Aged Meat Research Articles

Prediction of troponin-T degradation using color image texture features in 10 d aged beef longissimus steaks

The objective was to use digital color image texture features to predict troponin-T degradation in beef. Image texture features, including 88 gray level co-occurrence texture features, 81 two-dimension fast Fourier transformation texture features, and 48 Gabor wavelet filter texture features, were extracted from color images of beef strip steaks (longissimus dorsi, n=102) aged for 10d obtained using a digital camera and additional lighting. Steaks were designated degraded or not-degraded based on troponin-T degradation determined on d 3 and d 10 postmortem by immunoblotting. Statistical analysis (STEPWISE regression model) and artificial neural network (support vector machine model, SVM) methods were designed to classify protein degradation. The d 3 and d 10 STEPWISE models were 94% and 86% accurate, respectively, while the d 3 and d 10 SVM models were 63% and 71%, respectively, in predicting protein degradation in aged meat. STEPWISE and SVM models based on image texture features show potential to predict troponin-T degradation in meat.

Genome scan for meat quality traits in Nelore beef cattle

Meat quality traits are economically important because they affect consumers' acceptance, which, in turn, influences the demand for beef. However, selection to improve meat quality is limited by the small numbers of animals on which meat tenderness can be evaluated due to the cost of performing shear force analysis and the resultant damage to the carcass. Genome wide-association studies for Warner-Bratzler shear force measured at different times of meat aging, backfat thickness, ribeye muscle area, scanning parameters [lightness, redness (a*), and yellowness] to ascertain color characteristics of meat and fat, water-holding capacity, cooking loss (CL), and muscle pH were conducted using genotype data from the Illumina BovineHD BeadChip array to identify quantitative trait loci (QTL) in all phenotyped Nelore cattle. Phenotype count for these animals ranged from 430 to 536 across traits. Meat quality traits in Nelore are controlled by numerous QTL of small effect, except for a small number of large-effect QTL identified for a*fat, CL, and pH. Genomic regions harboring these QTL and the pathways in which the genes from these regions act appear to differ from those identified in taurine cattle for meat quality traits. These results will guide future QTL mapping studies and the development of models for the prediction of genetic merit to implement genomic selection for meat quality in Nelore cattle.

Nitrite-embedded packaging film effects on beef color as influenced by meat age and muscle type

Nitrite-embedded packaging film effects on beef color as influenced by meat age and muscle type

Changes in tenderness and cathepsins activity during post mortem ageing of yak meat

Tian, J.-C., Han, L., Yu, Q.-L., Shi, X.-X. and Wang, W.-T. 2013. Changes in tenderness and cathepsins activity during post mortem ageing of yak meat. Can. J. Anim. Sci. 93: 321-328. Very little research has been conducted on yak meat tenderization. In this study we investigated the changes in physical characteristics (e.g., pH, water-holding capacity, texture profile analysis, shear force) and cathepsins L, B and H activities in the tenderization process. These traits were quantified in longissimus dorsi muscle from 10 yaks during 192 h post mortem. Samples were aged at 4°C for 0, 12, 24, 36, 48, 72, 120, 168 and 192 h. pH decreased (P<0.05) from 6.84 to 5.54 in the first 72 h and did not change significantly during the next 120 h. Water-holding capacity showed an overall decreasing trend (P<0.05). Shear force decreased? (P<0.05) and myofibrillar fragmentation index increased? (P<0.05), and it was concluded that ageing can improve yak meat tenderness. Our results on texture profile analysis showed a decr...

Changes in tenderness and cathepsins activity during post mortem ageing of yak meat

Tian, J.-C., Han, L., Yu, Q.-L., Shi, X.-X. and Wang, W.-T. 2013. Changes in tenderness and cathepsins activity during post mortem ageing of yak meat. Can. J. Anim. Sci. 93: 321–328. Very little research has been conducted on yak meat tenderization. In this study we investigated the changes in physical characteristics (e.g., pH, water-holding capacity, texture profile analysis, shear force) and cathepsins L, B and H activities in the tenderization process. These traits were quantified in longissimus dorsi muscle from 10 yaks during 192 h post mortem. Samples were aged at 4°C for 0, 12, 24, 36, 48, 72, 120, 168 and 192 h. pH decreased (P&lt;0.05) from 6.84 to 5.54 in the first 72 h and did not change significantly during the next 120 h. Water-holding capacity showed an overall decreasing trend (P&lt;0.05). Shear force decreased? (P&lt;0.05) and myofibrillar fragmentation index increased? (P&lt;0.05), and it was concluded that ageing can improve yak meat tenderness. Our results on texture profile analysis showed a decrease in hardness (P&lt;0.05), springiness (P&lt;0.05) and chewiness (P&lt;0.05), reflected in a progressive softening during ageing (P&lt;0.05). Cathepsins L, B and H activity showed an increased trend (P&lt;0.05). In conclusion, our results show potential roles for cathepsins L, B and H in the tenderization process. This study provides further insights into the tenderization process of yak meat, which may ultimately be used for the advantageous manipulation of the process.

Calcium and potassium content in beef: Influences on tenderness and associations with molecular markers in Nellore cattle

Calcium (Ca) and potassium (K) are essential nutrients in animal nutrition. Furthermore, the Ca content can influence meat tenderness because it is needed by the proteolytic system of calpains and calpastatins, major factors in postmortem tenderization of skeletal muscles. K content, which is needed for muscle contraction, can also affect meat tenderness. This study showed that K positively affects the Warner–Bratzler shear force (WBSF), measured at 14days of meat aging, which means that higher levels of K are related to lower meat tenderness. Additionally, a significant effect (P≤0.015) of a SNP in the calcium-activated neutral protease 1 (CAPN1) gene on Ca content was observed. Metal content in beef can affect not only nutritional values but also meat quality traits. Part of this effect may be related to variation in specific genes.

Walking and Running are Associated with Similar Reductions in Cataract Risk

Habitual running has been associated with reduced risk of cataract development in one prospective study. The purposes of the current analyses were to provide further evidence of this potentially important benefit of vigorous exercise and to test whether moderate exercise (e.g., walking) provides as significant and equivalent reduction in cataract risk as vigorous exercise (e.g., running). Cox proportional hazard analyses of self-reported, physician-diagnosed incident cataracts versus baseline energy expenditure (METs) in 32,610 runners and 14,917 walkers during a 6.2-yr follow-up. Results are reported as hazard ratios (HR), percent risk reductions (100 (HR - 1)), and 95% confidence intervals (95% CI). Runners and walkers reported 733 and 1074 incident cataracts during follow-up, respectively. When adjusted for sex, race, age, education, smoking, and intakes of meat, fruit, and alcohol, lower cataract risk was significantly associated with both running (HR = 0.960 per MET·h·d, 95% CI 0.935-0.986) and walking (HR = 0.918 per MET·h·d, 95% CI = 0.881-0.956), with no significant difference in the risk reduction per MET-hours per day between running and walking or between men and women. Compared with running or walking at or below guideline levels (≤1.8 MET·h·d), incident cataract risk was significantly lower for running or walking 1.8-3.6 (16.4% lower, 95% CI = 6.4%-25.3%), 3.6-5.4 (19.0% lower, 95% CI = 5.6%-30.4%), 5.4-7.2 (26.2% lower, 95% CI = 11.2%-38.7%), 7.2-9.0 (34.1% lower, 95% CI = 10.0%-51.2%), and ≥9 MET·h·d (41.6% lower, 95% CI = 19.8%-57.4%). Moderate (walking) and vigorous (running) exercise were both significantly associated with lower cataract risk and their effects similar. Cataract risk appears to decrease linearly with increasing exercise energy expenditure through 9 MET·h·d.

Nitrite-embedded packaging film effects on fresh and frozen beef color development and stability as influenced by meat age and muscle type

Muscles (Longissimus lumborum, LL; Psoas major, PM, semitendinosus, ST) were aged (2, 9d postmortem), cut into steaks, anaerobically packaged (nitrite-embedded film, NEF), and displayed (fresh, 19d; frozen, 39d). Fresh NEF increased (P<0.05) in redness (first 48h). Upon opening fresh NEF (d 6) and overwrapping in PVC film, redness declined (P<0.05). NEF cooked LL had more red surface compared to non-NEF. Meat age influenced NEF color. Intact NEF maintained acceptable red color throughout display. Residual nitrite and nitrate associated with fresh NEF and nitrate in NEF cooked LL were found (P<0.05) in the outer layer. Consideration should be given to providing sufficient time for nitric oxide myoglobin development when using NEF which may be influenced by meat age and muscle differences. NEF packaging has potential to extend fresh beef color display life. NEF appears to offer the opportunity to display bright red beef in frozen display by limiting typical effects of photooxidation.

1H NMR and multivariate data analysis of the relationship between the age and quality of duck meat

To contribute to a better understanding of the factors affecting meat quality, we investigated the influence of age on the chemical composition of duck meat. Aging probably affects the quality of meat through changes in metabolism. Therefore, we studied the metabolic composition of duck meat using 1H nuclear magnetic resonance (NMR) spectroscopy. Comprehensive multivariate data analysis showed significant differences between extracts from ducks that had been aged for four different time periods. Although lactate and anserine increased with age, fumarate, betaine, taurine, inosine and alkyl-substituted free amino acids decreased. These results contribute to a better understanding of changes in duck meat metabolism as meat ages, which could be used to help assess the quality of duck meat as a food.

Monitoring post mortem changes in porcine muscle through 2-D DIGE proteome analysis of Longissimus muscle exudate

BackgroundMeat quality is a complex trait influenced by a range of factors with post mortem biochemical processes highly influential in defining ultimate quality. High resolution two-dimensional DIfference Gel Electrophoresis (2-D DIGE) and Western blot were applied to study the influence of post mortem meat ageing on the proteome of pork muscle. Exudate collected from the muscle following centrifugation was analysed at three timepoints representing a seven day meat ageing period.ResultsThe intensity of 136 spots varied significantly (p < 0.05) across this post mortem period and 40 spots were identified using mass spectrometry. The main functional categories represented were metabolic proteins, stress-related proteins, transport and structural proteins. Metabolic and structural proteins were generally observed to increase in abundance post mortem and many likely represent the accumulation of the degradation products of proteolytic enzyme activity. In contrast, stress-related proteins broadly decreased in abundance across the ageing period. Stress response proteins have protective roles in maintaining cellular integrity and a decline in their abundance over time may correlate with a reduction in cellular integrity and the onset of meat ageing. Since cellular conditions alter with muscle ageing, changes in solubility may also contribute to observed abundance profiles.ConclusionsMuscle exudate provided valuable information about the pathways and processes underlying the post mortem ageing period, highlighting the importance of post mortem modification of proteins and their interaction for the development of meat quality traits.

A New Insight into the Role of Calpains in Post-mortem Meat Tenderization in Domestic Animals: A review.

Tenderness is the most important meat quality trait, which is determined by intracellular environment and extracellular matrix. Particularly, specific protein degradation and protein modification can disrupt the architecture and integrity of muscle cells so that improves the meat tenderness. Endogenous proteolytic systems are responsible for modifying proteinases as well as the meat tenderization. Abundant evidence has testified that calpains (CAPNs) including calpain I (CAPN1) and calpastatin (CAST) have the closest relationship with tenderness in livestock. They are involved in a wide range of physiological processes including muscle growth and differentiation, pathological conditions and post-mortem meat aging. Whereas, Calpain3 (CAPN3) has been established as an important activating enzyme specifically expressed in livestock’s skeletal muscle, but its role in domestic animals meat tenderization remains controversial. In this review, we summarize the role of CAPN1, calpain II (CAPN2) and CAST in post-mortem meat tenderization, and analyse the relationship between CAPN3 and tenderness in domestic animals. Besides, the possible mechanism affecting post-mortem meat aging and improving meat tenderization, and current possible causes responsible for divergence (whether CAPN3 contributes to animal meat tenderization or not) are inferred. Only the possible mechanism of CAPN3 in meat tenderization has been confirmed, while its exact role still needs to be studied further.

Ultimate pH and ageing of meat affect the phase behaviour of mixtures of its proteins and iota carrageenan

The phase behaviour in non-gelling temperature condition (45 °C) of mixtures of iota (ι–) carrageenan (0.1%) and salt soluble proteins (0.4%) from 18 bovine M. longissimus dorsi et lumborum (LD) ranging in inherent ultimate pH (pHu) from 5.42 to 6.97 and aged 0, 1, 2, 7, 14, 21 and 28 days post-mortem were determined. Mixtures separated when centrifuged at 200 × g to form soluble/liquid and complex/gelled phases. Complex/gel formation and yield decreased (P < 0.001) with the increase in meat pHu. Meat proteins and ι–carrageenan contents increased in the liquid phase and decreased in the complex/gel phase with increase in meat pHu (P < 0.001). 50% of the mixtures formed complex/gels at pH 6.29. No formation of complex/gel was predicted with meat proteins or ι–carrageenan at pHu ≥6.81 and 7.43 respectively. Ageing of meat did not have a significant effect (P > 0.05) but tended to increase meat proteins and decrease ι–carrageenan complex/gel forming abilities, suggesting the possibility that with meat ageing there were higher tendencies for intra-interactions between meat proteins rather than interaction with ι–carrageenan. Result of phase contrast microscopy and SDS-PAGE of the liquid and complex/gel phases confirmed the outcome of the chemical analyses. Outcomes of this study can be used to formulate “minimally processed” combi-foods of a range of consistencies.

Recuperação da condição corporal, estimulação elétrica da carcaça e maturação da carne como fatores de melhoria nas características do lombo de ovelhas santa inês descartadas por idade

Effects of body condition (BC) recovery, carcass electrical stimulation (ES) and meat aging time (AT) were studied on the carcass and loin in Santa Ines ewes culled by age and slaughtered immediately after pup weaning or after BC recovery period. Carcass characteristics, shear force (SF), cooking loss (CL), meat color (L*, a*, b*) and sensory characteristics of Longissimus muscle were evaluated. It was concluded that BC recovery improved carcass characteristics and meat color brightness, however did not affect the tenderness. The ES and AT improved tenderness, reducing SF in 44 - 45% and in 51 - 59%, respectively, for 7 or 14 days of aging and 32 - 33% in non aged meat. ES affected the color parameters, clearing the meat. AT darkened and accentuated the brownish red color of meat and increased the cooking losses, from 15.2% (non aged) to 19.6% and 23.1%, respectively, for 7 and 14 days of AT. The sensory evaluation for tenderness corroborated the findings of the instrumental evaluation, which confirmed the effectiveness of ES in improving meat tenderness.

Quality of aged ewe meat in vacuum-packaging system for different storage periods.

Os consumidores acreditam que a maciez e a caracteristica organoleptica mais importante da carne. No entanto, ha grande variabilidade na maciez da carne disponivel para os consumidores, um metodo de reduzir a variabilidade e melhorar a maciez seria promover a maturacao da carne. O objetivo deste estudo foi avaliar a qualidade da carne maturada de ovelhas. O experimento foi conduzido na Universidade Estadual de Londrina. Foram utilizadas 18 ovelhas da raca Santa Ines. Apos o abate, o musculo Longissimus dorsi foram coletados e submetidos ao tratamento, tres diferentes tempos de maturacao: zero, quatro e oito dias a 5 ± 2 ° C. O aumento do tempo de maturacao provocou uma reducao no pH. Os valores de L *, a * e c* aumentam de forma linear com o tempo de maturacao. Os valores b * e h * apresentaram uma regressao quadratica. A contagem de mesofilos e psicrotroficos apresentaram um aumento linear. O indice de fragmentacao miofibrilar apresentou uma regressao quadratica, e a forca de cisalhamento diminuiu linearmente. Na analise sensorial, uma diferenca na intensidade de odor da carne foi observada. A contagem microbiologica indicou que a carne estava apta para consumo. A maturacao promoveu melhorias na qualidade da carne de ovelhas.

Quality of aged meat from Charolais vs nellore cattle

Quality of aged meat from Charolais vs nellore cattle

SmartStretch™ technology VI. The impact of SmartStretch™ technology on the meat quality of hot-boned beef striploin (m. longissimus lumborum)

The impact of SmartStretch™ technology and ageing (0 or 14days ageing) on the meat quality traits of m. longissimus lumborum hot-boned from adult cull cattle was assessed. Tenderness, as reflected in reduced shear force measurement, was significantly (P<0.05) improved in 0day aged stretched samples over the non stretched samples. After 14days ageing there was no longer any difference in the tenderness between stretched and non stretched samples and the aged meat was significantly tenderer than either the SmartStretch™ treated or non stretched meat aged for 0days. Sarcomere length was unchanged by stretching. Presentation traits such as purge loss and fresh colour were unaffected by the stretch treatment, whilst cooking loss was significantly (P<0.05) increased by stretching and ageing for 14days.

Species-specific expression of various proteins in meat tissue: Proteomic analysis of raw and cooked meat and meat products made from beef, pork and selected poultry species

The aim was to search for proteins differentiating the six species (cattle, pig, chicken, turkey, duck and goose) and relatively stable during the meat aging and only slightly degraded in ready-made products. The two-dimensional electrophoresis was used for analysis of the protein profiles from raw meat and frankfurters and sausages (15 products). The observed species-specific differences in protein expression in raw meat were retained in processed products after finishing the entire technological process. Regulatory proteins, metabolic enzymes, some myofibrillar and blood plasma proteins were identified, which were characterised by the electrophoretic mobility specific to the given species. Large differences in the primary structure were observed in serum albumin, apolipoprotein B, HSP27, H-FABP, ATP synthase, cytochrome bc-1 subunit 1 and alpha-ETF. Some of these proteins have potential to be used as markers in authentication of meat products.

Effects of Inhibitors on the Synergistic Interaction between Calpain and Caspase-3 during Post-mortem Aging of Chicken Meat

Calpain has been considered to be the most important protease involved in tenderization during the conversion of muscle into meat. However, recent evidence suggests the possible involvement of the key apoptosis protease, caspase, on post-mortem tenderization. This study used inhibitors of calpain and caspase-3 to treat chicken muscle immediately after slaughter and followed the changes in caspase-3 and calpain activities together with their expression during 5 days of aging. Addition of calpain inhibitors to the system resulted in significantly higher caspase-3 activities (p < 0.01) during storage. Western blot analysis of pro-caspase-3 and α-spectrin cleavage of the 120 kDa peptide (SBDP 120) showed that the addition of calpain inhibitors resulted in the formation of higher amounts of the active form of caspase-3 compared with the control (p < 0.01). Inclusion of inhibitors of caspase-3 led to lower calpain activities (p < 0.01) and dramatically reduced the expression of calpain-1 and calpain-2 (p < 0.01). Concomitantly, this inhibition resulted in greater calpastatin expression compared with the control (p < 0.01). The findings of this investigation show that calpain prevented the activation of caspase-3, whereas caspase-3 appeared to enhance the calpain activity during post-mortem aging through inhibition of calpastatin. It is therefore suggested that there is a relationship between caspase-3 and calpain which contributes to the tenderizing process during the conversion of muscle tissue into meat.

Heterosis for meat quality and fatty acid profiles in crosses among Bos indicus and Bos taurus finished on pasture or grain

Physicochemical properties and fatty acid profiles of meat from Bos indicus, Bos taurus and crossbred B. taurus×B. indicus bullocks (n=216), finished on pasture or grain, were used to estimate the effects of heterosis. Meat quality and fatty acid profiles generally benefited with crossbreeding, but the advantages from heterosis differed among finishing systems. The Warner–Bratzler shear-force in fresh and aged meat was reduced due to heterosis in pasture-finishing, but the effect was minor under grain-finishing. With pasture-finishing, heterosis caused an increase of 5% in CLA concentration, but few other changes in fatty acid profiles. In grain-finishing, heterosis caused a reduction in intramuscular fat and cholesterol, increased amounts of PUFA, n−6 fatty acids and PUFA/SFA ratio, and a decline in atherogenic index. The Δ9 desaturase estimated activity in crossbreds showed a behavior close to B. indicus, suggesting the existence of few loci and a dominance genetic effect on enzymes involved in fatty acid synthesis and metabolism.

Proteomic changes involved in tenderization of bovine Longissimus dorsi muscle during prolonged ageing

To study proteomic changes involved in tenderization of bovine Longissimus dorsi four Charolaise heifers and four Charolaise bull’s muscles were sampled at slaughter after early and long ageing (2–4°C for 12 and 26days respectively). Descriptive sensory evaluation of samples were performed and their tenderness evaluated by Warner–Bratzler shear force test. Protein composition of fresh muscle and of meat aged was analysed by cartesian and polar 2-D electrophoresis. Student’s t-test and Ranking-PCA analyses were performed to detect proteomic modulation, and the selected protein spots were identified by nano-HPLC-Chip MS/MS.This research has demonstrated that there are no differences between proteomic patterns of male and females Longissimus dorsi muscle, and that the extension of ageing beyond 12days, did not brings any concrete advantage in terms of sensory quality. Furthermore, the data presented here demonstrated that meat maturation caused changes of the abundance of proteins involved in metabolic, structural, and stress related processes.