Fabrication of food-derived bigels beads for the co-delivery of hydrophobic and hydrophilic bioactives: insights into environmental responsiveness and release mechanisms

Food-derived bioactives often suffer from poor physicochemical stability during processing and storage. To address this, we developed a novel dual-network bigel bead system for the efficient co-delivery of hydrophilic (l-ascorbic acid) and lipophilic (β-Carotene) compounds. Formulated by integrating sodium alginate (SA) or cellulose nanofiber (CNF) hydrogels with a monoglyceride oleogel, the system's structural characteristics, environmental responsiveness, and digestive behavior were systematically evaluated. Structural analyses (FTIR and DSC) revealed that the oleogel phase fundamentally reconfigured the hydrogel network. Stabilized primarily by hydrophobic interactions, this composite architecture exhibited excellent thermal stability and enhanced environmental adaptability. Notably, the bigel beads achieved encapsulation efficiencies exceeding 70% for both bioactives and demonstrated improved environmental adaptability, maintaining high cargo retention under cyclic pH and temperature stress. During in vitro digestion, the beads displayed a controlled, staged release profile: l-ascorbic acid release followed a zero-order kinetic model, whereas β-Carotene release fit the Korsmeyer-Peppas model. Ultimately, this tailored release significantly enhanced the bioaccessibility of both active compounds. This study provides an effective food-grade platform for the co-delivery and protection of multi-component nutraceuticals.