Sensory properties of hot-deboned ostrich (Struthio camelus var. domesticus) Muscularis gastrocnemius, pars interna

Cold-deboning is currently practiced in South African ostrich abattoirs. However, the advantages of hot-deboning include the reduction of costs and time, but there is always the risk of cold-shortening. The effects of hot-deboning of ostrich M. gastrocnemius, pars interna on meat sensory attributes were investigated. The data showed that the hot-deboned muscles’ pH₄₈ (6.57 ± 0.18) was significantly negatively correlated (r = −0.7813; P < 0.038) to the mean Warner–Bratzler shear force values (71.28 ± 18.62 N, 12.7 mm⁻¹ diameter) and positively correlated (r = 0.789; P < 0.035) to the mean scores for taste panel tenderness (66.39 ± 15.45). After storage for 48 h post-mortem, the hot-deboned muscles were found to be less juicy (P < 0.004) and, according to both sensory tenderness scores and Warner–Bratzler shear force values, tougher (P < 0.0001) than the cold-deboned muscles.     

Identification of halothane genotypes by calcium accumulation and their meat quality using live pigs

The three halothane genotypes (NN, Nn, and nm) were identified by measuring the capacity for Ca²⁺ accumulation by sarcoplasmic reticulum in whole muscle homogenate preparations of M. longissimus dorsi with a Ca²⁺ specific electrode at 35°C. Significant differences (P < 0·001) in deterioration (%) of Ca²⁺ accumulation, 12% for NN, 35% for Nn, and 81% for nn pigs, were observed after ageing the whole muscle homogenate preparations for 24 h in ice.

Predictions of meat quality in live pigs (n = 34) based on the values for water-holding capacity, assessed as fluid (g/0·5 g wet wt LD), and pH (fluid) by using small biopsy LD samples (Cheah et al. 1993) were performed on all the halothane genotypes. The halothane genotype NN (n = 11) showed a fluid value of 0·37 ± 0·01 and a pH (fluid) value of 6·62 ± 0·03 as compared with 0·61 ± 0·02 and 5·84 ± 0·04, respectively, for the halothane genotype nn (n = 13). The Nn pigs (n = 10) showed fluid (0·49 ± 0·03) and pH (fluid) (6·19 ± 0·11) values between those values observed for the two homozygotes (NN and nn). Predictions of meat quality in live pigs from biopsy LD muscles were confirmed from assessments on post-mortem LD muscles based on pH₁ and fibre optic probe (FOP) measurements.

The extent of deterioration (%) in Ca²⁺ accumulation showed high correlations with fluid (r = −0·861) and pH (fluid) (r = −0·831) in the biopsy LD samples, and with pH₁ (r = 0·663), FOP (r = −0·812), and drip (%) loss (r = −0·777) in the post-mortem LD samples.     

Meat quality characteristics of springbok (Antidorcas marsupialis). 1: Physical meat attributes as influenced by age, gender and production region

Springbok is the most extensively cropped game species in South Africa. The effects of age (adult, sub-adult, lamb), gender and production region on the physical attributes (pH₂₄, cooking and drip loss, Warner Bratzler shear force and colour) were determined using samples of the M. longissimus dorsi (LD) muscles of 166 springbok. Stressed animals had a higher (P < 0.05) pH₂₄ (6.3 ± 0.07), as observed in the meat originating from the Caledon region. This meat had lower (P < 0.05) cooking loss (27.2 ± 0.62%) and drip loss (1.8 ± 0.08%) values in comparison to meat originating from the other regions. Inverse correlations were noted between pH₂₄ and drip loss (r = −0.26, P < 0.01) and cooking loss (r = −0.42, P < 0.001). Shear force values (kg/1.27 cm diameter) correlated positively (r = 0.25, P < 0.01) with pH₂₄. Age-related effects on tenderness were small in comparison with pH₂₄ effects. CIELab colorimetric values were typical of game meat and venison (L^* < 40, high a^* and low b^* values). It was noted that pH₂₄ correlated negatively (r = −0.51, P < 0.001) and positively (r = 0.33, P < 0.001) with the hue-angle and the chroma value of colour, respectively. Springbok originating from Caledon had a significantly (P < 0.05) higher a^* value, indicating meat to be more red with higher colour saturation.     

Variation in post-mortem rate of glycolyis does not necessarily affect drip loss of non-stimulated veal

In this study the effect of the rate of post mortem pH fall on the water-holding capacity of meat from moderately chilled veal carcasses was investigated. Also the relationship between muscle protein denaturation and drip loss of veal was examined. Three groups of 10 Friesian Holstein male veal calves each were selected on the basis of their pH in M. longissimus thoracis et lumborum (LTL) at 3 hr post mortem (pH₃): (1) fast pH-fall, pH₃ < 6.2; (2) intermediate pH-fall, 6.5 < pH₃ < 6.6; (3) slow pH-fall, pH₃ > 6.7. After 48 hr of chilling the LTL was excised from the carcass and sampled for determination of drip loss, filter paper wetness, sarcomere length, protein solubility and transmission value. Differences in pH₃ were not associated with differences in drip loss, filter paper wetness or differences in protein denaturation. It is suggested that at the relatively high veal carcass chilling rate the effect of rate of pH-fall on protein denaturation and thus on drip loss is negligible. Drip loss of veal was highly correlated with both solubility of sarcoplasmic (r = −0.67; p < 0.001) and total muscle protein (r = −0.54; p < 0.01) and with transmission values (r = 0.66; p < 0.001). These results indicate that protein denaturation measurements may be a good predictor for drip loss of veal.     

The effect of post-exsanguination infusion on the composition, exudation, color and post-mortem metabolic changes in lamb

Twenty-four lamb carcasses were assigned to three treatment groups: (1) control (Ctr), (2) infused with 10% (vol/wt) of a tenderizing blend (NCa), and (3) NCa plus 0·015 CaCl₂ (WCa). Results indicated that the infused carcass solution was retained in the following order: shoulder > lion > leg. Infusion had no effect (P > 0·05) on drip and cooking losses in refrigerated samples. Samples frozen and then thawed from infused carcasses had greater thaw drip (P < 0·05) and cooking losses (P < 0·01) than control samples. The amounts of drip and cooking losses were in the order: WCa > NCa > Ctr. Frozen storage preserved the red color but lowered the lightness and yellowness of ovine muscles; the opposite effect was observed following refrigerated storage. Infused samples were lighter and yellower than control in both fresh and frozen samples (P < 0·01). WCa had less red color (P < 0·01) than NCa and Ctr at all times and storage conditions. Infusion lowered (P < 0·05) the temperature of carcasses over the first 3 h postmortem (pm) compared with Ctr. The rate of glycolysis was higher in infraspinatus (IS) than in longissimus thoracis et lumborum muscle (LTL or longissimus). In both IS and LTL, glycolysis was completed within the first 6 h postmortem in NCa, whereas in Ctr and WCa, it took 12–24 h for glycolysis to be completed. The rate of glycolysis was in the order: NCa > WCa > Ctr.     

Effects of early post-mortem pH and temperature on beef tenderness

The tenderness of loin steaks, prepared from beef sides after chilling, is strongly influenced by muscle temperature in the first 3 h after slaughter. Maintenance of about 37°C within the Longissimus muscle during this time, whether by heavy fat cover or by ambient-temperature manipulation, results in appreciable tenderness enhancement. Early post-mortem muscle pH (which varies over a wide range) also affects tenderness significantly; provided early and exceptionally fast chilling does not induce cold shortening, slow glycolysis promotes tenderness. Low-frequency (2 Hz) electrical stimulation, which accelerates glycolysis but causes negligible tissue disruption, significantly toughens the loin; in its normal mode (50–60 Hz), therefore, stimulation produces its desirable tenderising effect mainly—and perhaps solely—by fibre fracture.     

Tenderness of pork muscles as influenced by chilling rate and altered carcass suspension

Tenderness improvements in porcine muscles (M. longissimus dorsi, LD; M. semimembranosus, SM; M. biceps femoris, BF) were evaluated in a total of 72 carcasses by using combinations of three different chilling rates (fast, delayed fast, slow) and two different suspension methods (Achilles tendon, pelvic bone).

Tenderness was improved by fast chilling in LD, SM and BF by the pelvic suspension as compared to conventional suspension in the Achilles tendon (P < 0·05). The lengthening of the sarcomeres in SM and BF as produced by pelvic suspension exceeded those found in LD, without having proportional additional effect on the tenderness. While the pelvic-induced tenderization did not change significantly by delayed fast chilling, additional tenderization in BF and SM was obtained by combining pelvic suspension with slow chilling. In conventionally suspended sides, tenderness was unaffected by delayed fast chilling—with slow chilling, however, improvements were observed in LD and SM to a similar extent as obtained by the pelvic suspension. In the LD muscle, the tenderizing effect produced by treatments was largest in muscles having pH values 45 min post stunning above 6·1 (P < 0·05).     

The influence of porcine growth hormone on muscle fibre characteristics, metabolic potential and meat quality

Treatment of lean female pigs with porcine growth hormone (placebo or 80 μg pGH per kg body weight per day) for 6 weeks from 50 kg to 86 kg body weight did not change the frequency and the percentage area of muscle fibre types (ST, FTa and FTb fibres) and muscle capillarity of M. longissimus dorsi, M. gluteus medius and M. psoas major. The mean fibre cross-sectional area increased 5·3%, albeit nonsignificantly, corresponding to a 6·6% increase in carcass meat. The muscles contained slightly less dry matter and protein, and the lipid content of M. longissimus dorsi decreased 19% after pGH treatment. In the backfat the fatty acid composition changed towards a higher ratio of polyunsaturated to saturated fatty acids. The pH_u of M. longissimus dorsi was unaltered, while the pH₄₅ was reduced by pGH. The muscle glycogen level and the activity of lactate dehydrogenase (LDH), citrate synthetase (CS), and 3-OH-acyl-CoA-dehydrogenase (HAD) of M. longissimus dorsi were unchanged by pGH. The haem pigment, shear force, sarcomere length and eating quality of loin chops, were unaffected by pGH treatment. The results show that pGH treatment did not change the muscle characteristics in a way that affects the meat quality of M. longissimus dorsi in lean female pigs.     

Evaluation of lean meat quality in pigs using two electronic probes

The Danish Fat-O-Meater grading probe (FOM) and the Fibre Optic Probe (FOP) developed at IFR, Bristol, were evaluated for their potential ability to predict lean meat quality in a sample of 76 pig carcasses showing a wide range of quality in the M. longissimus dorsi. When probings were made after chilling at about 20 h post mortem the correlations between probe value (FOP_u and FOM_u) and reflectance (EEL value), drip loss during storage and subjective assessment score for colour-structure were high (FOP_u and reflectance, r = 0·89; drip loss, r = 0·78; subjective assessment, r = 0·90. FOM_u and reflectance, r = 0·88; drip loss, r = 0·73; subjective assessment r = 0·81). Nevertheless, probe values could not be used to unambiguously group samples into normal, pale, soft, exudative (PSE) or dark, firm, dry (DFD) classes. Correlations between probe values at 45 min post mortem and measures of ultimate meat quality were much lower. Neither probe could potentially differentiate between normal and DFD meat at this time and differentiation between normal and PSE meat was also poorer.     

The relationship of muscle fibre size to tenderness of beef

Steaks were removed from loins of beef carcasses at 1, 3, 6 or 14 days post mortem for fragmentation index (MFI), Warner-Bratzler Shear Force (SF) and sensory panel tenderness evaluation. Also, after 1 day of storage, samples were removed for histological observations. Greatest improvement in tenderness, SF and MFI occurred within the first 6 days of storage. Sensory panel tenderness was correlated (P < 0·01) with SF and MFI. Average muscle fibre size was correlated (P < 0·01) with tenderness and SF at days 1 and 3, but not at days 6 and 14. Evidently, muscle fibre size is important to tenderness prior to post-mortem storage of meat and proteolysis, but becomes less of a factor in tenderness after 6 days of storage.     

The effects of electrical stimulation and ageing on beef tenderness

Seventeen beef carcasses from cattle with a range of breeds, ages and body conditions were used in this trial. The four treatments applied to each carcass were control (C), electrical stimulation (ES), ageing for 28 days (A) and electrical stimulation plus ageing for 28 days (ES + A). Post-mortem muscle pH was measured at 0, 0·5, 4 and 24h post-stimulation. Significantly lower muscle pH values (P < 0·01) were achieved by the stimulated carcass side sompared to the unstimulated side at 0·5 (pH 6·47 vs. 6·91) and 4 h (pH 5·96 vs. 6·44) post-stimulation.

Warner-Bratzler shear and taste panel methods were used to assess the tenderness of Longissimus dorsi muscle samples from each of the four treatments. The ES, A and ES + A treatments were significantly more tender (P < 0·01) than the control treatment. The ES and the A treatments resulted in a similar improvement in tenderness compared to the control. The ES + A treatment was significantly more tender (P < 0·01) than the ES treatment alone, but there was no significant difference in tenderness between the A and the ES + A treatments.     

A repeat national survey of muscle pH values in commercial pig carcasses

Measurements of pH values at 45 min post-slaughter (pH₁) in m. longissimus were taken in a total of 5598 commercial bacon weight carcasses. pH values at 24 h post-slaughter (pH₂) were taken on a further 5598 carcasses. The overall mean pH₁ was 6.39 with 15.1% of values less than 6.0. The overall mean pH₂ was 5.64, none of the values recorded were greater than 6.5. This survey shows a small increase over the 1983 study in the incidence of potentially Pale Soft and Exudative (PSE) carcasses. It found no evidence of a Dark, Firm and Dry (DFD) problem related to high ultimate pH.     

Identification and characterization of pigs prone to producing 'RSE' (reddish-pink, soft and exudative) meat in normal pigs

RSE (reddish-pink, soft and exudative) meat was investigated using pigs of three different halothane genotypes. A significantly lower pH_1h, value was observed in RSE compared with that of RFN (red, firm and non-exudative) -meat, both of which have values higher than 6.0 at 1 hr post-mortem. Drip loss (%) in RSE-meat was ≥7%, which was twice that of RFN-meat. Normal values for fibre optic probe and Minolta L and a were observed for RSE-meat. RSE-meat could be derived from NN and Nn pigs, and its formation could be induced from RFN-prone pigs by poor post-slaughter management. Pigs expected to produce RSE-meat were identified using small biopsy samples of M. longissimus dorsi (LD). Predicted RSE-meat in live pigs was confirmed by post-mortem assessments of meat quality using LD muscle. With NN Landrace-Yorkshire × Duroc pigs, 15.6% were identified to be RSE-prone in live pigs, and a further 6.7% RSE was induced after slaughter from RFN pigs. The rate of glycolysis determined from biopsy LD samples and at 1 hr post-mortem (pH_1h) were significantly (p < 0.001) faster in RSE than in RFN-prone pigs, but significantly slower than those of PSE-prone pigs. Good correlations (p < 0.001) were observed between biopsy fluid (F) values, an indicator of water-holding capacity (WHC), and drip loss (r = 0.652) from post-mortem LD muscle, and between biopsy pH (F), an indicator for the rate of glycolysis, and F (r = −0.828). These results show that the skeletal muscle test using biopsy LD muscle could be employed to reduce the incidence of RSE-meat.     

Effects of early-postmortem glycolytic rate on beef tenderness

Electrical stimulation (ES) was applied at 500 V to one side from each of 60 beef carcasses at 30 to 40 min postmortem. Wide ranges of early-postmortem glycolytic and cooling rates were produced in the musculature by use of three different forms of ES (in addition to non-ES treatment of the contralateral sides) and application of chilling routines of four different degrees of severity. Panel and Warner-Bratzler shear evaluations of loin steaks from all 120 sides showed that tenderness was highest when glycolysis had proceeded at an intermediate rate (corresponding to the attainment of a 3-h pH of about 6·1) and was appreciably lower on both sides of this mid-value. The toughening effect of rapid glycolysis (relative to that of a moderately increased glycolytic rate) persisted through 14 days of aging at 2°C.

These observations appear to be incompatible with the view that lysosomal enzymes contribute significantly to ES-induced tenderization. They also indicate that the effect of ES on tenderness is highly dependent on the subsequent cooling rate, very slow chilling sometimes accelerating the already high rate of pH fall to such an extent that the tissue is significantly toughened. Finally, they suggest that the goal of maximizing the early-postmortem rate of pH decline in bovine muscle is misguided and, if attained, will cause sub-optimal tenderness.     

The protective effect of electrical stimulation and wrapping on beef tenderness at high pre rigor temperatures

A three factorial experimental design involving electrical stimulation (ES/NES), wrapping (wrapped/unwrapped) and pre rigor temperature (15 °C or 35 °C) was applied to 70 beef M. longissimus lumborum muscles to obtain a wide variation in shear force and drip loss. The shear force of all treatment groups decreased during ageing. As anticipated, wrapping and electrical stimulation had positive effects on shear force. However, high pre rigor temperature (35 °C) did not result in higher shear force values if the muscles were electrically stimulated, wrapped or both. The results suggested that electrical stimulation protects against the negative effects of high pre rigor temperatures. The drip loss of all treatment groups increased during ageing in a manner that was unrelated to treatment but was correlated to tenderness (r² = 0.70; p < 0.0001). It was concluded that the application of electrical stimulation, whatever the pre rigor temperature, protects beef from toughening through the prevention of rigor shortening and the avoidance of inhibition of ageing enzymes.     

The influence of RN genotype, including the new V199I allele, on the eating quality of pork loin

The eating quality of M. longissimus dorsi (LD) from RN⁻ homozygotes, RN⁻ heterozygotes and RN⁻ non-carriers was investigated in a Swedish Hampshire×Finnish Landrace pig population. The recently identified new allele (V199I, here denoted rn*) at the RN locus was also detected among the pigs selected and included in the sensory evaluation. The number of animals varied from 10 to 15 in the five genotype groups; RN⁻/RN⁻, RN⁻/rn+, RN⁻/rn*, rn+/rn+ and rn+/rn* (in total 59 pigs). In addition, one pig was determined to be rn*/rn* but was excluded from the analysis. The three genotypes in which the RN⁻ allele was represented (RN⁻/RN⁻, RN⁻/rn+ and RN⁻/rn*) had higher glycogen and lower protein contents as well as lower ultimate pH (measured 48 h post-mortem) in LD than the non-carriers (rn+/rn+ and rn+rn*). Of the sensory parameters evaluated (tenderness, chewing time, chewing residual, juiciness, meat flavour and acidity), the five RN genotypes only affected acidity significantly; the RN⁻ allele contributing to a more acid taste in LD. The influence of the rn* allele resembled that of rn+ on the sensory parameters. When the material was divided into three groups (homozygous, heterozygous and non-carriers of the RN⁻ allele) the juiciness was found to be significantly influenced by RN genotype, and LD from animals that were homozygous and heterozygous with respect to the RN⁻ allele exhibited a higher juiciness than LD from non-carriers. The RN⁻ allele also tended to contribute to greater tenderness, which was significantly higher in LD from heterozygous carriers than from non-carriers of the RN⁻ allele. A more rapid decline in pH (measured as pH at 45 min and 3 h post-mortem) contributed to a greater tenderness in LD (according to a trained panel and Warner-Bratzler shear force). In addition to the RN genotype, the decline in pH was influenced by carcass weight, which varied between 71 and 97 kg, and by stunning procedure, which changed during the course of the study from individual to group stunning with CO₂. The individual stunning procedure contributed to a lower pH in the initial post-mortem phase (pH₄₅), whereas a higher carcass weight and the RN⁻ allele lowered the pH in the mid-post-mortem region (pH_3h and pH_24h), significantly (P0.05). The pH continued to decline after 24 h post-mortem and the ultimate pH was not reached until 48 h post-mortem. The cooking loss, juiciness and acidity were related to the specific characteristics of the RN⁻ carriers, such as higher glycogen content, lower protein content and lower ultimate pH (pH_48h).     

The influence of high post-mortem temperature and differing ultimate pH on the course of rigor and ageing in pig Longissimus dorsi muscle

This study was performed in order to assess the effect of temperature and differing ultimate pH (pH_u, 24 h post mortem) on the development of rigor mortis in pig Longissimus dorsi muscle. The rigor development (isometric tension and shortening) was measured continuously during the first 24 h post mortem, using an apparatus wherein muscle strips were held at constant temperatures of 12 or 35°C. pH_u was manipulated by adrenaline injections preslaughter.

The rates of pH fall, adenosine triphosphate (ATP) and creatine phosphate (CP) breakdown were markedly increased at 35°C compared to 12°C. For both temperatures, no delay phase was observed with regard to the development of shortening. Rigor resulted in higher maximum isometric tension and shortening and in shorter time needed to reach maximum values at 35°C than at 12°C. The results are discussed in connection with pH, ATP and CP data. The extent of ageing from 2 to 4 days post mortem, estimated through myofibrillar length determinations, was higher for 12°C than for 35°C.

pH_u affected significantly most of the traits under study, but its effect depended in some cases upon the rigor temperature. At 12°C, the traits related to the kinetics of rigor development were significantly affected by pH_u, but this was not the case at 35°C. Maximum isometric tension was significantly related to pH_u at 35°C (r = 0·86, P < 0·001), but such a relationship was not found at 12°C. Myofibrillar lengths were significantly affected by pH_u, but in an opposite manner from one temperature to another. A positive relationship was found at 12°C and a negative one at 35°C.

These results illustrate the importance of the interaction between the extent of pH fall and temperature with regard to post-mortem changes in pig muscle.     

Drip loss of case-ready meat and of premium cuts and their associations with earlier measured sample drip loss, meat quality and carcass traits in pigs

Drip loss of 374 samples taken from porcine M. longissimus dorsi and M. semimembranosus was measured by using the “bag method” (BM), EZ-DripLoss (EZ-DL) from premium cuts (PC) and in retail tray (case-ready meat; CRM). This provided a comparison between these methods and their relationships to other meat quality and carcass traits. Samples were prepared at 24 h post-mortem (pm) and were measured 24 and 48 h after preparation (at 48 and 72 h pm) using the BM and after 48 h (at 72 h pm) with the EZ-DL and PC. Drip loss of meat kept in retail trays was measured after 7 days (CRM₇) and daily within a week (CRM_1–7). Average drip loss was 1.80% and 3.10% using the BM after 24 and 48 h, respectively. EZ-DL and CRM₇ showed higher drip losses of 4.71% and 4.00%. Daily loss of CRM_1–7 showed a concavely shaped curve and increased from 1.57% to 5.64% after 7 days. High correlations were obtained between drip loss of CRM₇ and BM (r = 0.88) or the EZ-DL (r = 0.91). The development of drip loss in case-ready meat fitted by linear-quadratic regression (y = 0.439 + 1.245x − 0.072x²) showed that high drip loss measured earlier by bag and EZ-DripLoss methods was highly associated with a high intercept (r = 0.63–0.72), a high linear increase (r = 0.77–0.81), but larger decrease in increments (r = −0.82 to −0.86) during weekly stored meat in retail trays as supplied at consumer level. Because the positive linear regression coefficient was substantially higher than the negative quadratic regression coefficient, the development of drip loss is mainly dependent on the initial drip loss. Therefore, animals with high drip loss within 72 h post-mortem also showed undesirable high drip loss curves over the entire retail period. Relationships between drip loss and other meat quality traits were similar for BM, EZ-DL and CRM₇. Of these the correlation between pH₂₄ and drip loss was highest with r = −0.54, −0.49 and −0.47 for BM, EZ-DL and CRMH₇, respectively. Interestingly, a correlation of r = −0.35 between blood pH value and CRML₇ was obtained. Carcass traits such as loin, ham, shoulder, belly weight or loin eye area showed only marginal correlations to drip loss. In conclusion, EZ-DL was the most appropriate method to predict drip loss of case-ready meat in retail trays and its development during a 7 day storage period.     

Evaluation of halothane sensitivity and prediction of post-mortem muscle metabolism in pigs from a muscle biopsy using (31)P NMR spectroscopy

Phosphorus nuclear magnetic resonance (³¹P NMR) measurements were made on biopsy samples from pig muscles. Two experiments were performed, one in France and one in Czechoslovakia. In experiment 1, the muscle samples were obtained by surgery from the Biceps femoris muscle of 10 pigs with various genetic types (5 Large White, 1 Large White × Landrace, 4 Pietrains). In experiment 2, the muscle samples were obtained by shot biopsy from the Longissimus dorsi muscle of 11 Belgian Landrace × Duroc pigs, of which 6 were halothane-negative and 5 halothane-positive. The pigs were slaughtered by electrostunning and exsanguination respectively 3 weeks and 1 week after the biopsy, and meat quality traits (pH₁, reflectance and water holding capacity) were determined. The changes in adenosine triphosphate (ATP), creatine phosphate (CP), inorganic phosphate (P_i) and pH, as deduced from NMR, were faster in Pietrains than in Large Whites, and in halothane-positive than in halothane-negative pigs. The value of the CP/P_i ratio at 40 min after taking biopsy allowed discrimination between halothane-positive and halothane-negative pigs. The values of pH, creatine phosphate and adenosine triphosphate, as measured at definite times on the biopsies, were correlated with the rate of post-mortem metabolism (r approx 0·8) and with meat quality traits. ³¹P NMR measurements combined with a rapid and efficient biopsy technique appear as an alternative tool for assessment of both halothane sensitivity and prediction of meat quality in pigs.