Mechanism of synergistic ultrasound-ethanol treatment in salted egg yolk: Rapid texture optimization and flavor enhancement

Conventional salted duck egg yolk (SEY) suffers from hard-core texture and undesirable flavor. This study aims to enhance SEY quality and elucidate the underlying mechanisms via high-intensity ultrasound (HIU)-assisted ethanol treatment. The results revealed that optimal 200 W treatment lowered hardness while increasing chewiness (2.22 g) and adhesiveness (0.67 g·<i>sec</i>), with oil exudation and sandiness rising by 59.97 % and 50.78 % respectively. These improvements correlated with elevated surface hydrophobicity (+13.15 %) and free sulfhydryl content (+65.38 %) compared to those in SEY. Structural analysis revealed HIU accelerated moisture transitions, formed microporous networks, and altered protein secondary structures with increased β-turns and decreased α-helix/random coils. Volatile profiling identified 87 compounds, where cavitation-driven lipid oxidation significantly increased key flavor enhancers: ethyl decanoate (+83.78 %) and hexyl hexanoate (+381.08 %). These synergistic modifications produced superior sensory qualities (>70 points). In conclusion, this study provides an efficient and practical solution to the textural and flavor challenges in conventional SEY production.