Ultrasound-assisted membrane filtration: Toward matrix-responsive structure-function framework.

Ultrasound-assisted membrane filtration has traditionally been investigated as a process-intensification strategy for improving permeate flux, reducing fouling, and enhancing membrane performance. However, current approaches largely overlook the matrix-dependent mechanisms through which ultrasound influences fouling evolution, membrane behavior, and the physicochemical properties of food-derived bioactive compounds. This review critically examines the interactions among cavitation, membrane filtration, food matrix composition, and bioactive compounds under ultrasound-assisted conditions, with particular emphasis on proteins, polysaccharides, lipids, minerals, phenolic compounds, and microbial-derived materials as matrix-specific foulants. The evidence indicates that fouling behavior is intrinsically matrix dependent and governed by the combined effects of food matrix composition, membrane physicochemical properties, and ultrasound operating conditions, which together influence interfacial interactions, colloidal organization, and bioactive stability. Based on these mechanistic relationships, this review proposes the Fouling Potential Score (FPS) as a literature-derived qualitative conceptual framework for organizing matrix-, membrane-, and ultrasound-related descriptors associated with fouling behavior and supporting hypothesis generation. The FPS is not a quantitative scoring system or a validated predictive model; rather, it provides a structured representation of mechanistic tendencies reported across the literature and requires future experimental validation and quantitative development.