Tunable physicochemical properties, oral sensation, and digestive behavior of gelatin/κ-carrageenan-beeswax-based bigel beads: effects of fabrication parameters and phase ratio

Abstract

In this study, we optimized the fabrication of bigel beads using a combination of orthogonal experiments and response surface methodology, with special focus on refining the gelling bath parameters and extrusion techniques. We systematically investigated the influence of the oil–water phase ratio on the properties of bigel beads and comprehensively evaluated their performance in simulated oral processing and gastrointestinal digestion. Our key findings were that the gelling bath composed of 75% ethanol and 0% Tween at 0 °C achieved the highest gelation rate (0.9882), while the optimal extrusion parameters that yielded the maximum sphericity (0.9751) were a pump rate of 0.13 mL/min, height 0.93 cm, and temperature 65 °C. The elevated oil-phase content significantly enhanced both the particle size and sphericity of the bigel beads, transformed the bigel type from O/W to bi-continuous, and increased the hardness and cohesiveness. Furthermore, a higher oleogel percentage exacerbated frictional interactions during simulated mastication, compromised structural stability, and consequently promoted the release of free fatty acids. These results provide novel insights into the fabrication protocols and structure–function relationships of bigel beads, contributing to the development of functional food materials.

Keywords

Bigel beads / Gelling bath / Extrusion / Sphericity / Friction

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