• Asian-Australasian Journal of Animal Sciences
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• v.33 no.8
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• pp.1339-1351
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• 2020

Objective: It is well recognized that beef cuts from a low quality grade are usually associated with tougher, drier and less flavorful. Thus, the present study aimed at investigating the combined effects of postmortem ageing and sous vide (SV) cooking followed by oven roasting or blowtorching on the eating quality of low quality grade Hanwoo beef striploins. Methods: Hanwoo beef striploins (quality grade 3) obtained from 36 month-old Hanwoo steers were used, and the samples were chiller aged for 0 and 14 d at 4℃. After ageing, the samples were prepared into 2.5-cm steaks which were then SV cooked at 55℃ for 5 h and then raised to 60℃ for 1 h, and thereafter the SV-cooked the steaks were further roasted in oven for 20 min (SV+OV) or blowtorched (SV+TC) for 2 min. The cooked samples were analyzed for microbiological quality, browning index, Wanrner-Bratzler shear force (WBSF), aroma flavor compounds and sensory properties. Results: The SV cooking significantly reduced the WBSF values in beef samples (p<0.05). Blowtorching after SV cooking led to a browner surface of the beef steaks (p<0.05). The samples treated with SV+OV or SV+TC exhibited higher levels of Maillard reaction-derived aroma flavor compounds such as; pyrazines and sulfur-containing compounds compared to those just SV cooked. More especially, the SV+OV- or SV+TC- treated samples presented significantly higher flavor and overall acceptability scores compared to those just SV cooked (p<0.05). Ageing beef for 14 d significantly improved the tenderness by reducing the WBSF and increasing the tenderness scores. Conclusion: Thus, the combination of postmortem ageing and SV cooking followed by additional treatments (blowtorching or oven roasting) could be used to improve the eating quality especially tenderness and flavor as well as overall acceptability of low grade Hanwoo beef.

• Animal Bioscience
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• v.34 no.7
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• pp.1181-1192
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• 2021

Objective: The objective of the current study was to investigate the effects of dietary hatchery by-products (HBPs) as a replacement of fish meal (FM) on growth performance, relative organ weight, plasma measurements, immune organ index, meat quality, and tibia characteristics of broiler chickens. Methods: A total of 720 broiler chickens (3 d of age) were randomly allotted to 1 of 9 treatments with 8 replicates. Each replicate consisted of 5 male and 5 female birds. The basal diet was formulated to contain 5.0% commercial FM, whereas eight treatment diets were prepared by replacing 25%, 50%, 75%, or 100% of FM in the basal diet with infertile eggs (IFE) or a mixture of various HBPs (MIX); therefore, the inclusion levels of IFE or MIX in the experimental diets were 1.25%, 2.50%, 3.75%, or 5.00%. The diets and water were provided on an ad libitum basis for 32 d. Results: Increasing inclusion levels of IFE as a replacement of FM in diets had no effects on growth performance, plasma measurements, immune organ index, and tibia characteristics of broiler chickens. Increasing inclusion levels of IFE in diets increased (linear, p<0.05) meat lightness (L^*) but decreased (linear, p<0.05) meat redness (a^*). The breast meat pH at 1-h postmortem was increased (linear, p<0.05) by increasing inclusion levels of IFE in diets. Likewise, increasing inclusion levels of MIX in diets had no effects on growth performance, relative organ weight, plasma measurements, immune organ index, and tibia characteristics. However, increasing inclusion levels of MIX in diets increased (linear, p<0.05) 1-h postmortem pH but decreased (linear, p<0.05) 24-h postmortem pH of breast meat. Increasing inclusion levels of MIX in diets decreased (linear, p<0.05) thiobarbituric acid reactive substances values of breast meat. Conclusion: Both IFE and MIX are suitable alternatives to FM as protein ingredients in broiler diets.

• Animal Bioscience
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• v.37 no.4
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• pp.697-708
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• 2024

Objective: The objective of this study was to investigate the influence of dietary supplementation of Eucommia ulmoides leaf extract (ELE) on muscle metabolism and meat quality of pigs with and without pre-slaughter transportation. Methods: In a 43-day feeding experiment, a total of 160 pigs with an initial body weight 60.00±2.00 kg were randomly assigned into four groups in a completely randomized design with 10 replicates. Pigs in groups A and C were fed a basal diet and pigs in groups B and D were fed a basal diet supplemented with 0.5% ELE. Pigs were slaughtered with (group B and D) or without (group A and C) pre-slaughter transport. Muscle chemical composition, postmortem glycolysis, meat quality and muscle metabolome were analyzed. Results: Dietary ELE supplementation had no effect on the proximate composition of porcine muscle, but increased free phenylalanine, proline, citruline, norvaline, and the total free amino acids in muscle. In addition, dietary ELE increased decanoic acid and eicosapentaenoic acid, but decreased heptadecanoic acid, oleic acid, trans-oleic acid, and monounsaturated fatty acids in muscle. Meat quality measurement demonstrated that ELE improved meat water holding capacity and eliminated the negative effects of pre-slaughter transport on meat cooking yield and tenderness. Dietary ELE reduced muscle glycolytic potential, inhibited glycolysis and muscle pH decline in the postmortem conversion of muscle to meat and increased the activity of citrate synthase in muscle. Metabolomics analysis by liquid chromatographic tandem mass spectrometric showed that ELE enhanced muscle energy level, regulated AMP-activated protein kinase (AMPK) signaling, modulated glycogenolysis/glycolysis, and altered the metabolism of carbohydrate, fatty acids, ketone bodies, amino acids, purine, and pyrimidine. Conclusion: Dietary ELE improved meat quality and alleviated the negative effect of pre-slaughter transport on meat quality by enhancing muscle oxidative metabolism capacity and inhibiting glycolysis in postmortem muscle, which is probably involved its regulation of AMPK.

• Anatomy and Cell Biology
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• v.57 no.1
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• pp.70-84
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• 2024

Methamphetamine (METH) can potentially disrupt neurotransmitters activities in the central nervous system (CNS) and cause neurotoxicity through various pathways. These pathways include increased production of reactive nitrogen and oxygen species, hypothermia, and induction of mitochondrial apoptosis. In this study, we investigated the long-term effects of METH addiction on the structural changes in the amygdala of postmortem human brains and the involvement of the brain- cAMP response element-binding protein/brain-derived neurotrophic factor (CREB/BDNF) and Akt-1/GSK3 signaling pathways. We examined ten male postmortem brains, comparing control subjects with chronic METH users, using immunohistochemistry, real-time polymerase chain reaction (to measure levels of CREB, BDNF, Akt-1, GSK3, and tumor necrosis factor-α [TNF-α]), Tunnel assay, stereology, and assays for reactive oxygen species (ROS), glutathione disulfide (GSSG), and glutathione peroxidase (GPX). The findings revealed that METH significantly reduced the expression of BDNF, CREB, Akt-1, and GPX while increasing the levels of GSSG, ROS, RIPK3, GSK3, and TNF-α. Furthermore, METH-induced inflammation and neurodegeneration in the amygdala, with ROS production mediated by the CREB/BDNF and Akt-1/GSK3 signaling pathways.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.716-722
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• 2005

Carcass weight and backfat thickness are primary yield grading factors. Insulin-like growth factor (IGF)-I/-II, transforming growth factor $\beta$1 (TGF-$\beta$1), and epidermal growth factor (EGF) regulate the proliferation and differentiation of cells including adipocytes. Also, interleukin (IL)-2/-6, cortisol, and dehydroepiandrosterone-sulfate (DHEA-S) are known to be related to muscle growth and fat depth. However, the relationships between endocrine factors and carcass grade have not been studied. Therefore, this study aimed to measure the concentrations of endocrine factors in serum and muscle, and to investigate the relationship of endocrine factors with carcass grade. A total of 60 crossbred gilts (Duroc${\times}$Yorkshire${\times}$Landrace) were used. Blood from the jugular vein was collected at antemortem (7 days before slaughter) and postmortem periods, and M. Longissimus was collected at 45 min and 24 h after slaughter. The concentrations of IGF-I/-II, EGF, TGF-$\beta$1, IL-2/-6, cortisol and DHEA-S were analyzed by radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA). In general, IGF and EGF concentrations in serum and muscle of grade A carcasses were found to be higher than those of grade C carcasses at antemortem and postmortem periods, whereas the pattern of TGF-$\beta$1 concentration was reversed. In particular, the concentrations of muscle IGF-I (24 h postmortem) and serum TGF-$\beta$1 (antemortem) were significantly different between grades A and C (p<0.05). The present results indicate that serum and muscle growth factors affect carcass weight and backfat thickness, and indirectly suggest the possibility that carcass grade could be predicted by expression of serum and/or muscle growth factors.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.598-604
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• 2007

The current study was conducted to evaluate carcass characteristics, objectives and sensory meat qualities of Hanwoo longissimus muscle as affected by ultimate pH. Twenty-four steers and bulls ($556{\pm}53$ kg and $0.63{\pm}0.32$cm for live weight and backfat thickness, respectively) were used. As there was a linear relationship (r = 0.77) between lean meat color and ultimate pH, cattles were thus segregated into normal $pH{\leq}5.8$, Normal, n = 13) and DFD (pH>5.8, n = 11) groups. Normal pH group had significantly (p<0.05) higher carcass weight, marbling score and backfat thickness than those for high pH group, while fat color and lean meat color were inverse. In principle component analysis for co-ordinates of DFD and normal meats, fat color, lean meat color, texture, time to pH 6.2 and pH at 24 h postmortem were associated with the positive range of the first factor (67.5%) while backfat thickness marbling score and temperature at 24 h were placed in negative values. The rate constant of decline in pH (pH k) did not differ between the two groups, implying that initial pH (i.e., pH at slaughtering) differed between two groups. Contour mapping of pH k between pH at 1 and 24 h postmortem indicated that high pH k was related to lower pHs at 1 and 24 h postmortem. This suggested that the high pH cattles (i.e., DFD cattle) resulted from their own potential. Although the time to reach pH 6.2 was significantly (p<0.05) shorter for normal meat (i.e., 3.2 h) than that for DFD one (i.e., 19.8 h), there were no significantly differences in both WB-shear force and sensory attributes. Given that the experimental animals were sampled from a similar group, which implies a similar myoglobin pigment content, the current data suggested that pre- and post-slaughter animal handling likely had a significant effect on ultimate pH and consequently meat color of Hanwoo longissimus muscle, and also small animals with lower marbling score and backfat thickness had a higher risk for DFD meat.

• Journal of Animal Science and Technology
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• v.58 no.6
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• pp.23.1-23.17
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• 2016

Background: The functionality of myofibrillar proteins is a major factor influencing the quality attributes of muscle foods. Nonetheless, the relationships between muscle type and oxidative changes in chevon during ageing are meagrely elucidated. Postmortem changes in antioxidant status and physicochemical properties of glycolytic gluteus medius (GM) and oxidative infraspinatus (IS) muscles in goats were compared. Methods: Twenty Boer bucks (9-10 months old, body weight of $36.9{\pm}0.725kg$) were slaughtered and the carcasses were subjected to chill storage ($4{\pm}0.5^{\circ}C$). Analyses were conducted on GM and IS muscles sampled on 0, 1, 4 and 7 d postmortem. Results: Chill storage did not affect the antioxidant enzyme activities in both muscles. The IS had greater (P < 0.05) superoxide dismutase and catalase activities than GM. Carotenoid and tocopherol contents did not differ between muscles but decreased (P < 0.05) over storage. The IS had higher (P < 0.05) glycogen and ultimate pH and lower (P < 0.05) shear force and cooking loss than GM. The carbonyl content, % metmyoglobin, drip loss and TBARS increased (P <0.05) while free thiol, metmyoglobin reducing activity (MRA), shear force and myoglobin decreased (P < 0.05) over storage. Muscle type had no effect (P > 0.05) on free thiol, MRA and TBARS. The GM had lower (P < 0.05) redness on d 0 and 1 than IS while the IS had greater carbonyl, % metmyoglobin and drip loss than GM on d 7. The reflective density of slow myosin heavy chain (MHC) was higher (P < 0.05) while the density of fast MHC and actin was lower (P < 0.05) in IS than GM. Regardless of muscle type, the density of MHC decreased (P < 0.05) while that of actin was stable over storage. Nonetheless, the degradation of fast and slow MHC was greater (P < 0.05) in IS than GM. Muscle type had no effect (P > 0.05) on consumer preference for flavour, juiciness and overall acceptability. However, IS had higher (P < 0.05) tenderness score than GM on d 1 and 4 postmortem. Intramuscular fat was higher (P< 0.05) in IS compared with GM. Fatty acid composition did not differ between the muscles. However, GM had lower (P < 0.05) n-6/n-3 ratio than IS. The n-3 and n-6 PUFA declined (P < 0.05) while the SFA increased (P < 0.05) over storage. Conclusion: The changes in myofibrillar proteins and physicochemical properties of goat meat during postmortem chill storage are muscle-dependent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.279-286
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• 1996

Cultivated tilapia (Oreochromis niloticus) in the fresh water were acclimated to the sea water to improve palatability of the fish meat. Physicochemical properties in the rigor mortis of those fish meats were investigated during storage at $0^{\circ}C,\;10^{\circ}C\;and\;20^{\circ}C$. The faster onset of rigor mortis was occurred in acclimated meat than fresh water cultivated meat. Both meats stored at $0^{\circ}C$ showed faster figro mortis than at $10^{\circ}C\;and\;20^{\circ}C$. Significant difference was not observed between the breaking strength and the rigor index. The breaking strength reached maximum over 12hrs after death and then gradually declined, and the rigor index was slowly increased and reached maximum over 18hrs after postmortem. Low temperature and acclimation to the sea water affected the degradation of adenosine triphosphate (ATP), accumulation of inosine monophosphate (IMP) or lactate. These results suggest that the palatability of tilapia muscle cultivated in the fresh water could be improved by acclimation to the sea water which induces the prerigor at the early state of postmortem and the physical changes of fish muscle.

• Food Science of Animal Resources
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• v.41 no.4
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• pp.650-663
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• 2021

The objective of this study was to examine the relationship between meat quality attributes and the changes of sarcoplasmic protein acetylation and myofibrillar protein acetylation in lamb longissimus thoracis et lumborum muscles at different postmortem phases. Protein acetylation, color, pH, shear force, myofibril fragmentation index and cooking loss were measured. The total level of acetylated sarcoplasmic proteins showed a negative relation with pH, a positive relation with a^*, b^* and cooking loss at the pre-rigor phase. Sarcoplasmic proteins acetylation affected postmortem pH by regulating glycolysis, which in turn affects color and cooking loss. The total level of acetylated myofibrillar proteins showed a positive relation with shear force at the pre-rigor phase. Myofibrillar proteins acetylation affected meat tenderness by regulating muscle contraction. This study indicated that acetylation played a regulatory role of meat color, water-holding capacity, and tenderization process at early postmortem.

• Proceedings of the PSK Conference
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• 2002.04a
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• pp.216.3-217
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• 2002