Effects Of Postmortem Temperature Research Articles

Effects of postmortem temperature on the physicochemical characteristics of prerigor Pekin duck breast muscles

The effects of postmortem (PM) temperature on prerigor Pekin duck breast muscle quality were assessed. Breast meat was obtained from 90 ducks within 15 min PM and then divided into 3 storage temperature groups at 0, 15, and 30°C for 24 h PM. Results revealed that the meat stored at 0°C had a higher pH value than that stored at 30°C. The R-value tended to increase between 15 min, 2 h, and 24h PM, whereas the water-holding capacity decreased significantly (P < 0.05) with increasing storage time. The drip loss of treatment in meat stored at 30°C was higher than in those stored at 0 and 15°C. As storage periods increased, cooking loss of meat stored at each temperature increased significantly (P < 0.05) at 2 h, but storage temperature does not affect cooking loss of duck breast muscle. The shear force of breast meat at 24 h PM had the lowest value, but meat stored at 30°C increased at 2 h and decreased at 24 h PM. Meat stored at 15°C showed a longer sarcomere length than meat stored at 0 and 30°C. The rate of muscle shortening was high during the 2 h PM for meat at the 3 temperatures. It is concluded that the different temperatures in the range of 0 to 30°C affected the muscle shortening or meat quality of the duck breast meat.

Effects of postmortem temperature and time on the water-holding capacity of hot-boned turkey breast and thigh muscle

Turkey breast and thigh muscles were excised immediately after slaughter and held from 0.25 to 4 h postmortem at 0, 12 or 30 °C to determine postmortem time and temperature effect on muscle pH, drip loss, sarcomere length, homogenate supernatant weight, salt-soluble protein and cooking yields. Higher temperature and longer storage time induced greater drip losses in breast. Longer storage time induced greater drip losses but the least drip loss occurred at 12 °C in thigh muscle. High temperature increased the supernatant weight in breast but decreased that in thigh. Storage time increased supernatant weight and supernatant salt soluble protein levels in both muscles. Homogenate cooking yields of breast containing water, salt and phosphate (HWSP) were higher for 0 and 12 °C compared with 30 °C, and increased with storage. The low postmortem temperature (0 °C) decreased homogenate cooking yields in thigh. These findings indicate that lower postmortem temperatures (0 and 12 °C) and shorter storage time (24 h) produced the greatest water-holding capacity in turkey breast muscle, whereas high and low postmortem temperatures (30 and 0 °C) and longer storage (168 h) produced the least water-holding capacity in raw turkey thigh muscle.

The effect of high post-mortem temperature on the development of pale, soft and exudative pork: Interaction with ultimate pH

The effects of post-mortem temperature and ultimate pH (pH u, 24 h post mortem) on the development of the pale, soft and exudative (PSE) characteristics in pig longissimus dorsi muscle were studied. Ten out of the 13 pigs used received pre-slaughter injections of adrenaline in order to deplete muscle glycogen stores. The two muscles from each pig were held at 12 or 35°C during rigor mortis development. Results from covariance analysis, using pH u as covariate, showed that a high temperature (35°C) resulted in a dramatic increase in internal light scattering (FOP) 24 h post mortem and a significant decrease in water- and salt-soluble proteins. Cooking loss, sarcomere length and drip loss did not vary significantly with rigor temperature. Interaction between temperature and pH u was estimated by assessing the relationship between pH u and the difference between the two rigor temperatures for selected traits. The best predictive model was a segmented quadratic model with a plateau which gave significant results for FOP, drip loss, water- and salt-soluble proteins. The effect of temperature decreased curvilinearly when pH increased until a constant value above which no noticeable difference was recorded (drip loss, water- and salt-soluble proteins) or a constant difference was reached (FOP). The pH values corresponding to the convergence points differed from one trait to another. They ranged from 5·72 to 6·22. These results illustrate the importance of muscle glycogen content at slaughter and subsequent pH u with regard to the development of temperature-induced PSE meat.

Effect of post-mortem temperature on beef tenderness

Beef adductor muscles were incubated for 4 h post mortem at 10°C and for 4 h and 6 h post mortem at 30°C, 37°C and 42°C. Half of the muscles were cooked just after incubation and the other half was first stored for two days at 4°C and then cooked. Meat kept for 4 h or 6 h at 42°C and for 6 h at 37°C and cooked at once had a significantly (p<0·05) lower shear force than meat kept for 4 h at 37°C, 4 h at 30°C, 6 h at 30°C or 4 h at 10°C. The respective significant differences were also found when the meat was cooked two days after incubation. Organoleptic evaluation showed that meat incubated for 6 h at 37°C or for 4 h at 42°C was not significantly more tender than other samples. However, meat kept for 6 h at 42°C was more tender (p<0·5) than the other samples. After two days of storage, meat incubated for 6 h at 37°C and for 6 h at 42° was more tender (p<0·05) than meat kept for 6 h at 30°C. It was concluded that high temperature conditioning at 37°C or higher for 6 h (4 h at 42°C) just after slaughter makes meat more tender than conventional cooling systems.