• Food Science of Animal Resources
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• v.42 no.5
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• pp.816-832
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• 2022

To evaluate the effects of early postmortem vacuum packaging (VP) on meat quality during postmortem chilled storage, hot-boned lamb was vacuum-packaged at 1, 6, 12, 24, and 48 h postmortem and stored around 2℃ until 168 h postmortem, with lamb packaged in plastic wrap as the control (aerobic packaging). Intramuscular pH decline was delayed when lamb was vacuum packaged at 1, 6, and 12 h postmortem (p<0.05). The lamb vacuum-packaged at 1 h postmortem (VP-1h group) had significantly lower shear force values and purge losses accompanied by lower free thiol group values than other treatments during postmortem storage and was also higher in extractable calpain-1 activity by 6 h postmortem (p<0.05). Free thiol group concentrations were significantly higher after VP at 6 and 12 h postmortem (p<0.05). Packaging lamb under vacuum very early postmortem produced the lowest shear force and purge loss, likely by slowing heat loss and muscle temperature decline, implying that lamb quality is improved by VP when applied very early postmortem. This was at the expense of protein oxidation, which was unrelated to other meat quality measurements, most likely because potential contracture during hot boning confounded its impact. Further research is required to understand the implications of the interaction between protein oxidation, VP, and hot boning on the acceptability of lamb.

• Animal Bioscience
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• v.36 no.2_spc
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• pp.374-384
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• 2023

Skeletal muscle metabolism regulates homeostatic balance in animals. The metabolic impact persists even after farm animal skeletal muscle is converted to edible meat through postmortem rigor mortis and aging. Muscle metabolites resulting from animal growth and postmortem storage have a significant impact on meat quality, including flavor and color. Metabolomics studies of postmortem muscle aging have identified metabolisms that contain signatures inherent to muscle properties and the altered metabolites by physiological adaptation, with glycolysis as the pivotal metabolism in postmortem aging. Metabolomics has also played a role in mining relevant postmortem metabolisms and pathways, such as the citrate cycle and mitochondrial metabolism. This leads to a deeper understanding of the mechanisms underlying the generation of key compounds that are associated with meat quality. Genetic background, feeding strategy, and muscle type primarily determine skeletal muscle properties in live animals and affect post-mortem muscle metabolism. With comprehensive metabolite detection, metabolomics is also beneficial for exploring biomarker candidates that could be useful to monitor meat production and predict the quality traits. The present review focuses on advances in farm animal muscle metabolomics, especially postmortem muscle metabolism associated with genetic factors and muscle type.

• 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.

• 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 Poultry Science
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• v.25 no.2
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• pp.55-64
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• 1998

This study was carried out to investigate the postmortem changes in physico-chemical characteristics of chicken meat with different breeds. Thigh and breast meats from Korean Native Chicken(KNC, 15-wk old), Wangchoo(15-wk old), and broiler(7-wk old) were stored at 5 ˚C. Differences in postmortem pH changes were not recognized among breeds, and pH showed by the lowest value at the 1st day of postmortem in all breeds. Breast meat had tendency to drop pH faster than thigh meat. Heme pigment contents showed no differences among breeds. KNC showed the lowest cholesterol contents in all breeds, total collagen contents showed the lowest value at the 1st day of postmortem, and thereafter it was gradually increased. Heat soluble collagen contents was lowest in Wangchoo. Water soluble and salt soluble protein showed the lowest extractability at the 1st day of storage. Broiler showed the highest extractability of these proteins and Wangchoo showed the lowest. Water holding capacity(WHC) had increasing tendency whilst cooking loss had decreasing tendency by the ageing. WHC of breast and thigh meat showed the highest values in KNC and broiler, respectively. Myofibrillar fragmentation index (MFI) was significantly increased in all breeds by the ageing. Breast and thigh meat showed almost same MFI in KNC and broiler, and in KNC and Wangchoo, respectively. Hardness of breast meat showed decreasing tendency by the ageing.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.739-743
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• 2006

Postmortem proteolysis of breast (BM) and leg (LM) muscles from Taiwan colored chickens (TCC) and silkie bantams (SB) at $5^{\circ}C$ were compared. Myofibrils were prepared from BM and LM samples that were randomly taken from the carcasses of SB and TCC after 0, 1, 3, 7 and 14 days of storage at $5^{\circ}C$. pH of samples was determined, and degradation of myofibrillar proteins was analyzed by the SDS-PAGE and western blots. The results showed that pH was lower in BM than in LM samples from both avian strains. Appearance of 30 kDa components and disappearance of titin and nebulin were more rapidly as seen on SDS-PAGE in BM than in LM samples. Western blots labeled with a monoclonal antibody to desmin also demonstrated that desmin degraded more quickly in BM samples. Our data might suggest that postmortem proteolysis occurred more rapidly in BM than in LM from both TCC and SB.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.5
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• pp.721-724
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• 2002

Postmortem Proteolysis of breast (BM) and leg (LM) muscles in Chiayi native chickens at $5^{\circ}C$ were compared. Myofibrils were purified from BM and LM samples that were randomly taken from carcasses after 0, 1, 3, 7 and 14 days of storage at $5^{\circ}C$. Fragmentation of myofibrils were determined, and degradation of myofibrillar proteins were analyzed by the SDS-PAGE and western blots. The results showed that myofibril fragmentation index (MFI) was significantly (p<0.05) higher in BM than in LM samples. Disappearance of titin and nebulin and appearance of the 30 kDa component were more rapidly as seen on SDS-PAGE in BM than in LM samples. Western blots labeled with a monoclonal antibody to desmin also demonstrated that desmin degraded more quickly in BM samples. Our data suggested that postmortem proteolysis occurred more rapidly in breast muscles in Chiayi native chickens.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.712-718
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• 1992

This experiment was carried out to investigate some physico-chemical properties of myofibrillar proteins isolated from alkaline and acid rigor muscles of rabbit. The degree of fragmentation was about 0.35 at 3 days of postmortem in acid rigor muscle fiber, whereas it was only 0.3 at 7 days of postmortem in alkaline rigormuscle fiber. $Mg^{2+}$-activated ATPase activities of actomyosin were increased to the highest level at 1st day in acid rigor and at 3rd day in alkaline rigor muscle fiber. $Ca^{2+}$-activated ATPase activities of actomyosin were slightly increased at postmortem. $Mg^{2+}$-, and $Ca^{2+}$-activated ATPase activities were higher in alkaline rigor muscle than those in acid rigor muscle at postmortem. Solubility of actomyosin increased with postmortem but no differences were observed in rigor types. SDS-PAGE(sodium dodecyl sulfate polyacrylamide gel electrophoresis) band patterns of myofibrils did not show significant differences between rigor types, but newly 30.000 dalton proteins were appeared at 3 day postmortem in both rigor types.

• Fisheries and Aquatic Sciences
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• v.20 no.7
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• pp.13.1-13.7
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• 2017

In order to evaluate the maximal storable period of the raw crab for a non-thermal muscle separation, the quality changes of the leg meat of red snow crab (Chionoecetes japonicus) during freeze storage were investigated. Fresh red snow crabs were stored at $-20^{\circ}C$ for 7 weeks, and the leg muscle was separated by a no heating separation (NHS) method every week. During the storage, considerable loss of the leg muscle did not occur and microbiological risk was very low. In contrast, discoloration appeared at 2-week storage on around carapace and the leg muscle turned yellow at storage 3-week. In physiochemical parameters, protein and free amino acids gradually decreased with storage time, expected that proteolytic enzymes still activated at $-20^{\circ}C$. At 4-week storage, the sensory acceptance dropped down below point 4 as low as inedible and notable inflection points in pH and acidity were observed. The volatile base nitrogen was low, though a little increase was recorded. These results suggested that the maximal storable period at $-20^{\circ}C$ of the raw material was within 2 weeks and it was depended on external factor such as the discoloration. The present study might be referred as basic data for approaches to solve quality loss occurred in non-thermal muscle separation.

• The Korean Journal of Food And Nutrition
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• v.10 no.3
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• pp.401-406
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• 1997

This study was carried out to compare the extractability and ATPase activity of actomyosin extracted shank, rib and loin muscle of beef meat stored at 8$^{\circ}C$. The extractability of actomyosin in shank, rib and loin muscle were 36.74, 72.55 and 56.77mg/g early in the storage, respectively. The extractability of the rib and loin muscle were similar, the shank muscle was processed differently with their. The Mg- and Ca-ATPase activity of the shank muscle rised to 3 days, but decreased the 6th day. And Mg- and Ca-ATPase activity of the rib muscle was similar during storage period, the loin muscle made a slow descent. The strength of Mg- and Ca-ATPase activity showed in the order shank, rib and loin muscle. The EDTA-ATPase activity of the shank and rib muscle was difference according to storage period and ionic strength, but the loin muscle was increase in succession with magnitude of ionic strength.