Emulsion foams from structural perspectives: foaming mechanisms, in-situ imaging characterizations, sensory...

Saturated fat crystals are key to stabilizing emulsion foams but contradict healthy dietary trends. Unlike conventional formulation-centered reviews, this work establishes a unified structural perspective to systematically sort out foaming mechanisms of five typical emulsion foam systems-O/W, W/O/W, W/O, O/W/O, and bigel-based emulsion foams-and further elaborates their structural differences in the foaming process, interfacial stabilization, and phase evolution. For low-fat/low-saturated-fat goals, two potential strategies are: (i) efficient water-based stabilizers to replace/reduce fat-crystal foaming; (ii) oil-continuous emulsion foams as fat alternatives to oleofoams. For structurally complex novel foams, in-situ imaging techniques (cryo-SEM, XCT, MRI, Raman imaging) when combined with AI show great promise for advanced non-destructive characterization. Sensory evaluation covering oral tribology and flavor perception is discussed to bridge laboratory findings with consumer acceptance. Finally, current food applications-aerated foods, fat replacers, active ingredient carriers, and 3D printing inks-are critically assessed here.