Effect of sampling site within two muscles, bodyweight, sex, and feeding level on the quality of meat from pigs

Abstract

Taste panel assessments of the longissimus muscle and objective measurements on two parts of the semimembranosus muscle were used to assess the effects of liveweight (40, 80, 100 kg), sex (male, castrate male, female), and level of feeding on the meat quality of 54 Landrace x Large White pigs. Relative to the darker distal part, the paler proximal portion of the semimembranosus muscle was more tender, had longer sarcomeres, a lower pH, and a slightly lower water-holding capacity. Changes in quality along the longissimus muscle within the loin as assessed by taste panel were small. Differences in tenderness or Warner-Bratzler shear values were small and inconsistent between treatment groups, but meat from the lightweight males was generally less tender. For the dark portion of the semimembranosus muscle, lower ultimate pH values and higher reflectance values were found for the 40 kg group, the castrates and females, and the restricted feeding group. Water-holding capacity improved with increasing weight and at higher pH values.

A comparison of the Duroe, Hampshire, Landrace, and Large White as terminal sire breeds of crossbred pigs slaughtered at 85 kg liveweight

“…Early reports of positive relationships between intramuscular fat levels and eating quality of pork generally involved pigs with much higher levels of Ultimate muscle pH and palatability of pork The significant curvilinear relationship between ultimate muscle pH and tenderness with a maximum shear force at a pH of just below 6 agrees well with the results of Dransfield et al (1985) for pigmeat, and also with results for beef (Howard & Lawrie 1956;Purchas 1988). Overall taste-panel acceptability was affected by pH in a similar way, as might be expected in light of the close positive association shown to exist between this characteristic and tenderness here and in studies with beef (Dransfield et al 1982).…”

“…Measurements on fresh samples of pH (after homogenising c. 1.2 g in 6 ml of 0.05M sodium iodoacetate), colour (reflectance at 685 nm), and Wamer-Bratzler shear values (12 shears of 13 x 13 mm cores after cooking at 70 0 e for 90 min) were as described by Purchas et al (1988).…”

“…Panelists were not selected and were not trained for this series of 12 sittings. The scoring systems used for the acceptability of tenderness.j uiciness,flavour,and forflavour strength were similar to those described by Purchas et al (1988), with 100 mm-long lines and descriptive terms at the ends and in the centre. The descriptive terms and the corresponding scores at 0,50, and 100 mm respectively were "like extremely"(100), "neither like nor dislike"(50), and "dislike extremely"(O) for tenderness, flavour and juiciness, and "very strong"(100), "moderate"(50), and "very bland"(O)for flavour strength.…”

The influence of diets supplemented with conjugated linoleic acid, selenium, and vitamin E, with or without animal protein, on the quality of pork from female pigs1

“…Mean pHu values for both the LM and SM were all less than 5.75 (Table 1), suggesting that preslaughter stress levels were low, but the SM pHu was significantly greater than that for the LM (P < 0.001). Warner et al (1993) also reported nonsignificantly greater pHu values for SM, with the smaller difference possibly attributable to the known variation in pHu between pale and dark portions within the SM (Purchas et al, 1988). Lower pHu values for the supplemented animal group were shown for both muscles (P < 0.04, Table 1).…”

Effects of ractopamine on the growth and carcass quality of entire male and female pigs fed ad libitum or at a restricted level

“…Meat from the caudal slice was also used for pH assessment after homogenising c. 1.5 g in 6 ml of 0.05M sodium iodoacetate. Two 25 mm steaks were cut adjacent to the slices used for colour assessment, and after cooking at 70°C for 90 min, and chilling overnight, meat tenderness was assessed by measuring the Warner-Bratzler (WB) shear force on cores with 13 x 13 mm cross-sections (Purchas et al 1988). For Experiment 1, the WB shear machine was fitted with the usual triangular cutting plate, but for Experiment 2, a cutting blade with a square hole was used (Purchas & Aungsupakorn 1993), and a measure of the total work done in addition to the peak force was obtained.…”