A G R I C U LT U R A L A N D F O O D S C I E N C E V.M. Tomovic et al. (2014) 23: 9–18 9 Technological quality and composition of the M. semimembranosus and M. longissimus dorsi from Large White and Landrace Pigs Vladimir M. Tomović1*, Božidar A. Žlender2, Marija R. Jokanović1, Mila S. Tomović3, Branislav V. Šojić1, Snežana B. Škaljac1, Tatjana A. Tasić4, Predrag M. Ikonić4, Milena M. Šošo1 and Nevena M. Hromiš1 1University of Novi Sad, Faculty of Technology, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia 2University of Ljubljana, Biotechnical faculty, Jamnikarjeva 101, 1000 Ljubljana, Slovenia 3Technical school “Pavle Savić”, Šajkaška 34, 21000 Novi Sad, Serbia 4University of Novi Sad, Institute for Food Technology, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia e-mail: tomovic@uns.ac.rs The effects of pig breed (Large White and Landrace) in combination with muscle type (M. semimembranosus and M. longissimus dorsi) on T 45min , T 24h , pH 45min , pH 24h , colour (CIEL*a*b* values), water-holding capacity (filter paper press method: ratio of the area of pressed meat film – M and the wet area on the filter paper – T; M/T value) and moisture, protein, total fat and total ash content were investigated. Interaction effect between breed and muscle was not found (p>0.05) for any parameter. The T 45min , T 24h , pH 45min , and M/T value were influenced by the muscle, whereas T 24h was also influenced by the breed. The pH 45min was higher (p<0.01) and water-holding capacity was bet- ter (p<0.001) in M. semimembranosus muscle than in M. longissimus dorsi muscle. Based on the criteria for CIEL* and M/T values, pork meat was classified into seven technological quality classes. The percentages of pale and ex- udative, reddish-pink and exudative, and reddish-pink and non-exudative pork were 23.5, 26.5, and 27.7%, respec- tively. Composition was in the characteristic range for modern lean pigs. Key words: pig, Large White, Landrace, M. semimembranosus, M. longissimus dorsi, technological quality, composition Introduction The technological quality attributes of meat include: pH value, color, texture, water-holding capacity (WHC) and chemical composition (Rosenvold and Andersen 2003, Olsson and Pickova 2005, Sevón-Aimonen et al. 2007). These parameters are influenced by multiple interacting factors including breed, genetics, feeding, pre-slaughter treatment and stunning, slaughter method, chilling and storage conditions, as reviewed by Rosenvold and Andersen (2003). It is believed that pH is one of the keys to understanding post-mortem muscle glycolysis. A number of authors report that the rate of post-mortem pH fall is an important determinant of colour and WHC. An abnormally rap- id rate of glycolysis early post-mortem in the muscles produces poor pork quality (pale and exudative meat). On the other hand, higher ultimate pH is associated with darker colour and better WHC (Bendall and Swatland 1988, Brewer et al. 2001, Lawrie and Ledward 2006). Fresh pork has been traditionally classified into three technological quality categories, according to the measure- ments of pH value, colour, firmness (texture) and drip loss (exudation): PSE (pale, soft, exudative), RFN (reddish-pink, firm, non-exudative or normal pork) and DFD (dark, firm, dry). The RFN meat is considered the ideal pork quality class (Kauffman et al. 1992, Joo et al. 2000a). Pork meat that is classified as RFN has a desirable color, normal tex- ture and WHC. One of the most important and the most frequently found quality deviation of pork meat is a PSE defect (Bendall and Swatland 1988, Kauffman et al. 1992, Warner et al. 1997, Joo et al. 2000a, O’Neill et al. 2003, van de Perre et al. 2010). On the other hand, the incidence of DFD meat is low and less relevant to industry (Ben- dall and Swatland 1988, Kauffman et al. 1992, van Laack et al. 1994, O’Neill et al. 2003, van de Perre et al. 2010). Manuscript received September 2013 A G R I C U LT U R A L A N D F O O D S C I E N C E V.M. Tomovic et al. (2014) 23: 9–18 10 The development of PSE is caused by excessive protein denaturation due to a combination of a low pH and a high muscle temperature early post-mortem. The opposite of PSE is DFD muscle, which is caused by a depletion of gly- cogen content at the time of slaughter, resulting in a high ultimate pH 24h and a higher susceptibility to the micro- biological spoilage (Bendall and Swatland 1988, Warner et al. 1997, Lawrie and Ledward 2006, Barbut et al. 2008). Beside these three traditional categories, during the last two decades many authors introduced two additional intermediate quality variations: RSE (reddish-pink, soft, exudative) and PFN (pale, firm, non-exudative). RSE pork has normal color, but a soft texture and an exudative character similar to PSE, whereas PFN pork has the texture of meat of good quality, but has undesirable color, similar to PSE (Kauffman et al. 1992, van Laack et al. 1994, Warner et al. 1997, Joo et al. 2000a, O’Neill et al. 2003). Over the years RSE and PFN have also been recognized as serious quality defects (Kauffman et al. 1992, van Laack et al. 1994, Joo et al. 2000a, O’Neill et al. 2003, van de Perre et al. 2010). Incidence of inferior muscle quality, especially with PSE and RSE defects, has an economic impact in the pork in- dustry (Kauffman et al. 1992, Joo et al. 2000a, O’Neill et al. 2003, Huff-Lonergan and Lonergan 2005, Sevón-Ai- monen et al. 2007). For this reason, evaluation of technological quality of pork represents an important step in meat production and processing. In international practice the evaluation of pork quality is based on very different parameters and criteria. The most popular parameters, which enable identification of defective meat, include the pH value, measured in the mus- cle tissue 30–60 minutes (pre-rigor state) and 24 hours post-mortem (post-rigor state), meat colour (reflectance – lightness – CIEL* value) and WHC (numerous analytical methodologies: filter paper press, filter paper, bag, tray, EZ-DripLoss, absorption or centrifugation methods or determination of cooking loss), measured 24 hours post- mortem (Bendall and Swatland 1988, Honikel 1998, 1999, Sevón-Aimonen et al. 2007). Moreover, other param- eters like: electrical conductivity (Joo et al. 2000a, Lee et al. 2000) or impedance (Swatland 1995) help to identify defects in pork meat quality (Bendall and Swatland 1988, Honikel 1999). Characteristics should be easily measur- able, what means that a destructive cutting of a carcass must not occur. Therefore, the easy accessible M. semi- membranosus and M. longissimus dorsi are recommended as representative muscles (Honikel 1999). The measurement of pH values is the most direct way to obtained information about meat quality characteris- tics. The pH 45min identifies potential PSE pork, especially if the value is less than 6.0 (Bendall and Swatland 1988, O’Neill et al. 2003, Lawrie and Ledward 2006). However, CIEL* value is probably the best overall indicator for PSE and DFD pork (Brewer et al. 2001). Skeletal muscle tissue is composed of approximately 75.0% water, 19.0% protein, 2.5% lipid, 1.5% non-protein ni- trogenous compounds, 1.0% carbohydrate and non-nitrogenous components and 1.0% inorganic matter (Keeton and Eddy 2004, Lawrie and Ledward 2006). Meat tissue composition varies according to differences in species, chronological and physiological maturity at harvest, plane of nutrition, genetic predisposition, and anatomical loca- tion of cuts (muscles) within a carcass (Keeton and Eddy 2004, Olsson and Pickova 2005, Lawrie and Ledward 2006). The Autonomous Province of Vojvodina (the northern part of the Republic of Serbia) is a region where the num- ber of animals of the porcine species and the production of pork meat are of high economic importance. The most common white purebreds of pigs used in Vojvodina, as well as in Serbia, for pork production are the Large White and the Landrace. Also, they are commonly used in crossbreeding programs. This cross is often used as the female line in commercial herds. Dark purebreds such as Duroc, Hampshire or Pietrain are often used as a male line (Lawrie and Ledward 2006, Sevón-Aimonen et al. 2007, The Danish Standard 2007, Barbut et al. 2008, Tomović et al. 2011). The objective of this study was to determine the technological quality (pH, colour – CIEL*a*b* values and WHC – M/T value – filter paper press method) and composition (moisture, protein, total fat and total ash content) of two economically most important muscles (M. semimembranosus and M. longissimus dorsi) from two major white purebreds (Large White and Landrace) used for pork production in Vojvodina (Republic of Serbia). Based on the criteria for colour (CIEL* value) and WHC (M/T value), data of this study were used to classify pork quality into different categories. A G R I C U LT U R A L A N D F O O D S C I E N C E V.M. Tomovic et al. (2014) 23: 9–18 11 Materials and methods Animals, sampling, slaughter and preparing This study was carried out on 81 (females and castrated males) Large White (LW) and 83 (females and castrated males) Landrace (L) pigs. The pigs were fattened at the 4 production farms in Vojvodina under identical conditions (Tomović et al. 2011). The pigs were randomly selected from both purebreds at an individual live weight between 95 and 110 kg, and about 6 months old. Four to five pigs from both breeds fattened at the same farm were tak- en during one production day per week for a total of 20 weeks. All the pigs were slaughtered in the two biggest slaughterhouses in Vojvodina according to routine procedures. After transport, which took 1–2 hours, pigs were allowed to rest for about 2–3 hours in the abattoir. Stunning was performed electrically (220 V, 2 A, 8–12 sec- onds) in a V-restrainer with a pair of stunning tongs. After stunning, the animals were shackled by one hind leg and exsanguinated and scalded (5 minutes, 62 °C) vertically. Carcasses were then individually placed in a dehairer and any remaining hair was removed using flame and knife. The evisceration was finished about 45 minutes post- mortem. Carcasses were conventionally chilled for 24 hours in a chiller at 0–4 °C. M. semimembranosus (SM) and M. longissimus dorsi (LD) were excised from the right side of each carcass. Iden- tification of the muscles was performed according to UNECE (2008). The meat samples were trimmed of visible adipose and connective tissue. Technological quality characteristics were measured on fresh muscles (SM muscle: central part, LD muscle: central part between 3rd and 4th from the last rib). After determination of technologi- cal quality characteristics, each muscle was homogenized (Waring 8010ES Blender, USA, capacity: 1 liter, speed: 18000 rpm, duration of homogenization: 10 seconds, temperature after homogenization: <10 °C), vacuum pack- aged in polyethylene bags and stored at –40 °C until determination of composition. Composition of SM and LD muscles for 40 pigs from each purebred was determined. Technological quality measurements Temperature was measured at the start 45 minutes (T 45min ) post-mortem and at the end 24 hours (T 24h ) post-mor- tem of the chilling process in the SM muscles, and in the LD muscles, on the right side of every carcass, using a portable digital thermometer with a 12 cm stem (Consort T651, Turnhout, Belgium). The pH value was measured 45 minutes (pH 45min ) and 24 hours (pH 24h ) post-mortem using the portable pH meter (Consort T651, Turnhout, Belgium) equipped with an insertion glass combination electrode (Mettler Toledo Greif- ensee, Switzerland). The pH meter was calibrated before and between the measurements using standard phos- phate buffers (pH values of calibration buffers were 7.00 and 4.01 at 25 °C) and adjusted to the expected temper- ature of measured muscles (ISO 2917 1999). Measurements were performed in triplicate. Based on the initial pH (45 minutes post-mortem) the pork quality was classified as potential PSE (pH<6.0) or nor- mal (pH≥6.0). On the other hand, based on the ultimate pH (24 hours post-mortem) the pork quality was classi- fied as normal (pH<6.0) or DFD (pH≥6.0) (Kauffman et al. 1992, Warner et al. 1997, Joo et al. 2000a, O’Neill et al. 2003, Lawrie and Ledward 2006). After chilling samples for colour measurements were taken perpendicularly to the long axis of muscle, the mini- mum thickness of samples was 2.5 cm. Eight replicate measures of surface colour were performed on each sam- ple, after 60 minutes of blooming at 3 °C (Honikel 1998). The CIEL* (lightness), CIEa* (redness) and CIEb* (yel- lowness) colour coordinates (CIE 1976) were determined using MINOLTA Chroma Meter CR-400 (Minolta Co. Ltd. Osaka, Japan) with D-65 lighting, a 2° standard observer angle and the 8-mm aperture in the measuring head. The instrument was calibrated using a Minolta calibration plate (No. 11333090, Y=92.9, x=0.3159, y=0.3322). The colour quality was calculated on the basis of all individual lightness (CIEL* value) measurements, according to cri- teria for pork (pale colour: CIEL*>50, reddish-pink colour: CIEL*=43–50, dark colour: CIEL*<43) as defined by Joo et al. (1999), Joo et al. (2000a, 2000b), Tomović et al. (2008) and Tomović et al. (2013). Determination of the water-holding capacity (WHC) was based on measuring water released when pressure was applied to the muscle tissue (exudative juice). Exudative juice was assessed using a filter paper press method (Grau and Hamm 1953, van Oeckel et al. 1999). A cube of 300±25 mg of meat from the inside of the muscle sample was placed on a filter paper (Schleicher & Schull No. 2040 B, Dassel, Germany) between two plexiglas plates. Plates were then screwed together tightly for exactly 5 minutes. The analysis was performed in triplicate. The WHC was expressed as the ratio of the area of pressed meat film (M) and the wet area on the filter paper (T), as determined by mechanical polar planimeter (REISS Precision 3005, Bad Liebenwerda, Germany). The WHC quality was calculated on the basis of all individual M/T values measurements, according to criteria for pork (exudative meat: M/T<0.35, A G R I C U LT U R A L A N D F O O D S C I E N C E V.M. Tomovic et al. (2014) 23: 9–18 12 non-exudative meat: M/T=0.35–0.45, dry meat: M/T>0.45) as defined by Hofmann et al. (1982). Thus, combining three criteria for colour and three criteria for WHC technological pork quality was classified into 9 quality classes. Composition Moisture (ISO 1442 1997), protein (nitrogen x 6.25, ISO 937 1978), total fat (ISO 1443 1973) and total ash (ISO 936 1998) contents of muscles were determined according to methods recommended by International Organization for Standardization. All analyses were performed in duplicate. Statistical analysis All data are presented as mean and standard deviation (SD). Data were analyzed statistically with factorial ANOVA and post-hoc test (Dunckan’s test). Two-way analysis of variance was performed; 2 breeds x 2 muscles. Levels of significance p<0.05, p<0.01, and p<0.001 were used. Correlation coefficients among quality characteristics of pork were also calculated. Statistical analysis was conducted using Statistica software version 10 (StatSoft, Inc. 2011). Results and discussion Overall technological quality of pork No significant (p>0.05) interaction effect between breed and muscle type was found for all determined techno- logical parameters (Table 1). The initial (45 minutes post-mortem) mean temperatures in the SM muscles of both LW and L breeds were 40.2 and 40.1 °C, respectively (Table 1). At the same time, in the LD muscles significantly lower mean temperatures (p<0.001) were found than those in the SM muscles, within each breed, i.e. initial temperature was significantly influenced by the type of the muscle. Difference between mean temperatures in SM and LD muscles for both breeds was identical, 1.5 °C. Similarly, at the end of chilling (24 hours post-mortem), mean temperatures in LD muscles were significantly lower (p<0.001) than those in the SM muscles. Ultimate temperature was also significantly (p<0.001) influenced by the breed. Mean ultimate temperatures ranged from 2.9 (LD of L) to 5.0 °C (SM of LW). All the in- dividual ultimate temperatures were lower or equal 7 °C. According to EU Council Directives (ECC No. 433/1964), as well as Serbian Regulation (2011), pork must not be cut and deboned before reaching 7 °C in the deep leg. Table 1. Mean values (±SD) of the technological quality of M. semimembranosus (SM) and M. longissimus dorsi (LD) of Large White (LW) and Landrace (L) pigs. Parameter Breed p-value LW L Muscle Muscle Breed Muscle Breed x MuscleSM LD SM LD Initial and ultimate temperature (°C) T 45min 40.2aov±0.34 38.7bpw±0.54 40.1aov±0.40 38.6bpw±0.60 0.175 <0.001 0.916 T 24h 5.0aov±1.28 3.2cqx±0.84 4.3bpw±1.40 2.9cqx±0.88 <0.001 <0.001 0.148 Initial and ultimate pH pH 45min 6.26ao±0.27 6.16bop±0.26 6.20abop±0.26 6.14bp±0.30 0.165 0.008 0.556 pH 24h 5.78±0.20 5.74±0.21 5.72±0.20 5.70±0.24 0.056 0.255 0.801 Colour CIEL* (lightness) 48.11±3.97 48.72±3.64 47.99±3.92 49.31±4.56 0.598 0.052 0.423 CIEa* (redness) 10.91±2.33 10.91±1.82 11.04±2.13 10.12±2.41 0.183 0.058 0.057 CIEb* (yellowness) 6.76±2.48 6.31±2.28 6.78±1.91 6.70±2.41 0.418 0.295 0.468 Water-holding capacity M/T 0.38aov±0.07 0.33bpw±0.07 0.36aovw±0.07 0.33bpw±0.06 0.139 <0.001 0.316 abcindicates significant difference within raw at p<0.05, opqindicates significant difference within raw at p<0.01, vwxindicates significant difference within raw at p<0.001. M = area of the pressed meat film; T = wet area on the filter paper. A G R I C U LT U R A L A N D F O O D S C I E N C E V.M. Tomovic et al. (2014) 23: 9–18 13 Initial pH value was significantly influenced (p=0.008) by the type of the muscle (Table 1). In the SM muscles ini- tial pH values were significantly (LW breed, p<0.05) or numerically (L breed, p>0.05) higher than those in the LD muscles. In SM muscles from LW and L breeds, the mean initial (45 minutes post-mortem) pH values were 6.26 and 6.20, respectively, while in LD muscles these values were 6.16 and 6.14, for LW and L breeds, respectively. Similarly, at the end of chilling (24 hours post-mortem), mean ultimate pH in SM muscles were numerically higher than those in LD muscles within each breed. However, ultimate pH was not significantly influenced (p>0.05) by the type of muscle. All mean ultimate pH values, which ranged from 5.70 (LD of L) to 5.78 (SM of LW), were in the characteristic range for pork (5.3–5.8; Smulders et al. 1992, Honikel 1999). As expected (Table 2), in the present study the pH 45min was significantly positively correlated with the pH 24h (r=0.42 for LW and r=0.48 for L, p<0.001). CIEL*a*b* values (lightness, redness and yellowness) were not significantly influenced (p>0.05) by the type of muscle (Table 1). The highest (lightest colour) and the lowest (darkest colour) numerical CIEL* mean values were found in LD and SM muscles of L breed. These values were 49.31 for the LD and 47.99 for the SM muscle. Accord- ing to the mean values for lightness (CIEL* value), the colour of all investigated groups of SM and LD muscles rep- resent normal meat quality (reddish-pink colour: CIEL*=43–50, Joo et al. 1999, Joo et al. 2000a 2000b, Tomović et al. 2008, Tomović et al. 2013). Furthermore, the mean CIEa* values (redness) ranged from 10.12 (LD of L) to 11.04 (SM of L). Almost identical mean CIEb* values were determined in all investigated groups of muscles. The mean CIEb* value ranged from 6.31 (LD of LW) to 6.78 (SM of L). WHC (M/T value) was significantly influenced (p<0.001) by the type of muscle (Table 1). For both breeds, SM mus- cles had significantly better WHC (M/T=0.38 for LW and 0.36 for L, a bigger M/T ratio indicating a better WHC) than LD muscles (M/T=0.33, for both breeds). According to the mean M/T values, the WHC of both SM groups of muscles represent normal meat quality (non-exudative meat: M/T=0.35–0.45, Hofmann et al. 1982), while both LD groups of muscles represent poor pork quality (exudative meat: M/T<0.35, Hofmann et al. 1982). As expected (Table 2), pH 45min and pH 24h were significantly negatively correlated with CIEL* value (r=–0.29 and r=– 0.58, respectively, for LW, p<0.001; r=–0.50 and r=–0.61, respectively, for L, p<0.001) and significantly positively correlated with M/T value (r=0.27 and r=0.37, respectively, for LW, p<0.001; r=0.39 and r=0.29, respectively, for L, p<0.001). Additionally, CIEL* value was significantly negatively correlated with M/T value (r=–0.52 for LW and r=–0.47 for L, p<0.001). These correlations are in agreement with Bendall and Swatland (1988), van Laack et al. (1994), Lee et al. (2000), Brewer et al. (2001) and van de Perre et al. (2010). Table 2. Overall correlation coefficients (r) among technological quality parameters of Large White (LW) and Landrace (L) pigs. Breed – LW Breed – L Parameter pH 24h CIEL* M/T pH 24h CIEL* M/T pH 45min 0.42*** –0.29*** 0.27*** 0.48*** –0.50*** 0.39*** pH 24h –0.58*** 0.37*** –0.61*** 0.29*** CIEL* –0.52*** –0.47*** ***indicates significant difference at p<0.001. M = area of the pressed meat film; T = wet area on the filter paper. Incidence of different technological quality classes of pork According to criteria for initial pH (pH 45min <6.0), in this study, the percentage of potential PSE pork was 14.8% for SM of LW, 28.4% for LD of LW, 24.1% for SM of L and 27.7% for LD of L (Table 3). Overall, based on criteria for pH 45min , 23.8% of investigated muscles were potentially classified as PSE. In addition, the percentage of DFD pork with pH 24h ≥6.0 (Kauffman et al. 1992, Warner et al. 1997, Joo et al. 2000a 2000b, O’Neill et al. 2003) was 13.6% for SM of LW, 14.8% for LD of LW, 12.0% for SM of L, and 15.7% for LD of L. Overall, based on criteria for pH 24h , 14.0% of investigated muscles were classified as DFD. In this study, the colour of SM and LD muscles was defined as pale when ultimate CIEL*>50, reddish-pink when ultimate CIEL*=43–50 or dark when ultimate CIEL*<43 (Table 3). The highest incidence of the pale (43.4%) and dark (10.8%) colour and lowest incidence of reddish-pink (45.8%) colour was found in LD muscles of L breed. The incidence of pale, reddish-pink and dark colour in other three investigated groups of muscles were similar, i.e. the incidence of pale colour ranged from 29.6% (SM of LW) to 33.3% (LD of LW), reddish-pink ranged from 60.5% (LD of LW) to 62.7% (SM of L) and dark ranged from 6.2% (LD of LW) to 8.6% (SM of LW). Overall, based on criteria for A G R I C U LT U R A L A N D F O O D S C I E N C E V.M. Tomovic et al. (2014) 23: 9–18 14 CIEL*, 34.1% of investigated muscles were classified as pale pork (CIEL*>50), 57.6% as reddish-pink pork (CIEL*= 43–50), and 8.2% as dark pork (CIEL*<43). Combining criteria for pH 45min and CIEL* value to define pork quality of each individual SM and LD muscle, it was calculated that 62.8% of muscles with pH 45min <6.0 had CIEL* value higher than 50 (calculated data are not shown). Also, the incidence of pale (CIEL*>50) colour in all investigated groups of SM and LD muscles was higher than the incidence of the initial pH below 6.0 (Table 3). In addition, combining criteria for pH 24h and CIEL* value to define pork quality on each individual SM and LD muscle, it was calculated that 34.8% of muscles with pH 24h ≥6.0 had CIEL* value lower than 43 (calculated data are not shown). Also, the incidence of dark (CIEL*<43) colour in all investigated groups of SM and LD muscles was lower than the incidence of the ultimate pH above 6.0 (Table 3). In this study, according to WHC, SM and LD muscles were defined as exudative when M/T value <0.35, non-exuda- tive when M/T value between 0.35–0.45 or dry when M/T value >0.45 (Table 3). The incidence of non-exudative pork in SM and LD muscles from both breeds was very similar (53.1% of SM : 37.0% of LD from LW versus 51.8% of SM : 37.3% of LD from L). Compared to incidence of non-exudative pork, the incidence of exudative pork in SM muscles was 34.8% lower for LW and 13.9% for L, while the incidence of exudative pork in LD muscles was 60.3% higher for LW and 64.6% for L. The highest incidence of dry pork was found in SM muscles of LW breed (12.3%), and the lowest in LD muscles of L breed (1.2%). Overall, based on criteria for M/T value, 50.0% of investigated muscles were classified as exudative pork (M/T<0.35), 44.8% as non-exudative pork (M/T=0.35–0.45) and 5.2% as dry pork (M/T>0.45). Combining criteria for pH 45min and WHC to define pork quality of each individual SM and LD muscles, it was cal- culated that 71.8% of muscles with pH 45min <6.0 had M/T value lower than 0.35 (calculated data are not shown). Further, the incidence of exudative pork (M/T<0.35) in all investigated groups of SM and LD muscles was higher than the incidence of the initial pH below 6.0 (Table 3). In addition, combining criteria for pH 24h and WHC to de- fine pork quality of each individual SM and LD muscles it was calculated that 13.0% of muscles with pH 24h ≥6.0 had M/T value higher than 0.45 (calculated data are not shown). Also, the incidence of dry pork (M/T>0.45) in all investigated groups of SM and LD muscles was lower to the incidence of the ultimate pH above 6.0 (Table 3). The results of this study are in accordance with the conclusion of Bendall and Swatland (1988), van Laack et al. (1994), Joo et al. (1999) and Joo et al. (2000a 2000b) that the initial and ultimate pH values were not always a reli- able predictor for ultimate pork quality and its relation to both color and WHC of pork muscle should be more care- fully investigated, although it is evident that pH values are significantly related to both colour and WHC (Table 2). The detection of different pork quality is an important issue for meat industry in order to reduce economic losses and to proportionate the best destination to fresh meat. Generally, PSE/DFD meat is identified on the base of pH value, colour (CIEL* value) and WHC. While in some cases PSE/DFD meat is identified only on the base of colour (CIEL* value) and WHC (van Laack et al. 1994, Joo et al. 1999, Joo et al. 2000a 2000b). In this paper, colour (CIEL* value) and WHC (M/T value), measured 24 hours post-mortem, were used to assign SM and LD muscles to 1 of 9 quality classes (Table 3). Based on the lightness (CIEL* value) and M/T value, SM and LD muscles were classified into PE (pale and exudative), PN (pale and non-exudative), RE (reddish-pink and exu- dative), RN (reddish-pink and non-exudative), RD (reddish-pink and dry), DN (dark and non-exudative), and DD (dark and dry) pork. Two extreme combination of CIEL* and M/T values resulting in PD – pale and dry, and DE – dark and exudative pork quality were not identified. Generally, in SM muscles the higher percentages of PN (LW : L = 13.6% : 12.0%), RN (LW : L = 34.6% : 33.7%), RD (LW : L = 8.6% : 2.4%) and DD (LW : L = 3.7% : 1.2%) pork, and the lower percentages of PE (LW : L = 16.0% : 18.1%), RE (LW : L = 18.5% : 26.5%) and DN (LW : L = 4.9% : 6.0%) pork were determined. In contrast, in LD muscles the lower percentages of PN (LW : L = 7.4% : 9.6%), RN (LW : L = 24.7% : 18.1%), RD (LW : L = 2.5% : 0.0%) and DD (LW : L = 1.2% : 1.2%) pork, and the higher percentage of PE (LW : L = 25.9% : 33.7%), RE (LW : L = 33.3% : 27.7%) and DN (LW : L = 4.9% : 9.6%) pork were determined. Overall, the percentages of PE, PN, RE, RN, RD, DN, and DD pork were 23.5, 10.7, 26.5, 27.7, 3.4, 6.4, and 1.8%, respectively. With these seven categories of pork quality (Table 3) it is evident that although colour and WHC are significantly related (Table 2) their specific biochemical properties vary independently. This results are is in accordance with the conclusions of Bendall and Swatland (1988), van Laack et al. (1994), Joo et al. (1999) and Joo et al. (2000a 2000b). A G R I C U LT U R A L A N D F O O D S C I E N C E V.M. Tomovic et al. (2014) 23: 9–18 15 Ta bl e 3. In ci de nc e of d iff er en t M . s em im em br an os us ( SM ) an d M . l on gi ss im us d or si ( LD ) te ch no lo gi ca l q ua lit y cl as s ba se d on p H v al ue , c ol ou r (C IE L* ) an d w at er -h ol di ng c ap ac ity ( M /T v al ue ) of L ar ge W hi te (L W ) a nd L an dr ac e (L ) p ig s. Pa ra m et er Cr ite ri on Br ee d A ll m us cl es LW L M us cl e SM LD SM LD In ci de nc e N % N % N % N % N % pH 45 m in p os t- m or te m Pa le , s of t a nd e xu da tiv e po rk pH 45 m in <6 .0 0 12 14 .8 23 28 .4 20 24 .1 23 27 .7 78 23 .8 N or m al p or k pH 45 m in ≥6 .0 0 69 85 .2 58 71 .6 63 75 .9 60 72 .3 25 0 76 .2 pH 24 h p os t- m or te m N or m al p or k pH 24 h< 6. 00 70 86 .4 69 85 .2 73 88 .0 70 84 .3 28 2 86 .0 D ry , f ir m a nd d ar k po rk pH 24 h≥ 6. 00 11 13 .6 12 14 .8 10 12 .0 13 15 .7 46 14 .0 Co lo ur (C IE L* ) Pa le p or k CI EL *> 50 24 29 .6 27 33 .3 25 30 .1 36 43 .4 11 2 34 .1 Re dd is h- pi nk p or k CI EL *= 43 –5 0 50 61 .7 49 60 .5 52 62 .7 38 45 .8 18 9 57 .6 D ar k po rk CI EL *< 43 7 8. 6 5 6. 2 6 7. 2 9 10 .8 27 8. 2 W at er -h ol di ng c ap ac ity (M /T ) Ex ud at iv e po rk M /T <0 .3 5 28 34 .6 48 59 .3 37 44 .6 51 61 .4 16 4 50 .0 N on -e xu da tiv e po rk M /T =0 .3 5– 0. 45 43 53 .1 30 37 .0 43 51 .8 31 37 .3 14 7 44 .8 D ry p or k M /T >0 .4 5 10 12 .3 3 3. 7 3 3. 6 1 1. 2 17 5. 2 Co lo ur (C IE L* ) a nd w at er -h ol di ng c ap ac ity (M /T ) Pa le a nd e xu da tiv e po rk (P E) CI EL *> 50 a nd M /T <0 .3 5 13 16 .0 21 25 .9 15 18 .1 28 33 .7 77 23 .5 Pa le a nd n on -e xu da tiv e po rk (P N ) CI EL *> 50 a nd M /T =0 .3 5– 0. 45 11 13 .6 6 7. 4 10 12 .0 8 9. 6 35 10 .7 Re dd is h- pi nk a nd e xu da tiv e po rk (R E) CI EL *= 43 –5 0 an d M /T <0 .3 5 15 18 .5 27 33 .3 22 26 .5 23 27 .7 87 26 .5 Re dd is h- pi nk a nd n on -e xu da tiv e po rk (R N ) CI EL *= 43 –5 0 an d M /T =0 .3 5– 0. 45 28 34 .6 20 24 .7 28 33 .7 15 18 .1 91 27 .7 Re dd is h- pi nk a nd d ry p or k (R D ) CI EL *= 43 –5 0 an d M /T >0 .4 5 7 8. 6 2 2. 5 2 2. 4 0 0. 0 11 3. 4 D ar k an d no n- ex ud at iv e po rk (D N ) CI EL *< 43 a nd M /T =0 .3 5– 0. 45 4 4. 9 4 4. 9 5 6. 0 8 9. 6 21 6. 4 D ar k an d dr y po rk (D D ) CI EL *< 43 a nd M /T >0 .4 5 3 3. 7 1 1. 2 1 1. 2 1 1. 2 6 1. 8 M = a re a of th e pr es se d m ea t f ilm ; T = w et a re a on th e fil te r pa pe r. A G R I C U LT U R A L A N D F O O D S C I E N C E V.M. Tomovic et al. (2014) 23: 9–18 16 The results of this study show high percentage of pale meat (PE + PN = 34.1%) and exudative meat (PE + RE = 50.0%), i.e. the high percentage of pale and/or exudative meat (PE + PN + RE = 60.7%) in SM and LD muscles (Table 3). Similar incidences of PSE, PFN and RSE pork were obtained in other studies (Kauffman et al. 1992, van Laack et al. 1994, Joo et al. 2000a, O’Neill et al. 2003, van de Perre et al. 2010). It has been estimated that as much as 50% or more of the pork produced has unacceptably high purge or drip loss (Kauffman et al. 1992, Huff-Lonergan and Lonergan 2005). Composition of pork No significant (p>0.05) interaction effect between breed and muscle was found for composition (Table 4). Also, moisture, protein, total fat and total ash content were neither affected by the breed nor by the type of muscle. The mean moisture content ranged from 75.63 (LD of L) to 75.72% (SM of L), and the mean protein content ranged from 21.62 (SM of L) to 21.79% (LD of LW). Furthermore, the mean total fat content ranged from 1.35 (SM of LW) to 1.48% (LD of L), and the mean total ash content ranged from 1.12 (LD of LW and L) to 1.14% (SM of LW). Com- position of all investigated groups of SM and LD muscles analyzed in the present study were in agreement with the values reported for pork (Lawrie and Ledward 2006, Australia: Greenfield et al. 2009, Denmark: National Food Institute 2009, Finland: National Institute for Health and Welfare 2009, Italy: INRAN 2009, USA: The US Depart- ment of Agriculture’s 2011). As expected (Table 5), in the present study, moisture content was significantly nega- tively correlated with protein (r=–0.74, for LW, p<0.001; r=–0.43, for L, p<0.001), total fat (r=–0.35, for LW, p<0.01; r=–0.38, for L, p<0.01) and total ash content (r=–0.44, for LW, p<0.001; r=–0.23, for L, p<0.05). Additionally, pro- tein content was significantly negatively correlated with total fat content (r=–0.30, for LW, p<0.01; r=–0.60, for L, p<0.001). According to Keeton and Eddy (2004) the content of moisture, protein and ash decrease with increas- ing amounts of fat in the tissues. Table 4. Average (± SD) composition (%) of M. semimembranosus (SM) and M. longissimus dorsi (LD) of Large White (LW) and Landrace (L) pigs. Parameter Breed p-value LW L Muscle Muscle Breed Muscle Breed x Muscle SM LD SM LD Moisture 75.67±0.46 75.64±0.46 75.72±0.34 75.63±0.43 0.758 0.417 0.670 Protein 21.74±0.38 21.79±0.49 21.62±0.43 21.70±0.56 0.177 0.364 0.827 Total fat 1.35±0.29 1.39±0.28 1.40±0.39 1.48±0.50 0.219 0.355 0.740 Total ash 1.14±0.09 1.12±0.10 1.13±0.10 1.12±0.09 0.629 0.294 0.990 Table 5. Overall correlation coefficients (r) among pork composition of Large White (LW) and Landrace (L) pigs. Breed – LW Breed – L Parameter Protein Total fat Total ash Protein Total fat Total ash Moisture –0.74*** –0.35** –0.44*** –0.43*** –0.38** –0.23* Protein –0.30** 0.16 –0.60*** 0.07 Total fat 0.09 0.10 *indicates significant difference at p<0.05; **indicates significant difference at p<0.01; ***indicates significant difference at p<0.001. A G R I C U LT U R A L A N D F O O D S C I E N C E V.M. Tomovic et al. (2014) 23: 9–18 17 Conclusion Investigating the effect of pig breed (Large White and Landrace) in combination with muscle (M. semimembrano- sus and M. longissimus dorsi) on technological quality and composition of pork, the following was concluded: (i) T 24h was significantly (p<0.001) influenced by breed, (ii) T 45min , T 24h , pH 45min , and WHC (M/T value) were significantly (p<0.01 or <0.001) influenced by the type of muscle, (iii) the pH values were not a reliable predictor for ultimate pork quality, (iv) based on the lightness (CIEL* value) and M/T value (WHC) M. semimembranosus and M. longis- simus dorsi were classified into seven quality classes: PE (pale and exudative, 23.5%), PN (pale and non-exudative, 10.7%), RE (reddish-pink and exudative, 26.5%), RN (reddish-pink and non-exudative, 27.7%), RD (reddish-pink and dry, 3.4%), DN (dark and non-exudative, 6.4%), and DD (dark and dry, 1.8%) pork, (v) composition was in the characteristic range for modern lean pigs. Acknowledgments Research was financially supported by the Ministry of Education, Science and Technological Development, Repub- lic of Serbia, project TR31032. These results are also part of the project No 114-451-3464/2013 (Improvement of meat quality from indigenous and modern pig breeds produced in Vojvodina for the production of traditional dry fermented sausages and dry cured meat products), which is financially supported by the Provincial Secretariat for Science and Technological Development, Autonomous Province of Vojvodina, Republic of Serbia, and the project No 651-03-1251/2012-09/45 (Characterization of sensory and physicochemical attributes of protected traditional dry fermented meat products from Slovenia and Serbia) within the Serbien – Slovenia science technology coopera- tion for years 2012-2013. References Barbut, S., Sosnicki, A.A., Lonergan, S.M., Knapp, T., Ciobanu, D.C., Gatcliffe, L.J., Huff-Lonergan E. & Wilson, E.W. 2008. Progress in reducing the pale, soft and exudative (PSE) problem in pork and poultry meat. Meat Science 79: 46–63. Bendall, J.R. & Swatland, H.J. 1988. A review of the relationships of pH with physical aspects of pork quality. Meat Science 24: 85–126. Brewer, M.S., Zhu, L.G., Bidner, B., Meisinger D.J. & McKeith. F.K. 2001. Measuring pork color: effects of bloom time, muscle, pH and relationship to instrumental parameters. Meat Science 57: 169–176. CIE. 1976. International Commission on Illumination, Colorimetry: Official Recommendation of the International Commission on Illumination, Publication CIE No. (E-1.31). Paris, France: Bureau Central de la CIE. ECC No. 433/1964. Council Directive of 26 June 1964 on health conditions for the production and marketing of fresh meat. Grau, R. & Hamm, R. 1953. Eine einfache Methode zur Bestimmung der Wasserbindung im Muskel. Naturwissenschaften 40: 29–30. Greenfield, H., Arcot, J., Barnes, J.A., Cunningham, J., Adorno, P., Stobaus, T., Tume, R., Beilken S. & Muller, W. 2009. Nutrient composition of Australian retail pork cuts 2005/2006. Food Chemistry 117: 721–730. Hofmann, K., Hamm, R. & Blüchel, E. 1982. Neues über die Bestimmung der Wasserbindung des Fleisches mit Hilfe der Filterpa- pierpressmethode. Die Fleischwirtschaft 62: 87–92. Honikel, K.O. 1998. Reference methods for the assessment of physical characteristics of meat. Meat Science 49: 447–457. Honikel, K.O. 1999. Biochemical and physico-chemical characteristics of meat quality. Meat Technology 40: 105–123. Huff-Lonergan, E. & Lonergan, S.M. 2005. Mechanisms of water-holding capacity of meat: The role of postmortem biochemical and structural changes. Meat Science 71: 194–204. INRAN (Istituto Nazionale di Ricerca per gli Alimenti e la Nutrizione). 2009. Banca Dati di Composizione degli Alimenti. Cited 9 Sep- tember 2013. Updated 2009. Available on the Internet: http://www.inran.it/646/tabelle_di_composizione_degli_alimenti.html ISO 1442 1997. Meat and meat products: Determination of moisture content (Reference method). International Organisation for Standardisation, Geneva, Switzerland. ISO 1443 1973. Meat and meat products: Determination of total fat content. International Organisation for Standardisation, Ge- neva, Switzerland. ISO 2917 1999. Meat and meat products: Measurement of pH (Reference method). International Organisation for Standardisa- tion, Geneva, Switzerland. ISO 936 1998. Meat and meat products: Determination of total ash. International Organisation for Standardisation, Geneva, Swit- zerland. ISO 937 1978. Meat and meat products: Determination of nitrogen content (Reference method). International Organisation for Standardisation, Geneva, Switzerland. Joo, S.T., Kauffman, R.G., Kim, B.C. & Park, G.B. 1999. The relationship of sarcoplasmic and myofibrillar protein solubility to colour and water-holding capacity in porcine longissimus muscle. Meat Science 52: 291–297. A G R I C U LT U R A L A N D F O O D S C I E N C E V.M. Tomovic et al. (2014) 23: 9–18 18 Joo, S.T., Kauffman, R.G., Warner, R.D., Borggaard, C., Stevenson-Barry, J.M., Lee, S., Park, G.B. & Kim, B.C. 2000a. Objectively pre- dicting ultimate quality of post-rigor pork musculature: I. Initial comparison of techniques. Asian Australasian Journal of Animal Sciences 13: 68–76. Joo, S.T., Kauffman, R.G., Warner, R.D., Borggaard, C., Stevenson-Barry, J.M., Rhee, M.S., Park, B.S. & Kim, B.C. 2000b. Objectively predicting ultimate quality of post-rigor pork musculature: II. Practical classification method on the cutting-line. Asian Australa- sian Journal of Animal Sciences 13: 77–85. Kauffman, R.G., Cassens, R.G., Scherer, A. & Meeker, D.L. 1992. Variation in pork quality. Des Moines, Iowa, USA: National Pork Producers Council Publication. Keeton, J.T. & Eddy, S. 2004. Chemical and physical characteristics of meat/Chemical composition. In: Jensen, W. K., Carrick, D. & Dikeman, M. (eds.) Encyclopedia of meat sciences. Oxford, UK: Elsevier Ltd. p. 210–218. Lawrie, R.A. & Ledward, D.A. 2006. Lawrie’s meat science. 7th ed. Cambridge, England: Woodhead Publishing Ltd. & CRC Press LLC. Lee, S., Norman, J.M., Gunasekaran, S., van Laack, R.L.J.M., Kim, B.C. & Kauffman, R.G. 2000. Use of electrical conductivity to pre- dict water-holding capacity in postrigor pork. Meat Science 55: 385–389. National Food Institute Denmark. Technical University of Denmark 2009. http://www.foodcomp.dk/v7/fcdb_grpsearchres.asp?- MainGrp=07. Accesed 9 September 2013. National Institute for Health and Welfare. 2011. Fineli – Finnish Food Composition Database. http://www.fineli.fi/index.php?lang=en. Accessed 9 September 2013. Olsson, V. & Pickova, J. 2005. The influence of production systems on meat quality, with emphasis on pork. Ambio 34: 338–343. O’Neill, D.J., Lynch, P.B., Troy, D.J., Buckley, D.J. & Kerry, J.P. 2003. Influence of the time of year on the incidence of PSE and DFD in Irish pigmeat. Meat Science 64: 105–111. Rosenvold, K. & Andersen, H.J. 2003. Factors of significance for pork quality – A review. Meat Science 64: 219–237. Serbian Regulation 2011. Pravilnik o veterinarsko-sanitarnim uslovima, odnosno opštim i posebnim uslovima za higijenu hrane životinjskog porekla, kao i o uslovima higijene hrane životinjskog porekla. Sl. glasnik RS 11. (in Serbian). Sevón-Aimonen, M.-L., Honkavaara, M., Serenius, T., Mäki-Tanila, A., Puonti, M. 2007. Genetic variation of loin and ham quality in Finnish Landrace and Large White pigs. Agricultural and Food Science 16: 89–102. Smulders, F.J.M., Toldra, F., Flores, J. & Prieto, M.1992. New technologies for meat and meat products. Utrecht, The Netherlands: Audet Tijdschriften. StatSoft, Inc. 2011. STATISTICA (data analysis software system). Version 10. Cited 9 September 2013. Updated 2013. Available on the Internet: http://www.statsoft.com/ Swatland, H.J. 1995. Near-infrared birefringence and transmittance of pork in relation to pH, sarcomere length, cold-shortening, and causes of paleness. Food Research International 28: 153–159. The Danish Standard. 2007. Danish Quality Guarantee. 1st ed. Copenhagen, Denmark: Danish Meat Association. The US Department of Agriculture’s. 2011. Nutrient Data Laboratory. http://ndb.nal.usda.gov/ Accessed 9 September 2013. Tomović, V.M., Jokanović, M.R., Petrović, Lj.S., Tomović, M.S., Tasić, T.A., Ikonić, P.M., Šumić, Z.M., Šojić, B.V., Škaljac S.B. & Šošo, M.M. 2013. Sensory, physical and chemical characteristics of cooked ham manufactured from rapidly chilled and earlier deboned M. semimembranosus. Meat Science 93: 46–52. Tomović, V.M., Petrović, Lj.S. & Džinić, N.R. 2008. Effects of rapid chilling of carcasses and time of deboning on weight loss and technological quality of pork semimembranosus muscle. Meat Science 80: 1188–1193. Tomović, V.M., Petrović, Lj.S., Tomović, M.S., Kevrešan, Ž.S. & Džinić, N.R. 2011. Determination of mineral contents of semimem- branosus muscle and liver from pure and crossbred pigs in Vojvodina (northern Serbia). Food Chemistry 124: 342–348. UNECE (United Nations Economic Commission for Europe) standard. 2008. Porcine meat – carcases and cuts. 2006 ed. New York and Geneva: United Nations Publication. van de Perre, V., Ceustermans, A., Leyten, J. & Geers, R. 2010. The prevalence of PSE characteristics in pork and cooked ham – Ef- fects of season and lairage time. Meat Science 86: 391–397. van Laack, R.L.J.M., Kauffman, R.G., Sybesma, W., Smulders, F.J.M., Eikelenboom, G. & Pinheiro, J.C. 1994. Is colour brightness (L- value) a reliable indicator of water-holding capacity in porcine muscle? Meat Science 38: 193–201. van Oeckel, M.J., Warnants, N. & Boucqué, C.V. 1999. Comparison of different methods for measuring water holding capacity and juiciness of pork versus on-line screening methods. Meat Science 51: 313–320. Warner, R.D., Kauffman, R.G. & Greaser, M.L. 1997. Muscle protein changes post mortem in relation to pork quality traits. Meat Science 45: 339–352. Technological quality and composition ofthe M. semimembranosus and M. longissimus dorsi fromLarge White and Landrace Pigs Introduction Materials and methods Animals, sampling, slaughter and preparing Technological quality measurements Composition Statistical analysis Results and discussion Overall technological quality of pork Incidence of different technological quality classes of pork Composition of pork Conclusion Acknowledgments References