Flexible control of bigel microstructure for enhanced stability and flavor release during oral consumption

Edible delivery systems such as emulsions and gels that possess flexible oral flavor sensation and comprehensive stability under freeze–thaw processing are highly demanded in the frozen food industry. Bigels were fabricated via emulsification of stearic acid based oleogel with konjac glucomannan (KGM)-gelatin (G) based binary hydrogel. By varing the KGM/G mass ratio (γ) and oleogel/hydrogel volume ratio (φ) of bigels, modulation over the micromorphology, tribology, flavor sensation and cheese stick imitating capacity were achieved. Notably, as φ increased from O4:W6 to O5:W5, the microstructural transformation from oleogel-in-hydrogel to bicontinuous morphology emerged as a remarkable feature. The influence of γ was evident in bicontinuous bigels, significantly enhancing water holding capacity (WHC) by 3.38-fold as γ transitioned from 1KGM:5G to 6KGM:5G during freeze–thaw cycles. φ and γ both played pivotal roles in altering the microstructure and rheological properties of the bigels, enabling customizable release of bioactive components and flavor perception. Oleogel-in-hydrogel bigels effectively prevented bioactive compound leakage during freeze–thaw conditions, while bicontinuous bigels demonstrated sustained flavor release during oral mastication. Release behaviors were dual-controlled by φ and γ, reducing oil-soluble flavor release with increased φ and lowering hydrophilic volatile release with elevated γ. Moreover, bigel-based cheese sticks showcased lower viscosity, higher creep recovery rates, and enhanced mouthfeel during minimal oral chewing, suggesting their potential in mimicking the properties of commercial counterparts. These findings extend insights into bigel design for tailored flavor release and bioactive preservation in food products.