Sequential physical field pretreatment modulates tilapia soup quality: a multi-omics investigation of processing...

Traditional tilapia soup production faces critical bottlenecks: low soluble solids release from fish tissue into broth, insufficient nutrient leaching, and severe flavor loss. Although individual physical treatments enhance soup quality, the sequential effects of distinct physical fields remain poorly characterized. This study investigated the effects of two physical field processing sequences (colloid milling followed by ultrasonication, CMUFS, and ultrasonication followed by colloid milling, UCMFS) on the microstructure, nutritional composition, flavor profile, and overall quality of tilapia soup, using untargeted metabolomics, volatilomics, electronic sensory technology, and correlation network analysis. Results showed that the CMUFS group produced smaller droplets (D_4,3 = 16.51 μm) and a more stable suspension, yet exhibited lower total hydrolyzed amino acid content (284.9 mg/100 mL) and a poorer amino acid score (13.4). This was attributed to initial shear-induced protein aggregation that could not be fully disrupted by subsequent ultrasonication, entrapping nutrients within dense matrices. Conversely, UCMFS achieved a higher amino acid score (24.9, 86% improvement) and richer flavor richness (electronic tongue richness value of 0.663), despite larger droplets (D_4,3 = 28.77 μm) and reduced stability. The sequence of ultrasonication followed by colloid milling avoids shear-induced protein aggregation, achieves thorough dispersion of the material, and reduces damage to the protein conformation caused by the shearing, enhancing substrate availability for Maillard reactions and lipid oxidation pathways. Metabolomics analysis identified 15 differential metabolites involved in lipid and amino acid metabolism, confirming UCMFS improves both nutritional value and flavor quality. These findings provide a theoretical basis for sequence-guided quality regulation of aquatic soup production.