Nanocrystal technology is one of the few bioavailability-enhancing strategies that has already been clinically validated and commercialized. The concept is straightforward: reduce the active pharmaceutical ingredient to particles in the nanometer range and stabilize their enormous surface energy with small amounts of polymers or surfactants. Because the drug itself is the carrier, nanocrystals achieve exceptionally high drug loading and can be adapted to many routes of administration, from oral tablets to injectable suspensions. According to the Noyes–Whitney relationship, dissolution rate increases as surface area grows, so nanosizing dramatically accelerates how quickly drug particles dissolve in the gastrointestinal tract. Beyond faster dissolution, nanocrystals also raise the apparent saturation solubility, since the increased surface free energy of very small particles creates a higher concentration gradient driving absorption, ultimately improving bioavailability for the poorly water-soluble compounds that dominate modern drug pipelines.

The review organizes the manufacturing landscape into three families of approaches. Top-down methods, such as wet media milling and high-pressure homogenization, break coarse crystals apart using mechanical forces. Wet media milling, in which drug suspensions are agitated with small grinding beads, is the workhorse of the industry because it is scalable, applies to nearly insoluble compounds and avoids organic solvents. Bottom-up methods, by contrast, build nanoparticles from dissolved molecules, most commonly through antisolvent precipitation, in which a drug solution is mixed with a poor solvent to trigger rapid nucleation. These approaches offer fine control over particle size but are sensitive to mixing dynamics and solvent removal challenges. Hybrid methods combine both principles—for example, precipitating a drug and then milling the resulting suspension—to exploit the strengths of each. The authors emphasize that each technique carries process-specific parameters that directly shape the critical quality attributes of the final product, from particle size distribution to dissolution behavior.

That sensitivity to process conditions is precisely why the review champions quality by design, or QbD, the regulatory philosophy codified in International Council for Harmonisation guidelines Q8, Q9 and Q12. Rather than testing quality into a finished product, QbD builds it in from the start. The workflow begins by defining a quality target product profile—the intended clinical performance of the medicine—and translating it into critical quality attributes such as particle size, zeta potential, crystallinity and dissolution rate. Risk assessment tools then identify which formulation variables, called critical material attributes, and which process parameters most strongly influence those attributes. Design of experiments is used to map the response surface, establish a design space within which quality is assured, and define control strategies that keep the process in its proven acceptable range throughout the product lifecycle.

Applied to wet media milling, the review’s flagship example, this framework becomes strikingly concrete. The quality target product profile dictates the critical quality attributes; milling parameters such as bead size, bead loading, milling speed, milling time, drug concentration and temperature are screened as critical process parameters. Stabilizer selection is treated with equal rigor: the type, concentration and physicochemical properties of polymers and surfactants are considered potential critical material attributes. Cellulosic polymers, poloxamers, polysorbates and even natural stabilizers such as tea saponins and proteins have all been explored, each interacting differently with the newly created crystal surfaces. The right stabilizer must wet the particles, adsorb rapidly onto fresh surfaces created during fracture, and provide either electrostatic or steric repulsion strong enough to prevent the particles from re-aggregating the moment milling stops.

Stabilization is not merely a matter of keeping particles apart; it is a battle against thermodynamics. The review details the principal physical instabilities that threaten nanosuspensions, including Ostwald ripening, in which small particles dissolve and redeposit onto larger ones because solubility increases with curvature, a phenomenon described classically by the Lifshitz–Slyozov–Wagner theory. Aggregation and sedimentation follow if the stabilizing layer is too weak, while uncontrolled crystallization can convert an amorphous surface layer back to a stable, slowly dissolving form. Because these instabilities accelerate with polydispersity and temperature, the choice of stabilizer concentration becomes a genuine design decision rather than a trial-and-error guess. QbD turns this chemistry into a controllable variable: by linking stabilizer attributes to measured quality outcomes through designed experiments, formulators can predict how a formulation will behave before it ever reaches the milling vessel.

Nanocrystal suspensions, however, are rarely the final dosage form. The review extends the QbD framework to solidification and scale-up, two stages where many promising formulations fail. Liquid nanosuspensions are physically fragile, so they are commonly converted into dry powders by spray drying, freeze-drying or fluidized bed coating onto carrier particles. Each drying method introduces its own risks: freeze-drying can cause particles to fuse during ice sublimation unless cryoprotectants are added, while spray drying exposes particles to heat and rapid evaporation that can induce aggregation or polymorphic changes. Scale-up compounds the difficulty, because milling efficiency depends on energy density and flow patterns that do not translate linearly from laboratory bead mills to production equipment. Mechanistic process modeling, the authors note, has been used to establish design spaces and control strategies for milled suspensions, offering a route to transfer a validated process across scales without re-deriving it from scratch.

The industrial credentials of the technology are substantial. Nanocrystal-based products have reached the market across multiple therapeutic areas and administration routes, including long-acting injectable suspensions for psychiatric and oncology indications, oral formulations and dermal applications. Recent research continues to expand the frontier: nanocrystals embedded in hydrogels for intratympanic delivery of dexamethasone to treat hearing loss, transdermal systems for rotigotine and meloxicam, ophthalmic suspensions, pulmonary formulations of budesonide, and even veterinary and agricultural uses such as herbicide nanosuspensions that suppress Ostwald ripening in the field. In oncology, sterile nanosuspensions of mebendazole and other agents are being explored for brain tumor therapy, while QbD-optimized nanocrystals of sotorasib, a KRAS inhibitor, demonstrate how modern targeted cancer drugs with extreme insolubility can be rescued by nanosizing combined with biosurfactant stabilization.

The review’s expert opinion distills a decade of accumulated evidence into a single message: nanocrystal development should be viewed as an integrated process in which particle properties, stabilization mechanisms, preparation methods, solidification and scale-up are closely interconnected. Treating these elements in isolation, the authors argue, is what historically made nanocrystal formulation slow and unpredictable. QbD supplies the connective tissue—a systematic understanding of how formulation variables and process parameters jointly determine quality attributes, enabling predictive development rather than iterative guesswork. As regulatory agencies worldwide continue to encourage lifecycle management and continuous improvement under ICH Q12, the authors conclude that QbD-based predictive development and quality control strategies will improve developmental efficiency and, crucially, accelerate the industrial and clinical translation of nanocrystal medicines, turning one of pharmaceutical science’s most versatile tools into a reliably engineered platform for the next generation of poorly soluble drugs.

Subject of Research: Application of quality by design principles to drug nanocrystal formulation, stabilization, manufacturing and industrial translation

Article Title: Application of quality by design in drug nanocrystal development: principles, stabilization, manufacturing strategies, and industrial applications

Article References: Jeong, J.-S., Ha, E.-S., Kim, J.-S., Yoon, N.-Y., Jung, H.-W., Kim, M.-G., Nam, J., Shin, E., Park, H., & Kim, M.-S. (2026). Application of quality by design in drug nanocrystal development: principles, stabilization, manufacturing strategies, and industrial applications. Journal of Pharmaceutical Investigation. https://doi.org/10.1007/s40005-026-00834-1

Image Credits: AI Generated

DOI: 10.1007/s40005-026-00834-1

Keywords: drug nanocrystals, quality by design, poorly water-soluble drugs, wet media milling, stabilizers, critical quality attributes, Ostwald ripening, bioavailability enhancement, spray drying, freeze-drying, pharmaceutical manufacturing, nanosuspensions

Herbal medicines are notoriously difficult to manufacture consistently. Unlike a synthetic pill, whose active ingredient is a single, precisely defined molecule, a plant-derived extract is a shifting cocktail of polyphenols, tannins, and flavanols whose proportions depend on soil, weather, harvest timing, drying conditions, and dozens of processing choices. A tea made in one kitchen may differ dramatically from one made in another, and even a factory following a traditional recipe can produce batches that vary widely in potency. Most previous studies of espinheira-santa examined isolated steps in this chain; the team, led by Alberto Araujo de Caux of the State University of Campinas (UNICAMP), set out to map and control the entire journey at once.

The framework they used, Quality by Design, is a regulatory philosophy codified in the International Council for Harmonisation guideline Q8. Instead of testing finished products and rejecting bad batches, QbD demands that manufacturers understand their process so deeply that quality is built in from the start. The researchers began by defining a Quality Target Product Profile: a water-soluble dry extract of M. ilicifolia with industrially manageable powder properties that preserved the chemistry of the original aqueous extract. From that goal they derived fifteen Critical Quality Attributes, ranging from total polyphenol and tannin content to residual moisture, powder flowability, hygroscopicity, and even color.

Next came process mapping and risk assessment. Using Failure Mode and Effects Analysis, consistent with ISO 14971 standards, the team scored potential failures across seven stages: harvesting, drying, milling, extraction, concentration, spray drying, and granulation. Each hazard was rated for probability, detectability, and severity, producing Risk Priority Numbers that flagged which variables deserved experimental scrutiny. The mass balance of the full chain proved sobering: roughly 570 grams of dried leaves were needed to yield just 100 grams of finished granules, a cumulative yield of 17.6 percent, with extraction and spray drying accounting for the largest losses. Drying emerged as the operational bottleneck, demanding 72 hours of forced-air circulation while everything downstream together took barely a tenth of that time.

The extraction step, the chemical heart of the process, was attacked first with a Plackett-Burman screening design. This statistical tool allowed the researchers to test nine factors simultaneously in just twelve trials per method, for both decoction and infusion as prescribed by the Brazilian Pharmacopoeia. Two factors rose decisively above the noise: the drug-to-extract ratio, varied between 1 and 2 percent, and the degree of fragmentation of the dried leaves, comparing shredded material with finely powdered drug. Grinding the leaves increased the surface area available to the solvent, boosting the recovery of polyphenols, tannins, and the marker flavanols epicatechin and catechin. Surprisingly, factors that home herbalists obsess over, such as boiling time, extraction duration, and vessel material, had little consistent effect within the studied ranges.

The screening results carried a striking practical implication. Across the 24 laboratory trials, extracted polyphenol content ranged from about 40 milligrams to more than 145 milligrams per batch, a more than threefold difference in the dose a patient would receive from preparations all nominally following pharmacopoeial guidance. In other words, subtle variations in how an infusion or decoction is prepared could translate into substantially different therapeutic exposures, a finding that underscores why standardization matters for traditional remedies.

Scale-up introduced its own surprises. When the extraction was transferred to pilot-scale equipment thirty times larger, the team ran a Central Composite Design testing drug-to-extract ratios of 4 to 6 percent and agitation from 0 to 400 revolutions per minute. Agitation, negligible at bench scale, became a determining factor in the larger vessel, a classic illustration of why process behavior cannot simply be extrapolated. Higher stirring rates improved contact between solvent and plant matrix, while increasing the drug-to-extract ratio raised absolute yields of markers but diluted their relative concentration, hinting at solvent saturation. All pilot conditions produced extracts meeting Brazilian Pharmacopoeia specifications for total tannins, above 2 percent, and epicatechin, above 0.28 percent.

The final transformation, spray drying followed by granulation, was optimized with a 17-assay Central Composite Rotatable Design exploring maltodextrin concentration from 0 to 60 percent, feed rate from 3.9 to 8.1 milliliters per minute, and inlet air temperature from 120 to 200 degrees Celsius. Maltodextrin, a common carrier, dramatically reshaped the powder’s personality: more carrier produced lighter, better-flowing granules but diluted the active markers, raising the dose a patient must swallow. Temperature and feed rate modulated moisture, density, and the Carr index of compressibility. For granulation, the team chose hydroxypropyl methylcellulose as a binder rather than the more common polyvinylpyrrolidone, because PVP can form insoluble complexes with tannins and lock away the very compounds that give the medicine its activity. Residual moisture stayed below the critical 5 percent threshold in every run, confirming the spray dryer’s protective effect on a heat-sensitive botanical matrix.

Desirability analysis, which blends all quality goals into a single optimization score, revealed an honest limit: no single spray-drying condition could satisfy every attribute simultaneously, with global desirability falling below 0.7. The team therefore validated two candidate conditions in triplicate. The first, close to the modeled optimum, used no maltodextrin, a 20 percent feed rate, and 160 degree inlet air, delivering nearly 14 percent polyphenols and dense, fast-wetting granules. The second, with 45 percent maltodextrin, sacrificed chemical concentration for improved flow and reduced hygroscopicity. Process yield and marker retention proved statistically indistinguishable between the two, demonstrating that formulation choices could tune the product’s physical behavior without compromising chemical integrity, precisely the kind of flexible, evidence-based control that a Design Space is meant to provide.

The broader significance extends beyond one Brazilian shrub. Espinheira-santa has long been confounded with lookalike species such as Sorocea bonplandii and Zollernia ilicifolia, which share its popular name and can adulterate commercial supplies, making authenticated, chemically consistent manufacturing all the more urgent. By showing that a medicinal plant can be taken from a registered experimental field, through botanically verified harvesting, statistically optimized extraction, and validated drying and granulation, the UNICAMP team has offered a template for modernizing phytotherapy across the board. The authors note that future work should incorporate high-shear and fluidized-bed granulation for true industrial scale, assess raw material variability from different suppliers, and conduct long-term stability and biological activity studies. But the core message already stands: a plant that indigenous Mapuche communities prized centuries ago, and that Brazilian clinics prescribe today, can meet the same quantitative standards of reproducibility demanded of any synthetic drug, provided every leaf, liter, and degree along the way is treated as a measurable, controllable variable.

Subject of Research: Quality by Design development of a Monteverdia ilicifolia herbal medicine from plant harvesting to granulated extract

Article Title: Quality by design driven development of a Monteverdia ilicifolia herbal medicine: from plant to granules

Article References: de Caux, A. A., Klier Monteiro Filho, J. C., Barbosa da Silva e Medeiros, R., Villa Nova Rodrigues, M., Alves, M. N., Soares Forte, M. B., Rodrigues, M. I., & Ferreira Rodrigues, R. A. (2026). Quality by design driven development of a Monteverdia ilicifolia herbal medicine: from plant to granules. Frontiers in Natural Products, 5, Article 1887810. https://doi.org/10.3389/fntpr.2026.1887810

Image Credits: AI Generated

DOI: 10.3389/fntpr.2026.1887810

Keywords: Monteverdia ilicifolia, espinheira-santa, Quality by Design, design of experiments, herbal medicine, spray drying, granulation, process validation, polyphenols, tannins, risk assessment, pharmaceutical manufacturing

The research team, led by Annamalai Jeyakumari with Vinod Abhiroop and Krishnamoorthy Elavarasan, prepared four sardine fish oil emulsion formulations, coded SE1 through SE4, using low- and medium-molecular-weight chitosan as the variable biopolymer. Low-molecular-weight chitosan, derived from shrimp shell with a viscosity of 75.2 centipoise, was paired with bovine gelatin and maltodextrin in SE1 and SE2, while medium-molecular-weight chitosan, with a viscosity of 386 centipoise, formed the basis of SE3 and SE4. The fish oil-to-wall material ratio was maintained at 1:4 by weight across all formulations, and the oil loading differed between the pairs, with SE1 and SE3 containing 0.5 percent fish oil and SE2 and SE4 containing 1.0 percent. Wall materials were dissolved in 1 percent acetic acid solution, the oil was added gradually under magnetic stirring, and the coarse emulsions were homogenized at 20,000 rpm for 5 minutes before being converted into powder by spray drying at an inlet air temperature of 160 degrees Celsius and an outlet temperature of 70 degrees Celsius.

The choice of chitosan as an encapsulating biopolymer rests on its structure, a beta (1,4)-linked copolymer of D-glucosamine and N-acetyl-D-glucosamine, which confers biodegradability, biocompatibility, film-forming capacity, and inherent antioxidant and antimicrobial activities. However, chitosan alone performs poorly as an emulsifier, so it must be combined with complementary wall materials. Bovine gelatin, extracted by hydrolyzing collagen, contributes excellent film-forming, emulsifying, and gelling properties, while maltodextrin acts as a drying aid with high water solubility, low hygroscopicity, and good powder-forming ability. Tween 20 was included as a non-ionic emulsifier to reduce interfacial tension and facilitate the formation of fine oil droplets. The interplay of these polymers determines how effectively the wall matrix wraps around the lipid droplets during the rapid moisture evaporation that characterizes spray drying, and the study set out to quantify precisely how chitosan molecular weight alters that interplay.

Measurements of the emulsions with a nanoparticle analyzer revealed significant differences in droplet size, polydispersity index, and viscosity among the formulations. SE1 exhibited the smallest droplet size at 1023 nanometers, followed by SE2 at 1258 nanometers, while SE3 and SE4 produced larger droplets of 1638 and 1845 nanometers respectively. The increase in particle size with rising chitosan molecular weight was attributed to enhanced intermolecular interactions and chain entanglement, which form larger droplets during emulsification. Polydispersity index values were lower for the low-molecular-weight formulations, 0.40 to 0.41, indicating narrower droplet size distributions, whereas the medium-molecular-weight systems showed higher values of 0.51 to 0.56, suggesting greater heterogeneity. Viscosity increased dramatically from roughly 9 centipoise in the low-molecular-weight emulsions to about 93 to 94 centipoise in the medium-molecular-weight systems, a more than tenfold jump that reflects the stronger chain entanglement of the longer chitosan molecules.

When the emulsions were spray dried, the resulting powders showed moisture contents ranging from 2.49 to 4.23 percent, all within the acceptable range for spray-dried lipid powders, which is critical for suppressing microbial growth, caking, and oxidative deterioration during storage. Encapsulation efficiency, the key indicator of how well the wall matrix retains oil within the microcapsules and minimizes surface oil exposed to pro-oxidant conditions, varied significantly from 53.26 to 82.06 percent. SE3, the medium-molecular-weight chitosan formulation with 0.5 percent fish oil, achieved the highest encapsulation efficiency at 82.06 percent, while SE2, the low-molecular-weight system with 1.0 percent oil, recorded the lowest at 53.26 percent. Protein content of the powders ranged from 21.00 to 36.75 percent, reflecting the proportion of gelatin in each wall blend, while fat content varied between 10.18 and 11.88 percent and ash remained low at 0.46 to 0.49 percent.

Powder flow characteristics, evaluated through bulk density, tapped density, Carr’s Index, and the Hausner ratio, differed significantly among the treatments. SE3 exhibited the most desirable flow properties, with the lowest Carr’s Index at 26.93 percent and the lowest Hausner ratio at 1.37, compared with values as high as 47.56 percent and 1.91 in SE2. According to conventional classification, an Hausner ratio above 1.34 and a Carr’s Index above 25 percent indicate poor flowability, and indeed all samples in the study fell into that category, a limitation commonly reported for microencapsulated oil powders. Nevertheless, the relative superiority of SE3 suggests that the denser encapsulating matrix formed by medium-molecular-weight chitosan improved powder handling. Hygroscopicity values ranged narrowly from 8.43 to 9.12 percent, and SE3 combined high encapsulation efficiency with moderate moisture uptake, consistent with the reported negative correlation between encapsulation efficiency and hygroscopicity.

Differential scanning calorimetry added a thermal dimension to the comparison. All formulations displayed a small transition between 50 and 75 degrees Celsius, attributed to the release of physically bound water from the microcapsule matrix, followed by prominent exothermic peaks associated with structural breakdown of the encapsulating wall. These decomposition peaks appeared at 166.15 degrees Celsius for SE1, 152.14 for SE2, 175.96 for SE3, and 167.18 for SE4. SE3 exhibited the highest decomposition temperature, indicating greater resistance to thermal degradation and a more compact, robust microcapsule structure arising from stronger interactions among the wall materials. Because the decomposition temperatures exceeded 150 degrees Celsius, the researchers concluded that the microencapsulated sardine oil could withstand moderate thermal processing conditions common in the food industry, including baking, extrusion, and blending with dry ingredients, without significant degradation of the encapsulating matrix.

The decisive test came from the storage studies, in which the powders were held for 21 days under both ambient conditions at 28 plus or minus 2 degrees Celsius and refrigerated conditions at 4 degrees Celsius, with oxidative stability monitored through thiobarbituric acid reactive substances, expressed as milligrams of malondialdehyde per kilogram. Under ambient storage, SE3 started with the lowest initial TBARS value of 0.41 and fluctuated only between 0.41 and 0.54 throughout the 21-day period, demonstrating an effective barrier against oxygen diffusion. In stark contrast, SE2 and SE4 rose sharply during the first week to 3.82 and 3.51 respectively, and SE1 climbed gradually from 1.77 to 2.57. Under refrigeration, SE3 again maintained the lowest values, ranging from 0.44 to 0.60, while SE4 showed moderate protection at 0.65 to 1.13 and the low-molecular-weight formulations fared worse. The consistently low TBARS values of SE3 under both conditions were linked to its higher encapsulation efficiency and reduced surface oil, which limited the lipid fraction accessible to pro-oxidative attack.

The study concludes that a wall system comprising 0.5 percent medium-molecular-weight chitosan, bovine gelatin, maltodextrin, and 0.5 percent fish oil is an effective carrier for sardine oil, delivering the highest encapsulation efficiency, the lowest oxidation markers, and the greatest thermal resistance among the formulations evaluated. Refrigerated storage provided additional protection for all samples, but the formulation itself proved the dominant factor in preserving oxidative quality. The researchers suggest that these microencapsulated sardine oil powders possess significant potential as omega-3-rich ingredients for functional foods and nutraceutical formulations, from bakery and dairy products to powdered beverages, instant soup mixes, and nutritional supplements, where processing and storage stability are critical for maintaining product quality and nutritional value. By demonstrating that the molecular weight of a single biopolymer can swing encapsulation efficiency by nearly 30 percentage points and suppress oxidation markers by more than sixfold, the work offers food technologists a precise, actionable lever for engineering stable omega-3 delivery systems.

Subject of Research: Microencapsulation of sardine fish oil with chitosan-based polymer blends for oxidative stability

Article Title: Microencapsulation of sardine fish oil using different molecular weight chitosan and polymer blends: a comparative study on oxidative stability and encapsulation characteristics

Article References: Jeyakumari, A., Abhiroop, V., & Elavarasan, K. (2026). Microencapsulation of sardine fish oil using different molecular weight chitosan and polymer blends: a comparative study on oxidative stability and encapsulation characteristics. Frontiers in Marine Science, 13, Article 1906530. https://doi.org/10.3389/fmars.2026.1906530

Image Credits: AI Generated

DOI: 10.3389/fmars.2026.1906530

Keywords: fish oil, omega-3, microencapsulation, chitosan, spray drying, oxidative stability, maltodextrin, gelatin, functional foods, sardine oil, sardine, fish

The principle behind the ELSD is elegantly simple. In liquid chromatography, a separated analyte dissolved in a mobile phase arrives at the detector, where the eluent is nebulised into a fine spray. The droplets pass through a heated evaporator tube that strips away the solvent, leaving behind dry analyte particles. A laser beam then illuminates the particle stream, and the scattered light provides the detection signal. Because the response depends on scattering rather than on any optical absorption by the analyte itself, the detector can handle an enormous range of compounds. But the signal strength ultimately hinges on how many particles there are, how large they are, and what shape they have taken after drying, and until now no one had measured those quantities directly inside a working instrument.

The Cambridge team chose three analytes with deliberately contrasting properties: caffeine, which serves as the standard calibration sample in Agilent ELSD instruments; dextran, a large-molecular-weight water-soluble polymer representative of the macromolecules the detector is often asked to analyse; and citric acid, a small non-cyclic molecule with low volatility. Aqueous solutions of each were prepared at concentrations of 0.125, 0.25, 0.5, and 1 grams per litre, sonicated to ensure complete dissolution, and fed continuously into an Agilent 1290 Infinity II ELSD. Steady-state operation, rather than the conventional pulsed injections from a chromatography column, was essential because the particle sizing instruments and electron microscopy required far longer sampling timescales than a transient pulse could provide.

Reconstructing the initial droplet distribution posed a formidable measurement challenge. Water evaporates so rapidly that no single instrument can capture the full size range in situ. The researchers therefore combined two complementary techniques. A phase Doppler particle analyser, or PDPA, provided rapid, spatially resolved measurements of droplets larger than roughly two micrometres, sampled just one millimetre from the nebuliser tip along the spray centreline. Below that threshold, an aerodynamic aerosol classifier paired with a condensation particle counter covered the gap between about 200 nanometres and two micrometres, though it required sampling through tubes and could not resolve individual positions in the spray. To bridge the two regimes, the team used dioctyl sebacate, a low-vapour-pressure oil with negligible evaporation at room temperature, as a non-evaporating surrogate liquid measurable by both instruments simultaneously.

By comparing the well-mixed PDPA and classifier measurements across the overlapping size range, the researchers derived diameter-dependent loss and transfer functions that corrected for gravitational settling in the liquid trap and diffusional and inertial losses in the sampling lines. The result was a reconstructed log-normal droplet distribution for the oil surrogate with a mode near 450 nanometres and a geometric standard deviation of 1.08. Applying established correlations for twin-fluid coaxial pneumatic nebulisers, which relate the Sauter mean diameter to the Reynolds, Weber, and Ohnesorge numbers of the liquid and gas flows, the team then translated this distribution to water. Because water has a higher surface tension than the oil, more energy is needed to shatter the liquid jet, and the predicted water droplet mode shifted upward to about 550 nanometres, with a correspondingly lower peak number concentration to conserve the liquid volume flow.

Downstream of the evaporator, the dried particles were characterised with a scanning mobility particle sizer operated over a size range of 8 to 232 nanometres, with each condition repeated three times for reproducibility. The measurements revealed clear differences among the analytes. Citric acid produced the lowest overall concentrations and the smallest mean diameters, consistent with its high effective density, while dextran behaved remarkably similarly to caffeine despite its much larger molecular weight, hinting at comparable effective densities after drying. In every case, the peak of the distribution grew with analyte concentration, and the distributions were skewed toward larger sizes rather than perfectly log-normal, a signature of size-dependent impaction at the instrument’s Y junction and labyrinth diffuser cartridge, which strip out the largest droplets before they reach the evaporator.

A simple mass-conservation calculation, equating the analyte mass in an initial droplet to the mass of a final spherical particle at bulk density, provided a sanity check on the measurements. For a concentration of 1 gram per litre, the model predicted final mode diameters of 46 nanometres for citric acid and 52 nanometres for caffeine, which could be compared against measured modes of 35 and 65 nanometres respectively. The discrepancies proved informative in both directions. The under-prediction for caffeine pointed to a lower effective particle density than the bulk crystal value, a conclusion borne out by microscopy showing that dried caffeine particles are far from spherical. The over-prediction for citric acid suggested that dissolved analyte may lower the surface tension of the solution, producing smaller initial droplets than the pure-water reconstruction assumes.

Scanning electron microscopy of particles collected on carbon-coated transmission electron microscopy grids, platinum-coated for conductivity and imaged at 5 kilovolts, exposed striking morphological diversity. Caffeine formed elongated, needle-like crystalline particles, echoing literature reports of caffeine crystallising into needles in bulk, a shape with potentially significant consequences for how the particles scatter the detector’s laser light. Dextran yielded approximately spherical particles spanning a wide range of diameters, frequently agglomerated into larger clusters, matching previous observations of dried dextran. Citric acid, unexpectedly, produced roughly spherical, non-agglomerated particles that preferentially collected around the holes of the grids, suggesting liquid-like surface properties during deposition. This contrasts sharply with bulk drying studies, in which citric acid forms crystals with multi-layer agglomerate networks, indicating that crystallisation within atomised droplets follows a different path than crystallisation in a bulk solution.

The study establishes, for the first time, a full experimental picture of particle formation and evolution inside an ELSD, from atomisation through evaporation to detection, and provides the benchmark data against which a companion paper validates a numerical model of aerosol transport, evaporation, and scattering in the instrument. Because the light-scattering signal depends directly on particle size, number, and morphology, the findings explain why detector response varies across analytes and open a route to optimising instrument geometry and operating conditions for specific applications. The authors suggest that the combined experimental and modelling framework could enable improved detector designs and more robust analytical methods across pharmaceutical, biomaterials, and food science research, turning a long-standing black box into a quantitatively understood instrument.

Subject of Research: Experimental characterisation of droplet drying and particle formation inside an evaporative light scattering detector

Article Title: Size distribution and particle morphology of analytes dried through the evaporative light scattering detector – Part 1

Article References: Bertani, F., Hassim, J., & Hochgreb, S. (2026). Size distribution and particle morphology of analytes dried through the evaporative light scattering detector – Part 1. Aerosol Research, 4(2), 311-323. https://doi.org/10.5194/ar-4-311-2026

Image Credits: AI Generated

DOI: 10.5194/ar-4-311-2026

Keywords: evaporative light scattering detector, aerosol science, particle size distribution, nebulisation, spray drying, phase Doppler particle analysis, aerodynamic aerosol classifier, scanning electron microscopy, caffeine, dextran, citric acid, liquid chromatography

The chemistry behind this promise is striking. Immunoglobulins, chiefly IgG, make up roughly 70 to 80 percent of the total protein in first-day colostrum, and their concentration can reach 50 to 100 milligrams per milliliter in the first days after delivery, orders of magnitude above the levels found in mature milk. Total protein in day-one colostrum approaches 15 percent by weight before falling to around 3 percent within days. Alongside the antibodies sit lactoferrin, an iron-binding glycoprotein with antibacterial, antiviral and anti-inflammatory activity; lactoperoxidase, an enzyme that generates reactive compounds lethal to a broad range of bacteria; and growth factors such as IGF-1 and TGF-beta that drive epithelial repair and tissue regeneration. Proline-rich polypeptides add a further layer of immune regulation, capable of damping down overactive responses of the kind seen in allergy and autoimmunity.

What makes bovine colostrum particularly attractive compared with colostrum from other species is a combination of potency, abundance and cross-species compatibility. The IgG concentration in bovine colostrum is nearly 100 times higher than in human colostrum, and many of its bioactive molecular structures are conserved across mammals, allowing bovine-derived molecules to interact effectively with human receptors. Dairy cows also produce far more colostrum than a calf can consume, creating a renewable surplus that can be harvested without compromising animal welfare. Regulatory agencies in several countries already recognize bovine colostrum as a generally safe natural nutraceutical ingredient, and its production is scalable in a way that human, goat or camel colostrum simply is not.

The carbohydrate fraction of colostrum is proving equally interesting. Bovine colostrum contains between 0.7 and 1.2 milligrams per milliliter of oligosaccharides, the majority of them acidic, sialylated structures such as 3′-sialyllactose, which accounts for about 70 percent of the total. Forty distinct oligosaccharide compositions have been identified so far, and their levels peak immediately after parturition before declining within 48 hours. Unlike the predominantly fucosylated oligosaccharides of human milk, bovine milk oligosaccharides are mostly sialylated, and recent advances in enzymatic glycosylation are making it possible to modify their structures to resemble human milk oligosaccharides more closely. Glycoproteins such as the casein-derived glycomacropeptide add prebiotic value, promoting the growth of beneficial Bifidobacterium in the gut.

Turning this perishable fluid into a stable commercial ingredient is a technological challenge in its own right, and the review devotes considerable attention to processing science. Freeze-drying, or lyophilization, is described as the gold standard: by freezing colostrum and removing water through sublimation under reduced pressure, the process avoids the heat that would denature thermolabile proteins. Freeze-dried colostrum retains 85 to 95 percent of original IgG activity, and with cryoprotectants such as trehalose or maltodextrin, probiotic survival rates of 80 to 90 percent can be achieved. Spray-drying, by contrast, is the workhorse of industrial production, atomizing liquid colostrum into hot air at inlet temperatures of 140 to 180 degrees Celsius. Although somewhat harsher, optimized spray-drying can still preserve 70 to 80 percent of immunoglobulin activity while dramatically reducing microbial load and extending shelf life, which is why it remains the method of choice for large-scale manufacturing.

Clinical evidence is accumulating across a surprising range of conditions. In gastrointestinal medicine, colostrum has shown benefit in irritable bowel syndrome, ulcerative colitis and infectious diarrhea. A small pilot trial of a colostrum enema in ulcerative colitis saw symptom improvement in seven of eight treated patients, and hyperimmune colostrum tablets targeting enterotoxigenic E. coli provided roughly 90 percent protection against experimentally induced traveler’s diarrhea in challenge studies. Perhaps most striking is the interaction with painkillers: in a crossover trial, volunteers taking the NSAID indomethacin alongside whey protein saw intestinal permeability rise nearly threefold, whereas those co-administered bovine colostrum showed no significant increase at all, an effect attributed to growth factors that promote healing of the gut lining.

Athletes form another key target population. The first study of colostrum supplementation in sport, published in 1997, reported increases in serum immunoglobulin concentrations and explosive muscular power. Subsequent controlled trials have found improvements in lean body mass, cycling performance and recovery in runners, and one study of older adults undergoing resistance training showed enhanced leg press strength and reduced bone resorption at a dose of 60 grams per day. Supplementation has also been linked to reduced exercise-induced gut permeability and, in some studies, elevated secretory IgA in saliva, although these immune findings have not always been replicated. Researchers caution that the mechanisms remain unclear and that the effects probably cannot be explained by protein content alone, since whey protein controls with matching protein levels generally perform less well.

The newest frontier comes from omics technologies. Proteomic profiling has identified more than a thousand distinct proteins and peptides in bovine colostrum, revealing low-abundance bioactives such as osteopontin, milk fat globule membrane proteins and lactoperoxidase that participate in immune signaling, mucosal defense and tissue repair. Even more provocative is the discovery of microRNAs packaged within stable extracellular vesicles. These small regulatory RNAs, including miR-148a and miR-21, appear capable of surviving passage through the digestive tract and influencing gene expression in recipient cells, modulating T-cell differentiation, macrophage activation and the integrity of tight junctions in the intestinal barrier. Some evidence suggests these molecules may even cross species barriers, adding an epigenetic dimension to colostrum’s bioactivity that extends well beyond its traditional protein and peptide mechanisms.

The review is careful to balance enthusiasm with caution. Colostrum’s bioactive content varies substantially between batches depending on breed, diet, parity and collection time, raising standardization and labeling concerns in loosely regulated markets. Milk protein allergy and lactose intolerance remain relevant risks for sensitive individuals, and fresh colostrum is highly perishable and prone to contamination with pathogens such as E. coli, Salmonella and Listeria unless properly pasteurized or dried. Theoretical questions also persist about long-term exposure to concentrated growth factors, particularly for people with hormone-sensitive conditions, and the authors call for larger, well-designed, double-blind and placebo-controlled trials to confirm many of the reported clinical benefits.

Nevertheless, the overall trajectory is unmistakable. From functional foods and infant nutrition to sports supplements and pharmaceutical formulations, bovine colostrum is being repositioned as a multifunctional bioactive matrix rather than a simple dairy byproduct. New encapsulation and delivery systems are being developed to improve the bioavailability and targeting of its fragile components, and metabolomic and transcriptomic studies continue to uncover candidates with antiviral and immunomodulatory potential. As consumer demand shifts toward natural products with immune-enhancing and regenerative properties, the review concludes that this ancient first milk, once valued only for the survival of newborn calves, may become a staple ingredient of future functional nutrition and therapeutic development, provided that quality control, sustainable sourcing and processing standardization keep pace with the science.

Subject of Research: Nutritional composition, bioactive components and therapeutic applications of bovine colostrum

Article Title: Health benefits and value addition of bovine colostrum (BC): a comprehensive review of its nutritional and functional potential

Article References: Riaz, S., Imran, A., Rasheed, M., Amjad, A., Shankar, A., Chauhan, G., Basharat, Z., Islam, F., Naeem, U., & Ndagire, C. T. (2026). Health benefits and value addition of bovine colostrum (BC): a comprehensive review of its nutritional and functional potential. Food Science of Animal Resources, 46(1), Article 55. https://doi.org/10.1007/s44463-026-00057-w

Image Credits: AI Generated

DOI: 10.1007/s44463-026-00057-w

Keywords: bovine colostrum, immunoglobulins, lactoferrin, growth factors, gut health, functional foods, nutraceuticals, freeze-drying, spray-drying, microRNAs, immune modulation, sports nutrition

The core challenge the researchers set out to solve is a molecular conflict of interest. Egg white is packed with high-quality proteins — ovalbumin, ovotransferrin, ovomucin and others — that gel, foam and emulsify beautifully, making it an attractive textural modifier for dairy products. But egg white also contains lysozyme, a potent antibacterial enzyme that cleaves the β-1,4 glycosidic bonds in bacterial cell wall peptidoglycan. That is excellent news for food preservation and terrible news for yogurt starters, which rely on Gram-positive lactic acid bacteria — Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus — to ferment lactose into lactic acid. Adding raw egg white to yogurt milk risks sabotaging the very organisms the fermentation depends on.

The team, led by Yunxiao Xie and Fang Geng, applied a pretreatment strategy they had developed in earlier work, abbreviated UHSD: liquid egg white is first blasted with 20 kHz ultrasound in pulsed mode for ten minutes while kept cold, then heated in a water bath at 72 °C for ten minutes, and only then spray-dried into a powder. The ultrasound cavitation and mechanical shear unfold protein aggregates, and the subsequent moderate heating promotes controlled aggregation and disulfide exchange between lysozyme and other egg white proteins. When the researchers measured apparent lysozyme activity using Micrococcus lysodeikticus cells as a substrate, the results were striking. Fresh egg white showed an apparent activity of 5660 U/mg. Conventional spray drying alone cut that by 54.6 percent, but the full ultrasound–heat–spray-drying sequence reduced it by 90.3 percent — a dramatic taming of the antibacterial enzyme while keeping the functional proteins largely intact.

With the pretreated powder in hand, the researchers formulated yogurts in which the powder partially replaced milk at 0, 1, 2 and 4 percent by mass, heat-treated the mixes at 72 °C for 30 minutes, inoculated them with a commercial two-strain starter, and fermented for ten hours. Every batch set into a stable gel with no visible whey separation, and all samples met the Chinese national standard minimum titratable acidity of 60 °T for fermented milk. Color measurements showed the supplemented yogurts became progressively lighter, with reduced red and yellow components — a subtle whitening effect that could be commercially appealing. Texture analysis, however, revealed a dose-dependent trade-off: hardness was unchanged at 1 and 2 percent addition but dropped significantly at 4 percent, and springiness peaked at the 1 percent level before falling at the highest dose.

The structural story behind those numbers emerged from microscopy and rheology. Scanning electron micrographs of freeze-dried yogurt showed that the control gel was relatively loose, with large pores, while the egg white-supplemented samples displayed progressively smaller gel particles and a more uniform, compact three-dimensional network — most pronounced at 4 percent. Rheological testing showed all samples were shear-thinning pseudoplastic fluids, but apparent viscosity shifted upward with increasing powder addition, and both the storage modulus G′ and loss modulus G″ rose across the frequency range, with G′ consistently exceeding G″, confirming elastic, weak-gel behavior throughout. In short, the egg white proteins were genuinely participating in the acid-induced casein network, cross-linking the gel and stiffening its response to deformation.

Yet a denser microstructure did not translate into proportionally better macroscopic performance. The 1 percent group achieved the highest water-holding capacity, significantly above all other groups, while the 4 percent group showed no advantage over the control, which held 64.3 percent of its water. The explanation lies in acidification. At 4 percent addition, the final pH rose by 2.3 percent relative to the control’s 4.38, and titratable acidity fell by 4.4 percent to 93.8 °T. Because yogurt gelation depends on acid gradually neutralizing the electrostatic repulsion between casein micelles as pH approaches their isoelectric point, a weaker fermentation slows and shallows that aggregation. The powder partially replaced milk, so the higher pH also reflects altered buffering and substrate availability — and the authors are careful to note that their design cannot separate the effect of added protein and solids from the specific contribution of the ultrasound–heat pretreatment itself, since a conventional spray-dried powder control was not included.

The most novel part of the study is its use of metatranscriptomics — sequencing the expressed RNA of the entire microbial community — to see how the starter cultures actually responded. From nine samples across the control, 1 percent and 4 percent groups, the team generated over 608 million raw reads, averaging roughly 7.77 gigabases per sample with Q30 quality scores above 95.7 percent. After removing ribosomal RNA, assembling transcripts de novo and annotating predicted proteins against the NR, KEGG, eggNOG and CAZy databases, they found that Bacillota transcripts dominated at over 98 percent in every group, with Streptococcus thermophilus and Lactobacillus delbrueckii as the core expressed species — exactly the signature of a healthy yogurt ferment. Ordination analyses showed the control clearly separated from both supplemented groups in transcriptional space.

The functional annotations told a coherent story. In the 4 percent group, transcript abundance assigned to glycolysis/gluconeogenesis, pyruvate metabolism and carbon metabolism all declined, consistent with the observed higher pH and lower acidity — the bacteria were transcribing fewer genes for lactose breakdown and lactic acid production. Carbohydrate-active enzyme genes showed the same pattern: glycoside hydrolase transcript abundance in the 4 percent group fell to about 48.7 percent of control levels, and glycosyltransferases to about 41.1 percent. Meanwhile, LEfSe analysis flagged lactic acid bacteria taxa such as Lactobacillaceae as differential in the 1 percent group, whereas the 4 percent group showed relatively higher representation of low-abundance, non-core taxa — possibly because the weakened acidification relaxed the selective pressure that normally suppresses non-yogurt microbes, and possibly because residual lysozyme, to which Gram-negative bacteria are more tolerant, subtly shifted the competitive balance. The authors stress that transcript abundance is not direct evidence of altered enzyme activity or metabolite concentrations, and that enzyme assays and metabolomics would be needed for confirmation.

The practical takeaway is a dose window rather than a free pass. At around 1 percent, the pretreated egg white powder delivered the best overall package: the highest springiness, the best water retention, a more compact gel network and a microbial community whose transcriptional profile remained firmly lactic-acid-bacteria dominated. At 4 percent, the same powder produced a visually denser network but softer texture, weaker acidification and a transcriptional drift toward non-core taxa. For an industry eager to boost protein content and improve texture with clean-label ingredients, that distinction matters enormously. The study also demonstrates the power of metatranscriptomics as a quality-control lens for fermented foods: instead of merely counting microbes, it reveals which metabolic programs are actively running, catching functional shifts that pH and texture measurements alone could only hint at. Future work with composition-matched controls will need to isolate what the ultrasound–heat pretreatment itself contributes, but the concept — defusing egg white’s antibacterial arsenal while enlisting its gelling proteins — now has both a physical and a molecular evidence base.

Subject of Research: Effects of ultrasound–heat pretreated egg white powder on yogurt quality, gel properties and microbial metatranscriptomic profiles

Article Title: Effects of ultrasound–heat pretreated egg white powder addition on the quality, gel properties, and metatranscriptomic profiles of yogurt

Article References: Xie, Y., Wang, X., Shui, Y., Hu, G., He, H., Wang, J., & Geng, F. (2026). Effects of ultrasound–heat pretreated egg white powder addition on the quality, gel properties, and metatranscriptomic profiles of yogurt. Food Chemistry: X, 39, Article 104550. https://doi.org/10.1016/j.fochx.2026.104550

Image Credits: AI Generated

DOI: 10.1016/j.fochx.2026.104550

Keywords: yogurt, egg white powder, ultrasound, lysozyme, gel properties, metatranscriptomics, lactic acid bacteria, food texture, spray drying, water-holding capacity, rheology, fermented dairy

The material at the heart of the study is alpha double-prime iron nitride, Fe16N2, an ordered tetragonal phase that has fascinated magnet researchers for decades. It is made entirely of abundant, inexpensive elements, yet it boasts a theoretical saturation magnetization of roughly 290 emu per gram and a magnetocrystalline anisotropy near 1.0 times ten to the seventh erg per cubic centimeter, figures that rival or exceed those of many rare-earth compounds. The catch has always been coercivity, the field required to demagnetize the material, which determines whether a magnet can actually hold its grip in a motor. Powders of Fe16N2 made by scalable methods have historically shown coercivities too low for demanding applications, and closing that gap has become one of the central challenges in the search for supply-chain-proof permanent magnets.

The physics of the problem is well understood. Coercivity in ferromagnetic particles rises as particle size shrinks toward the single-domain limit, which for Fe16N2 sits at roughly 73 nanometers. That insight has driven a generation of bottom-up synthesis efforts, from coprecipitation to hydrothermal routes, all aimed at producing nanoscale iron oxide precursors that can later be reduced to iron and nitrided with ammonia. The trouble is that oxide nanoparticles love to agglomerate and coarsen during hydrogen reduction, destroying the fine features that made them attractive in the first place. The original size and shape of the nanoparticles are rarely preserved, and the resulting nitride inherits a compromised microstructure and a disappointingly low coercivity.

Aerosol-assisted synthesis offers an appealing way out because it produces micrometer-scale particles that resist coarsening while remaining compatible with continuous, high-throughput manufacturing. Previous studies explored salt-assisted porosity and hollow particle structures to aid nitridation, but the coercivities reported for aerosol-derived Fe16N2 powders remained modest, generally between 1.2 and 1.47 kilooersted. Most of that work focused on raising the fraction of the magnetic Fe16N2 phase rather than on engineering the particle microstructure itself. The new study, published in Advances in Industrial and Engineering Chemistry by researchers at the Korea Institute of Materials Science together with a collaborator from Hyundai Motor Company, takes the opposite approach: keep the chemistry of the final conversion steps identical, and instead vary the microstructure of the oxide precursor at the very start of the process.

The team prepared three distinct hematite, alpha-Fe2O3, precursors using two aerosol techniques and two different iron salts. The first route was ultrasonic spray pyrolysis, in which a 0.1 molar solution of iron nitrate was nebulized at 1.7 megahertz and carried by compressed air through a quartz tube reactor held at 700 degrees Celsius. Inside the hot zone, each droplet underwent solvent evaporation and thermal decomposition in a single step, yielding solid, spherical hematite particles with smooth, dense surfaces and an average diameter of just 0.5 micrometers. The second route was spray drying, a gentler two-step process in which droplets were atomized with a two-fluid nozzle and dried at only 220 degrees Celsius, leaving intermediate salt particles that were subsequently calcined in air at 450 degrees Celsius for four hours to form the oxide. Spray drying was performed with both iron nitrate and iron oxalate solutions at a much higher solid content of 10 weight percent, producing substantially larger particles, around 3.9 and 4.8 micrometers respectively.

The choice of salt turned out to matter enormously. The spray-dried nitrate powder retained its spherical shape but developed a rough surface of enlarged primary grains as hematite grew during calcination, with an average crystallite size of 31.6 nanometers measured by X-ray diffraction. The oxalate-derived powder, by contrast, emerged with a crumpled, fractured and highly porous texture. The reason lies in the thermal chemistry: iron oxalate decomposes at a higher temperature than iron nitrate, and as it breaks down it releases copious carbon monoxide and carbon dioxide gas that punches fine pores into the particle as it escapes. Because the decomposition happens later under identical calcination conditions, oxide formation is delayed, iron cation diffusion is limited, and grain growth is suppressed, leaving the oxalate-derived hematite with significantly finer crystallites of 20.7 nanometers on average.

All three precursors then passed through exactly the same conversion sequence. Hydrogen reduction at 330 degrees Celsius for four hours transformed the hematite into body-centered cubic alpha iron, and after a brief argon purge the gas flow was switched to ammonia for nitridation at 175 degrees Celsius for fifteen hours, yielding the body-centered tetragonal Fe16N2 phase. X-ray diffraction with whole-pattern profile fitting showed that every sample contained more than 90 weight percent of the desired phase, with the two nitrate-derived powders reaching purities of roughly 94 to 95 weight percent and the oxalate-derived powder coming in at about 90 percent. Remarkably, the final nitride crystallite size converged to a narrow window of 17 to 18 nanometers for all three samples, regardless of the crystallite size in the starting oxide. The researchers attribute this reset to the reduction step itself, in which oxygen removal and iron atom rearrangement govern the formation of new iron crystallites whose size is largely independent of the initial oxide state, while the subsequent low-temperature nitridation preserves that fine structure.

Electron microscopy revealed that the distinctive personalities of the three precursors survived the entire journey. The spray-pyrolyzed particles stayed as smooth spheres of about half a micrometer, merely roughened at the surface. The spray-dried nitrate particles shrank from 3.9 to 2.7 micrometers as oxygen left the lattice and kept their rough, porous surfaces. The oxalate-derived particles shrank only slightly, from 4.8 to 4.5 micrometers, but their porosity intensified during reduction and nitridation, producing a labyrinth of pore walls, edges and rough surfaces. Most of this architectural change occurred during hydrogen reduction, when vacancies and voids formed as oxygen was stripped away, while the low-temperature nitridation made only minimal further alterations. In effect, the microstructure engineered at the oxide stage was faithfully transmitted to the final magnetic powder.

The magnetic measurements delivered the study’s punchline. With crystallite size and phase purity held nearly constant across the three samples, coercivity varied systematically and dramatically: 1.14 kilooersted for the spray-pyrolyzed nitrate powder, 1.46 kilooersted for the spray-dried nitrate, and 1.86 kilooersted for the spray-dried oxalate. Because coercivity in iron nitride materials generally rises with Fe16N2 fraction, the fact that the least pure sample showed the highest coercivity rules out phase purity as the explanation, and the uniform crystallite size rules out that variable as well. The team points instead to domain-wall pinning, the mechanism by which defects, grain boundaries and surface irregularities impede the movement of magnetic domain walls and make the material harder to demagnetize. The oxalate-derived particles, with their abundant pore walls, edges and rough surfaces, simply offered far more pinning sites than their smooth-surfaced cousins. Notably, both spray-dried powders exceeded the 1.2 kilooersted recently achieved with salt-assisted spray pyrolysis, and they did so without any sacrificial templates or added process steps.

The trade-offs are honest and instructive. The high-coercivity oxalate powder showed a saturation magnetization at 2.5 tesla of about 153 emu per gram, lower than the roughly 190 and 185 emu per gram of the nitrate-derived samples, a consequence of its highly porous morphology reducing the density of magnetic material per unit volume alongside its slightly lower phase fraction. Even so, the study demonstrates something potentially transformative for magnet manufacturing: coercivity, the property that has most stubbornly resisted improvement in scalable iron nitride synthesis, can be tuned simply by choosing the aerosol route and the precursor salt. Spray pyrolysis and spray drying are both continuous, industrially mature processes that operate on gram-per-hour scales today, and the entire workflow, from dissolved iron salt to nitrided magnetic powder, involves nothing but water, air, hydrogen and ammonia. For a field racing to build high-performance magnets without rare earths, the message is that the path to a better magnet may begin not in the final nitridation furnace but in the microscopic architecture of a particle of rust.

Subject of Research: Aerosol synthesis and precursor microstructure control to enhance coercivity in rare-earth-free alpha double-prime Fe16N2 magnetic powders

Article Title: Scalable aerosol routes to enhance coercivity in α′′-Fe16N2 powders through α-Fe2O3 microstructure control

Article References: Jeong, J., Park, H. J., Koo, H. Y., Kim, D., Lee, J.-G., & Baek, Y.-K. (2025). Scalable aerosol routes to enhance coercivity in α′′-Fe16N2 powders through α-Fe2O3 microstructure control. Advances in Industrial and Engineering Chemistry, 1(1), Article 23. https://doi.org/10.1007/s44405-025-00026-9

Image Credits: AI Generated

DOI: 10.1007/s44405-025-00026-9

Keywords: Fe16N2, rare-earth-free magnets, coercivity, aerosol synthesis, spray pyrolysis, spray drying, hematite precursor, iron nitride, domain-wall pinning, permanent magnets, microstructure control, hydrogen reduction

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 stakes are higher than they might appear. In the nozzle zone of an industrial spray dryer, freshly formed droplets collide with so-called fines, tiny dry particles smaller than about 100 micrometers that are recirculated from the fluidized bed or cyclone back into the chamber. When a wet droplet meets a fine, the particle merges completely into the liquid. As the droplet surface partially dries, collisions instead produce sticking, the desired outcome that builds agglomerates. Dry too far, and the droplet surface becomes glassy and rigid, so particles bounce off and are lost as waste. The researchers set out to determine exactly where that sticky window lies, and whether it can be predicted from first principles rather than empirical rules.

The team used a sessile single droplet drying platform, in which droplets of roughly 400 micrometers were dispensed onto a surface and dried by a controlled air stream. Maltodextrin with a dextrose equivalence of 38 served as the model material, chosen because its diffusivity and sorption behavior are well characterized, making it ideal for physical modeling. Glass beads in the 70 to 110 micrometer range acted as stand-ins for fines particles, an approach validated in earlier work showing that collision outcomes are governed primarily by the state of the drying droplet rather than the identity of the collision partner.

A central concept in the study is the locking point, the moment when a drying droplet stops behaving like an ideal shrinking sphere and begins to deviate from its spherical shape. This deviation signals the onset of skin formation, when evaporation at the surface outpaces the diffusion of solute from the interior, creating a steep concentration gradient and a mechanically distinct outer layer. The researchers found that the locking point shifts linearly with drying conditions: raising the relative humidity of the drying air from 0 to 15 percent at 80 degrees Celsius delayed locking from about 6.6 to 11.8 seconds, while raising the air temperature from 70 to 90 degrees Celsius at zero humidity shortened it from roughly 9.4 to 5.1 seconds. Crucially, the normalized droplet radius at locking remained statistically unchanged across all conditions, hovering near 0.85 of the initial radius, suggesting that a critical surface solute concentration triggers skin formation regardless of how fast the droplet dries.

To probe stickiness directly, the team fired glass beads at droplets at controlled times during drying and classified each collision as merging, sticking or bouncing. The results were strikingly consistent: across relative humidities from 0 to 15 percent, sticking collisions clustered between 0.75 and 1.5 times the locking point time. Increasing humidity delayed the entire sequence of collision regimes but did not fundamentally change its structure. This confirms and generalizes earlier findings from experiments with different maltodextrin formulations and particle shapes, pointing to the state of the droplet skin, not the drying schedule itself, as the dominant factor determining collision outcomes.

The experimental work was paired with a one-dimensional droplet drying model that solves coupled heat and mass transfer equations in a Lagrangian reference frame, discretizing the droplet into 40 concentric shells. Water diffuses between shells while solids remain fixed, and the model tracks the evolving glass transition temperature at the droplet surface using the Couchman-Karasz relation, which captures how moisture depresses the glass transition. The model was validated against two independent measurements: the volume decrease of droplets up to the locking point, captured by automated image analysis of high-speed video, and the droplet temperature over time, measured with an infrared camera through a special AMTIR-1 window at 125 frames per second.

The thermography revealed a familiar but now precisely quantified pattern. Droplets initially hold a constant temperature set by evaporative cooling, which rises with ambient humidity because higher moisture in the air slows evaporation. Measured constant temperatures of 28, 33, 39 and 44 degrees Celsius at 0, 5, 10 and 15 percent relative humidity matched the corresponding wet bulb temperatures. Once the skin forms and evaporation slows, the droplet temperature climbs toward the air temperature. The model reproduced these trends well, with minor deviations attributed to the difficulty of characterizing the thermal contact between droplet and drying surface, a resistance the team captured with a single fitted parameter.

The key predictive insight emerged when the researchers plotted collision outcomes against the ratio of glass transition temperature to actual droplet temperature at the droplet surface, a dimensionless measure of how close the skin is to becoming glassy. Merging dominated below a ratio of about 0.6, when the droplet is still liquid-like. Sticking occurred between roughly 0.55 and 0.9, with the densest concentration of sticking collisions between 0.6 and 0.8. Bouncing took over above 0.8, as the skin approached the glassy state. Some overlap between regimes was expected and observed, since drying droplets develop spatially heterogeneous surfaces with softer and stiffer patches, and buckling after locking creates irregular geometries that influence individual collisions.

When the researchers normalized drying time by the locking point time, the curves for all tested humidities and temperatures nearly collapsed onto a single master curve, with the glass transition ratio reaching about 0.6 at locking. This collapse means the stickiness regime can be predicted for new drying conditions without running collision experiments for each one: model the droplet, find the locking point, and the sticky window follows as 0.75 to 1.5 times that time. The authors propose this as a general methodology for formulations where glass transition behavior is well defined, while noting limitations for materials such as globular proteins, for very high feed solids concentrations, and for the higher air temperatures used industrially, where the rapidly shortening locking time makes visual determination harder.

The practical payoff could be substantial. Better control of the nozzle zone means manufacturers can tune air temperature, humidity and fines recirculation to maximize agglomeration, improving powder solubility and reducing the fraction of product lost as unagglomerated fines. Because the framework rests on fundamental heat and mass transfer rather than formulation-specific calibration, it offers a route from single droplet physics to pilot and industrial scale spray drying. For an industry that dries everything from milk and coffee to enzymes and probiotics, knowing precisely when a droplet will stick, and being able to compute it in advance, turns a long-standing empirical art into a predictive science.

Subject of Research: Predicting the stickiness regime of drying maltodextrin droplets during spray drying using single droplet experiments and heat and mass transfer modeling

Article Title: Evaluating and predicting the stickiness regime of drying droplets across drying conditions

Article References: de Leeuw, S., Bekebrede, J., Schutyser, M., & van der Sman, R. (2026). Evaluating and predicting the stickiness regime of drying droplets across drying conditions. Current Research in Food Science, Article 101588. https://doi.org/10.1016/j.crfs.2026.101588

Image Credits: AI Generated

DOI: 10.1016/j.crfs.2026.101588

Keywords: spray drying, droplet drying, stickiness, agglomeration, glass transition, maltodextrin, locking point, thermography, mass transfer, food powders, collision regimes, relative humidity

The research, published in Food Science and Biotechnology, focused on developing spray-dried starter cultures for fermenting Pleurotus ostreatus, the common oyster mushroom. The team, led by Aem Nuylert with co-authors Benjamas Cheirsilp and Suppasil Maneerat, worked with two bacterial strains with complementary roles. Lactobacillus futsaii CS3, a lactic acid bacterium originally isolated from Thai fermented shrimp, is a known producer of gamma-aminobutyric acid, or GABA, an amino acid compound prized in functional foods for its potential calming and blood-pressure-lowering effects. Staphylococcus carnosus K21S22 served as a co-starter, contributing to the flavor and aroma development that makes fermented products appealing to consumers.

The central problem the researchers faced is one that haunts the entire probiotic and starter culture industry: spray drying is an efficient, scalable, and inexpensive way to turn liquid cultures into powders, but the process itself is lethal to many bacteria. As droplets are blasted through hot air in the drying chamber, cells experience simultaneous dehydration, heat shock, and oxygen exposure. Membranes rupture, proteins denature, and intracellular components leak out. Survival rates can plummet, which is why many commercial starter producers still rely on freeze drying, a gentler but far more energy-intensive and costly process that is difficult to scale for commodity applications.

Nuylert and colleagues attacked the survival problem from two directions. The first was preconditioning the cells before they ever reached the dryer. The team adapted Lactobacillus futsaii CS3 by growing it in the presence of 10 millimolar calcium chloride, a mild stress that triggers protective responses within the cell. This calcium adaptation strategy builds on earlier findings that intracellular calcium accumulation can stabilize bacterial membranes and improve heat resistance. In the study, the adapted cells showed markedly improved thermotolerance at 60 degrees Celsius, a temperature that would normally devastate unprotected lactic acid bacteria. The mechanism is elegant in its simplicity: by pre-stressing the cells with calcium, the researchers essentially taught them to brace for the thermal assault of spray drying.

The second line of defense was the protective carrier matrix in which the cells were embedded during drying. The researchers screened formulations and found that a matrix combining monosodium glutamate and maltodextrin, each at 10 percent, delivered the best results. Monosodium glutamate has a long history as a thermoprotectant in microbial preservation, helping to stabilize proteins and membranes during dehydration, while maltodextrin acts as a bulking agent that forms a glassy matrix around the cells, limiting molecular mobility and slowing degradation during storage. With this combination, post-drying survival reached 70.3 percent for Staphylococcus carnosus K21S22 and 59.2 percent for Lactobacillus futsaii CS3, figures that represent a substantial recovery of viable cells from an otherwise punishing process.

Survival through drying is only half the battle, however. A starter culture powder is useless if the cells die on the warehouse shelf. To test long-term stability, the team stored the dried powders in vacuum-packed conditions at 4 degrees Celsius for three months. The results were impressive: the cultures retained 86.4 percent viability for Lactobacillus futsaii and 84.1 percent for Staphylococcus carnosus. Vacuum packaging removes oxygen, limiting oxidative damage to cell membranes, while refrigeration slows the residual metabolic and chemical decay processes that gradually erode viability even in dried cells. Together, the drying formulation and the storage strategy produced a starter culture that could realistically sit in a food factory’s cold room for a full quarter and still perform.

The real test, of course, was whether these rehydrated powders could actually ferment mushrooms effectively. In application trials, inoculating oyster mushroom substrates with the spray-dried starters accelerated acidification and shortened the overall fermentation time compared with uncontrolled or slower fermentations. Rapid acidification is a critical safety and quality parameter in fermented foods, because a quick drop in pH suppresses spoilage organisms and pathogens before they can establish themselves. Faster, more predictable acidification also means shorter production cycles, which translates directly into economic benefits for manufacturers.

On the functional front, the cultures delivered on their GABA promise. Fermentations conducted with Lactobacillus futsaii CS3 alone produced GABA concentrations of 12.04 milligrams per gram, while the mixed culture of both strains achieved a nearly identical 12.02 milligrams per gram. This consistency is notable because it suggests that adding the Staphylococcus co-starter for flavor purposes did not come at the expense of the functional compound. For product developers, that is a valuable combination: a single fermentation process yielding both a bioactive ingredient and an improved sensory profile.

The sensory results added an intriguing layer to the findings. Using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry, the researchers profiled the volatile compounds generated during fermentation and found that the mixed starter produced a distinct relative volatile peak-area profile compared with the single-strain fermentation. In the taste panel, the mixed starter earned the highest taste acceptance score of 7.85 and the highest overall acceptance score of 7.63. Importantly, the authors were careful to note that no causal relationship between the volatile differences and sensory acceptance was inferred, a scientifically cautious position that acknowledges the complexity of flavor perception, where non-volatile taste compounds, texture, and aroma all interact in ways that volatile profiling alone cannot fully explain.

Taken together, the study outlines an industry-relevant strategy for transforming oyster mushrooms into value-added fermented products. The workflow is practical: precondition cells with calcium, dry them in an MSG-maltodextrin matrix, vacuum pack at refrigeration temperature, and inoculate mushroom substrate for a fast, GABA-producing fermentation with strong consumer acceptance. Because spray drying is already a mature industrial technology used for everything from milk powder to instant coffee, the barrier to adoption is comparatively low. As demand grows for plant-based and fungal-derived functional foods, shelf-stable starter cultures like these could help fermented mushroom products move from artisanal novelty to mainstream supermarket staple, bringing a scientifically optimized blend of taste and function to a wider audience.

Subject of Research: Spray-dried starter cultures for GABA-enriched oyster mushroom fermentation

Article Title: Spray-dried starter cultures (Lactobacillus futsaii CS3 and Staphylococcus carnosus K21S22) improve taste acceptance and GABA production in oyster mushroom fermentation

Article References: Nuylert, A., Cheirsilp, B., & Maneerat, S. (2026). Spray-dried starter cultures (Lactobacillus futsaii CS3 and Staphylococcus carnosus K21S22) improve taste acceptance and GABA production in oyster mushroom fermentation. Food Science and Biotechnology. https://doi.org/10.1007/s10068-026-02321-7

Image Credits: AI Generated

DOI: 10.1007/s10068-026-02321-7

Keywords: spray drying, starter cultures, Lactobacillus futsaii, Staphylococcus carnosus, oyster mushroom, fermentation, GABA, microencapsulation, calcium adaptation, vacuum packaging, sensory acceptance, functional foods