Designation and characterization of cold-set whey protein isolate-low acyl gellan gum emulsion-filled gel for enhancing limonene flavor perception: A study on structure, breakdown characteristics, and sensory perception in the human mouth

Flavor perception depends on food structure and oral processing behavior. Emulsion-filled gel (EFG) is a category of soft to solid food products that utilizes the advantages of emulsions to deliver lipid-soluble ingredients, such as the limonene flavor. This paper aimed to design a cold-set EFG system as a carrier to improve limonene flavor perception using whey protein isolate and low-acyl gellan gum (LAGG) (0-0.7% w/w). With increasing LAGG levels, the EFGs shifted towards forming a true gel structure with a brittle and hard 3D network based on the steady shear, amplitude (increasing G'LVE and decreasing tan delta LVE), frequency sweep (increasing K' and decreasing n'), and uniaxial compassion (increasing Young's modulus and decreasing fracture strain) tests. EFG with 0.7% LAGG needed a higher chewing process, and the fragmentation increased as EFG hardness increased. According to the time-intensity test, the highest and lowest limonene perception were found in the EFG-contained 0.3% (Imax: 5.14, area: 79.20) and 0.7% (Imax: 4.35, area: 57.40) LAGG. In conclusion, by manipulating the structure, custom architectures can be created in the oral cavity, resulting in specific performance and controlled release of their components.