Enzyme- and ion-induced high internal phase emulsion gels based on soy protein isolate, chitosan, and alginate as fat...

Fat analogues have attracted increasing attention in food science because of their potential benefits for environmental sustainability, animal welfare, and human health. However, a deeper understanding of the textural design and flavor regulation of such systems is still needed. In this study, a high-internal-phase emulsion gel (HIPEG) with desirable textural properties was developed as a plant-based fat analogue with efficient flavor encapsulation and controlled release behavior. Briefly, hydrophobically modified chitosan gel network (h-CSG) was incorporated into a soy protein isolate (SPI) solution, which was then homogenized with 75% flaxseed oil and gelled through enzymatic and ionic crosslinking. The incorporation of h-CSG reduced the interfacial tension of SPI and improved the stability of the HIPEG system. Relative to the control HIPEG without h-CSG, the h-CSG-containing samples showed enhanced viscoelastic properties, and gel strength increased with increasing h-CSG concentration. Among all formulations, the sample containing 0.75% h-CSG exhibited the best overall performance, with a storage modulus of 10⁴ Pa and a gel strength of 155.08 g, which were significantly higher than those of the HIPEG-0.25 (P < 0.05), while retaining satisfactory recovery properties. In addition, this HIPEG showed excellent ability to encapsulate and regulate the release of key flavor compounds, including aldehydes, ketones, and alcohols. Overall, this study provides new insights into the development of high-oil-content fat analogues with tunable texture and flavor-release properties.