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The effects of three different enzyme treatments on the structure and volatile compounds of egg yolk protein were investigated. The secondary and tertiary structures, as well as volatiles, were characterized using ultraviolet spectroscopy (UV), fourier transform infrared (FTIR) spectroscopy, free sulfhydryl group analysis, and gas chromatography-mass spectrometry (GC-MS). FTIR analysis revealed a decrease in the contents of intermolecular, intramolecular, and intermolecular antiparallel β-sheets while an increase in random coils was observed. The contents of α-helices and β-turns did not show significant changes, indicating a reduction in protein compactness. Enzymatic treatment led to an increase in hydrophobic interaction, electrostatic interaction, and hydrogen bond formation within the egg yolk hot gel (EYG). Structural characterization demonstrated that EYG formed large uniform air chamber cavities after lipase hydrolysis (LEYG), while EYG hydrolyzed by papain (PEYG) and by flavor protease (FEYG) exhibited more compact structures. In addition, the binding of proteins to flavor substances inhibited the release of volatile flavor compounds. These findings provide insights into enhancing the flavor and texture of egg yolk by modulating its protein structure. [Display omitted] • The enzyme treatment induced a significant alteration in the secondary structure, resulting in increased flexibility. • The flavor components potentially formed hydrophobic interactions with egg yolk, thereby improving their flavor profile. • The alteration of free sulfhydryl group could potentially result in a reduction in gel strength. • The interrelation among protein structure, gel texture, and flavor was investigated through diverse analytical approaches. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cholesterol removal treatment (CRT) can reduce the off-odor of EY. • The effect of CRT on the flavor of EY is evaluated by E-nose and GC–MS. • The texture, color, and taste of EY are not affected. • CRT reduces the degree of lipid oxidation by reducing the content of PUFA. The aim of this study was to investigate effects of cholesterol removal treatment (CRT) on the flavor, taste, texture, color, and nutritional value of hot gel egg yolk (EY). The off-odor, volatile components and taste of EY treated with CRT were studied by electronic nose (E-nose), gas chromatography-mass spectrometry (GC–MS) and electronic tongue (E-tongue). The effect of CRT on the nutritional value of EY was studied by amino acid and fatty acid analysis. The CRT significantly reduced the content of hexanal, 2-amyl-furan, 1-octene-3-ol, styrene and heptanal in EY1-EY4, also decreased its bitter taste without affecting other taste and elasticity. In addition, the CRT did not affect the essential amino acids (EAA) content and L*, a* and b* values of EY1-EY4, but it led to the reduction in polyunsaturated fatty acids (PUFA) content. In general, the CRT is an effective way to reduce the off-odor of EY without affecting consumer acceptance. [ABSTRACT FROM AUTHOR]