• Food Science of Animal Resources
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• v.35 no.4
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• pp.524-532
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• 2015

The objective of this study was to investigate the effects of high post-mortem temperature application on development of pale, soft, exudative (PSE) turkey meat characteristics in terms of local slaughter conditions. Within this scope, it was targeted to obtain PSE-like muscles benefiting from different post-mortem temperature applications. Immediately after slaughter, turkey Pectoralis major (n=15) muscles were kept at various post-mortem temperatures (0, 10, 20, 30, and 40℃) for 5 h. pH values of 40°C treatment were lower than four other treatments (p<0.05). L* values, drip loss, cook loss, and thawing loss of 40℃ group were higher than the other groups (p< 0.05). Napole yield of 40℃ treatment indicated that high post-mortem temperature decreases brine uptake. Protein solubility of 40℃ group was lower than 0℃ group (p<0.05). Expressible moisture did not differ between 0 and 40℃ treatments. Hardness, gumminess and chewiness of 40℃ treatment were higher than 0℃ treatment. The results of this research showed that high post-mortem temperature treatment induced development of PSE-like turkey meat, with lower pH, paler color, higher technological and storage losses, and reduced protein solubility and texture.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.721-733
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• 2019

Objective: The objectives of this study were to investigate the thermal gelation properties and molecular forces of actomyosin extracted from two classes of chicken breast meat qualities (normal and pale, soft and exudative [PSE]-like) during heating process to further improve the understanding of the variations of functional properties between normal and PSE-like chicken breast meat. Methods: Actomyosin was extracted from normal and PSE-like chicken breast meat and the gel strength, water-holding capacity (WHC), protein loss, particle size and distribution, dynamic rheology and protein thermal stability were determined, then turbidity, active sulfhydryl group contents, hydrophobicity and molecular forces during thermal-induced gelling formation were comparatively studied. Results: Sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed that protein profiles of actomyosin extracted from normal and PSE-like meat were not significantly different (p>0.05). Compared with normal actomyosin, PSE-like actomyosin had lower gel strength, WHC, particle size, less protein content involved in thermal gelation forming (p<0.05), and reduced onset temperature ($T_o$), thermal transition temperature ($T_d$), storage modulus (G') and loss modulus (G"). The turbidity, reactive sulfhydryl group of PSE-like actomyosin were higher when heated from $40^{\circ}C$ to $60^{\circ}C$. Further heating to $80^{\circ}C$ had lower transition from reactive sulfhydryl group into a disulfide bond and surface hydrophobicity. Molecular forces showed that hydrophobic interaction was the main force for heat-induced gel formation while both ionic and hydrogen bonds were different significantly between normal and PSE-like actomyosin (p<0.05). Conclusion: These changes in chemical groups and inter-molecular bonds affected protein-protein interaction and protein-water interaction and contributed to the inferior thermal gelation properties of PSE-like meat.

• Journal of Animal Science and Technology
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• v.60 no.1
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• pp.30.1-30.10
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• 2018

Background: The poultry industry suffers losses from problems as pale, soft and exudative (PSE), and dark, firm and dry (DFD) meat can develop in meat as a result of short- and long-term stress, respectively. These abnormalities are impacted by pre-slaughter animal welfare. Methods: This work evaluated the effects of open vehicle container microclimate, throughout the $38{\pm}10km$ journey from the farm to the slaughterhouse, on commercially turkey transported during the Brazilian winter season. The journey was initiated immediately after water bath in truck fitted with portable Kestrel anemometers to measure air ventilation, relative humidity, temperature and ventilation. Results: The inferior compartments of the middle and rear truck regions showed highest temperature and relative humidity, and lower air ventilation. In addition, the superior compartments of the front truck regions presented lower temperature and wind chill, and highest air ventilation. The breast meat samples from animals located at the inferior compartments of the middle and rear truck regions and subjected to with water bath (WiB) treatment presented highest DFD-like and had lowest PSE-like meat incidence than those from animals located at other compartments within the container. Lower incidence of PSE-like meat was observed in birds without water bath (WoB). Conclusions: Assessment on turkeys transported under Brazilian southern winter conditions revealed that breast meat quality can be affected by relative humidity, air ventilation, temperature, and transport under subtropical conditions promoting color abnormalities and the formation of simultaneously PSE-like and DFD-like meat.

• Journal of Animal Science and Technology
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• v.55 no.2
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• pp.95-101
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• 2013

The present study was conducted to test a hypothesis that pork quality traits would be influenced by the systemic and/or local bioavailability of insulin-like growth factor-I (IGF-I), transforming growth factor-${\beta}1$ (TGF-${\beta}1$), or epidermal growth factor (EGF) before or at slaughter. To this end, 60 cross-bred female market pigs weighing approximately 110 kg were slaughtered, after which Longissimus dorsi muscle (LM) samples taken at slaughter (D 0) and blood samples taken at D -7 and D 0 were analyzed. The 60 carcasses rendered 36 RFN (reddish-pink, firm, and non-exudative), 16 RSE (reddish-pink, soft, and exudative), and 6 PSE (pale, soft, and exudative); 2 DFD (dark, firm, and dry) also were found but were excluded in subsequent experiments. The $L^*$ and drip loss were greater in PSE vs. RFN and RSE and in PSE and RSE vs. RFN, respectively, as they should (P<0.05). The $pH_{45min}$ was less in PSE vs. RFN (P<0.05); $pH_{24h}$ tended to be less in the former (P=0.09). The LM IGF-I and TGF-${\beta}1$ as well as serum EGF concentrations were less in PSE than in RFN. None of the other LM and serum concentrations of the three growth factors differed across the three pork quality categories. The LM IGF-I and TGF-${\beta}1$ concentrations and serum EGF concentration at D 0 were negatively correlated with drip loss [r = -0.36(P<0.01), -0.44 (P<0.01), and -0.32 (P<0.05), respectively]. However, none of the serum and LM growth factor variables was correlated with $L^*$ or $a^*$ (redness) of LM. Taken together, results suggest that locally expressed IGF-I and TGF-${\beta}1$ and blood-borne EGF may have a beneficial effect on postmortem water holding capacity of the muscle and that pork quality traits could be predicted to some extent from concentrations of IGF-I and TGF-${\beta}1$ in muscle and EGF in serum at slaughter.