Changes of myofibrillar and centrifugal drip proteins and shear force of psoas major and minor and semitendinosus muscles from calves, heifers and cows during post-mortem ageing (2023)

In this study, pH, meat color analysis, microbial counts and Raman spectroscopic data were obtained from beef steaks stored at 4°C for up to 21days using two different packaging methods: vacuum (VP) and modified atmosphere packaging (MAP). Models using partial least square regression (PLSR), indicated that Raman spectroscopy was able to predict total viable counts (TVC) and lactic acid bacteria (LAB) measured at 21d post mortem (TVC in VP: R²_cv=0.99, RMSEP=0.61; TVC in MAP: R²_cv=0.90, RMSEP=0.38; LAB in VP: R²_cv=0.99, RMSEP=0.54; LAB in MAP: R²_cv=0.75, RMSEP=0.60). The results of this study demonstrate that Raman spectroscopy may have potential for the rapid determination of meat spoilage.

The aim of this study was to evaluate the effect of dietary supplementation of linseed and/or quinoa on tenderness and on proteome of lamb meat. Thirty-two Italian Merino lambs were distributed into 4 groups with different diet: control (CO) with no supplemental fat, linseed (LS), quinoa (QS) and QS+LS diets. Meat obtained by lamb fed linseed showed the lowest values of WBSF (P<0.001), hardness (P<0.01), gumminess (P<0.01) and chewiness (P<0.01). Proteomic changes of myofibrillar and sarcoplasmic proteins were estimated with SDS-PAGE, Western Blot and Two-Dimensional Gel Electrophoresis. In linseed group proteomic analysis revealed a degradation of desmin and TnT proteins complex and a major number of spots and phosphorylation isoforms of fast MLC2 patterns. Meat obtained by lamb fed quinoa showed a minor effect on the instrumental evaluation of meat tenderness and a major number of spots ascribed to sarcoplasmic proteins and fMHC. Data suggest that dietary supplementation may act on meat tenderness and on proteolytic pattern of myofibrillar fraction.

The relationship between meat tenderness and the protein composition of muscle exudates collected from broiler breast fillets deboned at different postmortem times was investigated. A total of 85 broilers were processed and breast fillets from each carcass were deboned at either 2 h (early-deboned, EB) or 24 h (control) postmortem. One fillet per carcass was used for 1 d postmortem meat tenderness measurements and the other fillet was stored at 4°C until 6 d postmortem for the collection of exudate prior to tenderness evaluation. Protein content and composition of muscle exudates were determined by a biuret assay and SDS-PAGE. Fillet pH, color, drip loss, and cook loss were also measured. Early-deboned fillets exhibited greater (P < 0.05) Warner-Bratzler shear force (WBSF) than controls at 1 d (7.4 vs. 3.1 kg) and 6 d (4.1 vs. 2.5 kg). Deboning time did not influence pH or color values (L*a*b*). Control fillets exhibited less drip loss after 6 d of storage (P = 0.005) and less cook loss at 1 and 6 d (P < 0.001). Exudate protein concentration was not influenced by deboning time. From the SDS-PAGE profiles of the exudates, the relative abundances of seventeen protein bands were quantified. Electrophoresis analysis revealed that, in general, the protein profiles of exudates from control and EB fillets were not distinct from each other. However, the band corresponding to 225 kDa was more abundant in controls (P = 0.021). Although the protein concentrations and SDS-PAGE profiles of muscle exudates varied widely between breast fillets, variations in exudate protein characteristics were not strongly associated with changes in the tenderness of broiler breast meat due to the combined effects of postmortem deboning time and post-deboning aging.

The effects of breed and aging time (1, 7, 14, 21d) were evaluated on physical meat properties and on sarcoplasmic protein changes in 24 young bulls from Romagnola×Podolian, Podolian and Friesian breeds. Aging affects lightness showing an increase in all breeds while changes in redness varied according to the breed. Podolian breed showed meat with the darkest and the reddest color and the lowest drip loss compared to the other breeds. Extending aging to 21d reduced drip loss from meat. SDS-PAGE and 2DE showed that many changes in the sarcoplasmic proteins occurred among breeds and during aging. During post-mortem some sarcoplasmic proteins decline in intensity after 21d highlighting that they were susceptible to aging. Protein identification and western blotting showed the presence of myosin light chains, Troponin T and tropomyosin proteins during aging, suggesting a degradation of myofibers and a more intense proteolysis especially in the Podolian breed.

This study determined the effects of extraction buffer pH and postmortem aging on the extraction of salt-soluble and water-soluble proteins from broiler pectoralis muscle. Deboned broiler breast fillets were collected at 4 h postmortem, packaged, and then stored at 4°C until 1, 5, or 8 d postmortem. After the designated aging period, salt-soluble and water-soluble protein extractions were performed using buffers at 7 different pH levels (pH 5.4, 6.4, 6.9, 7.2, 7.5, 8.0, 9.0). Protein concentrations of the extracts were measured and SDS-PAGE analysis was performed. Salt-soluble protein concentration increased (P < 0.0001) as buffer pH increased from pH 5.4 to 6.9 and then remained unchanged from pH 6.9 to 9.0. Water-soluble protein concentration increased (P < 0.0001) as buffer pH increased from pH 5.4 to 7.2 and then remained unchanged from pH 7.2 to 9.0. There was not a significant extraction buffer pH by aging treatment interaction for the total protein concentration of either the salt-soluble or water-soluble protein extracts. The protein concentrations of salt-soluble extracts were similar at both 1 and 8 d postmortem but lower (P < 0.0001) at 5 d postmortem. The protein concentrations of water-soluble extracts were similar at both 1 and 5 d postmortem, but higher (P < 0.0001) at 8 d. Both extraction buffer pH and postmortem aging influenced the SDS-PAGE protein profiles of salt-soluble and water-soluble protein extracts from breast muscles. Data demonstrate that postmortem aging and extraction buffer pH influence both the total amount and the composition of the myofibrillar and sarcoplasmic proteins that can be extracted from broiler breast fillets.

Modeling is an emerging technique to qualitatively understand the complex interactions among phenomena that affect meat quality and to make quantitative predictions of how these phenomena affect the many quality attributes that are important to consumers. This article reviews both causal and statistical modeling approaches, their advantages and disadvantages, and thus their applicability to different contexts and applications. Examples of each approach are provided, along with indications of the insights that can be gained from each.

Meat Science, Volume 105, 2015, pp. 46-52

The skeletal muscle protein troponin I (TnI) has been characterized as a potential thermally stable and species-specific biomarker of mammalian muscle tissues in raw meat and meat products. This study proposed a technique for the quantification of TnI comprising protein extraction and sandwich enzyme-linked immunosorbent assay (ELISA). The technique is characterized by a TnI detection limit of 4.8ng/ml with quantifiable concentrations ranging from 8.7 to 52ng/ml. The method was shown to be suitable for detection of TnI in mammalian (beef, pork, lamb, and horse) meat but not in poultry (chicken, turkey, and duck) meat. In particular, the TnI content in beef was 0.403±0.058mg/g of wet tissue. The TnI estimations obtained for the pork and beef samples using ELISA were comparable to the proteomic analysis results. Thus, the quantitative study of TnI can be a convenient way to assess the mammalian muscle tissue content of various meat products.

Poultry Science, Volume 95, Issue 11, 2016, pp. 2696-2706

Pale, Soft, and Exudative (PSE) broiler breast meat has poor protein functionality, which leads to quality problems and economic loss in the poultry industry. Proteomics has been applied to characterize the biochemical mechanisms governing tenderness, color, and water-holding capacity in meat. However, the proteome basis of PSE has not yet been characterized for broiler breast meat. Therefore, this study was conducted to determine the differences in meat quality (cooking loss and shear force), descriptive sensory characteristics, consumer acceptance, and whole muscle proteome between normal and PSE-like broiler breast meat. Male Hubbard × Cobb 500 birds (n = 1,050) were raised in commercial houses. Prior to harvest, a sample of the broilers (n = 900) were subjected to short-term stress (38°C for 2 h), and the remaining broilers (n = 150) were maintained at control conditions (21°C for 2 h). Broiler breast (Pectoralis major) meat was collected and characterized by pH₂₄ and L*₂₄ as normal (pH₂₄ 5.8 to 6.2, L*₂₄ 45 to 55) or PSE-like (pH₂₄ 5.4 to 5.7, L*₂₄ 55 to 65) samples. Normal broiler breast meat had lower shear force values than PSE-like meat (P < 0.05). Based on sensory descriptive analysis, normal cooked chicken breast meat was more tender and juicier than PSE-like breast meat (P < 0.05). Consumer sensory analysis results indicated that 81% of consumer panelists liked normal breast meat whereas 62% of the panelists liked PSE-like breast meat. Whole muscle proteome profiling identified fifteen differentially abundant proteins in normal and PSE-like broiler breast samples. Actin alpha, myosin heavy chain, phosphoglycerate kinase, creatine kinase M type, beta-enolase, carbonic anhydrase 2, proteasome subunit alpha, pyruvate kinase, and malate dehydrogenase were over-abundant (P < 0.05) in PSE-like broiler breast whereas phosphoglycerate mutase-1, alpha-enolase, ATP-dependent 6-phosphofructokinase, and fructose 1,6-bisphosphatase were over-abundant (P < 0.05) in normal meat. Thus, results indicated that differences in proteome abundance could be related to the meat quality differences between normal and PSE-like broiler breast meat.

LWT, Volume 86, 2017, pp. 20-24

The role of myowater-holding on the development of the hardness of Wooden Breast (WB) affected chicken breasts was investigated. Transverse (T₂) relaxation times and proportions of myowater populations (T_2B, T₂₁ and T₂₂) were assessed using low-field nuclear magnetic resonance (NMR) relaxometry and integrated with meat compression measurements. Two muscle conditions (M: Normal (N) vs WB), four sampling locations (L), four sampling times (T) and interactions (M x L and M x T) were considered. Compared to N, WB was harder, the extramyofibrillar myowater population (T₂₂) was increased and the relaxation time of the water trapped into the myofibrillar matrix (T₂₁) was also increased. A link between the T₂₁ relaxation time of water trapped into the myofibrillar matrix and hardness was suggested for the WB muscles. During storage, a redistribution of water occurred over time, as revealed by an increasing trend of the T₂₁ population, but a concomitant texture evolution did not reflect this change. The cranial/superficial part of the breasts exhibited the highest amount of the extramyofibrillar water population (T₂₂), and the texture of this muscle part was harder than the deep layers. However, the role of myowater on muscle hardness was not fully clarified by this study.

Meat Science, Volume 118, 2016, pp. 122-128

Longissimus dorci (LD) samples of different origin (imported and domestic) with pre-treatments (imported meat stored at −18°C for 6months, domestic meat stored at −18°C for 10days, and domestic meat stored at 4°C for 24h) were cooked as barbacoa and frozen using two treatments (air blast and liquid immersion) and then evaluated after 30days of storage. The results showed that the origin and pre-treatment of meat affected L*, a*, instrumental texture and microstructure; that the storage time affected pH, a_w, b* and microstructure; and that the freezing treatments did not affect the meat. Overall, the frozen cooked lamb dish barbacoa could present some problems at the conservation stage due to an increase in pH, a_w and changes in microstructure; however, the physical traits (color and texture) remained mostly unchanged and depended more on the quality of the raw meat.

Meat Science, Volume 141, 2018, pp. 44-49

The effects of nitric oxide (NO) and its induced protein nitrosylation on calpain-1 activation and protein proteolysis in beef during postmortem aging were investigated. Five semimembranosus muscles were removed from beef cattle carcass. Beef samples were incubated with one of following treatments for 24 h at 4 °C: control (normal saline), NO donor (100, 200 and 400 μM S-nitrosoglutathione (GSNO)) or nitric oxide synthase (NOS) inhibitor (0.05, 0.1 and 0.15 M Nω-Nitro-l-arginine methyl ester hydrochloride (L-NAME)). After incubation, the beef samples were vacuum-packaged and aged at 4 °C for 1, 4, and 7 days. Results showed that GSNO decreased and L-NAME increased the extent of calpain-1 autolysis at d 1. Degradation of desmin and troponin-T was increased by L-NAME while decreased by GSNO. These results suggest that NO could regulate calpain-1 autolysis and its proteolysis activity during postmortem aging in beef SM muscle.

Food Chemistry, Volume 148, 2014, pp. 1-6

The objective of this study was to investigate the contribution of caspase and calpain, on the proteolysis of calpastatin in postmortem beef muscle, by examining the influences of calpain inhibitor MDL-28170 and caspase-3 inhibitor DEVD-CHO on calpastatin degradation and the in vitro proteolysis of calpastatin by caspase-3, -6 and μ-calpain. In this study, both calpain- and caspase-3-inhibitors suppressed postmortem degradation of calpastatin. In vitro treatment of calpastatin with μ-calpain resulted in degradation products similar in size to those occurring naturally in aged beef muscle. With addition of caspase-3, only the 100kDa degradation fragment was present during the early phase of ageing, and subsequently, was likely to have been inactivated by calpain or other factors. Therefore, calpain was the major contributor to the proteolysis of calpastatin in postmortem beef muscle. While caspase-3 was involved in calpastatin degradation during the early postmortem period, calpastatin maybe plays an important role in bridging the gap between caspase and calpain systems.