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Meat Science 77 (2007) 190–195

MEATSCIENCE

Relationship between water mobility and distribution andsensory attributes in pork slaughtered at an age between 90 and 180 days

Hanne Christine Bertram a,*, Ida K. Straadt a, Jens A. Jensen a, Margit Dall Aaslyng b

a Department of Food Science, Faculty of Agricultural Sciences, University of Aarhus, Box 50, DK-8830 Tjele, Denmarkb Department of Meat Quality, Danish Meat Research Institute, Maglegaardsvej 2, DK-4000 Roskilde, Denmark

Received 11 September 2006; received in revised form 26 February 2007; accepted 5 March 2007

Abstract

Water mobility and distribution were measured in M. longissimus dorsi from 41 pigs slaughtered at an age of 90, 140, 161 or 182 daysusing low-field proton NMR relaxometry, and in order to investigate the impact on sensory attributes, a sensory evaluation of the porkwas performed in parallel. The sensory evaluation demonstrated a significant effect of slaughter age on juiciness of the meat, and a finaljuiciness score of 8.4, 7.7, 7.2 and 7.8 was obtained for meat from 90, 140, 161 and 182-day old pigs, respectively. The NMR measure-ments revealed that the higher juiciness in meat slaughtered at an age of 90 days could be ascribed to a longer relaxation time of theextramyofibrillar water, corresponding to more mobile water, in the fresh meat of 90-day old pigs compared with the older pigs. Inthe cooked meat the higher juiciness of meat from 90-day old animals could be ascribed to a more homogenous distribution of the myo-fibrillar water compared with meat from older pigs. In contrast, the NMR measurements showed no effects that could explain the higherjuiciness in meat from pigs slaughtered at an age of 182 days compared with meat from pigs slaughtered at an age of 140 or 161 days.Possibly the increase in juiciness when the age at slaughter is increased from 161 to 182 days should be ascribed to an increase in intra-muscular fat content, which was not evident in the NMR measurements.� 2007 Elsevier Ltd. All rights reserved.

Keywords: Meat; Juiciness; NMR; T2 relaxation; Myofibrillar water; Heavy pigs; Slaughter age; Slaughter weight

1. Introduction

Pork quality is affected by several factors includinggenotype and slaughter conditions. While a live slaughterweight of approximately 100 kg is the standard in Danishpork production, production of so-called heavy pigs thatare slaughtered around a live weight of 120 kg also takesplace. Moreover, recently a niche production of pigletsslaughtered at a live weight of around 30 kg has been intro-duced (Danish Crown, 2006). The effects of varying theslaughter live weight in the range between 100 and 160 kgon growth performance, carcass characteristics and meatquality traits have been investigated (Candek-Potokar,Zlender, Lefaucheur, & Bonneau, 1998; Correa et al.,

0309-1740/$ - see front matter � 2007 Elsevier Ltd. All rights reserved.

doi:10.1016/j.meatsci.2007.03.006

* Corresponding author. Tel.: +45 89 99 15 06; fax: +45 89 99 15 64.E-mail address: HanneC.Bertram@agrsci.dk (H.C. Bertram).

2006; Fisher, Lindner, Judas, & Horeth, 2006; Latorre,Lazaro, Valencia, Medel, & Mateos, 2004; Monin et al.,1999), while studies of the effect of varying the slaughterweight between 70 and 100 kg are more rare (Beattie,Weatherup, Moss, & Walker, 1999). In relation to meatquality the most pronounced effect of slaughter weightreported in these studies was on colour attributes. How-ever, a sensory evaluation also revealed a significant effectof slaughter weight on juiciness (Fisher et al., 2006). Inaddition, some of the studies have also reported effects ofslaughter weight on the water content of the meat (Beattieet al., 1999; Candek-Potokar et al., 1998; Fisher et al.,2006). Nevertheless, there is limited knowledge of howslaughter weight affects water mobility and distribution inthe meat, which are decisive for meat quality attributesrelated to water-holding capacity (WHC) (Bertram et al.,2001, 2003; Bertram, Dønstrup, Karlsson, & Andersen,

H.C. Bertram et al. / Meat Science 77 (2007) 190–195 191

2002; Brøndum et al., 2000; Renou, Monin, & Sellier, 1985;Tornberg, Andersson, Goransson, & von Seth, 1993) andjuiciness (Bertram, Aaslyng, & Andersen, 2005; Fjelkner-Modig & Tornberg, 1986; Hullberg & Bertram, 2005).Using low-field proton NMR relaxometry combined withsensory evaluation, the aim of the present study was toinvestigate how a slaughter age between 90 and 182 days(corresponding to a live weight of approximately45–150 kg) affects water mobility and distribution inM. longissimus dorsi and the impact on the sensory qualityof the meat.

2. Materials and methods

2.1. Animals and sampling

The study included a total of 41 pigs. All animals werecrossbreeds of Hampshire/Duroc boars crossed with Land-race/Yorkshire sows. Eight pigs were slaughtered at an ageof 90 days, 12 pigs were slaughtered at an age of 140 days,12 pigs were slaughtered at an age of 161 days, while theremaining nine pigs were slaughtered at an age of 182 days;the minimum, maximum and mean live weights for the dif-ferent ages are reported in Table 1. All pigs were slaugh-tered at the experimental abattoir at Research CentreFoulum. The same slaughter procedure was used for allanimals. The animals were anaesthetised with 80% CO2

for 3 min. After cutting and exsanguinations, the animalswere scalded at 62 �C for 3 min.

Twenty-four hour postmortem, 25 cm of M. longissimusdorsi starting from the last rib and in the posterior directionwas cut from each animal. This piece was divided into twosub-samples of 5 and 20 cm, which were vacuum-packed,stored for 3 days at 4 �C and subsequently frozen andstored at �20 �C until NMR and sensory analyses,respectively.

WHC and pH was determined on the contra lateralmuscle at 24 h postmortem approximately at the positionof the last rib. WHC was determined using the bag methoddescribed by Honikel (1998). In the calculation of drip loss,the percentage drip loss was corrected for the initial weightof the sample. pH24 h was measured with a pH meter (Radi-

Table 1Live and carcass weights for the four age groups

Minimum Maximum Mean

Live weight (kg)

90 days (n = 8) 38.6 54.3 45.3140 days (n = 12) 82.1 112.4 96.5161 days (n = 12) 77.7 152.7 120.9182 days (n = 9) 114.8 157.0 145.0

Carcass weight (kg)

90 days (n = 8) 26.8 42.2 33.7140 days (n = 12) 63.2 91.0 76.3161 days (n = 12) 58.2 125.2 97.0182 days (n = 9) 87.8 127.0 116.9

ometer PHM201, Denmark) equipped with a probe typeglass electrode (Methrom LL Glas Electrode WOC, Sch-witzerland). The electrode was calibrated at a temperatureof 4 �C. A two-point calibration was performed, and theused calibration buffers had a pH of 7000 and 4005 at25 �C (Radiometer, Denmark).

2.2. NMR measurements

The NMR relaxation measurements were performed ona Maran Benchtop Pulsed NMR Analyzer (ResonanceInstruments, Witney, UK) with a resonance frequency forprotons of 23.2 MHz. The NMR instrument was equippedwith an 18 mm variable temperature probe. Prior to mea-surements the 5-cm samples were thawed overnight at4 �C. From each 5-cm sample, two sub-samples (approxi-mately 4 cm along the fibre direction and 1 · 1 cm incross-sectional area) were cut, weighed (weight 1) andplaced in cylindrical glass tubes for the NMR measure-ments. The samples were tempered in a 25 �C water bathfor 15–20 min prior to measurement. Transverse relaxation(T2) was measured at 25 �C using the Carr–Purcell–Mei-boom–Gill sequence (CPMG), and measurements wereperformed with a s-value (time between 90� pulse and180� pulse) of 150 ls using a repetition delay of 3 s, anddata were acquired as the amplitude of every second echo(to avoid influence of imperfect pulse settings) in a trainof 4096 echoes as an average of 16 repetitions. After T2

relaxation measurements on the fresh samples, the sampleswere cooked in a water bath at 68 �C for 20 min, subse-quently tempered in a 25 �C water bath, lightly dabbedand weighed (weight 2), and the T2 relaxation measure-ments were repeated. Cooking losses were calculated fromweights 1 and 2.

The obtained T2 relaxation decays were analysed usingdistributed exponential fitting analysis (Menon, Rusinko,& Allen, 1991) by means of in-house-made scripts inMatlab.

2.3. Sensory analysis

A trained sensory panel of eight assessors was used. Allassessors came from the area around Roskilde and werefamiliar with pork assessments. They had all received abasic training in sensory assessments in accordance withISO 4121, ASTM-MNL 13, DIN 10964. The sensory anal-ysis was conducted as four sessions with 10–11 samples prsession. At session 1, two loins of 90-day old pigs and threeloins of each of the others age groups were analysed. Atsessions 2, 3 and 4, tow loins of 90 and 180 days, respec-tively, and three loins of the other two groups were ana-lysed. The meat was sliced in 2 cm chops and fried on afrying pan at 155 �C until an end point temperature of68 �C measured with a thermometer with a handheld probe(Testo 926, Testoterm, Buhl and Bundsoe, Virum, Den-mark) was reached. The chops were turned every 2 minduring frying.

Score 1 (58%)

-7 4

Scor

e 2

(33%

)

-3

3

Score 1 (53%)

-4 6

Scor

e 2

(30%

)

-3

3

90 days140 days161 days182 days

a

b

Fig. 1. PCA analysis. Score plot showing the first and second principalcomponent for PCA carried out on distributed NMR data obtained on (a)fresh meat and (b) cooked meat.

192 H.C. Bertram et al. / Meat Science 77 (2007) 190–195

After frying the meat was cut into strips of 11/2 cm ·4 cm and served for the assessors on preheated plates witha three digit random number. The meat samples were pre-sented under Northern daylight, and the following attri-butes were assessed on an unstructured 15 cm lineranging from no (0) to very high intensity (15 cm): Juicinessafter 5 chews (juiciness 1), juiciness after 10 chews (juiciness2), juiciness after 20 chews (juiciness 3), hardness at firstbite, and tenderness.

2.4. Statistics

Statistics were performed using the SAS system 8.2 (SASInstitute, Gary, NC, USA). The statistical models includedthe fixed effect of slaughter age. Moreover, for sensory datathe effects of assessor and the interaction between assessorand slaughter age were included as random effects.

On distributed NMR T2 relaxation data principal com-ponent analysis (PCA) was applied to the centered data toexplore any clustering behaviour of the samples using theUnscrambler software (CAMO, Norway) (version 9.2).Partial least square regressions were carried out to explorethe relationship between distributed NMR T2 relaxationdata and sensory data. During all regressions, Martensuncertainty test (Martens & Dardenne, 1998) was used toeliminate noisy variables, and all models were validatedusing full cross-validation (Martens & Martens, 2000).

3. Results

3.1. pH, WHC and cooking loss

Table 2 shows pH24 h, drip loss and cooking loss for thefour different slaughter ages. No significant effect of slaugh-ter age on pH24 h was observed. Although not significantly,a clear tendency for an increase in drip loss with increasingslaughter age from 90 to 161 days was observed. In addi-tion, a decrease in cooking loss was observed with increas-ing slaughter age.

3.2. NMR

Fig. 1a and b displays the score plots from a principalcomponent analysis carried out on the distributed NMRdata obtained on fresh and cooked meat, respectively.For both fresh and cooked meat a tendency for clustering

Table 2pH24 h, drip loss and cooking loss for the different treatments

90 days(n = 8)

140 days(n = 12)

161 days(n = 12)

182 days(n = 9)

P-value

pH24 h 5.61 (0.03) 5.58 (0.02) 5.55 (0.02) 5.59 (0.03) 0.44Drip

loss (%)6.0 (1.1) 7.2 (0.9) 8.8 (0.9) 8.1 (1.1) 0.23

Cookingloss (%)

25.0 (1.2) 23.5 (0.9) 24.3 (0.9) 21.6 (1.0) 0.12

LS Mean values are given. Standard errors are given in parentheses.

according to slaughter age is observed, however, the effectis most evident for samples from 90-day old pigs. The aver-age distributed T2 relaxation times measured in fresh andcooked pork are shown in Fig. 2a and b, respectively. Inthe fresh meat three T2 populations with relaxation timesaround 1–5, 30–100 and 100–800 ms are observed, themajor population being the one around 30–100 ms(Fig. 2a). A pronounced effect of slaughter age on the slow-est population at 100–800 ms is observed. In meat frompigs slaughtered at an age of 140–182 days, the slowestpopulation is located with a maximum around 200–250 ms, while in meat from the pigs slaughtered at an ageof 90 days, the maximum of this population is located ata much higher value (�400 ms). In the cooked meat mainlytwo T2 populations are observed; a minor component ataround 1–5 ms together with a major, broad componentaround 10–200 ms (Fig. 2b). A pronounced effect of

1 10 100 1000

Ampl

itude

0

1

2

3

4

90 days140 days161 days182 days

Relaxation time (ms)1 10 100 1000

Ampl

itude

0

1

2

3

4

a

b

Fig. 2. Average distributions of T2 relaxation times for the four slaughterages (a) fresh meat and (b) cooked meat. Arrows in (a) show the slowestrelaxation population that is affected by slaughter age.

4-6ms21-32 ms 48-100 ms 1465-1680 ms

Hardness

Juiciness 2Juiciness 3

Juiciness 1

Tenderness

1

-1

1-1

Hardness

Juiciness 1Juiciness 2

Juiciness 3

1

1-1

a

b

H.C. Bertram et al. / Meat Science 77 (2007) 190–195 193

slaughter age on the characteristics of the major populationis observed in the cooked meat, as the population is moresymmetrical in meat from 90-day old pigs. In cooked meatfrom 140–182-day old pigs the major population is asym-metrical and consists of two sub-peaks.

3.3. Sensory analyses

Results from the sensory evaluation are shown in Table3. Significant effects of slaughter age were found for all juic-iness assessments and hardness. For juiciness assessments

Table 3Results from sensory analyses of the meat

90 days(n = 8)

140 days(n = 12)

161 days(n = 12)

182 days(n = 9)

P-value

Juiciness 1 7.15a 6.79a 6.29b 6.75ab 0.01

Juiciness 2 7.98a 7.51a 7.01ab 7.46a 0.009

Juiciness 3 8.40a 7.72b 7.15c 7.83ab 0.003

Hardness 5.19ab 5.66a 5.33a 4.62b 0.04

Tenderness 8.95 9.12 9.00 9.78 0.12

LS Mean values are given. Standard errors are given in parentheses.Letters indicate significant differences within rows.

the highest score was always obtained for meat from pigsslaughtered at an age of 90 days. A decrease in juicinesswas observed with increasing slaughter age up to 161 days,however, at an age of 182 days the juiciness increasedagain. The lowest hardness score was observed in meatfrom pigs slaughtered at an age of 182 days, while the high-est hardness score was observed in meat from pigs slaugh-tered at an age of 140 days. Tenderness increased withincreasing slaughter age.

3.4. Relationship between sensory and NMR data

In order to elucidate the relationship between water dis-tribution determined by NMR and sensory attributes ofthe meat, PLS2 regressions were carried out with NMRvariables as X-variables and sensory attributes as Y-vari-ables, and Fig. 3a and b shows the obtained correlationloading plots for fresh and cooked meat, respectively. Onlysignificant NMR variables, which were identified by jack-

11-16ms 25-50ms

Tenderness

-1

Fig. 3. Correlation loading plot (1st and 2nd PLS component) of PLSR2with NMR variables as X and sensory attributes as Y. Significant NMRvariables identified by jack-knifing are shown. (a) Fresh meat, thevalidated explained variances are 77%/5% for X and 12%/6% for Y. (b)Cooked meat, the validated explained variances are 80%/6% for X and11%/7% for Y.

194 H.C. Bertram et al. / Meat Science 77 (2007) 190–195

knifing, are shown. In fresh meat positive correlationsbetween relaxation times of 4–6 ms, 48–100 ms and 1465–1680 ms and juiciness as well as tenderness are observed,while hardness is correlated with relaxation times of 21–32ms (Fig. 3a). In cooked meat a positive correlation isobserved between relaxation times of 25–50 ms and thesensory attributes juiciness and tenderness (Fig. 3b). Relax-ation times of 11–16 ms are negatively correlated with juic-iness/tenderness and positively correlated with hardness.

4. Discussion

One of the most important quality attributes of pork isjuiciness. The perceived juiciness of the meat is believed tobe linked to the water in the meat, and studies have showna correlation between cooking loss and juiciness (Bejerholm& Aaslyng, 2003; Bouton, Ford, Harris, & Ratcliff, 1975;Serra et al., 2004; Wood, Nute, Fursey, & Cuthbertson,1995), which could indicate a simple relationship betweenwater content and juiciness. However, it has also beenshown that cooking loss alone cannot explain the entire var-iation observed in juiciness (Toscas, Shaw, & Beilken,1999), and it has been hypothesised that the biochemical–biophysical state of the water in the meat, i.e. water mobilityand distribution, plays a major role for the juiciness of themeat (Trout, 1988). Proton NMR relaxation studies, whichenables us to study the intrinsic properties of the water inmeat, have demonstrated an association between watermobility and distribution and the sensation of pork juici-ness (Bertram et al., 2005; Bertram & Aaslyng, in press;Fjelkner-Modig & Tornberg, 1986; Hullberg & Bertram,2005). In the present study we investigated how differencesin juiciness as a function of slaughter age could be ascribedto differences in water mobility and distribution. NMR T2

data revealed pronounced effects of slaughter age on watermobility and distribution in the muscles, which is in agree-ment with a previous study (Bertram et al., 2002). A sensoryevaluation of pork from pigs slaughtered at an age of either90, 140, 161 or 182 days revealed a significant effect ofslaughter age on juiciness, as juiciness increased withdecreasing age from 161 to 90 days, and the highest juicinessscore was obtained at a slaughter age of 90 days. Distrib-uted T2 relaxation times revealed that the higher juicinessin meat slaughtered at an age of 90 days could be ascribedto a longer relaxation time of the extramyofibrillar water,corresponding to more mobile water, in the fresh meat of90-day old pigs compared with the older pigs. In the cookedmeat the higher juiciness of meat from 90-day old animalscould be ascribed to a more homogenous distribution ofthe myofibrillar water compared with meat from older pigs.Accordingly, the data indicate that in the fresh meat, themobility of the extramyofibrillar water is of utmost impor-tance for a high water release during chewing and therebythe perception of meat juiciness, while the pore size distribu-tion of the myofibrillar protein network plays the major rolein the cooked meat. Comparable findings have previouslybeen reported in both fresh and cooked meat (Bertram

et al., 2005; Bertram & Aaslyng, in press; Fjelkner-Modig& Tornberg, 1986).

In the cooked meat an effect of age on the shape of themyofibrillar water population was evident. A bimodalmyofibrillar population was observed in meat from pigswith an age between 140 and 180 days, while a more sym-metrical population was observed in meat from 90-day oldpigs. This tendency for a bimodal distribution of the myo-fibrillar water has also been reported earlier, and it wasobserved that it disappears as a function of aging (Bertram& Aaslyng, in press; Straadt, Rasmussen, Andersen, & Ber-tram, 2007) and with increasing cooking temperature (Ber-tram, Wu, van den Berg, & Andersen, 2006). The bimodaldistribution has been suggested to reflect structural con-straints in the meat, and accordingly the present study indi-cates that the thermal denaturation of these structuralcomponents is age-dependent. It has been shown thatchanges in intramuscular connective tissue during growthaffect toughness of pork (Fang, Nishimura, & Takahashi,1999), and possibly the same mechanisms are involved inthe water distribution. In agreement with earlier observa-tions (Bertram & Aaslyng, in press), a relationship betweenjuiciness and the bimodal distribution of the myofibrillarwater was found in the present study.

It is noteworthy that an increase in juiciness wasobserved when the slaughter age was increased from 161to 182 days, while this was not displayed in the distributedT2 relaxation times. The increase in juiciness with theincrease in age should possibly be ascribed to an increasein intramuscular fat. Intramuscular fat has a T2 relaxationtime around 60 ms (Laurent, Bonny, & Renou, 2000).However, considering the low amount of intramuscularfat present in M. longissimus dorsi, the contribution fromthis component to the distributed T2 relaxation time canbe expected to be negligible, which explains that theincrease in juiciness from 161 to 182 days is not evidentin the distributed proton NMR T2 relaxation times.

5. Conclusion

In conclusion, the present study demonstrated a rela-tionship between water mobility and distribution in porkand the sensation of meat juiciness. A higher juiciness scorein meat from pigs slaughtered at an age of 90 days could beascribed to a longer relaxation time of the extramyofibrillarwater, corresponding to more mobile water, in the freshmeat of 90-day old pigs compared with pigs slaughteredat an age between 140 and 180 days. In the cooked meatthe higher juiciness of meat from 90-day old animals couldbe ascribed to a more homogenous distribution of the myo-fibrillar water compared with meat from older pigs.

Acknowledgement

The authors thank The Danish Ministry of Food, Agri-culture and Fisheries for funding the project entitled ‘‘Char-acterisation of technological and sensory quality in foods’’.

H.C. Bertram et al. / Meat Science 77 (2007) 190–195 195

References

Beattie, V. E., Weatherup, R. N., Moss, B. W., & Walker, N. (1999). Theeffect of increasing carcass weight of finishing boars and gilts on jointcomposition and meat quality. Meat Science, 52, 205–211.

Bejerholm, C., & Aaslyng, M. D. (2003). The influence of cookingtechnique and core temperature on results of sensory analysis of pork-depending on the raw meat quality. Food Quality and Preference, 15,19–30.

Bertram, H. C., & Aaslyng, M. D. (in press). Pelvic suspension and fastpostmortem chilling: Effects on technological and sensory quality ofpork – A combined NMR and sensory study. Meat Science,doi:10.1016/j.meatsci.2007.01.010.

Bertram, H. C., Aaslyng, M. D., & Andersen, H. J. (2005). Elucidation ofthe relationship between cooking temperature, water distribution andsensory attributes of pork – A combined NMR and sensory study.Meat Science, 70, 75–81.

Bertram, H. C., Andersen, H. J., Karlsson, A. H., Horn, P., Hedegaard, J.,Nørgaard, L., et al. (2003). Prediction of technological quality(cooking loss and Napole Yield) of pork based on fresh meatcharacteristics. Meat Science, 65, 707–712.

Bertram, H. C., Dønstrup, S., Karlsson, A. K., & Andersen, H. J. (2002).Continuous distribution analysis of T2 relaxation in meat – Anapproach in the determination of water holding capacity. Meat

Science, 60, 279–285.Bertram, H. C., Karlsson, A. H., Rasmussen, M., Dønstrup, S., Petersen,

O. D., & Andersen, H. J. (2001). The origin of multi-exponential T2

relaxation in muscle myowater. Journal of Agriculture and Food

Chemistry, 49, 3092–3100.Bertram, H. C., Rasmussen, M., Busk, H., Oksbjerg, N., Karlsson, A. H.,

& Andersen, H. J. (2002). Changes in porcine muscle water charac-teristics during growth – An in vitro low-field NMR relaxation study.Journal of Magnetic Resonance, 157, 267–276.

Bertram, H. C., Wu, Z., van den Berg, F., & Andersen, H. J. (2006). NMRrelaxometry and differential scanning calorimetry during meat cook-ing. Meat Science, 74, 684–689.

Bouton, P. E., Ford, A. L., Harris, P. V., & Ratcliff, D. (1975). Objectiveassessment of meat juiciness. Journal of Food Science, 40, 884–885.

Brøndum, J., Munck, L., Henckel, P., Karlsson, A., Tornberg, E., &Engelsen, S. B. (2000). Prediction of water-holding capacity andcomposition of porcine meat by comparative spectroscopy. Meat

Science, 55, 177–185.Candek-Potokar, M., Zlender, B., Lefaucheur, L., & Bonneau, M. (1998).

Effects of age and/or weight at slaughter on Longissimus dorsi muscle:Biocehmical traits and sensory quality in pigs. Meat Science, 48, 287–300.

Correa, J. A., Faucitano, L., Laforest, J. P., Rivest, J., Marcoux, M., &Gariepy, C. (2006). Effects of slaughter weight on carcass compositionand meat quality in pigs of two different growth rates. Meat Science,

72, 91–99.Danish Crown. (2006). Personal communication. See http://www.bocuse-

dor.dk/Sponsorer/3.Fang, S. H., Nishimura, T., & Takahashi, K. (1999). Relationship between

development of intramuscular connective tissue and toughness of porkduring growth of pigs. Journal of Animal Science, 77, 120–130.

Fisher, K., Lindner, J. P., Judas, M., & Horeth, R. (2006). Schlachtkor-perzusammensetzung und Gewebebeschaffenheit von schwerenSchweinen. Archives of Animal Breeding, 49, 279–292.

Fjelkner-Modig, S., & Tornberg, E. (1986). Water distribution in porcineM. longissimus dorsi in relation to sensory properties. Meat Science, 17,213–231.

Honikel, K. O. (1998). Reference methods for the assessment of physicalcharacteristics of meat. Meat Science, 49, 447–457.

Hullberg, A., & Bertram, H. C. (2005). Relationships between sensoryperception and water distribution determined by low-field NMR T2

relaxation in processed pork – Impact of tumbling and RN – Allele.Meat Science, 69, 709–720.

Latorre, M. A., Lazaro, R., Valencia, D. G., Medel, P., & Mateos, G. G.(2004). The effects of gender and slaughter weight on the growthperformance, carcass traits, and meat quality characteristics of heavypigs. Journal of Animal Science, 82, 526–533.

Laurent, W. M., Bonny, J. M., & Renou, J.-P. (2000). Imaging of waterand fat fractions in high-field MRI with multiple slice chemical shift-selective inversion recovery. Journal of Magnetic Resonance Imaging,

12, 488–496.Martens, H., & Dardenne, P. (1998). Validation and verification of

regression in small data sets. Chemometrics and Intelligent Laboratory

Systems, 44, 99–121.Martens, H., & Martens, M. (2000). Modified jack-knife estimation of

parameter uncertainty in bilinear modelling by partial least squaresregression (PLSR). Food Quality and Preference, 11, 5–16.

Menon, R. S., Rusinko, M. S., & Allen, P. S. (1991). Multiexponentialproton relaxation in model cellular systems. Magnetic Resonance in

Medicine, 20, 196–213.Monin, G., Larzul, C., Le Roy, P., Culioli, J., Mourot, J., Rousset-

Akrim, S., et al. (1999). Effects of the halothane genotype andslaughter weight on the texture of pork. Journal of Animal Science,

77, 408–415.Renou, J. P., Monin, G., & Sellier, P. (1985). Nuclear magnetic resonance

measurements on pork of various qualities. Meat Science, 15,225–233.

Serra, X., Gil, M., Gispert, M., Guerrero, L., Oliver, M. A., Sanudo, C.,et al. (2004). Characterisation of young bulls of the Bruna delsPirineus catlle breed (selected from old Brown Swiss) in relation tocarcass, meat quality and biochemical traits. Meat Science, 66,425–436.

Straadt, I. K., Rasmussen, M., Andersen, H. J., & Bertram, H. C. (2007).Aging-induced changes in microstructure and water distribution infresh and cooked pork in relation to water-holding capacity andcooking loss – A combined confocal laser scanning microscopy(CLSM) and low-field nuclear magnetic resonance relaxation study.Meat Science, 75(4), 687–695.

Tornberg, E., Andersson, A., Goransson, A., & von Seth, G. (1993).Water and fat distribution in pork in relation to sensory properties. InE. Poulanne & D. I. Demeyer (Eds.), Pork quality: Genetic and

metabolic factors (pp. 239–258).Toscas, P. J., Shaw, F. D., & Beilken, S. L. (1999). Partial least squares

(PLS) regression for the analysis of instrument measurements andsensory meat quality data. Meat Science, 52, 173–178.

Trout, G. R. (1988). Techniques for measuring water-binding capacity inmuscle foods – A review of methodology. Meat Science, 23,235–252.

Wood, J. D., Nute, G. R., Fursey, G. A., & Cuthbertson, A. (1995). Theeffect of cooking conditions on the eating quality of pork. Meat

Science, 40, 127–135.