Comparative characterization of flavor precursors and volatiles of Taihe black-boned silky fowl and Hy-line Brown yolks using multiomics and GC-O-MS-based volatilomics

Comprehensive foodomics analysis reveals key lipids affect aroma generation in beef

Lipids are vital precursors to beef aroma compounds, but the exact lipid molecules influencing aroma generation remain unconfirmed. This study employs gas chromatography-olfactometry-mass spectrometry and absolute quantitative lipidomics to identify beef's aroma and lipid profiles and to examine lipid alterations post-thermal processing. The aim is to understand the role of lipids in aroma generation during beef's raw-to-cooked transition. Eighteen key aroma compounds were identified as significant contributors to the aroma of beef. 265 lipid molecules were quantified accurately, and we found that triglycerides containing C18:1 or C18:2 chains, such as TG(16:0_18:1_18:1), TG(16:0_18:1_18:2), TG(16:0_16:1_18:1), as well as phosphatidylcholine and phosphatidylethanolamine containing PC(16:1e_20:4), PC(16:0e_20:4), PC(18:2e_18:2), and PE(16:1e_20:4), played important roles in the generation of key aroma compounds in beef. C18:1, C18:2, C18:3, and C20:4 were key substrates for the formation of aroma compounds. In addition, lysophosphatidylcholine and lysophosphatidylethanolamine containing unsaturated fatty acid chains may serve as important aroma retainers.

The revelation of characteristic volatile compounds in egg powder and analysis of their adsorption rules based on HS-GC-IMS technology

The study constructed fingerprints and analyzed adsorption rules of volatile compounds (VOCs) in egg powder (EP) under different production processes, including egg white powder (EWP), egg yolk powder (EYP) and whole egg powder (WEP) by HS-GC-IMS. The 29 VOCs identified were primarily ketones and aldehydes. Characteristic VOCs responsible for flavor differences were clarified by difference comparison, clustering and PCA analysis. Additionally, variations in lipid and protein were the primary causes of the VOCs differences in EP through microscopy imaging, infrared and fluorescence spectroscopy. EWP's stretched structure favored fishy-smelling VOCs adsorption but limited total aldehyde binding due to strong hydrophobic interaction. EYP's higher β-sheet ratio and fewer hydrogen bond sites weakened its alcohol VOCs binding capacity. The abundance of ketone VOCs in EP was linked to their low steric hindrance. Therefore, this study elucidated the flavor differences reasons among EWP, EYP and WEP, laying foundation for EP applications in food industry.

Integrating Genomics and Transcriptomics to Identify Candidate Genes for Egg Production in Taihe Black-Bone Silky Fowls (Gallus gallus domesticus Brisson)

The Taihe Black-Bone Silky Fowl (Gallus gallus domesticus Brisson) possesses significant value in terms of consumption, medicinal applications, and ornamental appeal, representing a precious genetic resource and traditional Chinese medicinal material. However, considerable variation exists within populations regarding egg-laying performance. This study integrates a whole-genome selection signal analysis (SSA) with a transcriptome analysis to identify genes associated with egg-laying traits in Taihe Black-Bone Silky Fowls. We identified 31 candidate genes under selection from the high-yield chicken (HC) and low-yield chicken (LC) groups. Additionally, through RNA-seq analysis, 257 common differentially expressed genes (DEGs) were identified from four comparative groups. Two overlapping genes-LPL and SETBP1-were found in both the selected gene and DEG lists. These selected genes and DEGs were enriched in pathways related to ovarian development, including the lysosome pathway, the ECM-receptor interaction pathway, the TGF-beta signaling pathway, the Wnt signaling pathway, the PPAR signaling pathway, and the glycerolipid metabolism pathway. These research findings contribute to the breeding of Taihe Black-Bone Silky Fowls with high egg production traits and provide a theoretical foundation for exploring the regulatory mechanisms of avian reproduction.

Novel Insights into the Effects of Different Cooking Methods on Salted Egg Yolks: Physicochemical and Sensory Analysis

In this study, the flavor characteristics and physicochemical properties of salted egg yolk (SEY) under different cooking methods (steaming/baking/microwaving) were investigated. The microwave-treated SEY exhibited the highest levels of salt content, cooking loss, lightness, and b* value, as well as the highest content of flavor amino acids. A total of 31, 27, and 29 volatile compounds were detected after steaming, baking, and microwave treatments, respectively, covering 10 chemical families. The partial least squares discriminant analysis confirmed that 21 compounds, including octanol, pyrazine, 2-pentyl-furan, and 1-octen-3-ol, were the key volatile compounds affecting the classification of SEY aroma. The electronic nose revealed a sharp distinction in the overall flavor profile of SEY with varying heat treatments. However, no dramatic differences were observed in terms of fatty acid composition. Microwave treatment was identified as presenting a promising approach for enhancing the aroma profile of SEY. These findings contribute novel insights into flavor evaluation and the development of egg products as ingredients for thermal processing.

Comparative Metabolomic Profiling of Eggs from 3 Diverse Chicken Breeds Using GC-MS Analysis

Eggs, as a crucial source of essential nutrients for consumers, possess a high nutritional value owing to their rich composition of vital components essential for human health. While previous research has extensively investigated genetic factors influencing egg quality, there has been a limited focus on exploring the impact of specific strains, particularly within the African context, on the polar metabolite profile of eggs. In this extensive study, we conducted an untargeted analysis of the chemical composition of both albumen and yolk from 3 distinct strains of hens-Blue Holland, Sasso, and Wassache-raised under identical feeding conditions. Utilizing gas chromatography coupled with mass spectrometry (GC-MS), we meticulously examined amino acids, carbohydrates, fatty acids, and other small polar metabolites. In total, 38 and 44 metabolites were identified in the whites and yolk, respectively, of the 3 studied strains. The application of chemometric analysis revealed notable differences in metabolite profiles with 8 relevant metabolites in each egg part. These metabolites include amino acids (N-α-Acetyl-L-lysine, lysine, L-valine, L-Tryptophan), fatty acids (oleic acid, linoleic acid, palmitic acid and stearic acid), and carbohydrates (d-glucose, maltose, lactose). These findings shed light on strain-specific metabolic nuances within eggs, emphasizing potential nutritional implications. The ensuing discussion delves into the diverse metabolic pathways influenced by the identified metabolites, offering insights that contribute to a broader understanding of egg composition and its significance in tailoring nutritional strategies for diverse populations.

Insights into the mechanism of extracellular proteases from Penicillium on myofibrillar protein hydrolysis and volatile compound evolutions

To investigate the mechanism of Penicillium proteases on the hydrolysis of myofibrillar protein (MP) and volatile compound evolutions, enzymatic characteristics of Penicillium proteases, hydrolysis capacities for MP, interactions between Penicillium proteases and MP, and profile changes of volatile compounds were investigated. P. aethiopicum (PA) and P. chrysogenum (PC) proteases showed the largest hydrolysis activities at pH 9.0 and 7.0, and were identified as alkaline serine protease and serine protease by LC-MS/MS, respectively. The proteases of PA and PC significantly degraded myosin and actin, and PA protease showed higher hydrolysis capacity for myosin than that of PC protease, which was confirmed by higher proteolysis index (56.06 %) and lower roughness (3.99 nm) of MP after PA treatment. Molecular docking revealed that hydrogen bond and hydrophobic interaction were the major interaction forces of Penicillium proteases with myosin and actin, and PA protease showed more binding sites with myosin compared with PC protease. The total content of free amino acids increased to 6.02-fold for PA treatment and to 5.51-fold for PC treatment after 4 h hydrolysis of MP, respectively. GC-MS showed that aromatic aldehydes and pyrazines in PA showed the largest increase compared with the control and PC during the hydrolysis of MP. Correlation analysis demonstrated that Phe, Leu and Ile were positively related with the accumulation of benzaldehyde, benzeneacetaldehyde, 2,4-dimethyl benzaldehyde and 2,5-dimethyl pyrazine.