INFORM February 2025 Volume 36 (2)

FAT INNOVATIONS

inform February 2025, Vol. 36 (2) • 19

exceptional properties, such as a moisturizing effect, enhanced stability, adjustable properties, biocompatibility, and the capability for controlled release of active ingredients. This foundational research paved the way for advanced inves tigation into the use of bigels in 3D bioprinting, drug deliv ery, and other innovative biomedical applications (https:// doi.org/10.3390/gels9080648 and https://doi.org/10.1016/ B978-0-08-102179-8.00011-9). Bigels are biphasic systems composed of two gelled phases: an aqueous phase (hydrogel) and an oil-based phase (oleogel). This allows delivery of multiple bioactive molecules and nutraceuticals, while their physicochemical properties can modulate the release of the encapsulated compounds. Furthermore, the ability to tailor their physicochemical and structural properties can also have tremendous significance in ensuring bigels’ versatility concerning texture and sensory attributes in different food matrices. Though several food-grade bigels have recently been developed as fat substitutes, their application in food prod

ucts remains limited and is still in its early stages. Bigels can be used as a main component or part of a complex nutritionally enriched food. HOW BIGELS FORM Bigels are part of an important class of biphasic soft materi als, including emulsions and emulsion gels, that form three main categories: hydrogel-in-oleogel, oleogel-in-hydrogel, and bi-continuous bigels. The main distinction between bigels and other multiphase systems, like emulsions and emulsion gels, is that both phases (hydrogel and oleogel) are structured/gelled. Bigels are commonly produced by mixing the two phases using a hot and/or cold emulsification procedure. Different gelation mechanisms unfolded depending on the chosen ingre dients in either phase. In a hot emulsification procedure, a researcher melts the hydrogel and oleogel solutions and mixes them, usually under high shear conditions, to achieve emulsifi cation. While in the cold emulsification process, they gel both phases before mixing.

The three main categories of biphasic soft materials (from left to right): oleogel-in-hydrogel, bi-continuous, and hydrogel-in-oleogel bigels. Source: Davidovich-Pinhas lab via biorender.com.