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Metabolite profiles of chicken breast extracts and water mobility in breasts were studied using proton nuclear magnetic resonance (1H-NMR) spectroscopy and time-domain NMR (TD-NMR) relaxometry, respectively, using normal breast (NB), and wooden breast (WB) and white striping (WS) myopathies in broilers. One thousand eight hundred sixty broilers were raised to commercial standards, receiving the same diets that were formulated as per the different growth stages. At 49 D of age, 200 animals were slaughtered following routine commercial procedures, and at 4 h postmortem, the whole breast (pectoralis major muscle) was removed and visually inspected by an experienced meat inspector who selected NB (without myopathies) and samples with the presence of WS and WB myopathies. Fifteen breasts (5 each of NB, WS, and WB) were analyzed through TD-NMR relaxometry, and samples of approximately 20 g were taken from each breast and frozen at −80°C for metabolite profiling through 1H-NMR spectroscopy. Multivariate statistical analysis was used to evaluate the effect on water relaxometry and metabolite profile in accordance with the presence and type of myopathy in the breast. 1H-NMR data showed that the metabolite profiles in WS and WB breasts were different from each other and from NB. This pilot study shows that myopathies appear to be related to hypoxia, connective tissue deposition, lower mitochondrial function, and greater oxidative stress compared with NB. The longitudinal and transverse relaxation time of the breasts determined by TD-NMR relaxometry was shorter for NB than that for WS and WB, indicating greater water mobility in breasts affected by myopathies. 1H-NMR spectroscopy can be used to differentiate the metabolism of WS, WB, and NB, and TD-NMR has the potential to be a fast, simple, and noninvasive method to distinguish NB from WB and WS. As a practical application, the metabolomic profile as per the occurrence of breast myopathies may be used for a better understanding of these issues, which opens a gap to mitigate the incidence and severity of WS and WB. In addition, the present study brings an opportunity for the development of a new and objective tool to classify the incidence of breast myopathies through TD-NMR relaxometry.

The aim of this study was to explore the use of TD-NMR relaxometry and 1H NMR spectroscopy-based for detecting differences in meat quality attributes. There was limited association between various TD-NMR signals and any physicochemical parameters of fresh and aged meat differing in tenderness ratings. Samples were then divided into three groups based on statistical changes in metabolite concentration. Group A samples possessed near linear increases in metabolite concentration over aging time; whereas samples assigned to Groups B and C were characterized by increases in metabolites that peaked between 7 and 14 days, and up to 14 days aging, respectively. 1H NMR spectroscopy discriminated meat quality using changes in metabolites reflective of glycolysis, the citric acid cycle, protein degradation, amino acid generation and purine metabolisms. These data suggest segregation of meat quality is possible using both NMR technologies but additional work is necessary to understand fully their utility in a commercial industry setting.

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To clarify the relationship between beef genetic selection for growth and precocity with muscle metabolism and metabolites, we performed metabolomic analysis using Longissimus lumborum (LL) muscle from Nellore cattle with divergent selection for these traits (high growth, HG, low growth, LG, high precocity, HP, low precocity, LP). Genetic potential for growth affected muscle protein and energetic metabolism. HG animals had a high concentration of arginine, carnosine, and leucine compared to LG animals. HP animals presented a high concentration of glutamine, betaine, creatinine, isoleucine, carnitine, acetyl carnitine, and lower levels of glucose compared to LP animals, affecting protein and fatty acid metabolism. Intensity of selection (high or low) was correlated with changes in protein metabolism, and the type of selection (growth or precocity) affected fat metabolism. In conclusion, both HG and HP appear to be correlated with a high concentration of protein metabolites and changes in protein metabolic pathways, while selection for precocity is more correlated with changes in fat metabolism compared to animals selected for growth.

The aim of this preliminary study was to evaluate meat quality properties, muscle metabolite profile and metabolic pathways associated with the occurrence of dark cutting meat in Angus x Nellore crossbreed cattle. After 14 days' ageing, dark cutting meat presented a higher pH, lower cooking loss and colour parameters, and greater tenderness compared with normal meat. Dark cutting meat had a higher ATP level and lower concentrations of glucose-6-phosphate, lactate, glucose, serine, threonine, creatine phosphate, inosine, leucine, methionine, succinate and glucose-1-phosphate compared to normal meat. In dark cutting samples, the ultimate pH was positively correlated with carnitine and negatively correlated with glucose-6-phosphate. However, in normal meat, the ultimate pH presented a positive correlation with arginine, leucine, methionine, proline, threonine, tyrosine and valine. Pathway analysis showed that differentiation of the groups was linked to energetic pathways such as starch and sucrose metabolism, the pentose phosphate pathway, amino sugar, nucleotide sugar metabolism, and glycolysis or gluconeogenesis. In conclusion, the occurrence of dark cutting meat has a notable impact on meat quality attributes and concentrations of post-mortem glycolytic metabolites, appears to be correlated with mitochondrial activity and affects energetic metabolic pathways.

Identification of those cattle genetics with superior feed efficiency is necessary to increase the productivity of the entire beef industry. The aim of this study was to investigate metabolites profiling in the liver and muscle to identify physiological changes in animals in the livestock system with low or high residual feed intake. Liver and muscle were collected after slaughter from Nellore males, with high and low residual feed intake (H-RFI, n = 10 and L-RFI, n = 10, respectively). Metabolites were extracted with cold methanol/water solution (4:3 v/v). Metabolomics analyses were performed by 1D 1H nuclear magnetic resonance. Metabolites were identified using Chenomx and analysed using MetaboAnalyst 4.0. The residual feed intake classification did not change most of animal performance traits; however, animals with lower residual feed intake presented greater carcass dressing, lower carcass fat deposition. Sixty-three compounds were identified in the liver and 31 in muscle. Coexpression network analysis was carried out and identified four metabolite network modules correlated with the phenotypic traits, indicating common metabolites with a variate important projection score that influences residual feed intake. Metabolites in liver samples was correlated with energy and protein metabolism and on muscle with fat metabolism. Differences on energetic metabolism, including of carbohydrate- and fat-correlated compounds, according to residual feed intake can be assessed by importance of concentration of citrate, isocitrate, glucose-6-phosphate, nicotinamide adenine dinucleotide + hydrogen and creatine phosphate (in liver) and choline, glycine, glycerol, malonate, glucose-6-phosphate and 3-hydroxybutyrate (in muscle). Moreover, differences on protein metabolism, can be assessed by importance of creatinine, glutamine, urea and creatine phosphate concentration in liver and creatinine, creatine, anserine and carnosine in muscle. Animals with low residual feed intake presented changes in energy production, represented by carbohydrate and fatty acid metabolites, and decreased carcass fat deposition and protein turnover.

Although the Cu2+ -sorbitol complex [Cu2+ -Sorb] structure in crystalline state has been determined by X rays, it is not known in solution, where most studies of this complex are performed. Therefore, the goal of this work was to obtain information about the structure of this complex in aqueous solution using nuclear magnetic resonance and electron paramagnetic resonance spectroscopies. The magnetic resonance results indicate that the complex is formed at approximately pH 12. In this pH the sorbitol 1 H relaxation times were so short (broad line) that was not possible to use standard nuclear magnetic resonance parameters (nuclear Overhauser effect and spin-spin coupling constants values) to solve the three-dimensional structure. However, valuable structural information about the complex in solution was obtained. The relaxation results indicate that the Cu2+ ions are buried in the structure and not accessible to solvent; the 1 H and 13 C spectra shows strong paramagnetic shift effect indicating short distance between these nuclei and Cu2+ in the structure. No electron paramagnetic resonance signal was observed in pH 12 indicating strong Cu2+ - Cu2+ dipolar interaction, compatible to Cu2+ -Cu2+ distances measured in crystal, from 1.148 to 1.393 Angstroms. The complex self-diffusion coefficient (D) of 1.58 × 10-10 m2 /s value, determined by Diffusion-Ordered Spectroscopy, is compatible to a molecular weight of 3-6 KDa. Therefore, these results corroborate that the [Cu2+ -Sorb] complex is assembled in solution, at pH 12, with several structural parameters compatible to the toroidal hexadecacuprate supramolecular structure determined in solid state.