Identification of characteristic aroma compounds in chicken meat and their metabolic mechanisms using gas chromatography-olfactometry, odor activity values, and metabolomics.

Aroma has an important influence on the aroma quality of chicken meat. This study aimed to identify the characteristic aroma substances in chicken meat and elucidate their metabolic mechanisms. Using gas chromatography-olfactometry and odor activity values, we identified nonanal, octanal, and dimethyl tetrasulfide as the basic characteristic aroma compounds in chicken meat, present in several breeds. Hexanal, 1-octen-3-ol, (E)-2-nonenal, heptanal, and (E,E)-2,4-decadienal were breed-specific aroma compounds found in native Chinese chickens but not in the meat of white-feathered broilers. Metabolomics analysis showed that L-glutamine was an important metabolic marker of nonanal, hexanal, heptanal, octanal, and 1-octen-3-ol. Exogenous supplementation experiments found that L-glutamine increased the content of D-glucosamine-6-P and induced the degradation of L-proline, L-arginine, and L-lysine to enhance the Maillard reaction and promote the formation of nonanal, hexanal, heptanal, octanal, and 1-octen-3-ol, thus improving the aroma profile of chicken meat.

Multi-Omics Analysis of Genes Encoding Proteins Involved in Alpha-Linolenic Acid Metabolism in Chicken.

Alpha-linolenic acid (ALA, ω-3) is an antioxidant that reduces triglyceride (TG) levels in blood, a component of cell membranes and a precursor compound of eicosapentaenoic acid (EPA, ω-3) and eicosatrienoic acid (DHA, ω-3). Fatty acid content is a quantitative trait regulated by multiple genes, and the key genes regulating fatty acid metabolism have not been systematically identified. This study aims at investigating the protein-encoding genes regulating ω-3 polyunsaturated fatty acid (PUFA) content in chicken meat. We integrated genomics, transcriptomics and lipidomics data of Jingxing yellow chicken (JXY) to explore the interactions and associations among multiple genes involved in the regulation of fatty acid metabolism. Several key genes and pathways regulating ω-3 fatty acid metabolism in chickens were identified. The upregulation of GRB10 inhibited the mTOR signaling pathway, thereby improving the content of EPA and DHA. The downregulation of FGFR3 facilitated the conversion of ALA to EPA. Additionally, we analyzed the effects of ALA supplementation dose on glycerol esters (GLs), phospholipid (PL) and fatty acyl (FA) contents, as well as the regulatory mechanisms of nutritional responses in FFA metabolism. This study provides a basis for identifying genes and pathways that regulate the content of FFAs, and offers a reference for nutritional regulation systems in production.

Functionalized Cu3BiS3 nanoparticles for dual-modal imaging and targeted photothermal/photodynamic therapy.

Multifunctional nano-biomaterials with the integration of diagnostic and therapeutic functions have shown great promise in improving the efficacy of cancer therapy. Herein, a new nanoplatform based on functionalized Cu3BiS3 nanoparticles (NPs) is fabricated for tumour-targeted combination phototherapy. The as-synthesized hydrophobic Cu3BiS3 NPs are modified with DSPE-PEG/DSPE-PEG-NH2, followed by the conjugation of the photosensitizer chlorin e6 (Ce6) and the target ligand folic acid (FA). The introduced Ce6 can further form a chelate complex with Gd3+. The rationally designed Cu3BiS3-PEG-(Ce6-Gd3+)-FA NPs, which have high physiological stability and good biocompatibility, can specifically target FA-receptor over-expressed tumour cells. The Cu3BiS3-PEG-(Ce6-Gd3+)-FA NPs exhibit effective dual-modal CT and MR imaging in the xenografted HeLa tumours. Importantly, excellent in vivo anti-tumour effects have been achieved by synergistic photothermal/photodynamic therapy using the multifunctional NPs. We expect that this versatile nanoplatform will play a role in exploring precise cancer diagnosis and therapy.