Search

Metabolites are the final products of metabolism and provide insights into the biochemical balance of tissue systems. A cascade of reactions involving proteins, carbohydrates, and lipids affects meat color, tenderness, and flavor, specifically, metabolites that are key biomolecules in biochemical reactions associated with attainment of acceptable meat quality. Bioinformatics platforms, such as Kyoto Encyclopedia of Genes and Genomes (KEGG) databases and MetaboAnalyst, are utilized to help understanding the role of differentially abundant metabolites and characterizing their roles in cellular function/metabolism. However, the inability to identify all metabolites using a single platform and limited metabolite libraries specifically for meat/food remains a challenge. Therefore, the advances in metabolite separation, easy-to-use data processing, increased resolution of mass-spectrometry, and data analysis will help to make inferences or develop biomarkers related to meat quality. This review discusses how metabolomics can be exploited to characterize meat quality, the challenges, and current trends. SIGNIFICANCE: Metabolites play an important role in attaining consumer-preferred meat quality traits and nutritive value of foods. Visual appearance of fresh foods, such as muscle foods, are utilized by consumers to assess the quality at the retail market before making purchases. Similarly, tenderness and flavor of meats influence eating satisfaction and re-purchase decisions. Inconsistencies in meat quality lead to enormous economic losses to the food industry. For instance, consumers often associate a bright-cherry red color with freshness, and the US beef industry loses $3.74 billion annually due to discoloration during storage. Both pre-and post-harvest factors influence the extent of meat quality changes. Metabolomics offer robust tools to get a snapshot of small molecules such as acids, amino acids, glycolytic- and tricarboxylic acids, fatty acids, and sugars present in post-mortem muscle tissue and their role in meat quality. Further, using bioinformatics platforms enables characterizing the role of differentially present metabolites in meat quality as well as identifying biomarkers for desirable quality traits such as tender meat or color-stable carcasses. Innovative applications of metabolomics can be exploited to elucidate the underpinnings of meat quality and to develop novel strategies to enhance marketability of retail fresh meats., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Ningxiang pig is a breed renowned for its exceptional meat quality, but it possesses suboptimal carcass traits. To elucidate the genetic architecture of meat quality and carcass traits in Ningxiang pigs, we assessed heritability and executed a genome-wide association study (GWAS) concerning carcass length, backfat thickness, meat color parameters (L.LD, a.LD, b.LD), and pH at two postmortem intervals (45 min and 24 h) within a Ningxiang pig population. Heritability estimates ranged from moderate to high (0.30~0.80) for carcass traits and from low to high (0.11~0.48) for meat quality traits. We identified 21 significant SNPs, the majority of which were situated within previously documented QTL regions. Furthermore, the GRM4 gene emerged as a pleiotropic gene that correlated with carcass length and backfat thickness. The ADGRF1 , FKBP5 , and PRIM2 genes were associated with carcass length, while the NIPBL gene was linked to backfat thickness. These genes hold the potential for use in selective breeding programs targeting carcass traits in Ningxiang pigs.

High-pressure processing (HPP) negatively impacts fresh meat color. The objective of the study was to use a sarcoplasmic (meat extract) model to better understand the effects of HPP on meat color. Sarcoplasm was extracted at pHs of 5.6, 6.0, or 6.4 and fractioned based on centrifugation speed at 0, 3500 g, and 15,000 g for 5 min. The extracts were processed using a commercial HPP unit at 300 MPa, 450 MPa, and 600 MPa, along with a non-pressurized control. Myoglobin concentration decreased (P < 0.05) with increased HPP levels. Sarcoplasm treated with 300 MPa had the greatest oxymyoglobin content (P < 0.05) compared with the non-pressurized control and other HPP levels. Deoxymyoglobin and metmyoglobin content were greater at 600 MPa compared with non-pressurized control and other HPP levels. In summary, higher pH and lower pressure can improve redness of sarcoplasm., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The objective of this study was to assess the meat quality in second filial hybrid offspring of MSTN -/- cloning boars × Chinese Bama sows with initial mean body weight of 90.52 ± 0.68 kg. Compared with wild-type pigs, the feed utilization rate of MSTN -/- pigs showed an increasing trend (adjusted P = 0.06), loin eye area of MSTN -/- and MSTN +/- pigs increased (adjusted P < 0.01) and thickness of subcutaneous fat decreased (adjusted P < 0.01), the proportion of polyunsaturated fatty acids in meat of MSTN -/- pigs increased (adjusted P < 0.05). By means of histochemical staining, immunofluorescence, scanning electron microscopy, qRT-PCR and WB technologies, it was verified that the decreased meat color score of MSTN -/- pigs was related to the increase of type IIB muscle fiber, and the increased pork tenderness was related to the decrease of collagen content. Overall, this research provides reference for the further utilization of MSTN gene mutant pigs., Competing Interests: Declaration of Competing Interest The authors declare that there is no conflict of interest in relation to this work., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Variations in color, though a quality frustration, are common across the face of fresh and processed hams. Herein, we measured objective color across the semimembranosus (SM) muscle early postmortem and at 1440 min, then compared these differences against biochemical and metabolic characteristics responsible for pork quality development. Color (L*, a*) differed (P < 0.001) by zone and time but no interaction was evident. Lactate content and pH were highly correlated (R 2  = 0.92) at 30 min, but weakened (R 2  = 0.161412) by 1440 min. Lactate anaplerosis was not responsible for this lack of relationship. Glycolytic potential also differed across zone (P < 0.001) and time (P < 0.005). Differences in myoglobin expression and abundance, as well as mitochondrial DNA were notable (P < 0.05) across zone. These data suggest inherent differences in SM muscle are key determinants of ham color variation, while postmortem metabolism may play a lesser role in driving this quality attribute., (Copyright © 2021. Published by Elsevier Ltd.)

The objective of this study was to evaluate the effects of arginine (ARG) and/or lysine (LYS) supplementation on meat quality and oxidative stability of beef loins. Steers (n = 40) were split among four dietary treatments (control, ARG, LYS or ARGLYS). The loins (longissimus lumborum) were obtained at 1 day postmortem and aged either 14 or 28 days prior to cutting of steaks for 7 days of display. No impacts of diet treatments on instrumental tenderness, water-holding capacity and fatty acid profiles were found (P > 0.05). Extended aging significantly decreased lipid oxidative stability, color stability and reducing ability of loins. However, steaks from ARG and ARGLYS maintained superior color stability coupled with lower mitochondrial membrane permeability and higher cytochrome c redox stability compared to control (P < 0.05). These results indicate that ARG supplementation can improve color stability of beef loins possibly through delayed onset of mitochondrial-mediated apoptotic processes., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Principal component analysis (PCA) and the non-hierarchical clustering analysis (K-means) were used to characterize the most important variables from carcass and meat quality traits of crossbred cattle. Additionally, partial least square (PLS) regression analysis was applied between the carcass measurements and meat quality traits on the classes defined by the cluster analysis. Ninety-seven non-castrated F1 Angus-Nellore bulls feedlot finished were used. After slaughter, hot carcass weight, carcass yield, cold carcass weight, carcass weight losses, pH, and backfat thickness (BFT) were measured. Subsequently, samples of the longissimus thoracis were collected to analyze shear force (SF), cooking loss (CL), meat color (L*, chroma, and hue), intramuscular fat, protein, collagen, moisture, and ashes. Principal component 1 (PC1) was correlated with colorimetric variables, while PC2 was correlated with carcass weights. Afterwards, three clusters (k = 3) were formed and projected in the gradient defined by PC1 and PC2 and allowed distinguishing groups with divergent values for collagen, protein, moisture, CL, SF, and BFT. Animals from high chroma group presented meat with more attractive colors and tenderness (SF = 1.97 to 4.84 kg). Subsequently, the PLS regression on the three chroma groups revealed a good fitness and the coefficients are used to predict the chroma variable from the explanatory variables, which may have practical importance in attempts to predict meat color from carcass and meat quality traits. Thus, PCA, K-means, and PLS regression confirmed the relationship between meat color and tenderness.

Background: This study evaluated the acceptability (by sensorial and visual analyses) of meat from 40 Nellore heifers (finished in feedlots for 73 days) fed with different diets supplemented with essential oils (EOs) and an active principle blend. The five diets tested were: CON - a diet without essential oil and active principle blend (eugenol, thymol, and vanillin); ROS - a diet supplemented with rosemary EO; BLE - supplemented with a blend; BCL - a diet with clove EO+ blend; and BRC - a diet with rosemary, clove EOs + blend. The acceptability of diet and aging time was evaluated by consumers., Results: Diet affected consumer acceptability and visual analysis (meat color). The diets with EO and the blend showed better sensory acceptance by the consumers; meat aged for 7 days received higher scores than meat aged for 1 day. Meat from heifers that received both EOs + blend (BCL, BRC) obtained the highest scores in the visual evaluation., Conclusion: The use of natural compounds in ruminant diets improves the sensory characteristics of meat without damaging visual acceptability and may be an alternative to the conventional additive market. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

This research compared the distribution and mobility of water in the longissimus thoracis muscle of 51 Apulo-Calabrese and 52 crossbred pigs differing in growth performances. The Apulo-Calabrese and crossbreed pigs were fed the same diet and slaughtered at 135 and 155 kg live weight, respectively. Besides meat quality measurement, water status was assessed from transverse relaxation time (T 2 ) weighted signals registered by Time Domain Nuclear Magnetic Resonance (TD-NMR). A mixed model indicated that Apulo-Calabrese pigs had higher a* (P-value < 0.0001), chroma (P-value < 0.0001) and total intensity (P-value = 0.011) values. A Principal Component Analysis showed that the samples from Apulo-Calabrese had higher scores along Principal Component (PC) 2 (P-value = 4.07 × 10 -5 ) and lower scores along PC3 (P-value = 1.50 × 10 -7 ). However PC2 and PC3 explained a low fraction of the total variance, suggesting that few differences characterize meat quality traits of the two genetic types., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This study was performed to determine the slaughter and carcass traits, meat color, pH, nutrient composition, fatty acids, amino acids, and cholesterol content of local Turkish goose varieties. In the present study, a total of 80 geese from white, black, gray, and multicolored varieties were reared in an extensive production system at 28 wk of age. Quality analysis was performed on breast and thigh meat, as well as on the skin and abdominal fat of studied geese. Slaughter and carcass weights were significantly higher in the white variety (P < 0.01). Measured abdominal fat was lower in black and gray geese. Furthermore, the color and pH values were significantly different on breast, thigh, and skin among varieties. Additionally, measured breast meat b*, thigh meat L*, and b* values were higher in male geese. Breast meat protein levels were lower in black and gray geese, and also lower in the thigh meat of gray geese. Total breast meat amino acids were lower in white geese, and the amino acid content of thigh meat was lower in multicolored varieties. Moreover, differences in fatty acid composition were found among the studied varieties. However, cholesterol levels did not differ for either sex or variety., (© 2019 Poultry Science Association Inc.)

The objective of this study was to evaluate the effects of 2 Mexican oregano essential oils (MOO), from Poliomintha longiflora Gray (PLG) and Lippia berlandieri Schauer (LBS), in drinking water (DWt) on the performance, slaughter variables, and meat quality of broilers over a 40 D period of growth. A total of 180 non-sexed Ross-308 broilers (1-day-old) were randomly assigned to 3 treatments with 6 replications each (10 birds per replicate): CON = DWt control (without MOO); PLG = DWt + 400 mg/L of PLG; and LBS = DWt + 400 mg/L of LBS. The CON, PLG, and LBS broilers body weights were similar (P > 0.05) at all times. Feed intake (FI) was different by treatment (P < 0.05) at 7 and 28 D, and water intake (WI) was different (P < 0.05) at day 28. The CON treatment was highest (P < 0.05) at 28 D for FI and WI, whereas LBS was lowest (P < 0.05). Weight gain (WG) for CON, PLG, and LBS broilers was similar (P > 0.05), although WG for CON was slightly higher. In CON broilers, slaughter weight was highest (P < 0.05), but thigh yield was lowest (P < 0.05). The CON and PLG treatments were lower (P < 0.05) in thigh and leg cooking losses. The PLG treatment presented the highest values (P < 0.05) for breast-meat redness, saturation index, shear force, odor, taste, and overall sensory acceptability. The LBS was higher (P < 0.05) for breast-meat shear force, cohesiveness and resilience, but lower (P < 0.05) for sensory attributes. Mexican oregano essential oils at 400 mg/L can serve as natural alternative additives in DWt to improve broiler production and meat quality., (© The Author(s) 2019. Published by Oxford University Press on behalf of Poultry Science Association.)

Background: Deer-meat consumption is increasing in several countries based on claims that it is a healthy red meat. This study assessed the effect of slaughter age (low - 26 months and younger; medium - from 27 months to younger than 42 months; and high - 42 months and older) on carcass characteristics and meat physicochemical properties of 150 Iberian wild red deer., Results: Whole carcass yields of neck, backbone and flank increased (P < 0.001) with age, while yields of shoulder, tenderloin and leg decreased (P < 0.05) with age. The pH measured at 48 h post mortem at 9th rib level was not affected by age, while pH measured at 72 h post mortem at the longissimus thoracis et lumborum muscle decreased (P < 0.05) with age. Meat chemical composition was not affected by slaughter age, except for intramuscular fat (IMF), which increased (P < 0.05) with slaughter age. Finally, cooking loss and shear force were higher (P < 0.05) in meat from older deer., Conclusion: Most characteristics of meat from wild red deer depend on age at slaughter. The greater IMF of meat from older animals may render it more palatable. However, meat shear force also increased with age. Additional studies testing palatability seem to be necessary to evaluate the effects of slaughter age on the sensorial quality of meat from Iberian wild red deer. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

A quantitative analysis of protein phosphorylation in ovine LTL muscle with different color stability was performed in the present study using TMT labeling in combination with TiO 2 phosphopeptide enrichment. A total of 3412 phosphopeptides assigned to 1070 phosphoproteins were identified by mass spectrometry, of which 243 proteins were detected to be differentially phosphorylated between muscles of different color stability. Among these differentially phosphorylated proteins, 27 phosphoproteins were identified to be key color-related proteins by informatics analysis. Proteins involved in carbohydrate metabolism, especially glycolytic enzymes, were the largest cluster of protein determined to be color-related. In addition, the phosphorylation of myoglobin at Ser133 plays a negative role in the regulation of meat color stability. In summary, this study revealed that the phosphorylation of some glycolytic enzymes and myoglobin at specific serine residues may play critical roles in the regulation of meat color stability., (Copyright © 2017. Published by Elsevier Ltd.)

The aim of the current study was to assess the ability of a number of chemicals (acetic Acid (AA), citric acid (CA) lactic acid (LA), sodium decanoate (SD) and trisodium phosphate (TSP)) to reduce microbial populations (total viable count, Campylobacter jejuni, Escherichia coli, Salmonella typhimurium and Listeria monocytogenes) on raw beef using an immersion system. The following concentrations of each chemical were used: 3 & 5% for AA, CA, LA, SD and 10 &12% for TSP. Possible synergistic effects of using combinations of two chemicals sequentially (LA+CA and LA+AA) were also investigated. L*, a* and b* values were measured before and after treatments and ΔE* values were calculated in order to determine any changes in the color of meat due to the use of these chemicals. In general, all chemical treatments resulted in significantly (p<0.05) reduced bacterial counts when compared to untreated controls. The greatest reductions were obtained by using LA3%, SD5%, AA5%, LA5% and SD3% for TVC, C. jejuni, E. coli, S. typhimurium and L. monocytogenes, respectively. However, no significant difference in microbial load was observed between the different concentrations of each chemical used (p>0.05). The application of combinations of chemical immersion treatments (LA3%+AA3% and LA3%+CA3%) did not result in further significant reductions in microbial populations when compared to single chemical treatments (P<0.05). Assessment of color changes in meat following the application of chemical immersion treatments indicated that using AA or CA at either concentration and LA at 5% led to an increase in the ΔE* value of >3 immediately after treatment and after 24h storage. The remaining treatments did not result in significant changes to the color of raw beef., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The objective of this study was to identify metabolites that could be associated with oxidative stability of aged bovine muscles. Three muscles (longissimus lumbrum (LL), semimembranosus (SM), and psoas major (PM)) from seven beef carcasses at 1 day postmortem were divided into three sections and assigned to three aging periods (9, 16, and 23 days). Although an increase in discoloration was found in all muscles with aging, LL was the most color/lipid oxidative stable, followed by SM and PM (P < 0.05). Lower myoglobin and nonheme iron contents were observed in LL compared to those in SM and PM (P < 0.05). The HPLC-ESI-MS-based metabolomics analysis identified metabolites that were significantly responsive to aging and/or muscle type, such as acyl carnitines, free amino acids, nucleotides, nucleosides, and glucuronides. The results from the current study suggest that color and oxidative stability could be associated with aging but are also muscle-specific. Further studies determining the exact role of the identified metabolites in the color and oxidative stability of beef muscles are warranted.

This study investigated the relationships among a list of 23 protein biomarkers with CIE-L*a*b* meat color traits and ultimate pH on Longissimus thoracis (LT) and Rectus abdominis (RA) muscles of 48 protected designation of origin Maine-Anjou cows. The technological parameters were correlated with several biomarkers and were in some cases muscle-dependent. More biomarkers were related to pHu in LT than in RA muscle. Some consistencies were found, by the common correlation of pHu with MyHC-IIa and MyHC-IIx. The pHu of the LT muscle was also correlated with other cytoskeletal entities and proteins belonging to metabolism and cellular stress. In contrast to the relationships found between biomarkers and LT pHu, more proteins were related to the instrumental color coordinates in RA than in LT muscle. The regression equations were parameter- and muscle-dependent. Certain of the retained proteins explained more than one color coordinate. Hsp70-Grp75 was positive in the models of L*, a*, b*, and C* of LT and of b* in the RA muscle. Further heat shock proteins were strongly related with the meat color coordinates in both muscles. The involvement of metabolic enzymes and myofibrillar proteins in the meat color development was also verified in this experiment. This study confirmed once again the importance of numerous biological pathways in beef color.

The influence of protein phosphorylation on meat color stability was investigated in this study. Phosphatase and protein kinase inhibitors were added to minced ovine Longissimus thoracis et lumborum (LTL) muscle to manipulate the global phosphorylation of sarcoplasmic proteins. The data obtained show that the rate and extent of pH decline, along with lactate accumulation in postmortem muscle, were related to protein phosphorylation. Analysis of meat color and the relative content of myoglobin redox forms revealed that meat color stability was inversely related to the phosphorylation of sarcoplasmic proteins. Thus, this study suggests that protein phosphorylation may be involved in meat color development by regulating glycolysis and the redox stability of myoglobin., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The aim of the present research was to evaluate the influence of organic and non-organic production systems on color stability and lipid oxidation of broiler meat Pectoralis major (PM) stored under refrigeration (4°C) for 9 days. PM samples from organic (ORG) and non-organic (NORG) production systems were compared based on physicochemical analyses (instrumental color, myoglobin concentration, metmyoglobin reducing activity (MRA), pH, and lipid oxidation) performed in 4 different trials (n = 4). In general, NORG broilers demonstrated higher (P < 0.05) b* and lipid oxidation values than ORG, whereas ORG samples exhibited increased (P < 0.05) MRA, ratio of reflectance at 630 per 580 nanometers (R 630/580), and a* values. The lower color stability observed in NORG samples can be partly due to lipid oxidation. Therefore, the production system can affect color and lipid stability of broiler breast meat during storage., (© 2016 Poultry Science Association Inc.)

Demand for meat from free-range broiler chickens is increasing in several countries. Consumers are motivated by better animal welfare and other product attributes such as quality and taste. However, scientific literature is not unanimous about whether free-range access influences quality, composition, and taste of the meat. Because chickens normally do not use free-range areas optimally, it is possible that provision of more suitable shelter will lead to more pronounced differences between chickens raised indoors and outdoors. In this study, an experiment with 2 production rounds of 600 slow-growing broilers each was performed. In each round, 200 chickens were raised indoors (IN), 200 had free-range access to grassland with artificial shelter (AS), and 200 had free-range access to short-rotation coppice with willow (SRC). Free-range use, feed intake, and growth were monitored, and after slaughter (d72) meat quality, composition, and taste were assessed. Free-range use was higher in SRC than in AS chickens (42.8 vs. 35.1%, P < 0.001). IN chickens were heavier at d70 than AS and SRC chickens (2.79 vs. 2.66 and 2.68 kg, P = 0.005). However, feed intake and conversion did not differ. Breast meat of chickens with free-range access was darker (P = 0.021) and yellower (P = 0.001) than that of IN chickens. Ultimate pH was lower (5.73 vs. 5.79; P = 0.006) and drip loss higher (1.29 vs. 1.09%; P = 0.05) in IN versus AS chickens. The percentage of polyunsaturated fatty acids was higher in AS than in IN meat (35.84 vs. 34.59%; P = 0.021). The taste panel judged breast meat of SRC chickens to be more tender (P = 0.003) and less fibrous (P = 0.013) compared to that of AS and IN chickens, and juicier compared to the IN chickens (P = 0.017). Overall, free-range access negatively affected slaughter weight, but positively affected meat quality, taste, and composition. Only a few differences between AS and SRC were found, possibly due to limited differences in free-range use., (© 2016 Poultry Science Association Inc.)

The objective of this research was to determine the association of SNPs in the candidate genes Calpain (CAPN1), Calpastatin (CAST) and Myoglobin (MB) with colorimetric parameters (L *, a *, b *, C *, hue) in a F1 population (n = 164) obtained from crossing Bos taurus × Bos indicus and Bos indicus × Bos indicus. SNPs were analyzed using PCR-RFLP and SSCP. Colorimetric measurements were performed in the muscles Longissimus thoracis et lumborum (LTL) and Semitendinosus (ST) at 7, 14 and 21 days postmortem applying the methodology CIE L* a* b*. The CAST gene showed a significant effect on the b* and hue* parameters in both muscles. MB gene showed significant association with all colorimetric parameters in both LTL and ST muscles, except with b* parameter. The CAPN1 gene did not show any significant association. These results suggest an important role of genetics in meat color variation for cattle raised under the tropic conditions.

The aim of this study was to evaluate the dietary effect of mango extracts on lipid stability and the coloring of broiler chicken breast meat during frozen storage. The treatments consisted of broiler chicken diet without antioxidants (control) and diets containing antioxidants: 200 ppm of butylated hydroxytoluene (BHT), 200 ppm of mango peel extract (MPE), 400 ppm of MPE, 200 ppm of mango seed extract (MSE), and 400 ppm of MSE. The broiler breasts were stored for 90 days and analysis of lipid oxidation and color was performed every 30 days. The thiobarbituric acid reactive substances values increased during storage and at 90 days, but the 400 ppm MSE treatment yielded lower values, indicating greater antioxidant activity. During storage, the lightness values decreased and the redness increased. Additions of 200 ppm BHT and 400 ppm MPE increased yellowness at 60 days of storage. Thus, mango peel and seed extracts added to broiler chicken diets reduce lipid oxidation and maintain color in breast meat during frozen storage, with mango seed extract at 400 ppm being the most effective., (© 2015 Poultry Science Association Inc.)

Many studies on color biochemistry and protein biomarkers were undertaken in post-mortem beef muscles after ≥24 hours. The present study was conducted on Longissimus thoracis muscles of 21 Blond d'Aquitaine young bulls to evaluate the relationships between protein biomarkers present during the early post-mortem and known to be related to tenderness and pH decline and color development. pH values at 45 min, 3 h, and 30 h post-mortem were correlated with three, seven, and six biomarkers, respectively. L*a*b* color coordinates 24 h post-mortem were correlated with nine, five, and eight protein biomarkers, respectively. Regression models included Hsp proteins and explained between 47 and 59% of the variability between individuals in pH and between 47 and 65% of the variability in L*a*b* color coordinates. Proteins correlated with pH and/or color coordinates were involved in apoptosis or had antioxidative or chaperone activities. The main results include the negative correlations between pH45 min, pH3 h, and pHu and Prdx6, which may be explained by the antioxidative and phospholipase activities of this biomarker. Similarly, inducible Hsp70-1A/B and μ-calpain were correlated with L*a*b* coordinates, due to the protective action of Hsp70-1A/B on the proteolytic activities of μ-calpain on structural proteins. Correlations existed further between MDH1, ENO3, and LDH-B and pH decline and color stability probably due to the involvement of these enzymes in the glycolytic pathway and, thus, the energy status of the cell. The present results show that research using protein indicators may increase the understanding of early post-mortem biological mechanisms involved in pH and beef color development.

Quality determination of frozen food is a time-consuming and laborious work as it normally takes a long time to thaw the frozen samples before measurements can be carried out. In this research, a rapid and non-destructive determination technique for frozen pork quality was tested with a hyperspectral imaging (HSI) system. In this study, 120 pieces of pork meat were frozen by four kinds of methods with various freezing temperatures from -20 to -120°C. The hyperspectral images of the samples were acquired at the frozen state. Quality indicators including drip loss, pH value, color, cooking loss and Warner-Bratzler shear force (WBSF) of the samples were measured after thawing. The spectral characteristics of the frozen meat samples were studied and it was revealed that the reflectance at 1100nm had a close relationship with the freezing temperature (R=-0.832, p<0.01). Partial least squares regression (PLSR) was applied to establish the spectral models, and the models were then optimized. Results showed that the improved region of interest (ROI) method could be used to extract effective spectral information to withstand the interference of freezing, and choosing appropriate spectral bands and spectral pretreatment techniques were crucial to develop robust mathematical model. The performances of the models established were diverse based on different quality indicators. The coefficients of determination for prediction (Rp(2)) for L*, cooking loss, b*, drip loss and a* were 0.907, 0.845, 0.814, 0.762, and 0.716, respectively. However there were low correlations (Rp(2)) for pH and WBSF measurements. The current study indicated that HSI had the potential for non-destructive determination of frozen meat quality without thawing., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Metabolic intermediates of glycolysis and the tricarboxylic cycle can stabilize beef color through improved metmyoglobin-reducing activity. Inorganic redox reactive iron (RRI) forms are pro-oxidants that have been shown to oxidize myoglobin in model systems. This study investigated how RRI, in the presence of added metabolic intermediates lactate and succinate, influences myoglobin (Mb) redox stability and color of beef strip loin homogenates and how it affects mitochondrial respiration. Homogenates with added RRI and either lactate or succinate had lower (p < 0.05) a* values than control homogenates. Oxymyoglobin increased (p < 0.05) as ferrous ion increased in the lactate and succinate treatments. The presence of ferrous or ferric ions reduced the mitochondrial oxidation rates of lactate and succinate (p < 0.05). The benefit of color stability offered by the metabolic intermediates and mitochondria-assisted metmyoglobin reduction was reduced by inorganic iron ions.

Reducing spoilage and indicator bacteria is important for microbiological stability in meat and meat products. The objective was to evaluate the effect of different doses of gamma radiation on the shelf-life of lamb meat, vacuum-packed and stored under refrigeration, by assessing the microbiological safety, physicochemical stability and sensory quality. Lamb loin cuts (Longissimus dorsi) were irradiated with 1.5kGy and 3.0kGy. The samples, including control, were stored at 1±1°C during 56days. Samples were analyzed on zero, 14, 28, 42 and 56days by their microbiological and physicochemical characteristics. Sensory quality was carried out on day zero. The results showed a reduction (p<0.05) in the microbial load of the irradiated samples. The acceptance of lamb loins was not affected (p>0.05) by the radiation doses. Thus gamma irradiation at 3.0kGy was effective in reducing the content of microorganisms, without harming the physicochemical characteristics evaluated., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The glucocorticoid receptor (GR) is a ubiquitously acting transcription factor that is responsible for mediating the physiological response to stress and adaptation to environmental conditions. Genetic variation of a GR gene (NR3C1) may therefore contribute to multiple phenotypic alterations and influence relevant traits of animal production. Here, we examined effects of two non-synonymous mutations of the porcine NR3C1, leading to amino acid exchanges p.Glu13Asp (c.39A>C) and p.Val19Leu (c.55G>C) in the N-terminal domain of the GR, on meat quality and carcass composition. In addition, we explored their influence on transcriptional activity of GR in vitro. A commercial crossbreed Pietrain × (German Large White × German Landrace) herd (n = 545) in which genotypes and relevant traits had been collected was used to perform the association analysis. The single nucleotide polymorphism (SNP) c.55G>C was significantly associated with conductivity and meat color scores. These effects were highly consistent considering the physiological relationship between these traits. Association analysis of SNP c.39A>C also revealed significant effects on closely connected meat quality traits. In addition, SNP c.55G>C showed association with carcass traits, mainly those related to muscle deposition. The molecular mechanism of action of both amino acid substitutions remains obscure because neither showed significant influence on transcriptional activity of GR. Our study emphasizes NR3C1 as an important candidate gene for muscle-related traits in pigs, but further work is necessary to clarify the molecular background of the identified associations., (© 2013 Stichting International Foundation for Animal Genetics.)

The objective was to examine the effects of immunocastration on carcass traits and meat quality of Nellore and Nellore×Aberdeen Angus male animals finished in feedlot. Surgically castrated, immunocastrated, and intact animals were finished in feedlot for 90 days. The animals were harvested, and carcass traits were evaluated. Carcasses were chilled, and one 2.5-cm steak was fabricated from Longissimus thoracis muscle. The steaks were individually vacuum packaged and frozen at -18 °C. Frozen steaks were thawed, and pH, instrumental color, cooking loss, and shear force were determined. Immunocastrated animals demonstrated greater (P<0.05) hot dressing percentage and cold dressing percentage than their surgically castrated counterparts. Furthermore, steaks from immunocastrated and surgically castrated animals exhibited greater redness (P<0.05) and lower darkness (P<0.05) than steaks from intact animals, indicating possible advantage in retailing. The results suggested that immunocastration may be utilized to improve carcass traits and beef color in feedlot-finished Nellore and Nellore×Aberdeen Angus males., (© 2013.)

The objective was to evaluate the fatty acid profile and qualitative characteristics of meat from young bulls fed crude glycerin. Forty-four animals with an initial live weight of 368 ± 4 kg were used in a completely randomized design, with four treatments: no glycerin or addition of 6, 12 or 18% glycerin. The animals were slaughtered with 519.5 ± 14.9 kg of live weight. The meat characteristics assessed were chemical composition, shear force, fatty acid concentration, color and lipid oxidation. The addition of glycerin increased the content of ether extract (P<0.05) in the muscle. A linear increase was observed (P<0.05) in the oleic acid contents (C18:1 cis 9). The saturated fatty acid (SFA) contents linearly decreased in the muscle as a function of glycerin addition. The lightness (L*) and yellowness (b*) indices increased with the use of crude glycerin (P<0.05). The crude glycerin increased the intramuscular fat and oleic acid content in the longissimus dorsi muscle., (© 2013.)

Our objective was to evaluate the influence of lactate on in vitro redox stability and thermostability of beef, horse, pork, and sheep myoglobins. Lactate (200 mM) had no effect (P>0.05) on redox stability at physiological (pH7.4, 37°C) and meat (pH 5.6, 4°C) conditions. However, lactate increased (P<0.05) metmyoglobin formation at a condition simulating stressed live skeletal muscle (pH 6.5, 37°C). The redox stability of myoglobins at stressed live skeletal muscle and meat conditions was species-specific (P<0.05). Myoglobin thermostability at 71°C was lower (P<0.05) in the presence of lactate compared with controls and was influenced (P<0.05) by species. The results of the present study indicate that the effects of lactate on myoglobin are temperature and pH dependent. The observed lack of influence of lactate on myoglobin redox stability at meat condition suggests that the color stability of lactate-enhanced fresh meat is not due to direct interactions between the ingredient and the heme protein., (© 2013.)

Distiller grains (DG), which are the by-product from the bioethanol industry, represent an interesting alternative as animal feedstock. To our knowledge, little information is available on the inclusion of DG on the quality of meat from pasture-fed heifers. Thus, the aim of the present study was to evaluate the effect of DG inclusion in pasture-based systems on the main meat quality attributes of Charolais x Aberdeen Angus heifers. For this purpose, meat from heifers fed with a pasture-based diet without supplementation (P) or with 0.75% of live weight DG supplementation (PDG; DG plus dry-rolled corn, 50:50) or with 0.75% of live weight dry-rolled corn supplementation (PRC) was evaluated. Physical (pH, WHC, color, texture), sensory and nutritional (fat content, fatty acid, and amino acid profile) attributes were evaluated in beef samples. No effect of supplementation was observed on meat pH or color (p > 0.05). Meat from PDG heifers showed higher values of WBSF than meat from P heifers (p = 0.039). However, the overall tenderness evaluated by trained panelists showed no differences due to supplementation (p > 0.05). Our results indicate that the inclusion of DG as a partial corn-replacement supplementation for heifers under grazing represents a strategic tool not only related to meat quality, but also as an alternative to reduce food–feed competition. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to investigate the effect of pH change of cooked cured pork M. longissimus thoracis et lumborum on iridescence intensity and extent (= percentage of iridescent area) since interaction with light may be related to pH-induced alterations in microstructure. Muscles were injected with brines of different pH values, cooked, sliced perpendicular to muscle fiber direction, and visually evaluated by a panel of 20 experienced panelists. Results: Muscles with lowest pH (5.38) showed the lowest iridescence score of 4.63 (p < 0.05). Iridescence was greatest in muscles with normal (5.78) and high pH (6.03, respectively 6.59), but did not differ significantly (p > 0.05). Iridescence was positively correlated (p < 0.01) with pH and water content, and negatively correlated (p < 0.01) with cooking loss. Hence, hydration state and light scattering from microstructure may be important factors that determine the degree of iridescence in cooked meat products. [ABSTRACT FROM AUTHOR]

Background: pH, subcutaneous fat thickness (SFT), and color are fundamental variables to define the organoleptic characteristics of meat. However, multivariate relationships of those traits remain unexplored in bovine meat. Objective: To investigate the multivariate relationships among pH, subcutaneous fat thickness, and color parameters in bovine meat using canonical correlation analysis. Methods: A dataset containing 173 individual records of pH, SFT, and color parameters (a*: intensity of red color, b*: intensity of yellow color, and L*: lightness) from five Brazilian beef cut types (Breed: Nellore; cuts: acém, contrafilé, fraldinha, patinho and picanha) was constructed. Multivariate relationships between color variables (a*, b*, and L*) and chemical variables (pH and SFT) were explored using the CANCORR procedure of SAS. Results: Two canonical correlations between U (a*, b*, and L*; color variables) and V (pH and SFT; chemical variables) variates were significant (p

Background: pH, subcutaneous fat thickness (SFT), and color are fundamental variables to define the organoleptic characteristics of meat. However, multivariate relationships of those traits remain unexplored in bovine meat. Objective: To investigate the multivariate relationships among pH, subcutaneous fat thickness, and color parameters in bovine meat using canonical correlation analysis. Methods: A dataset containing 173 individual records of pH, SFT, and color parameters (a*: intensity of red color, b*: intensity of yellow color, and L*: lightness) from five Brazilian beef cut types (Breed: Nellore; cuts: acém, contrafilé, fraldinha, patinho and picanha) was constructed. Multivariate relationships between color variables (a*, b*, and L*) and chemical variables (pH and SFT) were explored using the CANCORR procedure of SAS. Results: Two canonical correlations between U (a*, b*, and L*; color variables) and V (pH and SFT; chemical variables) variates were significant (p<0.01). First and second canonical correlations were 0.463 and 0.282, respectively. Canonical weights for variates were for U1: a* = 0.707, b* = 0.406, and L* = -0.039; U2: a* = 0.364, b* = -0.898, and L* = 1.234; V1: pH = -0.376 and SFT = 0.935; V2: pH = 0.927 and STF = 0.356. Conclusion: Subcutaneous fat thickness significantly affected intensity of red and yellow colors, whereas pH significantly affected lightness. The results of this study may be useful for a better understanding of the role of muscle metabolism and its implications on the organoleptic characteristics of bovine meat. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the effect of the partial replacement of wheat with bakery waste in compound feed on slaughter characteristics, quality and composition of meat in a heavy population of domestic quail. A control group (n = 90), I experimental (n = 90), and II experimental groups (n = 90) quails from meat-producing population WG were formed, respectively fed with basic feed, 5% and 10% replacement of wheat in the feed with extruded baking waste. A slaughter analysis, qualitative and chemical analysis of the meat of male and female representatives of the three experimental groups was performed. The replacement of 5% and 10% of the wheat in the compound feed with extruded bakery waste does not have a negative effect on the slaughter characteristics of the studied quail population. No relationship was observed between the studied physicochemical characteristics of quail meat and the addition of 5% and 10% extruded bakery waste. A similar effect is not observed with regard to the color characteristics of the meat. An exception is the Chroma (C*), where there is a tendency to higher values on the basis of experimental groups. With an increasing proportion of wheat substitution with extruded baking waste, the fat content in breast meat increases (P<0.001). The study leads to the conclusion that the replacement of up to 10% of wheat in the combined feed for quails with extruded bakery waste does not adversely affect the slaughter characteristics, quality, and nutritional value of quail meat. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND This study evaluated the acceptability (by sensorial and visual analyses) of meat from 40 Nellore heifers (finished in feedlots for 73 days) fed with different diets supplemented with essential oils (EOs) and an active principle blend. The five diets tested were: CON – a diet without essential oil and active principle blend (eugenol, thymol, and vanillin); ROS – a diet supplemented with rosemary EO; BLE – supplemented with a blend; BCL – a diet with clove EO+ blend; and BRC – a diet with rosemary, clove EOs + blend. The acceptability of diet and aging time was evaluated by consumers. RESULTS: Diet affected consumer acceptability and visual analysis (meat color). The diets with EO and the blend showed better sensory acceptance by the consumers; meat aged for 7 days received higher scores than meat aged for 1 day. Meat from heifers that received both EOs + blend (BCL, BRC) obtained the highest scores in the visual evaluation. CONCLUSION: The use of natural compounds in ruminant diets improves the sensory characteristics of meat without damaging visual acceptability and may be an alternative to the conventional additive market. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chilling procedures have been widely used in livestock abattoirs since the development of refrigeration systems. The major criteria when applying chilling regimes is not only complying with regulations, but economic concerns, and also meat safety and quality assurance requirements. Given recent developments, an updated review is required to guide the industry to choose the best chilling method and to inspire the development of new approaches to chilling. Thus in this paper, the quality and microbial safety of beef, lamb, pork, venison, and bison resulting from different chilling treatments has been reviewed, as well as the underlying mechanism(s) for the different impacts on meat quality traits as a result of different chilling regimes. The effect of fast chilling on the tenderness of beef and lamb is a focus, as some new findings, have recently been reported, while multistep chilling is highlighted as it incorporates the advantages of fast chilling to reduce carcass weight loss, resulting in similar quality improvements as found with slow chilling. It is, suggested, that if spray chilling can be combined with the second phase of multi‐step chilling, it will benefit the meat industry in terms of both meat quality and safety. Future studies should focus on combinations of chilling methods with new technologies, such as medium voltage electrical stimulation, muscle stretching, or ultrasound and so on, to move meat quality and safety to a new level. [ABSTRACT FROM AUTHOR]

Summary: In recent years, Luchuan pigs in southern China have been used to produce high‐quality meat by crossbreeding them with Duroc boars; however, PSE (pale, soft and exudative) meat was frequently reported in the crossbred pigs, and the underlying reason remains unknown. We excluded the possibility of the well‐known causative mutations in RYR1 and PRKAG3 but identified the existence of an unfavorable allele of a splicing mutation (g.8283C>A) in PHKG1 in two Duroc boars and three Duroc × Luchuan crossbred pigs with PSE meat. An association analysis with 425 Duroc × Luchuan crossbred pigs revealed that the polymorphism of the splicing site of PHKG1 has significant association with the ultimate meat pH value (P = 0.035) and color score (P = 0.004). In addition, a strong cis‐eQTL (expression QTL) signal for the expression of PHKG1 was identified in 189 Duroc × Luchuan crossbred pigs, and the splicing mutation was proven to be significantly associated with the expression of PHKG1 (P = 4.01e‐11). Furthermore, RNA‐sequencing data analysis confirmed that 131 CC homozygotes had only one transcript (T1), with FPKM (fragments per kilobase of transcript per million) of 35.40 ± 7.28, and 58 CA heterozygotes had two types of transcripts (T1 and T2), with FPKM of 19.63 ± 5.11 and 9.20 ± 2.39 respectively. Based on the association and eQTL analysis results, we concluded that PSE meat in Duroc × Luchuan crossbred pigs is caused by the splicing mutation in PHKG1. Our findings further support the effect of the causative mutation in PHKG1 on meat quality. The GEO accession number for the data is GSE124315. [ABSTRACT FROM AUTHOR]

Meat color is attributed to myoglobin concentration and redox state. Myoglobin is a water-soluble hemoprotein with iron in its prosthetic group, which defines myoglobin's redox state via its valence state and ligand linked to the free coordination site. In fresh meat, myoglobin can be in one of three states in dynamic equilibrium: deoxymyoglobin, oxymyoglobin, and metmyoglobin. Myoglobin can chemically interact with numerous components in meat products, affecting its redox state. These structural alterations in myoglobin caused by processing conditions will affect its thermal stability and consequently meat product color. Presently, cured meat products are made with sodium nitrite, a curing agent that reacts with myoglobin in meat, forming nitrosomyoglobin, a stable compound that gives the final meat product a distinctive pink color. This work proposes a mathematical model for understanding myoglobin structural changes during the production of a cured meat product. Because of the phenomenological structure of the established model, valuable knowledge is obtained, allowing new possibilities to be explored in the color of meat products while considering the chemical state of myoglobin. The proposed phenomenological model is validated with an error of roughly 10%. • Mathematical model for understanding myoglobin structural changes of meat products. • Relationships between myoglobin structural changes and color in the meat product. • Reducing NaNO_2 employed in color generation and residual nitrite in meat products. • The model allows new possibilities to be explored in the color of meat products. [ABSTRACT FROM AUTHOR]

Iron is a trace element involved in many cardinal metabolic processes of almost all living organisms. It is well known that iron participates in oxygen transport as well as it is a cofactor in many fundamental enzymatic and nonenzymatic processes. Accordingly, disturbances of iron homeostasis can cause serious clinical consequences. In humans, dietary iron can enter the body in two main forms: heme and nonheme. The former is a component of many hemoproteins (including myoglobin, hemoglobin, cytochromes b and c) and is easily absorbed in the duodenal enterocytes. Red meat is an excellent source of heme iron, while the less bioavailable nonheme form is found in large amounts in milk products and vegetables. For this reason, consumers of meat have a better iron status than vegetarians and vegans. Heme iron found in muscle protein should be supplied to humans to prevent iron deficiency, which can lead to anemia. It is easily absorbed and its main source is red meat. In addition, heme iron, which is mainly found in myoglobin in meat, contributes to the desirable bright red color and to the most undesirable brown color of meat. Both heme and nonheme iron are catalysts of lipid oxidation in meat. This process lowers the nutritive value through oxidation of polyunsaturated fatty acids, which produces an undesirable flavor and aroma. The aim of this paper was to discuss the role of heme iron in the human diet. [ABSTRACT FROM AUTHOR]

The aim of this research was to apply color parameters determined with the computer vision systems (CVS) in detection of PSE (pale, soft, exudative) porcine semimembranosus muscles. Based on pH measurements taken 24 h post mortem , meat were classified into two quality groups: RFN (red, firm, normal, non-exudative) and PSE. The color parameters were evaluated using the CVS and in CIE L*a*b* scale. In order to confirm or deny incidence of PSE the selected characteristics of technological quality of meat were also determined. Using CVS and CIE L*a*b* the considerable differences in color lightness for PSE were observed when compared to normal meat. The obtained correlation and determination coefficients between color parameters characterized by lightness reached low values 0.44 and 19.4%, respectively. Considerable dispersion of results and overlapping ranges of color parameters obtained for selected meat quality groups have proven the possibility of CVS application for m. semimembranosus classification to be limited. [ABSTRACT FROM AUTHOR]

Meat color is an important quality variable that affects consumers' willingness to purchase and re-purchase meat. The importance of meat color has called for extensive research into the mechanism of colour stability. In many cases only color measurements that relate to how a sample is seen by the human eye, is needed. However, in other situations it is necessary to know the actual states of myoglobin on meat surfaces. Calculation of myoglobin states is not straightforward, neither are the principles used for preparing pure myoglobin states; a prerequisite for making the predictive models. In this presentation, we will discuss the methods used for preparing pure myoglobin states, plus the most common method used to calculate myoglobin states. In addition, we will introduce a new method of calculating myoglobin states. This new method uses the complete reflection spectrum instead of just selected wavelengths as used in the most common method for calculation ofmyoglobin states. The new method gives improved accuracy. [ABSTRACT FROM AUTHOR]

The application of high pressure offers some interesting opportunities in the processing of muscle-based food products. It is well known that high-pressure processing can prolong the shelf life of meat products in addition to chilling but the pressure-labile nature of protein systems limits the commercial range of applications. High pressure can affect the texture and gel-forming properties of myofibrillar proteins and, hence, has been suggested as a physical and additive-free alternative to tenderize and soften or restructure meat and fish products. However, the rate and magnitude at which pressure and temperature effects take place in muscles are variable and depend on a number of circumstances and conditions that are still not precisely known. This review provides an overview of the current knowledge of the effects of high pressure on muscle tissue over a range of temperatures as it relates to meat texture, microstructure, color, enzymes, lipid oxidation, and pressure-induced gelation of myofibrillar proteins. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central European Agriculture is the property of Journal of Central European Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Color changes in irradiated fresh meat occur because of the susceptibility of the myoglobin molecule, especially the iron, to alterations in the chemical environment and to energy input. The potential for iron electrons to exist in various states makes the environment adjacent to the iron atom particularly vulnerable to the presence of electron-donating compounds and high energy inputs (irradiation). Initial condition of the myoglobin (Fe++&z.dbnd6;O2, Fe+++), modification of oxidation–reduction potential of the tissue, and generation of ligand-forming compounds (CO) from endogenous organic compounds and water are enhanced or suppressed depending on the gas atmosphere, temperature, pH and myoglobin concentration of the system. Generation of stable red pigments or brown pigments which become red over time appears to be due to binding of irradiation-generated reactive oxygen species (⋅O2−) or gasses (CO) which become ligands bound by iron under altered reducing conditions. Rapid generation of large amounts of metmyoglobin when irradiation is conducted in an oxygen-containing environment appears to be an acceleration of the normal process by which myoglobin undergoes oxidation. Generation of green pigments appears to be due to breakdown of the porphyrin integrity and/or formation of sulfmyoglobin. Maintenance of ideal meat color during irradiation can be enhanced by various combinations of pre-slaughter feeding of antioxidants to livestock, optimizing the condition of the meat prior to irradiation, addition of antioxidants, gas atmosphere (MAP), packaging, and temperature control. [Copyright &y& Elsevier]