The gelling agents used to build oleogels are diverse, and each imparts distinct properties to the resulting network. Waxes, including candelilla, beeswax, and sunflower wax, form crystalline networks whose strength and thermal behavior depend on the chain length distribution of their hydrocarbon fractions and on the cooling history of the gel. Organogelators such as ethylcellulose build networks through polymer strand aggregation, while combinations of monoglycerides, phytosterols, and other small molecules can form tubular or fibrillar structures. Because the network architecture determines how oil is trapped, how the gel flows under shear, and how it melts or softens at elevated temperature, the choice of gelling agent is effectively a choice about the final food’s behavior during processing and consumption. This is why studies that systematically link gelator chemistry to functional performance in real foods, rather than in isolated gel systems, carry particular weight for the field.

Hydrogels operate on an analogous principle in the aqueous phase, using polysaccharides and proteins to build networks that hold water, modulate viscosity, and encapsulate hydrophilic compounds. Proteins such as whey, soy, and gelatin can form gels through heat-induced unfolding and aggregation, electrostatic complexation, or enzymatic crosslinking, while polysaccharides such as alginate, pectin, and carrageenan respond to ionic strength, pH, and hydration conditions. The stimulus-responsiveness highlighted in the review literature is especially relevant here: a hydrogel that remains intact in the acidic environment of the stomach but dissociates at intestinal pH can protect a sensitive cargo through gastric transit and release it where absorption is most favorable. Similar logic applies to temperature-triggered systems, which may remain stable during refrigerated storage but soften or release their payload at physiological temperature.

Bigels represent a further step in structural sophistication because they combine two gel phases that would normally be immiscible. In a typical bigel, an oleogel phase and a hydrogel phase are brought together under shear with the help of stabilizers and interfacial design, producing a material in which hydrophilic and lipophilic compounds can be compartmentalized separately. This compartmentalization matters for several reasons. It prevents reactive ingredients from contacting one another until the moment of consumption or digestion. It allows co-encapsulation of compounds with opposing solubility requirements. And it creates release profiles that can be tuned by adjusting which phase is continuous and which is dispersed, since a compound dissolved in the continuous phase will generally diffuse out faster than one sequestered in droplets of the dispersed phase. The phase ratio, droplet size distribution, and interfacial film composition therefore become design variables that food scientists can manipulate to achieve targeted delivery behavior.

The digestive fate of these systems deserves particular attention because the gastrointestinal tract subjects ingested materials to a sequence of environments that few laboratory tests replicate faithfully. In the mouth, shear forces and amylase begin to modify the matrix. In the stomach, acidic pH, pepsin activity, and mechanical churning act on the gel structure over periods ranging from minutes to hours. In the intestine, bile salts emulsify lipids, pancreatic lipase cleaves triglycerides, and the changing pH and ionic conditions continue to remodel whatever structure remains. A gel that appears stable in a beaker may disintegrate rapidly under gastric conditions, releasing its cargo prematurely, or conversely may resist digestion so effectively that its nutrients never become bioaccessible. Static in vitro digestion protocols that sequentially simulate oral, gastric, and intestinal phases have become standard tools for probing these transformations, and more advanced dynamic models that reproduce realistic transit times, pH profiles, and shear regimes are increasingly used to refine predictions.

Scattering and microscopy techniques underpin much of the structural insight in this field. Small-angle X-ray and neutron scattering can resolve features spanning from nanometers to hundreds of nanometers, revealing crystalline packing in wax networks, polymer mesh dimensions in hydrogels, and interfacial film thickness in emulsion gels. Confocal microscopy with selective fluorescent staining can map the spatial arrangement of oil and water phases in bigels, showing whether one phase forms connected channels or isolated domains. Rheology complements these methods by measuring how the network responds to deformation, distinguishing between elastic solids that hold their shape and viscous fluids that flow. When these measurements are collected at multiple stages of digestion rather than only on the freshly prepared gel, they allow researchers to construct a mechanistic narrative connecting formulation choices to structural evolution to nutrient release, which is precisely the framing that the current literature increasingly advocates.

The application of oleogels in baked goods illustrates how laboratory findings must confront the realities of industrial processing. Cookie production involves creaming of fat and sugar, which incorporates air bubbles that later expand during baking and set the final texture. A fat that does not cream properly will yield a dense, hard cookie regardless of its nutritional profile. During baking, the structuring fat must melt or soften at the right rate to allow expansion without collapse. After baking, it contributes to texture during chewing and to the migration of moisture during storage. Replacing conventional solid fat with a wax-based oleogel therefore requires that the gel network survive creaming shear, respond appropriately to oven temperatures, and deliver acceptable sensory properties, all while carrying functional compounds such as vitamin E that may themselves be heat-sensitive. Studies demonstrating complete replacement of solid fat in a real cookie formulation, with measurements of texture, color, and nutrient retention, thus provide evidence at a level of realism that model systems cannot.

High-temperature sterilization presents an even harsher challenge for gel-based systems. Retort processing, which is used to ensure the microbiological safety of shelf-stable meat products, exposes the food to temperatures well above those of normal cooking for extended periods. Proteins denature and aggregate further, polysaccharides may degrade, water held in gel networks can be expelled as the matrix contracts, and textures can shift from desirable to rubbery or mushy. Finding natural ingredients that help gels retain water and texture through such treatment is valuable both for product quality and for reducing the need for synthetic additives. Seaweed-derived ingredients are of particular interest in this context because they bring both water-holding polysaccharides and bioactive compounds, and their use in meat systems also aligns with efforts to reformulate processed meats toward improved nutritional profiles.

Bioaccessibility, the fraction of an ingested nutrient that is released from the matrix and made available for absorption, is the metric that ultimately connects delivery system design to nutritional benefit. A bioactive compound can be chemically intact in a food yet poorly bioaccessible if it remains trapped in an indigestible network or is degraded before release. Conversely, a gel that releases its cargo too early in the digestive tract may expose it to acidic conditions that promote degradation. The design goal is therefore not simply protection or simply release, but a controlled sequence in which the matrix survives processing and storage, resists premature disruption in the stomach, and disassembles at the appropriate point in the intestine. Achieving this requires that formulation studies measure bioaccessibility directly rather than inferring it from encapsulation efficiency alone, and the growing emphasis on digestion-coupled characterization reflects this recognition.

Several methodological themes emerge from the current body of work that will likely shape future research directions. First, the value of testing gels within finished foods under realistic processing conditions is now well established, and studies that bridge the gap between model gels and commercial products will continue to be needed. Second, the combination of structural characterization across length scales with digestion experiments offers a path toward predictive understanding, in which formulation changes can be anticipated to alter release behavior without exhaustive trial and error. Third, the use of plant-derived and food-grade gelators responds to consumer and regulatory pressure, and expanding the palette of such materials, including agricultural byproducts and underexploited seaweed species, broadens the options available to formulators. Fourth, the stability of bioactive compounds during processing, storage, and digestion must be tracked alongside structural performance, since a delivery system that protects structure but not payload fails its purpose.

The broader significance of this research area lies in its potential to reconcile nutritional goals with sensory expectations. Fat reduction, sugar reduction, and nutrient fortification all tend to compromise the textures that consumers enjoy, and the failure of many reformulated products in the marketplace reflects this tension. Gels that can be tuned independently in composition, structure, and responsiveness give formulators additional degrees of freedom, allowing fat to be restructured rather than removed, water to be bound rather than lost, and nutrients to be delivered rather than degraded. As the evidence base grows to encompass more food categories, more gelator combinations, and more complete digestive characterization, these systems will move from promising laboratory concepts toward practical tools for developing foods that are simultaneously healthier, stable, and enjoyable to eat.

Subject of Research: Next-generation oleogel and hydrogel systems for food structuring, digestion, and nutrient delivery

Article Title: Editorial: Next-generation oleogel and hydrogel systems: advances in structuring, digestion, and nutrient delivery in food matrices

Article References: Castelo-Branco, V. N. (2026). Editorial: Next-generation oleogel and hydrogel systems: advances in structuring, digestion, and nutrient delivery in food matrices. Frontiers in Soft Matter, 6, Article 2013976. https://doi.org/10.3389/frsfm.2026.2013976

Image Credits: AI Generated

DOI: 10.3389/frsfm.2026.2013976

Keywords: oleogels, hydrogels, bigels, food science, nutrient delivery, digestion, soft matter, food texture, bioactive compounds, stimuli-responsive materials, Editorial, Next-generation

A bigel is, at its core, a marriage of two gels that normally want nothing to do with each other. One phase is a hydrogel, a network of plant-derived polymers such as proteins or polysaccharides swollen with water. The other is an oleogel, an oil continuous phase trapped inside a solid-like scaffold built from gelators such as waxes, ethylcellulose, or plant sterols. Because both phases are immobilized in their own networks, the resulting material behaves like a solid or semi-solid yet contains substantial water and oil simultaneously. That combination lets formulators replace solid fats in products like spreads, sausages, and bakery items while also using the two compartments as chemically distinct cargo holds: hydrophilic bioactives dissolve into the hydrogel, lipophilic ones dissolve into the oleogel, and neither needs a synthetic solvent to stay put.

The review’s central claim is that this biphasic architecture functions as a release-mechanism regulator rather than a passive container. Three canonical morphologies dominate the literature: oleogel-in-hydrogel, in which oil droplets gelled internally are dispersed through a polymer matrix; hydrogel-in-oleogel, the inverse arrangement; and bicontinuous systems in which both networks interpenetrate. Each geometry favors a distinct digestive trajectory. An oleogel-in-hydrogel design tends to shield the lipid phase behind a swelling polymer wall, delaying contact between dietary lipases and the oil until the bolus reaches the small intestine. A hydrogel-in-oleogel configuration instead embeds the water-based payload inside a fat continuous phase, which can protect water-soluble compounds from the acidic, protease-rich environment of the stomach. Bicontinuous morphologies, meanwhile, offer intermediate pathways whose release kinetics can be steered by tuning the connectivity of each network.

Underlying these broad patterns are specific physical mechanisms that operate during gastrointestinal transit. The review emphasizes that parameters such as the hydrogel-to-oleogel ratio, the density of the oleogel network, and the design of the interface between the two phases modulate how accessible pancreatic lipase and bile salts are to the lipid fraction. When lipase and bile salts reach the oil phase easily, lipolysis proceeds quickly and any lipophilic cargo is liberated early. When the oil is locked inside a dense crystal network or behind a robust interfacial film, lipolysis slows, and release shifts toward the intestinal phase where absorption is most effective. On the aqueous side, the swelling and erosion behavior of the hydrogel network governs how quickly hydrophilic compounds diffuse out, with crosslink density and polymer composition acting as the primary dials.

Across the studies the authors compared, two design rules emerged with unusual consistency. Denser oleogel networks and better-stabilized interfaces reliably slow lipolysis and push release into the intestinal stage, meaning bioaccessibility can be engineered rather than left to chance. Phase architecture, in turn, dictates which payload enjoys protection: the phase that surrounds the other determines whether a hydrophilic or a lipophilic compound is the one shielded from premature exposure. This reframing matters because traditional single-phase delivery systems force formulators to choose one protection strategy for all cargo. In a bigel, a single spoonful of a functional spread could, in principle, carry vitamin D in its oil phase and vitamin C in its water phase, each released on an independently controllable schedule.

Interfacial engineering adds a third, largely independent design dimension. The review highlights three strategies: Pickering stabilization, in which solid particles such as protein or cellulose nanocrystals adsorb at the oil-water boundary and form a physical barrier; amphiphilic gelators that self-assemble into interfacial films; and polysaccharide-layer modification, in which charged biopolymers are deposited onto droplet surfaces to thicken or strengthen the boundary. Because these interfacial layers control how fast lipase, bile salts, and co-solutes can penetrate, they let formulators decouple the release rate from the bulk gelator selection. A wax chosen for its melting profile or clean label status no longer locks in a single release behavior; the interface can be tuned separately to slow or accelerate lipolysis as the application demands.

These structural choices translate into measurable digestive performance. Reported applications show improved encapsulation efficiencies for both hydrophilic and lipophilic bioactives, reduced gastric pre-release of compounds that would otherwise degrade or be absorbed prematurely, and antioxidant synergism when co-encapsulated compounds regenerate or protect one another. The dual-network architecture also acts as a physical barrier against oxidation, since each gelled phase limits oxygen diffusion into the compartment holding its oxidation-sensitive payload. For plant-based food developers, the appeal is twofold: the same material that replaces saturated fat also serves as a delivery vehicle, collapsing two formulation problems into one ingredient.

The review is candid about the obstacles standing between laboratory prototypes and commercial deployment. The most significant is the absence of unified quantitative frameworks that predict release behavior from compositional inputs. Formulators currently cannot feed a bigel recipe into a model and obtain a reliable release curve; instead, each system must be characterized empirically. Compounding this, the field relies heavily on static in vitro digestion models that mimic the mouth, stomach, and intestine in sequential beakers but lack the mechanical shear, enzymatic renewal, and absorption dynamics of a living gut. Without in vivo validation, the review warns, reported bioaccessibility figures may not survive contact with real digestive physiology.

Standardization of characterization methods is a related concern the authors raise implicitly through their cross-study comparisons. Because different laboratories measure network density, interfacial coverage, and release kinetics with different protocols, pooling results across the plant-based literature is difficult, and design principles risk remaining qualitative. The review’s contribution is to organize the existing evidence into a structure-digestion framework, connecting specific formulation levers to specific digestive outcomes so that future studies can test hypotheses rather than rediscover patterns. Whether the community adopts shared benchmarks will determine how quickly the field can move from descriptive case studies to predictive design.

If those constraints are addressed, the authors argue, plant-based bigels could be systematically positioned for commercial deployment in functional foods, nutraceuticals, and pharmaceutical applications within the next decade. The vision is a new generation of plant-based products in which texture, nutrition, and delivery timing are designed together: a vegan cheese that releases vitamin B12 only in the intestine, a spread that protects polyphenols through the stomach, or a nutraceutical matrix that co-delivers fat-soluble and water-soluble actives on independent schedules. For a field long dominated by single-phase emulsions and hydrogels, the bigel’s two-network logic offers something rare in food science, a structural attribute that doubles as a control system, letting designers write the digestive itinerary of a nutrient before the food ever leaves the factory.

Subject of Research: Structural design and digestive behavior of plant-based bigels for controlled nutrient delivery

Article Title: Designing plant-based bigels for controlled nutrient delivery: structural and digestive perspectives

Article References: Shetty, P., Paulin Patricia, P., Sushmithasri, R., & Rawson, A. (2026). Designing plant-based bigels for controlled nutrient delivery: structural and digestive perspectives. Frontiers in Soft Matter, 6, Article 1888400. https://doi.org/10.3389/frsfm.2026.1888400

Image Credits: AI Generated

DOI: 10.3389/frsfm.2026.1888400

Keywords: food science, bigels, controlled release, nutrient delivery, soft matter, plant-based, gastrointestinal digestion, oleogel, hydrogel, functional foods, Designing, controlled

The principle behind these systems is deceptively simple. Instead of chemically altering oil molecules the way hydrogenation does, oleogelation physically entraps edible oils within three-dimensional networks built by tiny amounts of gelators—waxes, fatty acids, monoglycerides, or phytosterols. The unsaturated fatty acid profile of olive, flaxseed, or sunflower oil remains intact, yet the liquid gains solid-like characteristics. Hydrogels work the same trick with water, using hydrophilic polymer chains from alginate, pectin, carrageenan, gelatin, or whey protein to hold large quantities of aqueous phase without dissolving. The result is a semi-solid matrix whose architecture, not its chemistry, determines how it feels in the mouth and how it breaks down in the gut.

The review draws a sharp technical distinction between two classes of structuring agents. Low molecular weight gelators, typically under 2000 daltons, self-assemble through weak non-covalent forces—hydrogen bonds, van der Waals interactions, π–π stacking, and hydrophobic effects—into fibrils, ribbons, helices, or crystalline platelets that entangle into a network. Waxes form dense crystalline platelets, while mixtures of β-sitosterol and γ-oryzanol assemble into tubular fibrillar structures stabilized by hydrogen bonding. Polymeric gelators, by contrast, immobilize liquids through chain entanglement, electrostatic association, and physical or chemical cross-linking, producing continuous matrices with interconnected pores. Each approach has trade-offs: crystalline networks deliver efficient oil structuring at low concentrations but can suffer from polymorphism, temperature sensitivity, and oil leakage, while polymer networks offer superior mechanical strength and thermal stability at higher production cost and lower reversibility.

Crystallization-driven gelation is the most prevalent oleogel mechanism. The gelator dissolves in oil at elevated temperature, then cooling triggers nucleation: small crystalline domains grow as chain segments align, entangle through intervening segments, and cluster into a three-dimensional meshwork that immobilizes oil in its voids by capillary action. The final gel properties depend heavily on crystal morphology, polymorphism, cooling rate, and gelator concentration—small changes in any of these can swing the mechanical properties, oil content, and release behavior dramatically. For high molecular weight polymers that cannot dissolve in oil, indirect methods come into play: a hydrogel or emulsion template is first built and cross-linked chemically, enzymatically with transglutaminase, or by radiation, then the aqueous phase is removed or replaced so the polymer framework stays undisturbed while oil is physically entrapped.

Hydrogel formation follows its own cross-linking logic. Physical hydrogels rely on reversible non-covalent interactions—hydrogen bonding in carboxymethyl cellulose and polyvinyl alcohol, ionic bonding in the famous calcium alginate egg-box structure, and hydrophobic clustering in amphiphilic polymers. These gels are biocompatible and stimuli-responsive but mechanically weak, prone to swelling, syneresis, and premature degradation under manufacturing stress. Chemical hydrogels, built from permanent covalent cross-links formed by grafting agents, polymerization with bifunctional monomers, gamma or electron-beam radiation, or enzymatic catalysis, are far more durable and structurally stable, though residual cross-linkers raise toxicity and biocompatibility questions that regulators scrutinize closely.

Where the review turns genuinely viral is in its treatment of digestion. Structured gels do not just change texture; they change metabolism. In conventional emulsions, lipid droplets are rapidly exposed to pancreatic lipase, producing sudden peaks in blood triglycerides. Oleogels create what researchers call the cage effect: a densely packed crystalline lattice forms a steric barrier that restricts lipase access to the oil–water interface, while the viscous internal environment slows the diffusion of free fatty acids out of the matrix. The consequence is delayed lipolysis, blunted postprandial lipemia, prolonged satiety, and a steadier release of mixed micelles—the bile-salt assemblies that lipophilic nutrients like curcumin, vitamin D, and lycopene need to cross the intestinal mucus barrier. Slower, coordinated lipid digestion can roughly double the absorption of these fat-soluble compounds.

Hydrogels add a second layer of precision: stimuli-responsive delivery. Alginate and pectin networks stay contracted at gastric pH around 2, protecting probiotics, antioxidants, and enzymes from denaturation, then swell or dissolve as pH rises to 6.5–7.0 in the small intestine, releasing their cargo exactly where absorption occurs. Some polysaccharide hydrogels resist human digestive enzymes entirely and break down only through microbial fermentation in the colon, enabling prebiotic effects and targeted colon health. The experimental evidence is striking: alginate–chitosan hydrogels preserved probiotic viability above 70 percent through gastric conditions, while free probiotics fell below 20 percent. κ-Carrageenan hydrogel beads achieved 74.61 percent encapsulation efficiency with sustained, pH-responsive release of curcumin, and curcumin-loaded bigels maintained 97.55 percent curcumin stability with improved digestion performance.

Bigels—hybrid structures containing both an aqueous gel phase and an oil gel phase—represent the review’s vision of all-in-one precision delivery. Because the two phases can be engineered to release their contents on different kinetic schedules, a single bigel can deliver an initial burst of flavor or energy from its hydrogel component in the mouth or upper gut, followed hours later by prolonged release of functional lipids from its oleogel component in the ileum. Incompatible nutrients such as hydrophilic vitamin C and lipophilic vitamin D3 can be co-encapsulated in one matrix, with a prebiotic released in the upper gastrointestinal tract while an antioxidant deploys in the lower regions. Emulsion gels extend this logic further, supporting co-delivery of multiple solutes within soft colloidal structures built from natural polymer self-assembly, cross-linking, crystallization, and molecular template assembly.

The food applications read like a menu from the near future. Ethylcellulose and wax oleogels can replace butter or lard in cookies and cakes, cutting saturated fat content by up to 80 percent while preserving crispness, and stabilize liquid cocoa butter to prevent fat bloom and keep chocolate glossier and heat-resistant. In plant-based meats, carefully tuned ratios of oleogels for fat content and hydrogels for moisture produce white fat particles that do not instantly melt, recreating the succulence of beef and pork; oleogels can also replace pork back fat in sausages with unsaturated olive or flaxseed oil. Bigels from sunflower and canola oil yield margarines that spread straight from the fridge with minimal trans fats, while hydrogel–oleogel substitutes for casein improve melting in vegan cheeses. These gels are also ideal inks for 3D food printing: their shear-thinning rheology lets them flow under pressure but hold shape at rest, allowing printers to deposit precise nutrient doses into customized snacks, and hydrogel coatings sprayed on strawberries or avocados measurably extend shelf life.

Commercialization remains the hard part. Scaling up requires precise thermal control and consistent gelator sourcing, and natural gelators vary batch to batch in rheology, strength, and encapsulation efficiency. Consumer acceptance hinges on mouthfeel, taste, and flavor release, while novel formulations must pass GRAS evaluation in the United States and EFSA safety assessment in the European Union, covering toxicity, digestibility, allergens, and migration. The clean-label trend may restrict synthetically produced systems, and few studies have yet combined performance data with techno-economic assessment or converted in vitro digestion results into validated in vivo human outcomes. Still, the trajectory is clear: personalized nutrition, AI-based formulation, sustainable gels from agricultural waste, and hybrid bigel systems are converging on a future where food structure is designed molecule by molecule. Oleogels and hydrogels are no longer laboratory curiosities—they are the emerging soft matter platforms for the next generation of nutritional foods, where what holds your food together may also decide how well it feeds you.

Subject of Research: Soft matter food structuring and targeted nutrient delivery

Article Title: Advanced oleogel and hydrogel systems: emerging platforms for food structuring and targeted nutrient delivery

Article References: Pandey, R., & Mathur, G. (2026). Advanced oleogel and hydrogel systems: emerging platforms for food structuring and targeted nutrient delivery. Frontiers in Soft Matter, 6, Article 1867312. https://doi.org/10.3389/frsfm.2026.1867312

Image Credits: AI Generated

DOI: 10.3389/frsfm.2026.1867312

Keywords: oleogels, hydrogels, bigels, food science, nutrient delivery, soft matter, digestion modulation, 3D food printing, Advanced, oleogel, hydrogel, systems

Bigels are biphasic gel systems in which an oleogel—a network of structuring agents that traps liquid oil without any solid fat—meets a hydrogel, a water-based gel built from proteins or polysaccharides. Unlike conventional emulsions, both phases in a bigel are already solid-like on their own. When they are blended together, the result is a hybrid material whose architecture can be tuned continuously between two extremes: droplets of oleogel suspended in a continuous hydrogel, droplets of hydrogel dispersed in a continuous oleogel, or a bicontinuous structure in which both networks interpenetrate.

The review, authored by Bing Li, Mingyu Qi, Hengpeng Wang, Hui Zhang, and Xiangren Meng of Yangzhou University together with Bimal Chitrakar of Hebei Agricultural University, synthesizes a rapidly growing body of literature on how composition and processing govern the phase structure and interfacial properties of these systems. According to the authors, the choice of gelling agents, the ratio of hydrogel to oleogel, and fabrication variables such as mixing speed and temperature all shift the balance between the two phases. That shift, in turn, determines whether the finished bigel behaves as a firm, sliceable solid or a soft, spreadable cream—a degree of control that is crucial when a fat substitute must adapt to wildly different food matrices, from cookie dough to mayonnaise.

The rheological fingerprint of a bigel is central to its utility. Studies summarized in the review show that as the oleogel fraction increases, bigels generally display higher storage modulus, greater firmness, and more pronounced solid-like behavior, while hydrogel-dominated formulations yield softer, more elastic textures. Phase inversion—where increasing the concentration of structuring proteins such as soy protein isolate flips the continuous phase from water-continuous to oil-continuous—offers another powerful lever. By understanding these structure-property relationships, formulators can dial in the exact mechanical response a given product demands, whether that is the plasticity of butter, the cohesiveness of sausage fat, or the flow of a cake batter.

On the fat-substitution front, the review catalogues impressive progress. Bigels built from candelilla wax oleogels and guar gum hydrogels, gelatin and kappa-carrageenan hydrogels paired with monoglyceride olive oil oleogels, and rice bran wax systems with gums and monoglycerides have all been deployed to replace saturated or trans fats in cookies, shortbread, sausages, and fermented meat products. In semi-dry sausages, bigel systems partially replaced pork backfat while preserving physicochemical and sensory characteristics. Fish oil-based bigels have been formulated into low-fat mayonnaise with outstanding sensory and antioxidant properties, effectively converting a reformulation challenge into a vehicle for omega-3 fatty acids. Plant-based bigels have even been 3D-printed into meat analogues, exploiting whole soybean particles as Pickering stabilizers.

The mechanism behind this success is structural mimicry. Animal fats and commercial shortenings are, at the microstructural level, assemblies of fat crystals surrounding liquid oil. A bigel reproduces this hierarchy using two mutually immiscible gel networks instead: the oleogel phase supplies the lipid body and lubrication, while the hydrogel phase contributes water-holding capacity, elasticity, and a creamy particle-like sensation on the tongue. Research on konjac glucomannan-gelatin binary hydrogel bigels has shown that composition and phase ratio can even be tuned to adjust oral sensation—how the material melts, coats, and breaks down during chewing—bringing reformulated products closer to the sensory benchmark of the full-fat originals.

Where bigels arguably shine even brighter is in nutrient delivery. Because the two phases are chemically distinct, a single bigel can load hydrophobic bioactives such as curcumin, lycopene, beta-carotene, or lutein into the oleogel network while simultaneously hosting hydrophilic compounds like riboflavin, epigallocatechin gallate, or N-acetylneuraminate in the hydrogel phase. This co-delivery capability addresses a chronic problem in functional food design: many nutraceuticals are either poorly soluble in water or unstable in oil, but rarely can a single carrier accommodate both classes at once. Bigel systems produced through whey protein isolate cold-set gelation have demonstrated simultaneous vehiculation of curcumin and riboflavin, while glycerol monostearate-modified bigels have improved the co-delivery of curcumin and catechins from tea.

Controlled release is the second half of the delivery story. The review highlights bigel formulations that protect sensitive cargo through the harsh acidic environment of the stomach and release it further down the gastrointestinal tract. Lycopene carried in monoglyceride-beeswax oleogel paired with gellan gum hydrogel survived delivery far better than in simpler systems, and lutein in a bigel matrix showed superior gastric protection with controlled release and an enhanced antioxidant profile. Probiotics have benefited as well: lecithin-stearic acid and whey protein bigels boosted the survival of beneficial bacteria during simulated digestion, and Lactobacillus plantarum encapsulated in soy lecithin-beeswax oleogel with flaxseed gum hydrogel showed enhanced survival during both storage and gastrointestinal transit—findings with obvious implications for functional yogurts and spreads.

Heat-triggered release adds another dimension. Bigels based on candelilla wax oleogels and guar gum hydrogels have been engineered to remain stable during storage but release their payload when heated during cooking or consumption, a property that could allow flavor or nutrient release precisely at the moment of eating. Interface engineering pushes this further: modifying the boundary between oleogel and hydrogel phases in bigel beads has enhanced stability and prolonged the release of encapsulated bioactives, effectively turning each bead into a programmable microcapsule.

The authors frame their synthesis as a roadmap rather than a victory lap. Mapping structure-property-application relationships across oleogel-in-hydrogel, hydrogel-in-oleogel, and bicontinuous bigel types, they identify actionable levers—oleogelator selection, hydrogel composition, phase ratio, and processing—for improving texture and nutritional performance in low-fat formulations. Challenges remain, including oxidation of unsaturated oils within oleogel networks, scale-up of fabrication processes, and long-term storage stability. But with global burden of disease data pointing to persistent malnutrition and obesity across 204 countries, a technology that lets manufacturers remove the worst fats while adding protective nutrients in the same structural gesture is the kind of quietly elegant solution that could reshape the supermarket shelf.

Subject of Research: Bigel biphasic gel systems for fat substitution and nutrient delivery in foods

Article Title: Bigel with tailored functional characteristics: applications in fat substitution and nutrient delivery

Article References: Li, B., Qi, M., Wang, H., Zhang, H., Chitrakar, B., & Meng, X. (2026). Bigel with tailored functional characteristics: applications in fat substitution and nutrient delivery. Food Science and Biotechnology. https://doi.org/10.1007/s10068-026-02292-9

Image Credits: AI Generated

DOI: 10.1007/s10068-026-02292-9

Keywords: bigels, oleogel, hydrogel, fat substitute, nutrient delivery, rheology, food structure, bioactive compounds, controlled release, low-fat foods, probiotics, food science