Biochemical and Physicochemical Changes in Spaghetti Meat During Refrigerated Storage of Chicken Breast

Differentially abundant proteins, metabolites, and lipid molecules in spaghetti meat compared to normal chicken breast meat: Multiomics analysis

Spaghetti meat (SM), a recently emerging muscle myopathy in chicken breast meat, is characterized by a loss of muscle fiber integrity, resulting in a spaghetti-like appearance. Understanding the differences in proteins, metabolites, and lipids through a multiomics approach in SM can identify its quality traits and elucidate its exact causes. The purpose of this study was to investigate differentially abundant proteins, metabolites, and lipid molecules in SM compared to normal chicken breast meat (Control). The supernatant from sample homogenates was subjected to ultra-high performance liquid chromatography (UHPLC) analysis for multiomic profiling. A total of 16 chicken breast fillets (Pectoralis major) representing Control (n = 8) and SM (n = 8) groups were collected from a commercial slaughterhouse. A total of 2593 molecules were identified and composed of 1903 proteins, 506 lipids, 181 compounds and 3 electrolytes. There were 632 differential molecules composed of 503 proteins, 76 lipids, 50 metabolites, and 3 electrolytes. In comparing SM and Control, the protein, metabolite, and lipid molecules with the greatest fold change were calponin, decanoylcarnitine, and ceramide [N‑hydroxy-sphingosine] (Cer[NS]) d18:1_26:1, respectively. Plasmenylphosphatidylcholine (Plasmenyl-PC) and triglycerides (TG) were significantly decreased and increased, respectively, in SM compared to Control. Acylcarnitines (AC) were significantly decreased in SM compared to Control. Decanoylcarnitine, lauroylcarnitine, linoleyl-carnitine, oleoyl-carnitine, hexanoylcarnitine were downregulated in SM compared to Control, and adenosine 5'-diphosphoribose and nicotinamide adenine dinucleotide (NAD) were downregulated in SM. Carbon metabolism, glycolysis/glucogenesis, ribosome, biosynthesis of amino acids, and aminoacyl-tRNA biosynthesis were selected in the top 10 enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, identified by using differential proteins. Hence, SM had different proteins, metabolites, and lipid molecules related to β-oxidation, carbon and energy metabolism, lipid formation, and protein and amino acid metabolism compared to Control. Results from this study showed physiological alterations found in SM myopathy. Therefore, to mitigate SM in broilers, interventions should: 1) increase NAD and carnitines, 2) reduce triglycerides, and 3) modulate β-oxidation and energy metabolism via nutritional, genetic, or systemic approaches.

Spatial transcriptomic differences in the breast muscle of grower broilers at 21 and 28 days of age

This study investigated transcriptomic differences between the caudal and cranial areas in breast muscle in the grower phase of broiler chickens (D 21 and D 28). A total of 66 one-day-old broiler chickens were allotted to 6 cage pens of 11 birds per pen. On D 21 and D 28, one bird per pen was randomly selected, and breast muscle samples were collected in the caudal and cranial areas of the Pectoralis major. RNA sequencing was conducted, followed by screening for differentially expressed genes (DEGs; P < 0.05) and multivariate analyses. A total of 24,498 genes were identified, and 8,831 genes had greater than 100 mean read count. On D 21, there were 666 DEGs, among which 482 and 184 genes were down-regulated and up-regulated, respectively, in the caudal area compared with the cranial area. There were 2 down-regulated and 56 up-regulated genes with a greater than 1.5-fold change (FC). On D 28, there were 872 DEGs, among which 408 and 464 genes were down-regulated and up-regulated, respectively. There were 12 down-regulated and 23 up-regulated genes with a greater than 1.5-fold change. Principal component analysis (PCA) plots showed that gene profiles were not distinctly separated between the caudal area and the cranial area of breast muscle on D 21 and D 28. On D 21, collagen type XI alpha 1 chain (COL11A1), fibromodulin (FMOD), myosin heavy chain 7B (MYH7B), carbonic anhydrase 3A (CA3A), tenomodulin (TNMD), COL12A1, carboxypeptidase Z (CPZ), lysyl oxidase like 2 (LOXL2), COL1A1, and COL1A2 were significantly down-regulated in the caudal area compared to the cranial area with a greater than 2-FC (P < 0.05). KEGG pathway enrichment analysis indicated that various pathways including regulation of actin cytoskeleton, ribosome, and focal adhesion were significantly different in the caudal area compared with the cranial area. These findings suggest that spatial differences in gene expression within the breast muscle could be linked to functional or developmental variations between regions, potentially influencing muscle growth, meat quality, and breast myopathies. Understanding these spatial transcriptomic differences may provide insights into identifying etiologies and developing strategies for breast myopathies.

Comparative metabolomic analysis of spaghetti meat and wooden breast in broiler chickens: unveiling similarities and dissimilarities

Introduction

Spaghetti meat (SM) and wooden breast (WB) are emerging myopathies in the breast meat of fast-growing broiler chickens. The purpose of the study was to investigate the metabolomic differences between normal (N), SM, and WB fillets 24 h postmortem.

Materials and methods

Eight chicken breasts for each experimental group were collected from a commercial processing plant. Supernatant from tissue homogenates were subjected to ultra-performance liquid chromatographytandem mass spectrometry (UPLC-MS) analysis.

Results and methods

A total of 3,090 metabolites were identified in the chicken breast meat. The comparison of WB and N showed 850 differential metabolites (P < 0.05), and the comparison of SM and N displayed 617 differential metabolites. The comparison of WB and SM showed 568 differential metabolites. The principal component analysis (PCA) plots showed a distinct separation between SM and N and between WB and N except for one sample, but SM and WB were not distinctly separated. Compared to N, 15-Hydroxyeicosatetraenoic acid (15-HETE) increased, and D-inositol-4-phosphate decreased in both SM and WB, indicating that cellular homeostasis and lipid metabolism can be affected in SM and WB. The abundance of nicotinamide adenine dinucleotide (NAD) + hydrogen (H) (NADH) was exclusively decreased between SM and N (P < 0.05). Purine metabolism was upregulated in SM and WB compared to N with a greater degree of upregulation in WB than SM. Folic acid levels decreased in SM and WB compared to N (P < 0.05). Steroid hormone biosynthesis was downregulated in SM compared to N (P < 0.05). Carbon metabolism was downregulated in SM and WB compared to N with greater degree of downregulation in WB than SM (P < 0.05). These data suggest both shared and unique metabolic alterations in SM and WB, indicating commonalities and differences in their underlying etiologies and meat quality traits. Dietary supplementation of deficient nutrients, such as NADH, folic acids, etc. and modulation of altered pathways in SM and WB would be strategies to reduce the incidence and severity of SM and WB.

Review: Myopathies in broilers: supply chain approach to provide solutions to challenges related to raising fast growing birds

This review is a summary of a Poultry Science Association symposium addressing myopathies in broilers' breast meat, focusing on the interactions between genetics, nutrition, husbandry, and meat processing. The Pectoralis major myopathies (woody breast [WB]; white striping [WS]; spaghetti meat [SM]) and Pectoralis minor ("feathering") are described, followed by discussing their prevalence, potential causes, current and future ways to mitigate, as well as detection methods (in live birds and meat) as well as ways to utilize affected meat. Overall, breast myopathies remain an important focus across the poultry industry and whilst a lot of data and knowledge has been gathered, it is clear that there is still a lot to understand. As there are multiple factors impacting the occurrence of breast myopathies, their reduction relies on a holistic approach. Ongoing balanced breeding strategies by poultry breeders is targeting the longer-term genetic component but comprehending the significant influence from nongenetic factors (short-term solutions such as nutrition) remains a key area of opportunity. Consequently, understanding the physiology and biological needs of the muscle through the life of the bird is critical to reduce the myopathies (e.g., minimizing oxidative stress) and gain more insight into their etiology.

Water properties in intact wooden breast fillets during refrigerated storage

The wooden breast (WB) condition notably alters moisture content and water holding capacity (WHC) in broiler breast fillets. The purpose of this study was to investigate water properties during refrigerated storage from 4 h to 168 h postmortem using time domain nuclear magnetic resonance (TD-NMR). Water properties measured included mobility (T), proportion (P), and abundance per 100 g of meat (A). Changes in meat quality indicators including compression force, color, pH, cumulative purge loss, and proximate composition were also measured. Compression force and energy of the WB fillets were higher than normal fillets (P < 0.05). Slopes of changes in lightness of the WB and normal fillets were different in skin and bone side (P < 0.05). The slope of the purge loss from the WB fillets was higher than the normal fillets (P < 0.05). Time domain nuclear magnetic resonance analysis showed 4 water populations in intact broiler fillets with transverse relaxation time (T2) constants at approximately 4 to 5 milliseconds (ms) (designated as 2b, corresponding to hydration water or bound water), 40 to 60 ms (designated as 21, corresponding to intra-myofibrillar water or immobilized water), 80 to 210 ms (designated as 22a, corresponding to extra-myofibrillar water or free water with lower mobility) and 210 to 500 ms (designated as 22b, corresponding to extra-myofibrillar water or free water with higher mobility) during early postmortem storage (between 4 h and 72 h postmortem) and only 3 populations (2b, 21, and 22a) after 72 h postmortem. There were interaction effects (P < 0.05) between storage time and WB condition for all water properties except T2b, A2b/100 g, and T22b. The linear change of T21, P21, A21/100 g, T22a, A22a/100 g, P22b, and A22b/100 g in stored WB samples were different from the normal fillets (P < 0.05). During storage, P21 and A21/100 g of the WB fillets exhibited faster linear increases than those of the normal fillets, whereas T21 and T22a of the normal fillets and A22a/100 g, P22b, and A22b/100 g of the WB fillets showed faster linear decreases (P < 0.05). Our data demonstrate that the WB condition affects changes in water properties in broiler fillets during postmortem refrigerated storage.

Effects of alternating electric field during freezing and thawing on beef quality

Alternating electric field (AEF) technology was used during freezing-thawing-aging (FA) of beef aged for 0, 1, 3, 5 and 7 days. Color, lipid oxidation, purge loss, cooking loss, tenderness, and T₂ relaxation time were determined for frozen-thawed-aged beef with AEF (AEF + FA) or without AEF (FA) and compared to aged only (OA) controls. FA increased purge loss, cooking loss, shear force values and lipid oxidation (P < 0.05) but decreased a* values compared with AEF + FA treatment. It also exacerbated the spaces between muscle fibers and contributed to the transformation of immobile water to free water. AEF served to maintain meat quality by reducing purge loss, cooking loss and increasing meat tenderness and maintaining color and lipid oxidation only in steak that was frozen before aging. This most likely occurred due to AEF increasing the speed of freezing and thawing and by reducing the space between muscle fibers compared to FA alone.