MUSCLE TEMPERATURE, pH AND RATE OF RIGOR DEVELOPMENT IN RELATION TO QUALITY AND QUANTITY CHARACTERISTICS OF PIG CARCASSES

1975 ◽  
Vol 55 (4) ◽  
pp. 527-532 ◽  
Author(s):  
A. H. MARTIN ◽  
H. T. FREDEEN ◽  
P. J. L’HIRONDELLE

A total of 306 pig carcasses of purebred Lacombes and crossbreds (sired by Duroc, Chester, and Pietrain boars) were used to study relationships between early postmortem muscle properties and subsequent meat quality. One hour post-mortem, 22, 36, and 42% of the carcasses were judged to have complete, partial, and nil muscular rigidity (rigor mortis), respectively. Two hours post-mortem, 9% of carcasses still showed no indication of stiffening of the musculature. Rapid rigor development was associated with significantly lower pH, higher transmission values (i.e. lower solubility of the sarcoplasmic proteins), higher deep muscle temperature, and greater leanness and muscularity. Shear values were negatively associated with muscle pH. Multiple regression analysis indicated that ultimate meat quality (% transmission) could be predicted with only moderate precision (R2 = 26%) from knowledge of pH and temperature up to 2 h post-mortem and the precision was not meaningfully improved by inclusion of rigor score.

1978 ◽  
Vol 26 (2) ◽  
pp. 229-232 ◽  
Author(s):  
W. C. Smith ◽  
A. Wilson

ABSTRACTMeasurements of longissimus dorsi pH at 45 min post mortem (pH1) were taken in 27 727 pig carcasses at four bacon factories. The overall least squares mean pH1 was 6·26 and 15·5% of carcasses had pHi values of 5·9 or less. Sex and commercial grade of carcass had little influence on muscle pHi or the incidence of values below pH 6·0. Factory differences were recorded in the distribution of muscle and within each there were marked producer effects in mean and the incidence of values below pH 6·0. Carcasses of Large Whites had fewer muscle pH1 values below 6·0 (12·4%) than those of British Landrace (18·7%), this being mainly due to a large breed effect at one factory. Although breed and testing background of sires of the carcasses examined and the first order interactions with factory had significant effects on muscle pHi and the incidence of values below pH 6·0, they were of little practical significance.


Author(s):  
C.M Weeding ◽  
E.J. Hunter ◽  
H.J. Guise ◽  
R.H.C. Penny

Pigs from 4 farms were slaughtered at 2 abattoirs, each with 2 slaughter handling systems. Pigs at abattoir 1 were electrically stunned, either in a floor pen holding 5 pigs or a race restrainer. A straight race 1m wide led to the floor pen. A stepped collection pen and single file race led to the race restrainer. At abattoir 2 a single file curved race led to a floor pen with electrical stunning and a circular collection pen led to a double race and dip-lift C02 stunner. Each replicate involved 2 farms sending 50 pigs to each abattoir. There were 16 replicates (3200 pigs). Stun system had a significant effect on the development of early rigor, muscle pH, muscle colour and skin blemish (GLM Analysis of Variance). At abattoir 1, pigs slaughtered through the race restrainer had a greater tendency to develop early rigor and more skin blemish. Pigs slaughtered through the race restrainer also had lower pH in the m. longissimus dorsi at both initial and ultimate readings post mortem. In general, pH readings were higher than would be expected in the pig m. longissimus dorsi. Muscle reflectance was higher in the m. longissimus dorsi of pigs slaughtered through the race restrainer at both initial and ultimate readings. Significant differences between means at abattoir 1 (two-sample t-tests) are contained in Table 1. At abattoir 2, the floor pen produced carcases with a greater tendency to develop early rigor and more skin blemish. There were no significant differences in muscle pH or colour. Significant differences between means at abattoir 2 (two-sample t-tests) are contained in Table 2.


1990 ◽  
Vol 51 (3) ◽  
pp. 461-468 ◽  
Author(s):  
J. R. Wythes ◽  
W. R. Shorthose ◽  
G. Fordyce ◽  
D. W. Underwood

ABSTRACTThe effects of pregnancy status (non-pregnant, early to mid (1 to 5 months) and late (> 6 months)) and month of pregnancy on live weight, carcass weight, dressing proportion, bruising and muscle properties were examined in 237 Shorthorn and Brahman crossbred cows (mean live weight 424 kg, 62% pregnant). The cows were transported 1155 km to an abattoir and given access to food and water until slaughter. Mustering to slaughter periods were 5, 6 or 7 days.The mean gross hot carcass weights for the 89 non-pregnant, 108 early to mid pregnant and 40 late pregnant cows were 207, 199 and 187 kg (P < 0·05). Their respective dressing proportions were 487, 469 and 443 g/kg (P < 0·05). Among the pregnant cows, carcass weight and dressing proportion decreased by 2·95 kg and 6 g/kg, respectively, for each month of pregnancy (P < 0·05).Cows in late pregnancy had lower mean initial yield (IY) and peak force (PF) shear values for m.longissimus dorsi (LD) than non-pregnant cows. The late-pregnant cows also had the greatest mean pH 24 h post mortem (pH24) and ultimate pH (pHu) values (P < 0·05). They also had a greater proportion of carcasses with high pHu values than the early to mid-pregnant and non-pregnant cows (0·30 v. 0·157 v. 0·079; (P < 005). Among the pregnant cows, mean pH24 increased by proportionately 0·038 and the proportion of high pH24 carcasses by 0·055 for each month of pregnancy (P < 0·05). Pregnancy status had no significant effect on mean fat depth, bruise score, PF-IY value or cooking loss.


2002 ◽  
Vol 2002 ◽  
pp. 174-174
Author(s):  
D. N. Hamilton ◽  
T. M. Bertol ◽  
M. Ellis ◽  
S. N. Carr ◽  
F. K. McKeith

Pale soft exudative pork (PSE) is a major problem affecting swine industries worldwide that results in significant economic loss because it reduces processing and saleable product yields. The PSE condition results from a rapid rate of muscle glycolysis early postmortem and a rapid drop in muscle pH while the temperature of the carcass is still high. Stress prior to slaughter can increase the rate of glycolysis and postmortem acidification. Blood acid-base has been used as an indicator of stress in pigs. The objective of this experiment was to investigate the relationship between blood acid-base status at slaughter and fresh meat quality in pigs.


2021 ◽  
Vol 51 (8) ◽  
Author(s):  
Daniel Santiago Rucinque ◽  
Andrea Gomes Chalbaud Biscaia ◽  
André Luiz Watanabe ◽  
Carla Forte Maiolino Molento

ABSTRACT: In Brazil, humane slaughter regulation is in use since 2000; however it is not applied to fish. This paper studied parameters for electrical stunning using direct current waveform in South American catfish (Rhamdia quelen) and its subsequent effects on muscular pH and rigor mortis. Seventy fish were allocated into two groups. In group 125, fish were stunned using 125 Volts (V), 30 Hz, duty cycle of 90% and 1.3 Amp (A) applied for 30 s; in group 400, fish were stunned with 400 V, 30 Hz, duty cycle of 27%, 0.9 A, for 30 s. Unconsciousness time was determined through behavioural assessment. After slaughter, ten fish from each group were refrigerated for both measurements muscular pH and rigor mortis index (RMI) at 0, 3, 6, 24, 72 and 120 h. In 125, 14.4% (5/35) of fish were not effectively stunned, in contrast with 400 in which 100% of fish (35/35) were effectively stunned. The unconsciousness duration was higher in 400 group (87.7±16.1 s) in contrast with group 125 (66.6 ± 16.1 s). Until 6 h post mortem ninety percent of fish reached maximum rigor mortis (RMI=100%).


2002 ◽  
Vol 82 (3) ◽  
pp. 311-320 ◽  
Author(s):  
Giuseppe Bee

The aim of this study was to determine whether glycolytic potential (GP) in pork muscle could be modified by the availability of carbohydrates in the diets and, if so, to what extent meat color and drip loss were affected. Biopsy samples of longissimus muscle (LM) from 48 Swiss Large White pigs (25 gilts, 23 barrows) weighing 70 kg were collected, and the GP was determined to vary from 111 to 187 μmol g-1 wet weight. At 90-kg body weight, pigs were moved into individual pens and assigned (blocked by GP and sex) to be fed 2.8 kg of a diet either high (H) or low (L) in available carbohydrate up to 104 kg. Pigs were fasted overnight (15 h) before slaughter. Glycogen, glucose, glucose-6-phosphate and lactic acid content were determined in samples of LM (predominantly glycolytic muscle) collected 30 min and 24 h post-mortem and in samples of the dark part of the semitendinosus (ST, oxidative part of the muscle) 24 h post-mortem. After slaughter, the decline in pH and temperature was recorded in the LM from 30 min to 24 h after bleeding. Regardless of the diet, content of glycolytic intermediates and lactic acid were higher in the LM compared to the ST. Diet did not alter the GP, and did not affect color or drip loss of the LM. However, in gilts fed the H diet muscle pH was lower by 0.2 units from 30 min until 6 h post-mortem than in gilts fed the L diet. These effects were not observed in barrows. ST of gilts fed the H diet had higher levels of glycolytic intermediates and lactic acid and, therefore, higher GP compared to gilts on the L diet, but no dietary effects occurred in barrows. Increased GP resulted in paler color and higher drip loss, whereas ultimate pH was not affected. The GP was positively correlated with L* (0.52), a* (0.49), b* (0.59) and drip loss (0.77) of the ST, whereas poor correlations were observed in the LM. In conclusion, dietary treatment only affected paleness and drip loss of the ST muscle and the effects were more pronounced in gilts than barrows. Increased GP resulted in paler meat with higher drip loss. Key words: Pig, glycolytic potential, meat quality, carbohydrate supply


2018 ◽  
Vol 30 (4) ◽  
pp. 304
Author(s):  
Brahim Hamad, Hebib Aggad, Leyla Hadef ◽  
Abdelghani Beddada ◽  
Bernard Faye

The aim of this study was to determine the effect of slaughter season on the postmortem metabolic characteristics of dromedary camel longissimus thoracis (LT) muscle. A total number of thirty male camels (5-7 years old) were included in this work. Ten camels were slaughtered according to season of the year (winter, spring and summer). The samples were analyzed for muscle pH, muscle temperature, electrical conductivity, drip loss (DL), cooking loss(CL) and thawing loss (TL). No significant (p> 0.05) effect of slaughter season on muscle pH and cooking loss was observed. However, slaughter season significantly (p< 0.05) influenced the electrical conductivity, muscle temperature, drip loss and thawing loss. All of these parameters were higher (p< 0.05) during summer as compared to winter and / or spring seasons. Moreover, several correlations between different studied parameters were reported. In conclusion, these findings indicated that slaughter season had a significant (p< 0.05) effect on several postmortem metabolic parameters of camels. Therefore, this study demonstrated that the electrical conductivity late postmortem measurement can be used as a suitable method for the evaluation of camel's meat quality.


1988 ◽  
Vol 39 (1) ◽  
pp. 87 ◽  
Author(s):  
JR Wythes ◽  
WR Shorthose ◽  
VH Powell

In three experiments, we studied the effects of duration of rest and nature of resting conditions before slaughter and of electrical stimulation, on carcass weight, bruising and muscle properties of cattle of known age. In experiment 1, 22 Droughtmaster steers (mean liveweight 284 kg) rested for 2.5 or 26.5 h following a 125 km road journey. In experiment 2, 82 Zebu crossbred cows (mean liveweight 416 kg) rested for 4 or 52 h after a 1310 km rail journey. Those rested for 52 h were allowed to rest either peacefully (P), subjected periodically to noise and disturbances (D) or mixed with unfamiliar cows (M). In experiment 3, 68 Hereford and Simmental x Hereford cows (mean liveweight 445 kg) rested for 28 h, after a 930 km road and rail journey, and during this time were subjected to resting treatments P, D or M. All cattle had access to water until slaughter, and were slaughtered at the same abattoir. All carcasses were electrically stimulated in experiment 1, but only half those in each treatment group in experiments 2 and 3. Electrical stimulation of carcasses had a much greater effect on tenderness than did resting conditions before slaughter. The LD muscles of stimulated carcasses were more tender than those of unstimulated ones. Of the 31 cattle slaughtered after a few hours' rest, only one carcass had a high pH value 24 h post mortem. The LD muscles of cattle rested for 26.5 h were more tender than those of cattle rested for 2.5 h. Resting treatment did not consistently affect mean carcass weight, pH24, time for LD muscle to cool to 20�C or cooking loss. Noise and disturbance during the resting period appeared to be more stressful than mixing (13.6 v. 4.5% carcasses with high muscle pH 24 h post mortem in experiment 3 only). Steers rested for 26.5 h had a higher mean bruise score than those rested for only 2.5 h, but there was no effect of resting time or resting conditions on bruising in cows.


2020 ◽  
Vol 60 (2) ◽  
pp. 288
Author(s):  
Qing-Chang Ren ◽  
Jing-Jing Xuan ◽  
Chuan-Yan Che ◽  
Xin-Chao Yan ◽  
Zhong-Ze Hu

In this trial we aimed to assess the effects of dietary supplementation of 4-O-methyl-glucuronoarabinoxylan (4OMG) on growth performance, thigh meat quality and small intestine development of female Partridge-Shank broilers. A total of 240 1-day-old female Partridge-Shank broilers were randomly distributed to four groups with three replicates of 20 within each group. Groups received either 0, 15, 20 or 25 g 4OMG/kg DM of diet. During the whole experiment of 60 days, broilers had ad libitum access to water and feed. At pen level, feed intake was recorded daily and broilers were weighed at the start and end of the experiment. For each group, three pens with a total of 20 broilers were randomly selected to determine the thigh meat quality and the small intestine development of broilers. Broilers fed diets with higher 4OMG had greater final liveweight (P = 0.004), daily bodyweight gain (P = 0.004) and gain-to-feed ratio (P &lt; 0.001), muscle pH values (P = 0.031) and redness (P = 0.001), duodenal weight index (P = 0.042), jejunal (P = 0.043) and ileal length (P = 0.049), duodenal (P &lt; 0.001) and ileal villus height (P = 0.008), but lower percentage of dead birds (P &lt; 0.001), drip loss (P = 0.042) and shear force value (P = 0.043) of the thigh muscles. These results indicate that increasing dietary supplementation of 4OMG may improve growth performance and meat quality of female Partridge-Shank broilers through better development of small intestine.


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