The research team, led by Ying Han and Xin Yang, screened a wide range of sugars, from monosaccharides like arabinose and fructose to polysaccharides and sugar derivatives, before settling on chitosan oligosaccharides, or COS, with a degree of polymerization of just 2 to 6 sugar units. Unlike fructose, which has previously been shown to induce curcumin self-assembly but merely stabilizes environmental charge without participating in the assembly itself, COS are the only naturally charged amino saccharides and carry meaningful biological activity of their own. That distinction matters: if the sugar is not just a passive inducer but an active structural partner, then the biological activities of both the carrier and the cargo can be exploited simultaneously. The resulting co-assembled nanoparticles achieved a drug loading content of 41.56 percent and an entrapment efficiency of 76.73 percent, figures that stand well above the roughly 10 to 15 percent loading typical of many conventional curcumin delivery systems.

Getting the particles to the right size proved to be the study’s central technical challenge. Initial co-assemblies formed regular spheres but aggregated into micron-scale clusters of roughly 1 to 1.2 micrometers, far too large for the enhanced permeability and retention effect that allows nanoparticles to accumulate passively in tumor tissue, which generally requires particles below about 200 nanometers. Intriguingly, the researchers found that almost none of the obvious processing variables mattered. Solvent polarity, tested across methanol, ethanol, dimethyl sulfoxide, acetone, and ethyl acetate, had no effect on particle size. Neither did carrier concentration, stirring speed, stirring time, or stirring method. Because the COS molecules themselves self-assemble into structures below 50 nanometers, the team concluded the micron-sized objects were agglomerates of small nanoparticles, and that the answer lay in controlling aggregation rather than formation.

The fix came from an unexpected quarter: an inorganic electrolyte. After testing various salts and surfactants, the team found that adding sodium carbonate during assembly kept the particles below the critical size threshold. Dynamic light scattering confirmed the adjusted particles measured around 200 nanometers, with scanning electron microscopy revealing irregular, sphere-like accumulations and transmission electron microscopy showing that each particle was itself composed of several smaller nanoparticles with a sharp light-dark contrast between center and edge. Contact angle measurements showed the composite surface had become substantially more hydrophilic than free curcumin, consistent with a structure in which hydrophobic curcumin is buried inside while hydrophilic COS chains face outward toward water. The particles carried a slightly negative zeta potential, a surface charge profile associated with improved blood compatibility, reduced clearance by the reticuloendothelial system, and longer serum half-life.

Spectroscopy and molecular dynamics simulations together revealed the forces holding the assembly together. Ultraviolet-visible spectra showed a slight red shift of curcumin’s characteristic 435-nanometer absorption peak upon incorporation, indicating hydrogen bonding between the sugar and the polyphenol, a shift that weakened as sodium carbonate levels rose, presumably because the salt competed with hydrogen ions and disrupted the bonding. When the nanoparticles were exposed to 0.2 percent sodium dodecyl sulfate, the absorption peak shifted blue, signaling disassembly and confirming that hydrophobic interactions also contribute to the structure. Fourier transform infrared spectroscopy showed characteristic shifts in the hydroxyl, carbonyl, and carbon-oxygen stretching regions of the composite relative to a simple physical mixture of the two components. Simulations performed with the COMPASS force field predicted strong hydrogen bonds between chitotetraose, the dominant oligomer in the mixture, and curcumin, with bond lengths of roughly 2.02 and 2.56 angstroms, and showed the molecules spontaneously tending toward spherical arrangements.

The functional payoff was dramatic. Free curcumin exhibits an apparent aqueous solubility of just 0.0923 percent, but once incorporated into the COS nanoparticles, that figure rose to 99.87 percent, an enhancement of approximately 1,100-fold. Under simulated gastrointestinal digestion, moving from gastric fluid at pH 2.0 containing pepsin to intestinal fluid at pH 7.0 containing pancreatin, the area under the release curve for the nanoparticles was more than 15 times higher than for free curcumin, indicating far greater gastrointestinal availability. The authors are careful to note that this demonstrates enhanced gastrointestinal release performance rather than directly establishing systemic bioavailability, but the implication for functional foods and nutraceuticals is clear: a curcumin that actually disperses in aqueous food matrices and survives to be absorbed.

Release behavior under other conditions reinforced the picture of a stable but responsive carrier. At physiological temperature, the nanoparticles released about 31 percent of their curcumin payload at pH 7.4, simulating blood circulation, about 33 percent at pH 6.7, simulating the tumor microenvironment, and about 45 percent at pH 5.6, simulating the endosomal and lysosomal compartments inside cells. The absence of an initial burst release suggests the hydrogen bonding and hydrophobic interactions that build the assembly also restrain premature curcumin leakage during transport. The particles showed no obvious change in particle size over 30 days of storage, and hemolysis assays on fresh mouse blood found rupture rates below the 5 percent safety threshold at all tested concentrations, supporting the system’s biocompatibility.

Biological testing showed the co-assembly did more than improve solubility. In 4T1 mouse breast cancer cells, the IC50 of the nanoparticles dropped to 10.54 micrograms per milliliter compared with 20.64 for free curcumin, a roughly 49 percent reduction corresponding to nearly a doubling of antiproliferative potency, with a combination index of 0.81 suggesting synergy between the sugar and the drug. In MCF-7 human breast cancer cells the effect was even more pronounced: the IC50 fell from 16.96 to 1.33 micrograms per milliliter, a 12.75-fold increase in apparent potency with a combination index of 0.78. Flow cytometry showed the nanoparticles pushed cells out of the G0/G1 phase and accumulated them in G2/M, with 46.33 percent of treated cells in that phase versus 3.75 percent of controls. Fluorescence microscopy confirmed time-dependent accumulation of the particles in the cytoplasm of 4T1 cells.

In tumor-bearing BALB/c mice, fluorescently labeled nanoparticles injected via the tail vein rapidly distributed to liver, kidney, and tumor tissue; signals in liver and kidney faded over time while the tumor retained a strong, persistent fluorescence, consistent with passive EPR-mediated targeting. Mice treated with the nanoparticles showed significantly lower tumor volumes than those given free curcumin or COS alone, with the relative tumor inhibition rate rising from 58 percent for free curcumin to 73 percent for the co-assembled formulation over 12 days of treatment. Body weight, liver and kidney function markers including ALT, AST, ALP, bilirubin, creatinine, uric acid, and blood urea nitrogen, and histopathological staining of major organs showed no significant toxicity. The work was funded by the National Natural Science Foundation of China and approved by the Experimental Animal Ethics Committee of Ningbo University.

What makes the study notable beyond its headline numbers is its simplicity. Lipid carriers can solubilize hydrophobic compounds but suffer from physical and oxidative instability; synthetic polymer nanoparticles offer design flexibility but involve materials and processes less suited to food applications. The COS-curcumin system requires nothing more exotic than mixing a water solution of short sugar chains with a curcumin stock in dimethyl sulfoxide under stirring, plus a pinch of sodium carbonate to tame aggregation. By establishing a direct structure-assembly-function relationship, in which molecular complementarity between hydrophilic oligosaccharides and the hydrophobic polyphenol drives both nanoparticle formation and performance, the researchers point toward carbohydrate-based nanomaterials as sustainable, food-compatible platforms for delivering not just curcumin but a broader class of poorly water-soluble phytochemicals into functional foods and nutritional products.

Subject of Research: Chitosan oligosaccharide-curcumin co-assembled nanoparticles for enhancing curcumin solubility and bioavailability

Article Title: Co-assembly of Highly Active Chitosan Oligosaccharide with Curcumin to Improve Its Bioavailability

Article References: Han, Y., Fu, S., Que, C., Zhang, Z., Song, A., Cao, J., Wang, J., Zhang, H., & Yang, X. (2026). Co-assembly of Highly Active Chitosan Oligosaccharide with Curcumin to Improve Its Bioavailability. Current Research in Food Science, Article 101582. https://doi.org/10.1016/j.crfs.2026.101582

Image Credits: AI Generated

DOI: 10.1016/j.crfs.2026.101582

Keywords: curcumin, chitosan oligosaccharides, nanoparticles, co-assembly, bioavailability, drug delivery, functional foods, nutraceuticals, hydrogen bonding, antitumor activity, water solubility, food science

The motivation behind the work lies in one of the most pressing challenges of the coming decades. The world’s population, which surpassed 7.6 billion in 2018, is projected to reach 9.2 billion by 2050, and food demand is expected to rise by anywhere from 59 to 102 percent. Global meat consumption is anticipated to climb in parallel, reaching an estimated 4.55 million tons by 2050, with developing countries accounting for 56 percent of feed grain consumption. Against this backdrop, cultured meat, produced by cultivating livestock cells rather than slaughtering animals, has attracted intense interest as a way to conserve finite resources, address animal welfare concerns, and reduce the environmental footprint of protein production. Yet conventional cultured meat approaches, which rely on cells alone, have largely been limited to simple forms such as patties.

This is where 3D bioprinting enters the picture. By depositing cell-laden materials layer by layer, bioprinting can produce constructs in a wide variety of shapes that more closely mimic traditional meat products. It also allows researchers to optimize the cell growth environment, shortening production time, minimizing raw material use, and improving cost-effectiveness, while opening the door to customized meat tailored to individual dietary preferences or health needs. The critical enabling ingredient in this process is the bio-ink itself, typically built from materials such as alginate and gelatin, whose properties ultimately determine the quality of the final product. Gelatin, a degradation product of collagen, is prized for its excellent biocompatibility and its ability to support cell attachment, proliferation, growth, and differentiation, all of which are essential for natural and efficient tissue formation.

What has been missing, the authors argue, is a food-focused perspective. Most prior studies of gelatin-based bio-inks have been rooted in tissue engineering and biomedical applications, prioritizing biocompatibility and mechanical performance without adequately considering edibility, food-grade applicability, and source-dependent functionality within a food system. For cultured meat, bio-ink materials must simultaneously provide structural stability and printability while remaining suitable for consumption and scalable for food production. Systematic comparisons of edible animal-derived gelatin sources under standardized formulation conditions have been scarce, so the Korean team set out to fabricate bio-inks from bovine, porcine, and fish gelatin powders under unified conditions and to evaluate how source and concentration independently and interactively influence rheological behavior, printability, and structural properties.

The experimental design was straightforward but rigorous. Beef gelatin from Holstein cattle, pork gelatin from Landrace-Yorkshire-Duroc pigs, and fish gelatin from salmon, all with molecular weights ranging from roughly 10 to 100 kilodaltons depending on source, were dissolved in distilled water at concentrations of 4, 12, 20, 32, and 40 percent by weight at 45 degrees Celsius. Because gelatin-only formulations showed insufficient thermal stability at the 37 degrees Celsius incubation temperature used in cell culture, each gelatin solution was mixed 1:1 with a 6 percent sodium alginate solution, a supporting polymer that improves structural stability during printing and post-printing incubation. The blends were loaded into printing cartridges and stored at 4 degrees Celsius before testing. Printability trials used a Cellink BIO-X bioprinter with 27-gauge conical nozzles, a print bed held at 10 degrees Celsius, a print speed of 5 millimeters per second, and a pressure of 150 kilopascals, followed by ionic cross-linking in a 100 millimolar calcium chloride bath.

The results revealed systematic patterns across nearly every measured property. As gelatin concentration increased, pH decreased in all three sources, a trend the researchers attribute to the rising content of acidic amino acids such as aspartic and glutamic acid, which elevate hydrogen ion concentration as collagen breaks down into gelatin. Notably, fish gelatin samples consistently showed the highest pH values, a difference thought to reflect the vitamins, minerals, and amino acid profiles specific to each livestock species. Because higher pH levels are associated with increased metabolic activity in cells, the authors suggest that bio-inks with elevated pH may be particularly suitable as scaffold materials for cultured meat production. Color measurements told a complementary story: lightness declined with increasing gelatin concentration while redness and yellowness rose, and beef gelatin samples were significantly more yellow than the others, likely because bovine gelatin contains more lysine and other amino acids susceptible to the Maillard reaction, the non-enzymatic browning that occurs when the powder is dried in the presence of atmospheric oxygen.

Viscosity, arguably the most important rheological property for extrusion printing, showed the sharpest source-dependent differences. Initial viscosity increased with gelatin concentration in all formulations, but pork gelatin exhibited the highest values across every concentration tested. The explanation lies in molecular architecture: pork gelatin possesses greater structural integrity of its beta and gamma chains, creating physical entanglements that impede polymer flow, whereas fish gelatin has a looser structure with weaker intermolecular bonds and lower levels of proline and hydroxyproline, the amino acids that govern gelation and melting point, making it heat-sensitive and unable to build high viscosity even at elevated concentrations. Intriguingly, the most concentrated pork gelatin formulations, at 32 and 40 percent, showed viscosity that declined over time, apparently because excessive intermolecular interactions at very high concentrations prevent the formation of a stable gel network and increase internal stress. This observation led the team to recommend keeping porcine gelatin below 32 percent when manufacturing bio-ink.

Printability tests drove the study’s central conclusion home. At 4 percent, all three gelatin types extruded as a liquid with no visible lattice formation whatsoever. Beef and fish gelatin at 12 and 20 percent could be extruded but collapsed rapidly, retaining lattice structures only up to 0.3 centimeters in height. Pork gelatin, by contrast, formed partial lattices at 12 and 20 percent and was the only formulation to maintain scaffold integrity up to 0.5 centimeters. At 32 and 40 percent, pork gelatin became so solidified that it could not be extruded at all, a consequence of hydrogen bonding and van der Waals forces increasing the material’s elastic restoring force until it behaved more like a solid than a printable viscoelastic fluid. The richer proline and hydroxyproline content of porcine gelatin appears to foster stronger hydrogen bonding and a more stable three-dimensional network, providing the internal binding strength needed to resist gravitational collapse after deposition.

Structural analysis and statistical correlation rounded out the picture. Under the microscope, pork gelatin scaffolds displayed rougher surfaces than the other sources, a feature that may actually benefit cultured meat production by increasing surface irregularities and contact area for cell attachment. The 20 percent pork gelatin sample showed significantly higher grid size and gel strength than all other formulations, a combination the researchers highlight as a favorable balance: larger grid sizes facilitate nutrient diffusion and material exchange within the printed structure, while greater gel strength preserves scaffold integrity during handling and culture. Pearson correlation analysis quantified these relationships, revealing a strong positive correlation between gel strength and viscosity with a coefficient of 0.88, and between grid size and gel strength with a coefficient of 0.89. Even color proved tightly linked, with redness and yellowness showing a near-perfect correlation of 0.99, suggesting that bio-ink color tone can be controlled predictably, an attribute the authors note matters for the appearance quality control of commercial cultured meat.

Taken together, the findings offer a practical recipe for the emerging cultured meat industry: choose pork gelatin, keep the concentration near 20 percent, and pair it with alginate for thermal stability. The work also underscores a broader lesson in biomaterials science, that seemingly minor differences in molecular composition, down to the amino acid content of a protein extracted from a particular animal’s skin, can cascade into dramatic differences in how a material flows, gels, and holds its shape under a printing nozzle. As the demand for alternative proteins accelerates, studies like this one, which treat food-grade applicability as seriously as mechanical performance, will help determine whether 3D-printed cultured meat can move from laboratory demonstration to dinner plate.

Subject of Research: Physicochemical and printability properties of animal-derived gelatin bio-inks for 3D-printed cultured meat scaffolds

Article Title: Physicochemical properties of 3D bio-ink prepared with beef, pork, and fish gelatin

Article References: Kang, K.-M., Lee, S.-H., & Kim, H.-Y. (2026). Physicochemical properties of 3D bio-ink prepared with beef, pork, and fish gelatin. Food Science of Animal Resources, 46(1), Article 66. https://doi.org/10.1007/s44463-026-00071-y

Image Credits: AI Generated

DOI: 10.1007/s44463-026-00071-y

Keywords: gelatin, bio-ink, 3D bioprinting, cultured meat, pork gelatin, printability, viscosity, gel strength, scaffolds, sodium alginate, food science, collagen

Lipid oxidation is one of the chief enemies of food quality. When unsaturated fatty acids react with oxygen, they form hydroperoxides, aldehydes, and a cascade of secondary products that ruin flavor, erode nutritional value, and raise safety concerns. Two measurements dominate the monitoring of this decay: the peroxide value, which tracks the early stage of peroxidation, and malondialdehyde, or MDA, a hallmark of advanced oxidative chain-scission. Photooxidation, in which light energizes the process, is among the most damaging pathways, yet the precise role of heme proteins in accelerating it has remained surprisingly underexplored.

The research team, led by Mahdi Hajimohammadi of Kharazmi University in collaboration with colleagues in Iran and Iraq, set out to close that gap. Rather than isolating purified hemoglobin, they used intact erythrocyte suspensions derived from commercially supplied sheep blood, preserving the protein’s native structure and redox environment. This choice made the system biologically realistic: hemoglobin remained embedded in the matrix it normally occupies, at the boundary between an aqueous phase and the oil droplets of a commercial canola oil emulsion. The mixture was illuminated by a solar simulator, an array of 276 LED lamps spanning 380 to 780 nanometers and delivering an intensity of roughly 59,660 lux, closely matching the spectrum of natural sunlight.

The results were striking. After 2.5 hours of irradiation in the presence of air, the peroxide value of the oil climbed to 9.7 milliequivalents of oxygen per kilogram, while control experiments kept in the dark, lacking hemoglobin, or starved of oxygen showed only trace oxidation. The conclusion was unambiguous: hemoglobin, oxygen, and light must all be present simultaneously for the reaction to proceed efficiently. Under true sunlight, the peroxide value reached an even higher 10.5, confirming that the laboratory simulator faithfully reproduces the outdoor process. Spectroscopic monitoring of the heme’s characteristic Soret absorption band at 407 nanometers revealed a 69.8 percent decline over extended irradiation, evidence that the photosensitizer itself is progressively degraded as it works.

To dissect the mechanism, the researchers deployed chemical scavengers as molecular interrogators. Adding butylated hydroxytoluene, a potent free-radical quencher, cut the peroxide value to 3.8, implicating carbon-centered radicals generated by hydrogen abstraction. Adding sodium azide, a classic singlet oxygen scavenger, suppressed oxidation even further, to 3.1, demonstrating that singlet oxygen, an excited and highly reactive form of molecular oxygen, is a major player. Both pathways operate at once, which helps explain why hemoglobin outperformed two benchmark oxidants: the dye Rose Bengal, a selective singlet oxygen generator that achieved a peroxide value of only 6.8, and potassium permanganate, a classical chemical oxidant that managed just 2.1 under comparable conditions.

Proton nuclear magnetic resonance spectroscopy provided product-level confirmation of the damage. Signals from vinylic protons on the oil’s carbon-carbon double bonds, at chemical shifts of 5.2 to 5.4 parts per million, fell by 31.2 percent, consistent with singlet oxygen attacking double bonds through ene reactions. Bis-allylic protons, at 2.7 to 2.8 parts per million, declined even more sharply, by 36.9 percent, a signature of radical-mediated hydrogen abstraction at the most vulnerable positions of polyunsaturated fatty acids. A new aldehydic resonance near 9.5 parts per million announced the formation of MDA, the definitive marker of advanced peroxidation and chain scission. Perturbations in the glycerol proton region around 4.1 parts per million suggested that radical-driven beta-scission was even cleaving the ester bonds of the triglyceride backbone, fragmenting the oil into smaller, more polar molecules.

An independent probe sealed the case for singlet oxygen. Anthracene, a compound that reacts selectively with singlet oxygen to form a colorless endoperoxide, lost roughly 33 percent of its absorbance at 375 nanometers after four hours of irradiation in the hemoglobin-oil system, and sodium azide largely halted the bleaching. The solvent experiments added a subtle layer of physical chemistry: oxidation efficiency followed the order acetonitrile, ethanol, acetone, methanol, then dimethyl sulfoxide, mirroring the known lifetimes of singlet oxygen in these media, which range from about 65 microseconds in acetonitrile down to 19 microseconds in DMSO. Highly coordinating solvents like DMSO may also interfere with the formation of ferryl heme intermediates, the high-valent iron-oxo species suspected of driving the radical pathway.

That ferryl pathway remains the tentative half of the mechanism. The authors are careful to note that they did not directly observe the ferryl species, hemoglobin iron in the +4 oxidation state bound to oxygen. Its involvement is inferred from indirect evidence: the suppressive effect of the radical scavenger BHT, the preferential depletion of bis-allylic protons, and the damping effect of DMSO. Previous work on related metalloporphyrin and hemoglobin systems has detected ferryl intermediates spectroscopically, lending plausibility to the interpretation, but direct confirmation in this food system awaits future study. Even so, the combined evidence supports a dual oxidative engine: singlet oxygen generated by energy transfer from the light-excited heme, working in parallel with a heme-iron radical chemistry that abstracts hydrogen from the lipid chains.

The implications stretch well beyond the shelf life of bottled oil. Hemoglobin is abundant, biodegradable, and essentially free, recovered as a by-product of meat processing that would otherwise be discarded. The study’s preliminary results suggest that this waste protein could be harnessed as a low-cost photosensitizer for sunlight-driven degradation of lipid-rich effluents from edible oil processing, replacing ozonation and Fenton treatments that demand harsh chemical oxidants and energy-intensive conditions. The authors caution that real industrial wastewater, long-term protein stability under continuous illumination, light penetration, oxygen transfer, and reactor scale-up all remain to be tested. Still, the vision is compelling: a circular food system in which blood from the slaughterhouse becomes a solar-powered catalyst for cleaning the oil industry’s dirtiest water, while simultaneously teaching food scientists exactly how to keep light and heme apart to protect the products on our shelves.

Subject of Research: Hemoglobin-mediated sunlight-induced lipid oxidation in edible oils and its potential for sustainable wastewater treatment

Article Title: Sunlight‐Induced Lipid Oxidation and Degradation of Edible Oil Mediated by Hemoglobin: Implications for Food System Sustainability

Article References: Hajimohammadi, M., Faraj, F. H., Boghdachi, M., Alwasiti, A. A., & Shnain, Z. Y. (2026). Sunlight‐Induced Lipid Oxidation and Degradation of Edible Oil Mediated by Hemoglobin: Implications for Food System Sustainability. Food Science & Nutrition, 14(10), Article e72423. https://doi.org/10.1002/fsn3.72423

Image Credits: AI Generated

DOI: 10.1002/fsn3.72423

Keywords: hemoglobin, lipid oxidation, singlet oxygen, edible oil, photosensitizer, photooxidation, malondialdehyde, ferryl heme, food science, wastewater treatment, circular economy, sunlight

The motivation behind the work is a genuine public health problem. Raw meat-based diets, particularly those fed to pets, retain their natural nutritional profile and palatability but carry inherent zoonotic risks in the shared living environments of animals and their owners. Regulatory bodies including the U.S. Food and Drug Administration and the American Veterinary Medical Association have warned about pathogen-contaminated raw pet food, yet conventional thermal sterilization destroys the very qualities that make raw diets appealing. High hydrostatic pressure offers an alternative: it transmits pressure uniformly through a product regardless of shape or size, works on sealed packages to prevent recontamination, has regulatory approval in major markets, and preserves heat-sensitive nutrients and flavors.

The study’s experimental design was deliberately broader than most previous work. Earlier investigations typically tested a narrow pressure range of 200 to 400 megapascals and examined either microbial safety or physicochemical quality in isolation. Here, pork samples were artificially contaminated with multiple strains of Escherichia coli, Bacillus cereus, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus, reaching initial populations of roughly 10^5 to 10^8 colony-forming units per gram. Vacuum-sealed samples were then treated in an industrial high-pressure sterilizer maintained at 21 degrees Celsius internally, creating a graduated pressure-time matrix that had never been systematically evaluated for raw pork intended for pet food.

The microbial results were striking and strongly pressure-dependent. Treatment at 500 megapascals for fifteen minutes produced the most pronounced inactivation across all organisms, and Salmonella Typhimurium and Listeria monocytogenes were reduced to below the detection limit during subsequent refrigerated storage. The mechanism is physical rather than chemical: compressive forces deform cell membranes and walls, increase membrane permeability, disrupt intracellular ion balance, dissociate ribosomes, and inactivate enzymes, ultimately collapsing cellular homeostasis. Pressures above 100 megapascals alter the phospholipid bilayer itself, impairing nutrient transport and energy metabolism.

Not every pathogen surrendered equally easily, however, and the species-specific patterns proved scientifically revealing. Although gram-positive bacteria are generally considered more pressure-resistant thanks to their thicker peptidoglycan layers, Listeria monocytogenes, despite being gram-positive, was completely eliminated under the harshest conditions, while Staphylococcus aureus showed the highest resistance of all organisms tested. Staphylococcus possesses a thick, highly cross-linked peptidoglycan layer of roughly 20 to 40 nanometers, and in the most intense treatment group its counts actually increased during storage, suggesting recovery and regrowth from sublethal injury. Bacillus cereus and E. coli also remained detectable under most conditions, with Bacillus spores protected by a multilayered structure that distributes pressure and maintains a dehydrated core stabilized by calcium-dipicolinic acid complexes.

The physicochemical consequences of pressure treatment were equally systematic. As pressure and holding time increased, water-holding capacity, shear force, and pH all rose above control values, while moisture and protein contents increased and fat and ash decreased. The researchers attribute these shifts to pressure-induced denaturation and reorganization of myofibrillar proteins. The non-covalent bonds that maintain protein structure, including ionic bonds, hydrogen bonds, and hydrophobic interactions, are voluminous and unstable under pressure, so when secondary and tertiary structures collapse, myosin partially unravels and exposes polar and charged groups that bind water. The resulting compact protein network traps moisture in a gel-like matrix but also cross-links myosin aggregates, making crack propagation difficult and increasing mechanical strength, which explains the higher shear force.

Color changes followed a nuanced pattern tied to the pigment myoglobin and to light-scattering physics. Lightness increased with pressure and time, redness peaked in the 300 megapascal groups before falling again at 500 megapascals, and yellowness was highest in the 500 megapascal, five-minute group. Previous research has shown that dramatic pressure-induced color changes in meat generally appear only above roughly 400 to 600 megapascals, leaving color largely preserved at lower intensities. The observed paleness here is attributed more to protein denaturation and microstructural changes that enhance light scattering than to straightforward myoglobin oxidation, a combined effect rather than a single pigment transformation.

Oxidation and spoilage chemistry told a two-sided story. Thiobarbituric acid reactive substances, a marker of lipid oxidation, rose with pressure and time, reaching their highest values in the 500 megapascal, fifteen-minute group and climbing further during storage. Pressures between 300 and 700 megapascals disrupt phospholipid membranes and expose lipids to oxygen and pro-oxidants, while structural changes in heme proteins can release iron ions that catalyze oxidative chain reactions. In contrast, volatile basic nitrogen, an indicator of protein decomposition and spoilage, was suppressed by treatment, with the 500 megapascal, five-minute group showing the lowest increase rate during storage at just 13.24 percent compared with 111.72 percent in the mildest group. Microbial inactivation and pressure-induced enzyme inactivation both limit the production of ammonia and volatile amines.

Correlation analysis tied the whole picture together. Pressure and holding time correlated negatively with all tested microorganisms, redness, and volatile basic nitrogen, while water-holding capacity, shear force, pH, lightness, yellowness, and lipid oxidation correlated positively, all consistent with cumulative pressure-induced effects on membranes, myofibrils, myoglobin, and enzymes. The authors conclude that while high hydrostatic pressure effectively inactivated Salmonella and Listeria, enhanced water retention, and suppressed spoilage markers, it also produced a paler appearance, increased lipid oxidation, and failed to achieve complete microbial elimination, with pressure-tolerant organisms surviving or recovering.

The practical takeaway is that pressure treatment should not be deployed as a stand-alone solution. The researchers recommend integrated hurdle strategies, combining pressure with salt addition, antimicrobial agents, optimized packaging, and strict refrigerated storage management, to push microbial safety further while preserving quality. For a food industry increasingly interested in minimally processed products, the study provides something rare: a complete pressure-time map showing exactly where pathogen reduction ends and quality degradation begins, at least for raw pork. As demand for raw pet food and clean-label meats grows, that map may prove one of the most useful tools yet for producers navigating the delicate balance between safety and freshness.

Subject of Research: Effects of high hydrostatic pressure processing on microbial inactivation and physicochemical quality of raw pork

Article Title: Application of high hydrostatic pressure on the microbial and physicochemical characteristics of pork

Article References: Baek, U.-B., & Kim, H.-Y. (2026). Application of high hydrostatic pressure on the microbial and physicochemical characteristics of pork. Food Science of Animal Resources, 46(1), Article 73. https://doi.org/10.1007/s44463-026-00091-8

Image Credits: AI Generated

DOI: 10.1007/s44463-026-00091-8

Keywords: high hydrostatic pressure, food safety, pork, microbial inactivation, non-thermal processing, Salmonella, Listeria monocytogenes, lipid oxidation, myofibrillar protein, water-holding capacity, raw pet food, food science

The achievement is notable because of what the protein lacks. Most well-studied sweet proteins carry stabilizing features that honey truffle sweetener simply does not have. Thaumatin, mabinlin, and brazzein contain multiple disulfide bonds and mixtures of alpha-helices and beta-sheets; neoculin is reinforced by extensive disulfide crosslinks; even monellin, which is largely beta-rich, retains a short stabilizing helix. Honey truffle sweetener, by contrast, is cysteine-free and helix-free—a compact bundle of beta-strands held together by sheet hydrogen bonding and loop geometry. Comparisons of residue-contact density showed the fold is not uniformly loose; its overall packing is comparable to thaumatin and denser than brazzein. But cavity analysis revealed a larger pocket volume per residue than reference proteins, and the absence of classic stabilizing elements left the protein vulnerable to heat.

The first step was to see the molecule in atomic detail. The team crystallized the protein and determined its structure at 1.58 angstrom resolution using synchrotron radiation at the Shanghai Synchrotron Radiation Facility, solving the structure by molecular replacement with an AlphaFold-predicted model as the search template. The structure revealed a characteristic arrangement of seven major beta-strands forming a slightly twisted antiparallel sheet, flanked by three shorter strands—a so-called 7-plus-3 topology—connected by solvent-exposed loops, including an extended and apparently flexible loop between strands three and four. This high-resolution map became the common reference for every subsequent design decision, from mutation evaluation to disulfide-bond planning.

With the structure in hand, the researchers screened every one of the 121 positions for potentially stabilizing substitutions using two complementary computational methods. Rosetta, a physics-based framework, estimated the energetic effect of each mutation after side-chain repacking and constrained relaxation, while ThermoMPNN, a deep-learning model, judged whether each amino acid substitution would be compatible with the local structural environment. From the overlapping and divergent predictions, the team selected 72 single-point variants for experimental testing. The results validated the strategy: 41 of the 72 variants showed a positive shift in melting temperature, and 27 exceeded a one-degree gain. The single best mutations, Q37A and S55G, raised the melting temperature by 3.91 and 4.23 degrees respectively.

But the raw computational scores turned out to be only modestly predictive. Correlations between predicted scores and measured stability changes across the 72 variants were weak, with Pearson coefficients of just 0.206 for Rosetta and 0.248 for ThermoMPNN. That gap is precisely where the study’s most innovative element comes in: a machine-learning framework the authors call SMRC-Net, which learns from the experimental data itself. The system combines a baseline melting-temperature estimate derived from a pretrained protein language model, ESM2, with a residual correction built from molecular dynamics descriptors—flexibility changes, solvent accessibility, residue contacts, and global perturbation measures calculated from simulations of the wild-type protein and 65 mutants.

Under repeated strict nested cross-validation, the sequence-only baseline explained about 44 percent of the variance in melting temperature, with a mean absolute error of 1.35 degrees. Adding the molecular dynamics residual correction lifted the explained variance to nearly 60 percent, cut the error to 1.15 degrees, and improved the rank correlation of variants from 0.540 to 0.698. When the frozen model was tested prospectively on ten Rosetta-designed mutants it had never seen, it correctly predicted the direction of the stability change for nine of the ten—a 90 percent directional accuracy. The single miss, T115I, was predicted to stabilize the protein but produced a small experimental decrease of 0.67 degrees.

Armed with validated stabilizing mutations, the team assembled them stepwise rather than all at once, a modular strategy that kept each combination experimentally testable. Ten substitutions were grouped into four modules of two or three mutations, each verified to raise the melting temperature before further assembly. Combining the three-residue modules produced a six-site variant at 67.77 degrees, and the gains proved nearly additive—the measured improvement differed from the sum of individual contributions by only 0.12 degrees. Two parallel assembly routes then produced eight-site intermediates, and their union yielded the ten-site variant Mut10-1 at 73.03 degrees, 18.43 degrees above the wild type.

The final flourish was structural rather than chemical: an engineered disulfide bond. Screening candidate cysteine pairs by geometric criteria with Rosetta’s DisulfidizeMover identified Q37C/D46C as the most favorable linkage. Introducing that single bond added another 6.95 degrees on its own, and when combined with the ten mutations it produced the final variant, FM, with a melting temperature of 82.07 degrees. Crucially, sensory evaluation by eight trained panelists showed that both Mut10-1 and FM retained sweetness thresholds similar to the wild-type protein—evidence that the stabilizing changes did not disrupt the receptor-binding surface responsible for the protein’s intense taste.

Practical stress tests underscored the difference. After one hour at 80 degrees Celsius, the wild-type protein had largely precipitated out of solution, while FM remained predominantly soluble; even after four hours, FM retained a substantial soluble fraction. Circular dichroism spectroscopy showed that FM’s secondary structure was largely preserved through the prolonged heating, and the engineered protein also stayed soluble and structurally intact across acidic, neutral, and alkaline conditions at pH 3, 6, and 9. Molecular dynamics simulations suggested why: the mutations did not rigidify the protein wholesale but redistributed local flexibility, modestly remodeled the residue-contact network, and stabilized a single dominant folded ensemble. An experimental test supported one long-range interaction in particular—disrupting the H16-F99 contact with a double mutant lowered the melting temperature by 5.2 degrees, confirming its role in tertiary stability.

The authors are careful about the limits. Sweetness was tested only on untreated samples, so whether the engineered protein survives heating and pH shifts while still tasting sweet in real foods remains unverified, and sensory testing in complex food matrices is the necessary next step. The SMRC-Net predictor is also calibrated specifically to this scaffold, though the authors argue the residual-learning architecture could be retrained for other compact proteins where molecular dynamics remains computationally feasible. Still, the demonstration is striking: a cysteine-free, helix-free beta protein with no natural stabilizing armor was transformed into a heat-tolerant, sweetness-preserving molecule through a coordinated workflow of crystallography, complementary computation, machine learning, and disciplined stepwise assembly. For a protein once undone by a warm afternoon, that is a remarkable turnaround—and a template for engineering the next generation of sugar substitutes.

Subject of Research: Computation-guided protein engineering to improve the thermal stability of the fungal sweet protein honey truffle sweetener

Article Title: Integrated Computation-Guided Thermostabilization of the Fungal Sweet Protein Honey Truffle Sweetener

Article References: Wang, Z., Wang, W., Zhu, F., Zhang, Y., Li, Y., Zhu, Z., Lu, Z., Huang, A., Yu, M., & Liu, S. (2026). Integrated computation-guided thermostabilization of the fungal sweet protein Honey Truffle Sweetener. Current Research in Food Science, 13, Article 101584. https://doi.org/10.1016/j.crfs.2026.101584

Image Credits: AI Generated

DOI: 10.1016/j.crfs.2026.101584

Keywords: sweet proteins, honey truffle sweetener, protein engineering, thermostability, crystal structure, Rosetta, ThermoMPNN, molecular dynamics, machine learning, disulfide bond, sugar substitute, food science

The team focused on a leavening combination of glucono-delta-lactone, commonly abbreviated GDL, and sodium bicarbonate. When these two food-grade compounds meet in water, GDL gradually hydrolyzes into gluconic acid, which then reacts with the bicarbonate to release carbon dioxide and produce sodium gluconate as a byproduct. This slow hydrolysis is precisely what makes GDL attractive compared with fast-acting acids such as citric acid, which floods dough with gas almost instantly and risks losing much of it before the gluten network can develop. Conventional formulation practice has always treated the stoichiometric ratio, the exact chemical balance between acid and base, as the gold standard for optimizing recipes. The researchers set out to test a provocative question: does the stoichiometric ratio actually represent the optimal functional balance, or are the two reaction products doing fundamentally different jobs that need to be tuned separately?

To answer this, the team designed an elegant experimental strategy. They prepared doughs at three sodium bicarbonate levels, 1.0, 1.5, and 2.0 percent of flour weight, each paired with the corresponding amount of GDL according to its neutralization value. Then, in a crucial second step, they decoupled the salt from the gas. By completely reacting GDL with sodium bicarbonate in water at 60 degrees Celsius for 24 hours, they generated a solution of pure sodium gluconate with all the carbon dioxide already released. This pre-formed salt was then added to dough formulations on top of the normal reaction, allowing the researchers to observe what the salt alone contributes, independent of any additional gas production. A yeast-leavened dough served as the commercial benchmark throughout.

The molecular story begins with the gluten proteins themselves. Using measurements of free sulfhydryl groups, disulfide bonds, intrinsic fluorescence, and surface hydrophobicity, the researchers tracked how protein structure shifted across the reaction levels. Moving from the low to the intermediate level, disulfide bond content rose while free sulfhydryl groups declined, a signature of the sulfhydryl-disulfide exchange reactions that knit gluten chains into a three-dimensional network. Fluorescence intensity and surface hydrophobicity also increased, indicating that hydrophobic amino acid residues such as tryptophan, tyrosine, and phenylalanine were being progressively exposed as protein chains unfolded in an ordered fashion. This moderate unfolding, driven by the gradual acidification of GDL hydrolysis, appears to be the sweet spot where proteins are flexible enough to interact but not so disrupted that the network collapses.

The high reaction level told a cautionary tale. At 2.0 percent sodium bicarbonate, disulfide bonding dropped to its lowest while free sulfhydryl groups peaked, and surface hydrophobicity climbed even higher. The researchers interpret this as evidence that the intense ionic environment generated by abundant sodium gluconate intensified electrostatic shielding between gluten chains, promoting irregular and excessive re-aggregation rather than orderly network construction. Zeta potential measurements reinforced this picture: the absolute value fell steadily from 32 millivolts at the low level to 26 millivolts at the high level, eroding the electrostatic energy barrier that normally keeps protein particles from clumping. Particle size distributions shifted correspondingly toward larger aggregates, with the 2.0 percent samples showing the broadest peaks and the strongest signals around 10,000 nanometers, hallmarks of runaway protein aggregation.

Because expanding dough is essentially a foam, the behavior of proteins at the air-water interface matters enormously. Proteins must diffuse to bubble surfaces, penetrate the interface, unfold, and rearrange into a cohesive film that resists deformation as bubbles grow. The researchers measured all of these stages using dynamic interfacial tension, adsorption kinetics modeling, and dilatational rheology. The intermediate reaction level proved optimal at every step: it produced the fastest penetration and rearrangement rate constants, and the highest elastic and viscous moduli of the interfacial films. Lissajous plots, which visualize how interfacial films respond to cyclic stretching and compression, showed that the 1.5 percent films retained a regular, resilient response even at large deformations, while the 2.0 percent films became increasingly distorted and heterogeneous. In short, moderate salt formation built the toughest bubble armor.

Microscopy and rheology translated these molecular findings into dough-level reality. Scanning electron microscopy and confocal laser scanning microscopy revealed that at the intermediate level, starch granules were uniformly embedded in a continuous, well-stretched protein network, and adding extra sodium gluconate made the network even more homogeneous. Dynamic rheology confirmed that the 1.5 percent plus salt dough had the highest storage and loss moduli of all formulations, meaning it was the most elastic and resistant to deformation. Rheo-fermentation measurements then delivered the most striking numbers: at the intermediate level, dough height reached 28 centimeters, already exceeding the yeast control at 22 centimeters, and salt supplementation pushed it to 32 centimeters. At the high reaction level, despite abundant gas production, the gap between gas release profiles with and without added salt revealed that much of the carbon dioxide was simply escaping from a weakened, poorly structured dough.

The final proof arrived in the steamer. Steamed bread made at the intermediate level with salt supplementation achieved the highest specific volume of the entire study, 2.63 milliliters per gram, with a fuller appearance, finer and more uniform crumb cells, and improved texture. The high reaction level produced larger but coarser and less evenly distributed gas cells, the result of bubble coalescence in a dough that could not hold what it had generated. The authors conclude that optimal steamed bread quality depends on a balance between adequate carbon dioxide generation and a sufficiently strong viscoelastic network to retain that gas, with moderate sodium gluconate formation providing the gas-holding capacity that gas alone cannot supply. Neither factor working alone can produce a superior product.

The implications extend well beyond steamed bread. The principle that in situ generated salts actively shape protein interactions, interfacial films, and dough mechanics, rather than serving as inert byproducts, could reshape how formulators approach any chemically leavened cereal product, from cakes to tortillas to biscuits. It suggests that acid and bicarbonate selection should account not only for gas release kinetics but also for the structural properties of the salt each pairing produces. The study does carry limitations the authors acknowledge: carbon dioxide could not be introduced independently into the dough, and pH was not treated as an explicit variable, so future work with controlled gas supplementation and pH monitoring will be needed to fully separate the contributions. Still, for a food industry actively seeking yeast-free alternatives driven by consumer interest and intolerance concerns, this research provides something rare: a mechanistic roadmap showing that the secret to great chemically leavened bread lies not just in making gas, but in making the right salt at the right time to keep it.

Subject of Research: Chemical leavening of wheat dough and steamed bread quality through coordinated carbon dioxide evolution and in situ sodium gluconate formation

Article Title: Insights into the Coordinated roles of CO 2 Evolution and in situ Generated Sodium Salts across Gluten Protein, Dough Development, and Steamed Bread Quality, in a Chemically Leavened System.

Article References: Wang, A., Mohammadi, N., Tong, L.-T., & Scannell, A. G. (2026). Insights into the Coordinated roles of CO2 Evolution and in situ Generated Sodium Salts across Gluten Protein, Dough Development, and Steamed Bread Quality, in a Chemically Leavened System.. Current Research in Food Science, Article 101585. https://doi.org/10.1016/j.crfs.2026.101585

Image Credits: AI Generated

DOI: 10.1016/j.crfs.2026.101585

Keywords: chemical leavening, steamed bread, gluten protein, sodium gluconate, glucono-delta-lactone, carbon dioxide, dough rheology, air-water interface, disulfide bonds, gas retention, yeast-free, food science

Researchers at the University of Jiroft in Kerman Province, Iran, set out to test whether aloe vera gel, used as an edible coating and enriched with fennel or lime peel essential oils, could extend the shelf life and microbial safety of table eggs stored under refrigeration. The team, led by Zahra Ranjbarinasab and Fatemeh Shahdadi, noted that although aloe vera gel and various essential oils have each been explored for egg preservation before, no previous study had investigated this particular combination for maintaining both the physicochemical quality and microbial stability of refrigerated eggs. Their findings point toward a natural, additive-free approach that could reduce food waste and economic losses in one of the world’s most consumed animal products.

The experimental design was straightforward but rigorous. The researchers obtained 300 fresh white-shelled chicken eggs from a local retail center, with an average weight of 62.39 grams, and excluded any showing cracks, shell defects, or surface contamination. The eggs were randomly divided into six groups: an uncoated control, eggs coated in pure 100 percent aloe vera gel, and four groups coated with aloe vera gel containing either 500 or 1000 parts per million of fennel essential oil or the same concentrations of lime peel essential oil. The essential oils were extracted by steam distillation using a Clevenger-type apparatus for three hours, following European Pharmacopeia guidelines, from dried Mexican lime peel and ground fennel seed. Each egg was dipped in its assigned coating for one minute, dried, dipped again, and dried once more before all samples were stored at 5 degrees Celsius for 30 days, with quality assessments performed on days 1, 15, and 30.

The choice of coating ingredients was far from arbitrary. Aloe vera gel is a transparent, viscous substance rich in carbohydrates, proteins, fibers, soluble sugars, vitamins, minerals, amino acids, organic acids, and phenolic compounds, and it has established antioxidant and antimicrobial credentials in food applications. Fennel essential oil, dominated by trans-anethole at roughly 65 to 78 percent of its composition, has demonstrated bacteriostatic effects against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. Lime peel essential oil is an even more complex mixture of more than 100 compounds, including limonene, citral, and linalool, and is prized for its potent antioxidant and antibacterial properties. By embedding these oils within the aloe vera matrix, the researchers aimed to create a coating that was simultaneously a physical barrier and an active antimicrobial delivery system.

The results on weight loss were striking. After 30 days of refrigerated storage, uncoated control eggs had lost 4.81 percent of their initial weight, while every coated group lost only about 3.35 percent, a roughly 30 percent reduction. The researchers attribute this to the formation of a semipermeable barrier on the shell surface that limits the diffusion of water vapor and carbon dioxide through the shell’s pores. Interestingly, adding essential oils provided no additional weight-loss benefit beyond the aloe vera gel alone, suggesting that the moisture barrier was supplied entirely by the gel matrix and that the oils’ contribution lay elsewhere, primarily in antimicrobial activity.

Internal quality told a similar story. The Haugh unit, the standard industry measure of albumen quality based on the height of the thick egg white, declined in all groups over the month, but coated eggs fared markedly better. Uncoated eggs fell from a Haugh unit of 76.21 on day one to just 54.17 by day 30, while eggs coated with aloe vera gel containing 1000 ppm of fennel essential oil retained a value of 65.74, and those with 1000 ppm lime peel oil reached 65.40. The mechanism is rooted in egg chemistry: as carbon dioxide escapes through the shell during storage, the albumen becomes more alkaline, protein structures break down, and the thick white thins into a watery state. By slowing carbon dioxide loss, the coatings delayed this alkalization and preserved the ovomucin network responsible for albumen viscosity.

The pH measurements reinforced this picture. Fresh albumen contains about 0.5 percent dissolved carbon dioxide, and its loss during storage can push albumen pH from around 7.2 toward 8.5 or higher. In this study, uncoated eggs climbed to an albumen pH of 8.26 after 30 days, whereas eggs coated with aloe vera gel plus 1000 ppm fennel oil reached only 7.60, and those with 1000 ppm lime peel oil reached 7.64. Yolk pH followed the same pattern, rising to 6.91 in controls but only to 6.54 and 6.57 in the highest-concentration fennel and lime peel treatments, respectively. Because yolk and albumen pH are both recognized freshness indicators, these numbers translate directly into longer commercial shelf life.

Functional properties also benefited. Albumen foaming capacity, which matters for baking and culinary performance, declined with storage in all groups, but coated eggs retained significantly more foaming ability than controls, with coated samples reaching about 7.5 milliliters of foam per gram of albumen at day 30 compared with 6.28 for uncoated eggs. The researchers explain that ovomucin stabilizes foam by forming insoluble films around air bubbles, and that coatings preserve this functionality by limiting the water and carbon dioxide losses that drive pH-driven protein degradation. Shell thickness, by contrast, was unaffected by either coating or storage time, indicating that the coatings act as surface barriers rather than altering the mineralized structure of the shell itself.

Perhaps the most compelling results came from the microbiological analysis. Total microbial counts rose in all groups over the storage period, but coated eggs consistently carried lower loads than controls. By day 30, uncoated eggs had reached 5.40 log CFU per gram, while eggs coated with aloe vera gel alone reached 4.67. The essential oil treatments pushed the counts down further still: 4.16 log CFU per gram for 1000 ppm fennel oil and 4.17 for 1000 ppm lime peel oil. The authors attribute this to a dual mechanism, in which the coating acts as a physical barrier against microbial penetration while simultaneously serving as a carrier for natural antimicrobial compounds. Aloe vera’s activity stems from anthraquinones, saponins, phenolics, and organic acids, while limonene and gamma-terpinene in lime oil disrupt bacterial cell membranes, and trans-anethole, fenchone, and methyl chavicol in fennel oil inhibit a wide range of pathogens and even biofilm formation.

The study does have limitations that the authors themselves acknowledge. Only two concentrations of each essential oil were tested, storage was confined to a single refrigerated condition for 30 days, and sensory properties and consumer acceptance of the coated eggs were not evaluated. Industrial scalability, long-term performance, and economic feasibility remain open questions. Nevertheless, the overall conclusion is clear: aloe vera gel enriched with 1000 ppm of either fennel or lime peel essential oil represents a promising natural coating for extending egg shelf life and maintaining quality during refrigerated storage. As food scientists worldwide search for alternatives to synthetic preservatives, this simple dip-and-dry treatment, built from ingredients with long histories of safe human use, offers an elegant demonstration that sometimes the best packaging material may already be growing in a garden.

Subject of Research: Edible aloe vera gel coatings enriched with fennel and lime peel essential oils for extending the shelf life and microbial safety of refrigerated eggs

Article Title: Enhancing the Shelf Life and Microbial Safety of Refrigerated Eggs Using Edible Coatings of Aloe Vera Gel Combined With Fennel and Lime Peel Essential Oils

Article References: Ranjbarinasab, Z., Shahdadi, F., Yousefi, M., Seyedimarghaki, Z., & Omidi, S. (2026). Enhancing the Shelf Life and Microbial Safety of Refrigerated Eggs Using Edible Coatings of Aloe Vera Gel Combined With Fennel and Lime Peel Essential Oils. Food Science & Nutrition, 14(10), Article e72389. https://doi.org/10.1002/fsn3.72389

Image Credits: AI Generated

DOI: 10.1002/fsn3.72389

Keywords: edible coatings, aloe vera gel, essential oils, fennel, lime peel, egg preservation, shelf life, microbial safety, Haugh unit, food science, natural preservatives, refrigerated storage

The review begins by distinguishing the vocabulary of flavor science. Flavor encompasses the overall sensory perception of food, including taste, touch, smell, sight, and even sound, while aroma refers specifically to the odor detected by the olfactory system. The compounds responsible range from naturally occurring phenolics, terpenoids, alcohols, esters, ketones, and pyrazines found in essential oils, spices, and citrus peels, to synthetic molecules engineered to mimic smoky, citrus, fruity, buttery, or caramel notes. Many of these molecules carry bonus biological activity, including antioxidant, anticancer, anti-inflammatory, and immune-boosting properties. But their volatility is their undoing. In products such as cookies and bread, flavors can be lost during baking or develop off-notes, which is why manufacturers increasingly turn to encapsulation, the practice of wrapping active compounds in protective carrier materials that shield them from degradation, delay their release, prevent oxidation, and ultimately enhance the eating experience.

Encapsulation operates across macro, micro, and nano scales, from capsules larger than 5,000 micrometers down to structures of just 1 to 100 nanometers. While the microscale dominates the food industry today, the review highlights growing evidence that nanoencapsulation offers superior stability, better controlled release, enhanced solubility in liquids, and improved penetration through biological barriers. The conventional toolbox includes physicochemical methods such as coacervation and emulsification, physicomechanical methods such as spray drying and freeze drying, and chemical methods based on polymerization and cross-linking. Each technique produces capsules that differ in size, morphology, release profile, and stability, and the authors stress that no single method is universally superior. Selection depends on the chemistry of the flavor compound, the carrier material, the intended food application, economic constraints, and production scale rather than encapsulation efficiency alone.

Spray drying remains the most widely applied industrial technique, prized for its simplicity, low cost, scalability, and high throughput. In this process, a flavor is dissolved or dispersed in a carrier matrix, atomized into a heated drying chamber, and rapidly converted into spherical particles, often under nitrogen to prevent oxidation. The review cites strawberry flavor encapsulation achieving 85 percent efficiency using maltodextrin, modified starch, and gum arabic at an inlet temperature of 190 degrees Celsius, yielding microcapsules with roughly 90 percent solubility. Yet the method has a critical weakness: retention of volatiles varies enormously with molecular weight. High-carbon volatiles may retain up to 95 percent of their aroma, while low-molecular-weight compounds such as acetaldehyde may retain as little as 20 percent, creating potential inconsistencies between liquid and powdered flavor versions. Powder adhesion to equipment and thermal reactions further complicate the picture, and most studies remain at laboratory scale with limited data on real processing conditions and long-term storage.

The cooler alternatives each carry their own trade-offs. Spray chilling, which solidifies lipid-encapsulated flavors in a cooling chamber at 34 to 42 degrees Celsius, minimizes thermal degradation and suits heat-sensitive compounds, but it is restricted to lipid-based carriers and requires flavors to remain stable at the lipid melting point. Applications include coating the potent aroma compound 2-acetyl-1-pyrroline with paraffin for stability and masking bitter plant extracts for dark chocolate. Freeze drying, which removes water by sublimation, excels at preserving heat-sensitive compounds and creates porous structures that facilitate controlled release, but its high energy consumption, long processing times, and cost confine it largely to high-value products such as coffee and spices. In a comparative study of chamomile extract, freeze drying better preserved total polyphenol content, yet spray drying achieved higher encapsulation efficiency of about 90 percent versus 84 percent, underscoring that the optimal choice depends on the core material and the priorities of the manufacturer.

Coacervation occupies a middle ground, forming micro- or nanocapsules by depositing proteins or polysaccharides around flavor droplets in an emulsion. It can encapsulate both hydrophilic and hydrophobic compounds at room temperature, protecting heat-sensitive flavors and achieving impressive efficiencies, with recent reports of cinnamon extract encapsulation in alginate reaching up to 97 percent while masking undesirable flavors. However, the process is notoriously sensitive to pH, ionic strength, polymer molecular weight, and solvent properties, which can produce variable particle sizes, aggregation, and elevated costs. The review notes that systematic studies of how the molecular characteristics of flavor compounds, such as electrical charge and hydrophobicity, influence coacervate formation remain limited, and calls for predictive models to improve reproducibility and industrial applicability.

Against this backdrop, electrospinning has emerged as the review’s most compelling alternative. The technique applies a high-voltage electrostatic field to a polymer solution containing the flavor, stretching it into elongated fibrous structures with diameters ranging from nanometers to micrometers, high surface-area-to-volume ratios, and interconnected porosity. Because the process operates under mild conditions without high temperatures, pressure, or harsh chemicals, it preserves the structural and sensory integrity of volatile compounds. Two advanced variants, emulsion electrospinning and coaxial electrospinning, produce core-shell fibers in which the aromatic compound is physically confined to the inner core and surrounded by an outer polymer layer, reducing contact with the environment and limiting burst release. Shell thickness, core-to-shell flow ratio, and polymer hydrophobicity can be tuned to precisely control release kinetics. Reported encapsulation efficiencies are striking: thyme essential oil in potato starch nanofibers reached 99 percent, saffron in gelatin reached 96 percent, and thymol in pullulan-whey composites reached 87 percent with release targeted to the small intestine.

The practical applications documented in the review read like a preview of future food packaging. Electrospun polyvinyl alcohol nanofibers loaded with laurel and rosemary essential oils reduced lipid oxidation in chicken breast fillets by up to 68 percent while improving microbial and color stability. Gelatin-chitosan nanofibers carrying thyme essential oil showed bactericidal activity against Clostridium perfringens in sausages, suggesting a viable alternative to nitrite. Polycaprolactone nanofibers incorporating lemon essential oil and a metal-organic framework extended the shelf life of red meat at 4 degrees Celsius by up to 18 days, and a bilayer acorn starch-zein film with cinnamon essential oil extended the shelf life of rainbow trout fillets by six days while cutting lipid oxidation by 44 percent. Perhaps most intriguingly, stimulus-responsive systems are now being designed to release flavors only when triggered by light, pH shifts, temperature, humidity, or even the spoilage enzymes secreted by contaminating microbes, enabling packaging that actively responds to the state of the food it protects.

Significant hurdles remain before electrospinning can displace conventional methods at scale. Production throughput is low, scalability is difficult, the range of food-grade solvents is limited, and the process is sensitive to parameters such as voltage, viscosity, humidity, and flow rate, with even small changes altering fiber morphology and release kinetics. Regulatory approval of a polymer in bulk form does not automatically extend to its nanofibrous form, because electrospinning can alter conformation, crystallinity, surface area, and degradation behavior, and data on gastrointestinal fate and long-term toxicity of electrospun nanostructures are sparse. The review concludes that electrospinning should be viewed as a complementary technology that expands the encapsulation toolkit rather than a universal replacement, and it calls for validation in real food matrices, predictive computational models including machine learning, greener solvent systems such as natural deep eutectic solvents, and comprehensive sensory and consumer studies. If those challenges are met, the fibers now spinning in laboratories could soon deliver aroma exactly when and where the palate demands it.

Subject of Research: Controlled-release encapsulation technologies for aromatic and flavor compounds in food systems

Article Title: Recent Advances in Technologies for the Controlled Release of Aromatic Compounds: From Encapsulation to Electrospinning

Article References: Mojarad, M., Shiravani, Z., Abedi, E., Jafarpour, D., Sayadi, M., & Bagher Hashemi, S. M. (2026). Recent Advances in Technologies for the Controlled Release of Aromatic Compounds: From Encapsulation to Electrospinning. Current Research in Food Science, Article 101586. https://doi.org/10.1016/j.crfs.2026.101586

Image Credits: AI Generated

DOI: 10.1016/j.crfs.2026.101586

Keywords: encapsulation, electrospinning, flavor compounds, aromatic compounds, controlled release, spray drying, freeze drying, coacervation, nanofibers, essential oils, food packaging, food science

The research team, led by Hikaru Ogi and Yoko Ichikawa of the University of Shizuoka together with colleagues at Tokoha University and Sagami Women’s University, obtained heart, stomach, liver, spleen, small intestine, large intestine, loin, and round samples from five wild-caught female sika deer and five wild-caught female wild boar, each estimated at three years of age, processed at a licensed facility in western Shizuoka Prefecture. The animals had been captured by licensed hunters as part of legally authorized population management, entirely independently of the study. For comparison, the researchers purchased matching tissues from three cattle and three pigs from a Shizuoka meat supplier. All samples were freeze-dried, pulverized, and stored frozen before analysis.

To simulate what happens when meat is cooked and eaten, the team applied a standardized in vitro digestion pipeline. Half a gram of each freeze-dried sample was mechanically disrupted with beads, heated at 70 degrees Celsius for 30 minutes to mimic cooking, and then subjected to two hours of gastric digestion with pepsin at pH 1.8, followed by two hours of intestinal digestion with trypsin and pancreatin. Enzymes were added at a nominal enzyme-to-protein ratio of 1:1,000, with the protein estimate derived from ultraviolet absorbance at 280 nanometers. After digestion, enzymes were heat-inactivated, and the soluble fraction was filtered for analysis. This common framework meant that every tissue from every species passed through exactly the same cooking and digestive gauntlet, allowing apples-to-apples comparisons across thirty-two species-tissue combinations.

The researchers measured three things: how much soluble protein and peptide material each digest released, how effectively that material scavenged DPPH free radicals, and how strongly it inhibited angiotensin-converting enzyme, or ACE, the enzyme that raises blood pressure. Soluble protein and peptide concentrations were estimated using the Waddell spectrophotometric method, which calculates concentration from the difference in absorbance at 215 and 225 nanometers. Both biological activities were expressed as IC50 values, the concentration of estimated soluble protein or peptide needed to achieve fifty percent of maximal effect, with lower values indicating greater potency. Statistical comparisons used Kruskal-Wallis tests followed by Dunn’s multiple-comparison tests with Holm adjustment, treating each tissue-outcome pair as a separate exploratory endpoint.

The yield results were strikingly tissue dependent. Wild boar stomach released roughly 27 milligrams of estimated soluble protein or peptide per gram of wet tissue, nearly triple the roughly 10 milligrams from sika deer stomach. Wild boar liver yielded about 34 milligrams per gram, significantly more than both sika deer liver at around 11 and cattle liver at under 10. Wild boar round outperformed pig round by nearly sevenfold, at about 34 versus 5 milligrams per gram. Yet the pattern reversed elsewhere: wild boar small intestine yielded less soluble material than pig small intestine, and sika deer spleen yielded less than both wild boar and cattle spleen. No significant differences appeared in heart or large intestine. An enzyme-only blank run through the same procedure produced a negligible concentration of 0.059 milligrams per milliliter, suggesting the digestive enzymes themselves contributed little to the measured signal.

When it came to antioxidant activity, wild boar emerged as the clear winner. The DPPH IC50 for wild boar liver digest was 9.38 milligrams per milliliter, significantly lower than the 44.02 milligrams per milliliter observed for cattle liver, meaning far less material was needed to neutralize half of the synthetic radicals. Wild boar loin also outperformed, with an IC50 of 16.53 milligrams per milliliter compared with 35.82 for sika deer loin and 58.10 for cattle loin. These findings align with a growing body of literature showing that meat proteins generate antioxidant peptides during digestion, and that such peptides are rich in hydrophobic and aromatic amino acids like leucine, tryptophan, and histidine, which can donate electrons or hydrogen atoms to radicals. The authors caution, however, that because sample-specific absorbance at 520 nanometers was not corrected with blanks, pigments in colored visceral digests may have influenced the measurements.

ACE inhibition told a different story. Here the standout was sika deer spleen, whose digest showed an IC50 of 3.10 milligrams per milliliter, significantly lower than the 19.48 milligrams per milliliter of wild boar spleen. Notably, sika deer spleen had produced less soluble material than wild boar spleen, yet inhibited ACE far more potently, a mismatch that underscores a central theme of the study: quantity of digestible protein does not predict bioactivity. ACE-inhibitory potency depends heavily on peptide molecular weight, hydrophobicity, charge, and especially the amino acid sequence near the C-terminus, which determines how well a peptide fits into the enzyme’s active site. Previous work has identified ACE-inhibitory peptides such as KAPVA and PTPVP in pork digests, and antihypertensive effects have been demonstrated in hypertensive rats, so the possibility that wild-game digests contain similar sequences is plausible, though not yet proven.

Indeed, the disconnect between yield and activity is perhaps the study’s most important conceptual contribution. Screening tissues solely on how much soluble protein they release would have missed sika deer spleen, a low-yield, high-activity tissue, and would have overrated others. The authors argue that this justifies activity-guided fractionation as the next step: isolating the active components from wild boar liver, wild boar loin, and sika deer spleen, identifying peptide sequences by liquid chromatography-tandem mass spectrometry, confirming activity with synthetic peptides, and eventually testing physiological effects in cells and animals. For a peptide to lower blood pressure in a living body, it must survive intestinal digestion, cross the epithelial barrier, remain stable in circulation, and reach its target, hurdles that many in vitro hits never clear.

The study is candid about its limitations. Sample sizes were small and unequal, with five wild animals but only three cattle and three pigs per tissue, limiting statistical power, and non-significant comparisons cannot be read as evidence of equivalence. The wild and domesticated groups also differed in diet, rearing conditions, and postmortem handling, so differences cannot be attributed to species alone. Enzyme dosing was based on an absorbance estimate rather than a direct protein measurement, the Waddell method can be confounded by UV-absorbing compounds in organ digests, and no reference compounds like Trolox or captopril were run alongside. Some undiluted samples even produced calculated ACE inhibition above one hundred percent, though IC50 values were computed only from concentrations bracketing the fifty percent mark.

Even with those caveats, the study opens a genuinely novel avenue. Japan’s deer and boar culls produce a vast, underused biomass, and if organs like wild boar liver or deer spleen can be shown to contain functional peptides, they could become ingredients for health-oriented foods rather than waste. The authors are explicit that this was a screening exercise, not a demonstration of health benefits, but it provides the systematic baseline that future characterization work can build on. In a country grappling simultaneously with wildlife overpopulation, food sustainability, and an aging population’s cardiovascular health, the idea that pest control could feed a functional-food industry is exactly the kind of unexpected connection that makes food science worth watching.

Subject of Research: Bioactive peptide yield and antioxidant and ACE-inhibitory activities of in vitro digests of wild sika deer and wild boar tissues compared with cattle and pig tissues in Japan

Article Title: Exploratory screening of wild-game tissues in Japan toward value-added utilization: estimated soluble protein/peptide yields and DPPH radical-scavenging and ACE-inhibitory activities after in vitro digestion

Article References: Exploratory screening of wild-game tissues in Japan toward value-added utilization: estimated soluble protein/peptide yields and DPPH radical-scavenging and ACE-inhibitory activities after in vitro digestion. (n.d.). https://doi.org/10.1007/s44463-026-00118-0

Image Credits: AI Generated

DOI: 10.1007/s44463-026-00118-0

Keywords: wild game meat, sika deer, wild boar, bioactive peptides, in vitro digestion, DPPH radical scavenging, ACE inhibition, visceral organs, value-added utilization, functional foods, food science, Japan

High-moisture extrusion is the industrial workhorse behind most plant-based meat alternatives. A protein dough, typically derived from soy or pea isolates, is hydrated, mixed and then pushed through a heated barrel where temperatures reach 135 degrees Celsius and intense shear forces from co-rotating screws knead the material. The molten protein then passes through a cooling die, where it solidifies into a ribbon with a lamellar, fibrous structure reminiscent of muscle tissue. The critical question has always been how this hierarchical anisotropy forms: which processes happen in the barrel, which in the cooling die, and how events at the nanometre scale cascade upward to determine the texture a consumer actually perceives when chewing.

To answer this, the researchers deployed an unusually broad arsenal of magnetic resonance methods. T2-weighted MRI at 14 tesla visualised the phase-separated architecture, distinguishing protein-rich domains from water-rich lamellae at the hundred-micrometre scale. Diffusion tensor MRI, a technique borrowed from clinical neuroimaging where it maps white matter tracts, was used to measure the directionality of water self-diffusion within each voxel, revealing the orientation of structures far below the imaging resolution. Chemical exchange saturation transfer MRI, performed at the extraordinary field strength of 28.2 tesla, probed the chemical composition of the two phases, detecting mobile proteins dissolved in the water-rich regions through their amide and relayed nuclear Overhauser enhancement signatures.

The team extruded commercial soy protein concentrate at 60 percent moisture and shifted the pH of the feed liquid to three values: acidic pH 5.0, near the isoelectric point of the protein; neutral pH 7.0; and alkaline pH 7.8. The results were striking. At neutral and alkaline pH, the extrudates displayed beautifully aligned lamellar structures running parallel to the extrusion direction, with weighted order parameters reaching 0.9 in sagittal views. At pH 5.0, by contrast, the macroscopic lamellar order collapsed almost entirely, with order parameters dropping to around 0.4 and no uniform aligned phase separation visible along the flow direction.

Yet the story at smaller length scales was inverted. Confocal laser scanning microscopy, capable of resolving features down to roughly 100 nanometres, showed that the acidic sample actually possessed a well-aligned fibrillar protein network at the sub-micrometre scale, with order parameters around 0.6, comparable to the neutral sample. The alkaline sample, meanwhile, lacked this fine-scale fibrillar alignment altogether, a consequence of strong electrostatic repulsion between highly charged protein fibrils far from their isoelectric point. This decoupling between order at different scales provided the central clue to the mechanism of structure formation.

The diffusion tensor measurements added quantitative weight to this picture. In the protein-rich lamellae of the pH 7.0 sample, water diffused preferentially along the extrusion direction, the fastest diffusion direction coinciding with the shear imposed by the extruder screws, while the slowest diffusion ran perpendicular to the lamellae. Fractional anisotropy values of about 0.3 in the protein-rich phase, against 0.2 in the water-rich phase, confirmed that the aligned protein fibrils observed microscopically were genuinely hindering water motion in a directional manner. Because the diffusion encoding time of 50 milliseconds probes water displacement over roughly 9 to 33 micrometres, the technique effectively senses the cumulative effect of countless sub-micrometre fibrils, bridging the gap between what microscopy and conventional MRI can each see.

To understand why the cooling die geometry matters, the researchers generated synthetic axial MRI images mimicking lamellar patterns for four die cross-sections: elliptical, bullnose, rounded-rectangle and sharp-cornered rectangular. The rotated Fourier transform analysis, a recently developed image-processing method that extracts orientational order from two-dimensional images, showed that elliptical dies produce highly homogeneous order parameters near 0.93, while progressively sharper corners carve out increasingly wide zones of disorder, with order parameters falling to 0.3 in the corners of the sharpest geometry. The experimental maps of real extrudates matched the sharp-cornered simulation almost exactly, with a disordered corner region roughly 1.5 millimetres wide, demonstrating that the die’s shape directly imprints its geometry onto the internal texture of the product.

Synthesising these observations, the authors propose a two-stage mechanism. Fibril formation and alignment at the sub-micrometre scale begin already in the extruder barrel and transition zone. The degree of this fine-scale alignment, governed by pH through electrostatic screening, then controls the rheology of the protein melt entering the cooling die. At pH 5.0, the strongly aligned fibrillar network raises the yield stress so much that the melt can no longer flow in laminar sheets through the die, and the macroscopic lamellar structure fails to form. At pH 7.8, weak fibril alignment keeps the yield stress low, allowing coarse lamellae to form but without the underlying fibrillar backbone. Only at an intermediate pH, where fibrillar alignment and electrostatic repulsion strike a balance, do both levels of hierarchy emerge in concert. As a compelling validation of the method’s specificity, the team showed that commercial high-moisture mozzarella, whose casein structure is aligned only by stretching at much lower temperatures, exhibits order at the hundred-micrometre scale but no diffusional anisotropy at smaller scales, consistent with small-angle neutron scattering showing isotropy below 90 nanometres.

The implications reach well beyond academic curiosity. Plant-based meat alternatives are a cornerstone of the protein transition, yet their texture remains the chief barrier to consumer acceptance. By establishing high-resolution MRI, diffusion tensor imaging and CEST as a versatile, non-destructive toolkit for quantifying hierarchical anisotropy in intact extrudates, the study gives food engineers, for the first time, a way to watch structure form across six orders of magnitude in length scale and to rationally tune pH, die geometry and processing conditions. The work was funded by the Dutch Research Council together with industrial partners including Unilever, Cargill, dsm-firmenich and FrieslandCampina, underscoring the commercial stakes. If the meat-like fibrousness of the next generation of plant-based products improves noticeably, it may well be because a scanner originally built for brains taught manufacturers how to build better fibres.

Subject of Research: Magnetic resonance imaging of hierarchical anisotropic structure formation in high-moisture soy protein extrudates

Article Title: Underpinning hierarchical anisotropic structure formation in soy protein high-moisture extrudates by Magnetic Resonance Imaging

Article References: Kuijpers, S. A., Gobes, M. I., Mayar, M., Vergeldt, F. J., Hohlbein, J., Huppertz, T., van Duynhoven, J. P., & Terenzi, C. (2026). Underpinning hierarchical anisotropic structure formation in soy protein high-moisture extrudates by Magnetic Resonance Imaging. Current Research in Food Science, 13, Article 101575. https://doi.org/10.1016/j.crfs.2026.101575

Image Credits: AI Generated

DOI: Not provided

Keywords: plant-based meat, high-moisture extrusion, soy protein, MRI, diffusion tensor imaging, CEST, food structure, anisotropy, pH-shifting, cooling die geometry, confocal microscopy, food science