtered annually according to FAOstat (2015). Camels are important to the national economies for many countries in the world by providing high quality food for humans. Due to high carcass weights, camels can provide a substantial amount of high-quality meat to fulfill the increasing demand for protein sources arising from the rapid growth of the human population (El-Mossalami et al. 1996; Saparov and Annageldiyev 2005). Although, the marketing systems for camel meat are not well organized, the demand for camel meat generally exceeds supply and the meat from young stock is particularly sought after, as is the use of camel meat in blended meat products (Kadim et al. 2008). Improvement of camel meat valorization through local or regional marketing systems would provide opportunities for the integration of pastoralists into the market. In comparison with red meat from some other domestic species, camel meat has been found to generally contain less fat and ash, more moisture, and similar protein concentrations (Kadim et al. 2008).

Camel meat quality is described as tough and coarse in taste compared to meats from other animals (Kadim et al. 2008). This may be partly due to it often being a by-product of primitive traditional systems of production where it is mainly obtained from old males and females that have become less effective in their primary roles of providing products and servicing, or as breeding females. However, evidence suggests that quality characteristics of camel meat are similar to beef if animals are slaughtered at comparable ages (Kadim et al. 2008, 2011). This chapter summarizes some characteristics of dromedary camel meat with special emphasis on carcass and meat quality characteristics. It should be noted that comparisons of these characteristics between camels and other meat-producing species within controlled experiments where all animals have been treated in a similar way have seldom been made.

4.2 Carcass Characteristics

The main carcass characteristics of importance are summarised in Table 4.1 together with an indication of the ways in which they have been shown to change with increasing carcass weight based mainly on information from several meat-producing species other than camels. There is little information on the patterns of change for camels, but there is no reason to expect the patterns to be very much different.

Table 4.1 Important carcass characteristics of meat-producing animals together with general comments on the ways in which these characteristics change with increasing carcass weight, based mainly on results obtained from species other than camels. The examples of changes given here assume that other factors such as genotype, gender, nutrition and processing procedures remain the same
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4.2.1 Carcass Conformation

The shape of the camel carcass differs radically from that of other meat animal carcasses. Apart from the obvious shape of the dorsal hump, the most notable feature is the restriction of hind-limb muscles near the pelvis such that they do not overlap with the abdominal muscles (Swatland 2013). Thus, when the hind-limb is stretched back in a hanging carcass, it forms an indentation cranial to the ileum. This is because the camel has long limbs capable of considerable rotation relative to the vertebral axis. In a sitting camel, the distal end of the femur projects downwards towards the ground. Whereas, the distal end of the femur projects upwards in other sitting meat animals.

Camel carcass conformation refers to the proportional size of carcass parts and the relationship of the thickness of tissues to skeletal size. The importance of carcass conformation as an indicator of commercial value is based on the assumption that carcasses with better conformation have advantages in terms of lean meat content and proportion of higher priced cuts (Kempster et al. 1982). Therefore, camel breeders can use carcass conformation as an indicator of animals that are good meat producers. Differences in camel carcass conformation between the different groups of dromedary camels has been described in terms of variations in carcass depth from the scapula to sternum, width behind shoulder, maximum shoulder width and gigot width (Table 4.2). Similarly, Nsosoa et al. (2000) found large differences in carcass depth measurements between animal breed types and concluded that an increase in carcass weight significantly increased linear measurements in absolute terms but reduced them relative to weight. However, lack of information for camel carcass conformation has led to difficulties in understanding camel carcass quality. Therefore, camel carcasses need a standard carcass conformation to enable easy communication of carcass data, research results and trading terms in the camel meat industry. Visually assessed conformation as a useful indicator of carcass composition in various meat animal species has been the subject of many studies in the literature (Kempster et al. 1982), but the camel has not been investigated in this regard.

Table 4.2 Effect of three levels of feed intake (1.5, 2.0 and 2.5% of body weight) on camel carcass linear measurements (Al-Kharusi 2011)
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4.2.2 Carcass Weight and Dressing-Out %

A wide range of carcass weights (125–400 kg) have been reported for camels, with the variation due to differences in body condition, nutrition, sex, breed or type and age at slaughter (Table 4.3). The male camel carcasses were heavier than those of females by 32–34% (327 vs. 262 kg) (Mekonnen 2004). Kurtu (2004) found that the range of carcass weight of Ethiopian camels was 225–280 kg and 149–190 kg for males and females, respectively. Higher carcass weights of 240 and 232 kg of male and female Sudanese camels, respectively, were reported by Yousif and Babiker (1989), while a carcass weight of 231 kg was reported for male and 196 kg for female Sudanese camels (Wilson 1998). Average carcass weight of the Iranian camel was higher for males (300–400 kg), than for females (250–350 kg) (Khatami 1970). Hettrampf (2004) reported an average carcass weight for male 283 kg and 251 kg for female camels. Bakkar et al. (1999) found that the average camel carcass weights of three feeding groups (6–14 months of age) were 180.6 kg for concentrate plus alfalfa hay, 170.7 kg for concentrate plus Rhodes grass hay, and 168.1 kg for concentrate plus wheat straw treated with ammonia gas.

Table 4.3 Carcass weights and dressing-out percentages for male and female dromedary camels in several studies
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Camel carcass weight (including the hump) makes up about 55% of camel live weight (Herrmann and Fischer 2004), but carcass yield (DO%) of camels varies widely from 47.4% to 62.1% (Table 4.3). In general, the dromedary camel has a higher DO% value than cattle (Wilson 1998). Limited studies provide information on the relationship between slaughter weights, carcass weight and DO% calculated either on a live weight or an empty live weight basis for dromedary camels (Table 4.4) (Bahhamou and Baylik 1999; Biala et al. 1990; El-Gasim and El-Hag 1992; Kamoun 1995; Wilson 1998). The weight of hump which is mainly made up of fat may reach up to 40 kg and may account for 8.4% (5–13%) of the carcass weight (Kamoun 1995), thereby affecting DO%. Large fat camels had a DO% of 56.6%, whereas for relatively thin camels it was 51.4% (Yousif and Babiker 1989; Wilson 1998). For average carcass weights of 231–244 kg, hump weight varied from 4 kg to 31 kg (Kamoun 2004). An increase in DO% generally occurs as live weight increases.

Table 4.4 Live weights, carcass weight and dressing percentage in camel males
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Camel males had significantly higher DO% than females (Table 4.5), with values ranging between 51% and 54% for Ethiopian camels (Kurtu 2004). Higher differences in DO% between male and female camels, (57% for females and 63.8% for males) were reported by Yousif and Babiker (1989). In addition, Congiu (1953) reported a 56.1% DO% for male and 54.1% female Somali camels.

Table 4.5 Live weight, carcass weight and dressing-out% of dromedary camels
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4.2.3 Carcass Composition

Camel carcass sides are usually divided into forequarter and hindquarter by cutting between the 11 and 12th ribs. The forequarter can be divided into neck, shoulder, brisket, rib and plate (Herrmann and Fischer 2004; Kamoun 2004, Kadim and Mahgoub 2013). Khan et al. (2003) found that forequarters comprised about 34% of the total carcass, while the hindquarters constitute 25%. Excluding the hump (4.6%), the forequarter contributed 23.8% whereas the hindquarter contributed 21.3% of live weight in Somali × Turkana camels (Herrmann and Fischer 2004). In the same study, the forequarter, hind quarter, neck and hump constituted 44.3%, 39.7%, 7.1% and 8.6% of the carcass. The neck, being long, is usually separated from the carcass in the camel, contributed about 4% of live weight in the camel. The hindquarters average weights (% carcass) for camels ranged from 82 (45.2%) to 80 kg (47.6%). (Bakkar et al. 1999). Muscle, bone and fat components for the fore and hind quarters (Kamoun 1995) are given in Table 4.6. The hump fat accounted for 8.6% of the carcass weight, therefore, the higher proportions of fat in the forequarter may mainly be attributed to the hump fat. The back and leg cuts contained 77.6% and 74.1% of muscle respectively. The proportion of muscle, bone and fat in camels was 56%, 19% and 14%, respectively with muscle: bone ratio of 3.0 (Yousif and Babiker 1989). Wilson (1998) reported a proportion of 57% muscle, 26% bone and 17% fat in average camel carcasses. The proportion of muscle in nine Sudanese camels was 56%, with 19% bone, and 14% fat, with a muscle: bone ratio ranging from 2.7 to 3.0 (Yousif and Babiker 1989). The proportion of muscle in the camel carcass is comparable to that of cattle (Mahgoub et al. 1995a, b; Preston and Willis 1975) whereas carcass bone is higher and therefore the muscle to bone ratio is lower for camels (Babiker 1984). This may be attributed to the proportionately greater limb bone length in the camel. Males have higher ratios of forequarter to hindquarter mainly due to higher proportions of neck and hump. The forequarter/hindquarter ratio was 1.61% for males and 1.27% for females (Mekonnen 2004). The average weights of the forequarters, hindquarters, and the hump were 71.6 ± 11.6, 60.8 ± 8.8 and 7.5 ± 4.4 kg for males and 62.8 ± 9.9, 54.1 ± 14.9 and 7.4 ± 2.9 kg for female camels slaughtered at 10 years old (Mekonnen 2004).

Table 4.6 Muscle, bone and fat percentages in carcasses and different cuts from camel carcasses
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The species had a significant effect on carcass characteristics in a study in the Sabel environment in Niger Republic (Akpa et al. 2017; Table 4.7). Camel was superior in live weight, carcass weight, fore and hind quarters weights, legs and edible offal. Goat was better value in DO% but ranked the least in other carcass characteristics. The superiority of camel over other species in the carcass characteristics agreed with the reports of Al-Ani (2004), Saparov and Annageldiyev (2005) and Kadim et al. (2008). The camel yielded the highest live weight because the size of an animal positively influences the live and carcass weights of an animal (Hammond 1983) and because camel can thrive better in arid and semi-arid environments than cattle, sheep and goats. The high weight of fore quarter in camel than other red meat species agreed with the previous reports of Camfield et al. (1999) and Short et al. (1999) that the larger frame sized animals attain heavier final weights and have heavier carcasses than the smaller frame sized animals. The high dressing percentage of goat over camel could be attributed to proportionately lighter bones in goats than camels.

Table 4.7 Effect of species on carcass characteristics of camels, cattle, sheep and goats in Sahel environment (Akpa et al. 2017)
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The influence of sex and age of camel on carcass characteristics from the study of Akpa et al. (2017) are shown in Table 4.8. Generally, males were superior in carcass characteristics compared to females. The general superiority of males over females could be attributed to more fat deposition, especially at the renal region of the female animals and possibly due to the physiology of the male, which includes a faster growth rate and consequently, a greater elongation of bones (Wylie et al. 1997). Older camels were superior to young camels in carcass parameters (Hammond 1983; Abouheif et al. 1990; Kadim et al. 2008; Hamed et al. 2014). The significant effect of age on carcass characteristics may be attributed to the fact that more fat deposition occurs in older animals than on younger animals. Table 4.6 shows that the camel shoulder and leg cuts had a muscle proportion around 75%, while the neck and loin region had a muscle proportion of 71% and 60% respectively. The proportion of bone in carcass cuts was highest in the thoracic, dorsal and a minimum in the flank, while the proportion of fat was higher in the loin, which ranged between 14% and 19.3% while a minimum fat content was found in the neck, shoulder and leg cuts.

Table 4.8 Effect of age and sex on camel carcass characteristics (Akpa et al. 2017)
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4.2.4 Muscle Distribution

Distribution of muscle tissue in the carcass is important from a body development perspective. However, little is known about camel muscle distribution compared to cattle, sheep, pigs or goats. In general, muscle distribution is expressed as proportions of individual muscles and muscle groups relative to total carcass muscle in order to reflect muscle distribution in various carcass regions (Butterfield 1988). Table 4.9 shows the distribution of camel carcass muscle in nine major muscle groups in the nomenclature defined by Butterfield (1988). The largest proportion of muscle was in the proximal hind limb (about 30% of carcass muscle), which is made up of a large number of muscles including Gluteo biceps, Semimembranosus, Semitendinosus and Abductor. The contribution of this muscle group to total carcass muscle appears to be lower in camel than in cattle (29.9 vs. 34.1%) (Butterfield and May 1966: Mahgoub and Kadim 2013). The difference may be due to the proximal limb of camels being slender and shallow, possibly due to its role in camel movement and its role in camel squatting. The difference is more pronounced in the Gluteo biceps in camel, the Gluteal group, Semimembranosus and Semitendinosus are all in favour of cattle. However, the proportions of muscles in this group (muscle group 1) were similar to that in sheep and goats (Table 4.9). Muscle group 2 which contains the lower hind limb contributes about 4% of the total muscle with the gastrocnemius and soleus being the largest individual muscles. Its proportion in the carcass muscle appears to be lower than that in sheep and goats (Table 4.9). Muscle Group 3 which contains muscles surrounding spinal column contributed about 13% of the total muscle content. This is an important muscle group as its muscles contribute to high priced cuts including the sirloin, fore rib and rump. Some of its muscles will contribute to the chuck and blade cut in beef. It contains the largest muscle of the carcass, the Longissimus thoracis et lumborum muscle. Their proportion in camel was lower than that in sheep and goats (Table 4.9).

Table 4.9 Muscle groups (% total side muscle) in the carcass of camel, cattle, sheep and goats (Mahgoub and Kadim 2013)
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The abdominal muscle group (Muscle Group 4) makes up about 7% of carcass muscle content in the camel which was lower than in sheep and goats (Table 4.9). This muscle group, which is in the thin and thick flank cuts in beef and camel, are among the lower priced cuts. Proximal forelimb (Muscle Group 5) contributed to 18.5% of carcass muscle in the camel. This appears to be a much higher contribution than in cattle, sheep and goats. This is a very muscular area of the camel body because it needs to support the large neck and strong fore legs of the camel. Muscle group 6 includes muscle of the distal forelimb and contributed approximately 4% of the total muscle content. The extensor muscle group makes that the largest proportion of this group. The proportion of this group to total muscle is not much different from that of sheep and goats (Table 4.9). Muscle group 7, which contains muscles connecting the thorax to the forelimb, makes up 12% of total side muscle. This is an important group and it is well developed in the camel because of the large load of weight of the heavy forequarter in the camel. Its proportion in the camel carcass total muscle is greater than that in cattle sheep or goats (Table 4.9). The muscle group 8, connecting the neck to the forelimb, contributed to 2.8% of total muscle and is less significant. Muscle group 9 contains the intrinsic neck muscles is important and constitutes about 13.6% of carcass muscle, which is greater than that in sheep and goats. However, the neck cut is not among the high-priced cuts due to its high bone content. This is very pronounced in the camel with its extra-long neck. Generally, the most marked feature is that the camel has higher muscle proportions in the proximal forelimb and muscles connecting thorax to forelimb as well as intrinsic neck muscles. This resulted in the forequarter of the camel containing more muscles compared to other livestock (Mahgoub and Kadim 2013).

Camel forequarter has been reported to be heavier than the hind quarter although some authors attributed this to the presence of the hump (Kadim et al. 2008). Elgasim and El-Hag (1992) reported muscle content as percentage of total carcass muscle in Saudi camels as: 28, 22, 30 and 8 in hind legs, fore legs, ribs and backbone and neck. The expensive muscle group in the camel carcass appeared to be slightly higher than that in other livestock species (Mahgoub and Kadim 2013). This was mainly attributed to the higher proportions of the muscles in the proximal forelimb and muscles connecting forelimb to thorax. These muscles are well developed in order to carry the extra heavy neck. High contents of high-priced muscle groups indicate the economic value of the camel carcasses although it looks disfigured with slender distal limbs and sloping hind quarter. Muscle distribution over various parts of the carcass should be taken into consideration in camel meat processing and marketing. This includes devising a system of camel carcass grading, carcass cutting, and the pricing of commercial cuts.

4.3 Muscle Structure

Camel skeletal muscle fibres like those of other mammals are composed of thousands of myofibrils, each of which is made up of many protein filaments packed together (Fig. 4.1). Myofibrils are composed of thick and thin filaments arranged in units called sarcomeres. Myosin is the most abundant skeletal-muscle protein, in addition to being a key structural element, is also able to convert chemical energy into mechanical energy through structural changes. Actin, troponin and tropomyosin are the major proteins of the thin filament with actin having the main structural role, while tropomyosin and troponin are calcium-activated complexes involved with muscle contraction (Clark et al. 2002).

Fig. 4.1
figure 1

Microstructure of camel muscles

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Camel muscles contain high levels of oxidative enzymes compared to the red meat of other meat-producing animals. These enzymes are involved in metabolizing various types of energy substrate for ATP production, including glycogen, lipid, glucose, lactate, and amino acids (Saltin et al. 1994). Oxidative enzymes in camel muscles exhibit a high level of respiratory control with tightly coupled oxidative phosphorylation enabling the capacity of mitochondrial electron transport to rise along with the production of ATP. It has been reported that mitochondria in skeletal muscles are capable of undergoing adaptive changes in both composition and number of mitochondria (Lee and Lardy 1965). The adaptation of camels to various environments, therefore, may be due to the increase in number and size of mitochondria or/and an alteration in the composition of the mitochondria in camel skeletal muscles. Camel muscles, like those of most mammals, are composed of three fundamental fibre types categorized by biochemical and physiological methods, namely slow-twitch oxidative (Type I), fast-twitch oxidative glycolytic (Type IIA), and fast-twitch glycolytic fibres (Type IIB) (Saltin et al. 1994; Kadim et al. 2013) (Tables 4.10 and 4.11).

Table 4.10 Muscle composition in different locomotors muscles in the racing camel (n = 6, mean ± standard error) (Saltin et al. 1994)
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Table 4.11 Muscle fibre-type composition in six locomotors muscles in the dromedary camel (n = 10, mean ± standard error) (Kadim et al. 2013)
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Variations in the relative occurrence of type I, IIA and IIB fibres between camel muscles were reported by Kadim et al. (2009a, b, 2013), Kaseem et al. (2004) and Saltin et al. (1994). In this regard, Saltin et al. (1994) stated that type IIA muscle fibres are the dominant proportion of fibres in some camel muscles, while type IIB fibres were scarce. However, Kadim et al. (2013) found that camel muscle had similar proportions of the three muscle fiber types. Type II fibres can serve as an energy store during starvation, therefore, camels could also have a reasonable proportion of type II fibres to facilitate survival during starvation periods. In camel muscles, fibre types are heterogeneously mixed (Saltin et al. 1994), therefore, the high coefficient of variation values for type I, IIA and IIB fibres relate to a heterogeneous distribution of muscle fibre types in camels. The distribution of muscle fibre types in the longissimus dorsi of two camel types (red and black) indicated that the black camel has slightly more type IIB, less type I and less type IIA fibres than red camel (Kaseem et al. 2004). The proportion of Type I, IIA and IIB were 33.1%, 25.2% and 41.8% in dromedary camels Longissimus thoracis muscles, respectively (Kadim et al. 2009a).

4.4 Meat Quality Characteristics

For the purpose of this chapter meat quality is defined as “The combination of those intrinsic and extrinsic characteristics of meat that affect its level of acceptability or excellence for a consumer”. When defined in this way, meat quality represents a moving target as consumers or groups of consumers will differ in the relative importance about different aspects of quality. Most research emphasis has been historically placed on the intrinsic components of meat that affect its quality, such as those listed in Table 4.12. More recently, information on extrinsic characteristics, such as the ways in which animals have been treated and fed, have received increasing attention in terms of effects on consumer choices.

Table 4.12 Examples of categories of intrinsic characteristics of meat that play a role in determining its quality, together with some examples of specific characteristics within each category
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In addition to identifying characteristics that contribute to meat quality, considerable research has been conducted into characteristics within meat that can affect those characteristics, sometimes referred to as “intrinsic determinants”. There are too many of these to list here, but examples in the case of meat tenderness include the degree of contraction (as assessed by sarcomere length), the amount and solubility of collagen present, protease activity within the meat, the level of intramuscular fat, and the ultimate pH of meat. The extent to which these generalizations apply to meat from camels has not been fully explored, but, given the similarity of muscle structure across mammals, it would be expected that many of the findings with regard to beef, lamb and pork would apply to camel meat. Aspects of camel meat quality are discussed below under headings of meat composition, nutritive value, and palatability and appearance characteristics.

4.4.1 Meat Composition

The composition of camel meat is generally similar to meat from other species where an inverse relationship exists between the moisture or protein contents and the fat content (Table 4.13). Table 4.13 shows that the camel meat moisture content varies widely (from 72.2% to 77.7%). Kadim et al. (2006) reported that the moisture content of the camel meat decreases with increasing age. The differences between the maximum and minimum moisture contents of camel Longissimus thoracis muscles were 3.2%, 6.4% and 12.3% for age groups of 1–3, 3–5 and 6–8 years, respectively. However, Ibrahim et al. (2015) reported only small variation in moisture content between 3–4 and 6–7 year-old camels across four muscles with the exception of Longissimus thoracis muscle. Gheisari et al. (2009) found no differences in moisture content between camel meat and meat from other species at a similar age and sex. The protein content of camel meat ranges from 17.1% to 22.1% (Table 4.1). Meat from young camels has a similar protein content to that from young cattle, lambs and goats (Elgasim and Alkanhal 1992; Kadim et al. 2009b). Animal age affects fat content (1.1–6.2%) wherein meat from older camels containing a higher fat % (Kadim et al. 2006; Ibrahim et al. 2015). Other factors appear to affect the fat content of camel meat within similar age groups (Kadim et al. 2006, 2008, 2009 a, b). Table 4.7 shows that ash content varies between muscles. Gheisari et al. (2009) found that ash content of camel meat increased with age, but others found no effect of age (Kadim et al. 2006, 2008). Camel meat has a slightly lower ash content than beef, lamb and goat meat (Kadim et al. 2008).

Table 4.13 Chemical composition (g/100 g) of muscle tissue from different species
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4.4.2 Nutritive Value

The amount of camel meat required to supply the daily requirements of essential amino acids for an adult consumer is similar to that from lamb but is less than the amount required from beef. Leucine and lysine are among the highest essential amino acids in camel meat (Table 4.14). The camel meat essential amino acids contents varied slightly among different muscles. According to Dawood and Alkanhal (1995), the essential amino acid content of camel meat is not affected by the animal age. As with essential amino acids, non-essential amino acids contents also varied slightly between muscles and larger variations were found between studies (Table 4.14). In general, camel meat appears to be a similar or slightly better source of non-essential amino acids compared to beef, lamb, and goat meats. Elgasim and Alkanhal (1992), however, found low alanine level in camel meat compared to other red meats, Dawood and Alkanhal (1995); Al-Shabib and Abu-Tarboush (2004), but Kadim et al. (2011) found similar concentrations of alanine in camel meats and other red meats.

Table 4.14 Amino acid composition for several muscles of camels together with values for muscles of other meat-producing species (mg/100 g of muscle) (Kadim et al. 2013)
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The major saturated, monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids in different camel muscles are palmitic acid (C16:0), oleic acid (C18:1) and linoleic acid (C18:2), respectively (Table 4.15). The total saturated fatty acid (SFA) concentration was similar among the published reports (51.5–53%), but MUFA (29.9 and 41.4%) and PUFA (5.6% and 18.6%) fatty acids have been reported to be more variable (Rawdah et al. 1994; Kadim et al. 2011). On a fresh weight basis, the camel hump comprises about 64.2–84.8% fat with a very high content of saturated fatty acids of about 63.0% (Rawdah et al. 1994; Kadim et al. 2002). Palmitic acid, stearic acid (C18:0) and oleic acid are the most abundant fatty acids in the hump (Mirgani 1977; Emmanuel and Nahapetian 1980; Abu-Tarboush and Dawood 1993; Kadim et al. 2002). The fatty acid composition of six camel muscles was generally similar with the exception of palmitic and oleic fatty acids (Table 4.12). Palmitic acid is the most abundant saturated fatty acid in camel intramuscular fat followed by stearic acid, and myristic acid (C14:0). The main monounsaturated fatty acids in camel muscles were oleic acid followed by palmitoleic acid (C16:1). The main polyunsaturated fatty acids in the muscles were linoleic acid (C18:2n-6) and arachidonic acid (C20:4n-6). The percentage of polyunsaturated fatty acids in camel meat in this study was 11.92%, which is higher than beef (8.8%) and lower than buffalo (28.6%) and deer (31.4%) (Sinclair et al. 1982). The ratio of linoleic and linolenic acids in camel meat is about 13.9, which is much higher than that for cattle, sheep or goats (2.0, 2.4 and 2.8, respectively) (Sinclair et al. 1982).

Table 4.15 The fatty acid composition (% of total fatty acids) in the intramuscular lipid of the Infraspinatus (IS), Triceps brachii (TB), Longissimus thoracis (LT), Semitendinosus (ST), Semimembranosus (SM), and Biceps femoris (BF) muscles of the dromedary camel (Kadim et al. 2013)
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Calcium content (mg/100 g fresh lean weight) was reported to be in the range of 4.9–7.0 (Bekhit and Farouk 2013). Although, there was up to 144% variation in Ca content between different muscles, Co and Cr contents were in the range of 0.003–0.004 and 0.008–0.03 (mg/100 g fresh weight) (Kadim et al. 2006). Cu contents in camel meat ranged between 0.04 to 0.12 mg/100 g fresh weight. The foreleg muscles contain more Cu compared with other muscles (Rashed 2002). Fe content in camel meat (1.16–3.39 mg/100 g fresh meat) varied among different muscles, which is most probably due to the different physiological requirements for myoglobin of different muscles. As with other red-meat species, leg muscles containing oxidative fiber types have a higher iron concentration than glycolytic muscles. Potassium is the major element in camel meat (193.4–379.1 mg/100 g fresh weight) and Mg content in camel muscles ranges between 10.41–21.03 mg/100 g fresh weight (Kadim et al. 2009a, b). Leg muscles have higher K and Mg contents compared with the loin muscle (Bekhit and Farouk 2013). Meat from camel contained similar Mn content (0.01 mg/100 g fresh weight) across four different muscles (El-Faer et al. 1991; Elgasim and Alkanhal 1992). However, Rashed (2002) found that camel Longissimus thoracis contained higher Mn (mg/100 g dry matter) and the concentration varied among different muscles. Na content in camel Longissimus thoracis was in the range of 40.2–87.3 mg/100 g. The Longissimus thoracis muscle had the lowest Na content among the different camel muscles (Elgasim and Alkanhal 1992; Rashed 2002; Kadim et al. 2006). P is the second most abundant element in camel meat (105.6–199.0 mg/100 g fresh weight) and muscles from the leg and shoulder cuts have slightly higher P than those from ribs and neck cuts (El-Faer et al. 1991). S content was in the range of 54.99–136.57 mg/100 g fresh weight (Bekhit and Farouk 2013). The S content in four different muscles was varied by 17% only (El-Faer et al. 1991). Red meat is an important source of Zn and camel meat contains about 3.07 to 4.80 mg/100 g fresh weight (Bekhit and Farouk 2013). The variation between different muscles was 7.6% (Dawood and Alkanhal 1995).

The concentrations of Ag, Au and Ni in five camel meats have been reported at 0.06–0.12, 0.10–0.21 and 0.05–0.38 mg/100 g dry matter, respectively (Rashed 2002). The concentration of the three minerals varied among different muscles by 100%, 110% and 750% (Bekhit and Farouk 2013). The concentrations of Ni, Be and V increased in the Dromedary camel Longissimus thoracis muscle with the increasing animal age (Kadim et al. 2006). The level of Pb in camel Longissimus thoracis was 2.5 times the concentration in beef longissimus thoracis (Kadim et al. 2009b).

Concentration of water- and fat-soluble vitamins (mg/100 g fresh meat) in dromedary camel Longissimus thoracis, Semitendinosus, Biceps femoris, and Semimembranosus muscles are presented in Table 4.16. The water-soluble vitamins varied from a few micrograms to several milligrams per 100 g fresh meat sample. There were no significant differences in thiamine (B1) concentration between individual muscles for two different age groups. In beef there were differences in thiamine content between the loin muscles (0.2 mg/100 g) and leg muscles (0.8 mg/100 g) (Lombardi-Boccia et al. 2005). The thiamine concentration in dromedary camel muscles was higher than lamb, and lower than beef, veal, and horse (Lombardi-Boccia et al. 2005). The vitamin B6 concentration in camel muscles ranged from 0.53 to 0.62 mg/100 g, which is higher than reported by Moss et al. (1983) for pork meat. An average serving of camel meat (200 g) should provide about 80% of the required daily allowance (RDA) of vitamin B6 for the young adult male. There were small variations between dromedaries camel muscles for vitamin B12 concentrations with 50 g contain 1.1 μg. The camel meat containing more vitamin B12 than sheep and veal meats (Ono et al. 1984, 1986). Similarly, (Lombardi-Boccia et al. 2005) reported that among beef meat cuts, vitamin B2 concentration varied from 0.09 to 0.17 mg/100 g, with fillet showing the highest concentration. Beef (0.13 mg/100 g), veal (0.08 mg/100 g), lamb (0.195 mg/100 g) meats contained lower vitamin B2 concentration than camel meat (Lombardi-Boccia et al. 2005; Purchas et al. 2014). The small variations between camel muscles for vitamins may be due to small differences in muscle fibre types and intramuscular fat content.

Table 4.16 Concentrations of vitamins in Longissimus thoracis (LT), Semitendinosus (ST), Semimembranosus (SM) and Biceps femoris (BF) muscles of the dromedary camel (Ibrahim et al. 2017)
Full size table

4.4.3 Palatability and Appearance Characteristics

The ultimate pH of camel muscles, which can affect several meat quality characteristics including colour, tenderness and juiciness, is the outcome of many factors including pre-slaughter handling, postmortem treatment, glycogen storage and muscle physiology. A high ultimate pH is usually a consequence of low muscle glycogen due to pre-slaughter stresses, that may also be due to poor nutrition, and/or rough handling and/or long transportation (Kadim et al. 2008). There is a variation in the ultimate pH values between different camel muscles (Kadim et al. 2013) with ranges between 5.5 and 6.6 (Babiker and Yousif 1990; Kadim et al. 2006, 2009a, b, 2013), and with young animals tending to have meat with a higher pH than older camels due to lower levels of glycogen. Kadim et al. (2006) reported that meat from three-year-old camels had a mean pH value of 5.91 while for six-year-old camels it was 5.71. The breed of camel did not affect ultimate muscle pH (Suliman et al. 2011). The pH variations in camel meat with storage time have been reported by El-waziry et al. (2012).

Major variation in camel meat tenderness is related to the variability of muscle structures, glycogen concentration, collagen content, collagen solubility, and the activities of proteases and their inhibitors. The Triceps brachii muscle has been reported to have the highest shear force values, maximum connective tissue strength and lowest collagen solubility relative to Longissimus thoracis, Semitendinosus, Semimembranosus, Gluteus medius, and Vastuslateralis in camel, indicating that it is the toughest muscle in this group (Babiker and Youssif 1990; Kamoun 1995). The Gluteus medius and Longissimus thoracis muscles were the most tender and had less detectable connective tissue than other muscles. In contrast, Kadim et al. (2013) found that IS, TB, and LT camel muscles had lower shear force values than ST, SM, and BF muscles, which might be due to less connective tissue (Table 4.17). Average shear force values for meat from camels at 5–8 years of age was 48% and 40% higher than those of 1–3 and 3–5-year olds, respectively (Kadim et al. 2006). Differences due to age may be related to changes in muscle structure and composition as an animal matures, particularly in the nature and quantity of connective tissue (Asghar and Pearson 1980). Significant differences were found between the different ages (8, 16 and 26 months of age) and cuts for shear force values of meat from camels (Dawood 1995).

Table 4.17 Meat quality characteristics of six muscles of the camel carcass (10 animals) at 1.5–2 years of age (Kadim et al. 2013)
Full size table

Ageing at chiller temperatures causes an improvement in meat quality parameters over time and involves specific degradation of structural proteins within the myofiber (Hwang et al. 2003; Jaturasitha et al. 2004). The method adopted by Kadim et al. (2009a), where camel muscle was aged at 2–3 °C for 7 days to improve meat quality characteristics showed significant improvements in camel meat quality. The same authors found no differences in cooking loss with ageing of camel meat from 2 to 7 days. In contrast, Jouki and Khazaei (2011) found that storage time of camel meat from 1 to 6 days decreased water-holding capacity. The level of improvement in tenderness with ageing varies among different meat cuts, different ages of the animal, and species due to differences in the level of endogenous enzymes, contraction status and connective tissue content (George-Evins et al. 2004). In general, ageing can improve quality characteristics of meats that have relatively small amounts of connective tissue and that have not cold-shortened (Wheeler et al. 1999). Dawood (1995) reported that meat from eight-month-old camels had significantly higher water-holding capacities than meat from 26-month-old camels. The camel Longissimus thoracis and Biceps femoris muscles had higher 37.9 and 37.1% cooking loss than the 33.2% cooking loss in ST muscle (Babiker and Yousif 1990). An increase in cooking loss was observed in the Longissimus thoracis muscle when compared to the Supraspinatus, Triceps brachii, Semitendinosus, Semimembranosus and Biceps femoris (Table 4.17) with no significant differences between the last five muscles (Kadim et al. 2013). The variation between muscles might be due to location, activity, proportion of muscle-fiber types, pH, intramuscular fat and/or the ratio of water to protein of individual muscles. However, Suliman et al. (2011) found that Biceps femoris muscles had higher cooking loss than Longissimus thoracis muscles in four camel breeds. In accordance with the statement of Shehata (2005), young camels had higher cooking loss than old animals. Kadim et al. (2009a, b) found that meat from 2–3 year-old camels had significantly lower cooking loss (24.3%) than the values mentioned above due to age differences.

The protein degradation of camel meat after slaughter is related to the ultimate pH, with lower values increasing light scattering properties of meat and thereby increasing L*, a* and b* values. Low ultimate pH and high meat temperature might lead to more protein degradation resulting in higher colour values than higher ultimate pH meat samples. Babiker and Yousif (1990) reported that camel Longissimus thoracis muscles had higher lightness (L*), redness (a*) and yellowness (b*) values than Semitendinosus and Triceps brachii muscles. Suliman et al. (2011) reported that the color of the Biceps femoris muscle was not affected by breed. A high redness (a*) color for camel meat was associated with a lower lightness (L*), while higher lightness was associated with high fat content (Kadim et al. 2013). The same authors found that ST muscle had the darkest colored lean compared to Supraspinatus, Longissimus thoracis, Triceps brachii, Semimembranosus, and Biceps femoris camel muscles. The Longissimus thoracis, Semimembranosus, and Biceps femoris camel muscles had higher redness (a*) values than Semitendinosus muscle, while a* value for Supraspinatus and Triceps brachii muscles were in between. CIE a* values were similar among Longissimus thoracis, Semimembranosus and Biceps femoris muscles (Table 4.17). In camel meat, the highest average yellowness (b*) value was recorded in the Longissimus thoracis muscle with comparable values to the Triceps brachii and Biceps femoris muscles. The age of the camel has a significant effect on their meat color (Kadim et al. 2006). Meat color from 6–8 and 10–12 year old camels was darker (lower L*), redder (higher a*) and yellower (high b*) than 1–3 year old camels because of higher concentrations of myoglobin (Kadim et al. 2006).

4.5 Conclusion

Mature camels can reach live weights of about 650 kg and produce 350 kg carcass weights with DO% values of up to 62%, although this value can vary widely. However, actual carcass weights of camels currently slaughtered for meat are generally less than 250–400 kg. Camel carcasses contain about 57% muscle, 26% bone and 17% fat with the forequarter significantly heavier than the hindquarter. Camel carcass muscle distribution was comparable to that in other farm animal species with a pattern of more muscle in the fore quarter. This led to slightly higher proportions of muscle in the expensive muscle group (proximal hind and fore legs plus muscles around the vertebral column). Camel lean meat contains about 78% water, 19% protein, 3% fat, and 1.2% ash. The amino acid and mineral contents of camel meat are often higher than some other meat animals, due in part to lower intramuscular fat levels. The nutritional value of camel meat is similar to other red meats. The quality characteristics of camel meat are similar to those for beef when animals are slaughtered at similar ages. According to the composition and quality parameters of camel meat, it can be successfully marketed alongside meat from cattle, deer, sheep and goat. Pre and post mortem factors should be carefully considered in order to improve meat quality characteristics. Future research efforts need to focus on exploiting the potential of the camel as a source of meat through multi-disciplinary research into efficient production systems, and improved processing technology and marketing.