The research team raised 300 one-day-old male Cobb 500 broilers under commercial conditions until 49 days of age. At 21 days, the birds were randomly divided into three blocks of 100, each containing four groups of 25: an unenriched control, a single-level perch (Perch 1L), a two-level perch with three bars (Perch 2L), and a platform with inclined access planks. All structures shared the same length of 90 centimeters and height of 15 centimeters, differing only in geometry and surface configuration. The enrichment devices were introduced at 14 days of age with a seven-day habituation period, positioned between the feeder and the drinker to encourage interaction.

To assess leg health without invasive procedures, the researchers used a FLIR C3-X thermal camera at a distance of one meter, with emissivity set at 0.95 for featherless areas. They imaged four regions of interest: the left and right intertarsal articulations and the left and right plantar surfaces, at 21 and 49 days of age. Infrared thermography detects the infrared radiation emitted by a body surface, which depends on local blood flow, metabolic activity, and vascular tone. Inflammation typically raises surface temperature through increased perfusion and vasodilation, while reduced blood flow, tissue necrosis, or hyperkeratosis can lower it. This makes the technique a sensitive, non-invasive window into subclinical leg problems that are common in fast-growing broilers.

The thermographic results told a nuanced story. Across all groups, superficial temperatures of the intertarsal joints dropped with age, from about 36.4 degrees Celsius at 21 days to roughly 34.7 to 34.9 degrees at 49 days, a pattern consistent with normal development in featherless regions. But the Perch 2L group stood out. At 21 days, these birds already showed markedly lower joint temperatures than the other treatments, around 34.1 degrees, and their temperatures did not decline further with age. Their plantar surfaces, in contrast, warmed between the two sampling points. The authors interpret this combination as suggestive of an inflammatory response, noting that values in the range observed for Perch 2L have previously been associated with gross joint lesions in other studies. Because thermography cannot discriminate between causes of tissue damage, the researchers emphasize that histological confirmation would be needed.

Behavioral data added another layer. The team recorded 120 hours of video across the 12 pens at 28 and 42 days of age, scoring perching, resting, feeding, drinking, and preening using a standardized ethogram analyzed in CowLog software. Perching declined sharply as the birds grew heavier, and the platform was by far the least used enrichment, with observed perching behavior approaching zero by the later measurement. Preening, by contrast, occurred more frequently in the afternoon than in the morning across all groups, consistent with known circadian preferences. Feeding and drinking were unaffected by treatment. The researchers suggest that the platform’s metal mesh surface, dimensions, or simply its role as an obstacle in the pen may have made it unattractive for resting, while the birds’ increasing body weight and potential joint discomfort likely reduced perch use overall.

Live weight told a simpler story: enrichment had no effect. Mean body weight rose from 0.46 kilograms at 21 days to 2.76 kilograms at 49 days in all groups. Interestingly, however, a Pearson correlation revealed a significant negative relationship between individual body weight and overall surface temperature across the four measured regions, driven mainly by the intertarsal joints. Heavier birds ran cooler at the joint surfaces, a finding that aligns with the idea that increasing weight compromises leg health through reduced blood flow, skin thickening, or tissue damage.

The most unexpected results emerged after slaughter. The researchers evaluated raw thigh meat for pH, texture, color, electrical conductivity, and water-holding capacity at 0, 1, 2, 7, 10, and 15 days post-slaughter. Texture and yellowness showed no differences among groups. But water-holding capacity, a key technological trait that influences juiciness, yield, and consumer acceptance, was higher in the Perch 2L and Platform groups at day 15 of refrigerated storage. The authors propose that the additional locomotion required to navigate these structures may have promoted muscle development, altering collagen crosslinking, sarcomere length, and myofibril behavior during rigor and storage. They caution, however, that improved water-holding capacity should not automatically be read as evidence of better welfare, given the thermographic signs of possible inflammation in the Perch 2L group.

Color and electrical conductivity showed more transient, storage-dependent shifts. Lightness differed among treatments at day 7, with Perch 2L showing the highest value, while redness differed at day 2 and increased over time in the Platform group. Electrical conductivity, a marker of ionic mobility and membrane integrity, separated Perch 1L from the other groups only at day 10. The authors stress that these parameters should be interpreted as complementary indicators rather than direct surrogates for water retention, and that mechanistic relationships established in breast meat may not transfer directly to thigh meat, which has a more oxidative metabolism and higher myoglobin content.

The study’s broader message is methodological as much as biological. Environmental enrichment is often evaluated through single lenses, such as behavior or growth performance, but this integrated approach shows that a structure can be well used, leave thermal signatures of joint stress, and still improve certain meat quality traits, all without affecting body weight. Design characteristics like material, height, diameter, and geometry appear to shape both preference and physiological outcome, and the authors argue that no single measure can capture the full welfare picture. As the poultry industry faces growing pressure to adopt welfare-friendly housing, this work suggests that the path forward requires looking simultaneously at the living bird, its thermal signature, and the product it becomes.

Subject of Research: Effects of environmental enrichment designs on leg health, behavior, and meat quality in broiler chickens

Article Title: Integrating infrared thermography, behavioral assessment, and meat quality analysis to evaluate the effects of environmental enrichment in broiler chickens

Article References: Hernández-Sánchez, R. C., Martinez-Castañeda, F. E., Hernández-Ramírez, J. O., Salcedo-Gómez, M. P., Díaz-Sánchez, V.-M., Valencia-Viramonte, D. G., Olivares-Hernández, I. G., Solís-Garfias, J., Zambrano-Zaragoza, M. D. L. L., & Hernández-Trujillo, E. (2026). Integrating infrared thermography, behavioral assessment, and meat quality analysis to evaluate the effects of environmental enrichment in broiler chickens. Frontiers in Animal Science, 7, Article 1976355. https://doi.org/10.3389/fanim.2026.1976355

Image Credits: AI Generated

DOI: 10.3389/fanim.2026.1976355

Keywords: broiler chickens, environmental enrichment, infrared thermography, animal welfare, meat quality, water-holding capacity, perches, poultry science, leg health, behavioral assessment, precision livestock farming, Integrating

The team worked with Hom Thong bananas (Musa acuminata, AAA group), a cultivar widely consumed across Southeast Asia whose peel contains a comparatively thick, spongy albedo layer rich in complex carbohydrates. Rather than using harsh chemical solvents, the researchers purified the fiber enzymatically, a greener approach that operates under moderate conditions and causes less structural damage. The protocol was a carefully sequenced three-enzyme cascade: alpha-amylase at 80 degrees Celsius to break down starch, glucoamylase at 60 degrees Celsius to mop up the resulting sugars, and neutral protease at 50 degrees Celsius to strip away proteins. After washing with warm water and ethanol and drying to below ten percent moisture, what remained was an enzymatically purified dietary fiber, or EPDF, essentially the cell-wall skeleton of the albedo, stripped of everything the human small intestine could digest on its own.

The enzymatic treatment proved dramatically effective. The raw albedo contained 27.43 percent total dietary fiber on a dry weight basis, a figure held down by intracellular proteins, resistant starches, and other digestible carbohydrates that dilute the fiber measurement. After enzymatic purification, total dietary fiber jumped 2.09-fold to 57.13 percent, with insoluble fiber rising 2.20-fold from 22.69 to 50.01 percent and soluble fiber increasing 1.53-fold from 4.67 to 7.12 percent. The authors attribute this selectivity to the enzymes’ ability to dismantle the non-fiber matrix and release the structural polysaccharides, cellulose, hemicellulose, and pectin, that constitute the fiber proper. Compared with traditional acid or alkaline extraction, the enzymatic route achieved higher purity while preserving the structural integrity of the fiber, an attribute that matters because the physical architecture of a fiber largely determines how it behaves in food and in the gut.

With the purification method validated, the researchers turned to their central question: does ripening change the fiber itself? They classified bananas into three stages using peel color coordinates and soluble solids content: mature green, yellow-green, and fully yellow, then extracted fiber from each. The answer was emphatically yes. Total dietary fiber fell significantly from 58.15 percent in the mature green stage to 48.66 percent at yellow-green and 46.94 percent when fully yellow, driven almost entirely by a decline in insoluble fiber from 55.19 to 43.55 percent. Meanwhile, soluble fiber crept upward from 2.96 to 3.39 percent, raising the soluble-to-insoluble ratio from 0.054 to 0.078. Crude fiber dropped even more steeply, from 9.22 to 4.82 percent. These shifts mirror the endogenous enzymatic storm of ripening: xylanase activity rises and hemicellulose degrades, while pectin methylesterase and polygalacturonase solubilize insoluble pectic polysaccharides, converting rigid cell-wall material into softer, more fermentable forms.

Microscopy made this molecular story visible. Under the scanning electron microscope, fiber from mature green bananas displayed a rough, heterogeneous surface studded with pores, folds, and micro-fissures, an open architecture consistent with its high insoluble fiber content. The yellow-green sample occupied an intermediate state, more aggregated and compact but still rough, while fiber from fully yellow bananas showed a dense, smooth, nearly continuous surface with few visible openings. As the fruit’s own cell-wall enzymes remodel the polysaccharide network, the extracted fiber loses the porous, fibrous topology that makes the green-stage material so interactive with water and oil. Fourier-transform infrared spectroscopy added molecular detail: all samples retained the characteristic lignocellulosic framework, but the fully yellow spectra showed changes in the carbohydrate fingerprint region and in pectic ester and carboxylate bands, consistent with hydrolytic modification of hemicellulose and pectin rather than wholesale breakdown.

X-ray diffraction revealed a subtler trend. All three fibers showed the broad diffraction features of cellulose I-type structures, indicating that the ordered cellulose domains survived ripening intact. Yet relative crystallinity climbed steadily from 14.8 percent in mature green fiber to 17.1 percent at yellow-green and 26.3 percent when fully yellow. The authors interpret this not as new crystalline cellulose forming, but as a proportional effect: as the amorphous pectic and hemicellulosic components surrounding the cellulose are progressively modified and solubilized during ripening, the remaining ordered domains make up a larger share of the diffracting material. The raw, unpurified albedo, by contrast, showed a much higher crystallinity of 48.6 percent, reflecting crystalline constituents such as native starch that the enzymatic purification removed.

These structural differences translated directly into function. Fiber from mature green bananas dominated every hydration and adsorption measure: water-holding capacity of 5.00 grams of water per gram of fiber, oil-holding capacity of 2.84 grams per gram, cholesterol adsorption of 8.46 milligrams per gram, and glucose adsorption of 38.53 milligrams per gram, all significantly higher than the later stages, which declined in step with the smoothing of the fiber surface. Principal component analysis confirmed the pattern, with the first two components explaining 99.05 percent of the variance and separating the three ripening stages along an axis loaded with the hydration and adsorption variables. Swelling capacity was the lone exception, holding steady at 4.30 to 4.47 milliliters per gram across all stages, likely because the lignin-rich framework, whose spectral signature persisted even in fully yellow samples, preserved enough structural integrity to swell similarly regardless of maturity.

The prebiotic results added an unexpected twist. In anaerobic fermentation assays, all three fibers supported robust growth of Lactobacillus plantarum and Lactobacillus casei while viable counts of E. coli fell relative to the unsupplemented control, and prebiotic activity scores of 0.60 to 0.70 were broadly comparable to commercial inulin. But the star performer was not the green-stage fiber with its superior hydration; it was the intermediate yellow-green fiber, which achieved the highest score of 0.70, the largest pH drop of 2.42 units, the greatest titratable acidity at 0.577 percent lactic acid equivalents, and the highest acetate production at 0.483 grams per liter, exceeding even the inulin control on those fermentation measures. The authors suggest that fermentability depends not on soluble fiber content alone but on the combination of composition and structure: the yellow-green fiber’s layered surface with visible micro-fissures may offer an ideal balance of accessibility and substrate, whereas the fully yellow fiber’s denser surface, despite its higher soluble fiber ratio, did not confer an additional fermentation advantage.

The practical upshot is a maturity-based valorization strategy for a waste stream that currently exceeds 57.6 million metric tons of peel annually. Fiber from mature green albedo, with its exceptional water and oil retention and glucose and cholesterol adsorption, is a natural candidate for bakery products and formulated foods where moisture control and texture matter. Yellow-green fiber, the fermentation champion, suits fermented dairy or plant-based formulations where prebiotic activity is the goal. Fully yellow fiber, with the highest soluble fiber proportion, fits beverages, soups, and sauces. All the powders showed low water activity of 0.22 to 0.23, well below the 0.60 threshold that inhibits microbial spoilage, supporting shelf stability. By matching the ripening stage of the raw material to the intended application, processors could convert a disposal problem into a portfolio of differentiated functional ingredients, an elegant example of the circular bioeconomy turning fruit that has passed its prime into something genuinely valuable.

Subject of Research: Effects of banana ripening stage on the structure, functionality, and prebiotic activity of enzymatically purified dietary fiber from banana peel albedo

Article Title: Macromolecular and microstructural evolution of enzymatically purified banana albedo dietary fiber during ripening: Targeted valorization for functional and prebiotic applications

Article References: Sangkasanya, S., Ramirez, J. J. B., Inocencio, C. D. G., & Naknaen, P. (2026). Macromolecular and microstructural evolution of enzymatically purified banana albedo dietary fiber during ripening: Targeted valorization for functional and prebiotic applications. Food Chemistry: X, Article 104624. https://doi.org/10.1016/j.fochx.2026.104624

Image Credits: AI Generated

DOI: 10.1016/j.fochx.2026.104624

Keywords: banana peel, dietary fiber, albedo, ripening, enzymatic extraction, prebiotic, gut microbiota, food waste valorization, water-holding capacity, glucose adsorption, Lactobacillus, circular bioeconomy

The active ingredient at the heart of the study is zingibain, a cysteine endopeptidase designated EC 3.4.22.67. Like papain and bromelain, zingibain cleaves peptide bonds in proteins, but it shows a particular appetite for myofibrillar proteins, the contractile machinery of muscle, and for connective tissue proteins. Because myofibrillar proteins, chiefly myosin and actin together with regulatory proteins such as troponins and tropomyosin, account for 50 to 60 percent of total muscle protein, an enzyme that targets them efficiently can reshape the texture of a steak or a chicken breast from the inside out.

To test how such an enzyme behaves across different animals, the team prepared crude aqueous extracts from fresh ginger at three concentrations and compared them against commercial bromelain and papain preparations standardized to identical protein levels. The substrates were purified myofibrillar proteins extracted from chicken breast and pork loin, two muscles chosen as models with distinct structures and functional properties. Reactions ran at 4 degrees Celsius and pH 6, mimicking the refrigerated conditions of real marination, and proteolytic activity was tracked spectrophotometrically over time.

The kinetic data revealed a striking asymmetry. Ginger extract displayed its highest catalytic performance against chicken myofibrils, reaching the greatest maximum reaction velocity of any enzyme tested at the highest concentration, with a Vmax of about 84.77 units per milligram of enzyme protein. On pork myofibrils, the same extract was considerably less active. Bromelain, by contrast, performed comparatively better on pork, where lower apparent Km values at higher enzyme concentrations drove its catalytic efficiency sharply upward. The authors attribute these differences to the intrinsic architecture of the two muscles: in chicken, disruption of Z-disks and actin-myosin cross-bridges occurs relatively rapidly after slaughter, whereas porcine muscle weakens more slowly and resists enzymatic attack longer.

Having identified the most efficient preparations, the researchers moved from the model system to whole meat. Cubes of chicken breast and pork loin, all cut to identical dimensions, were marinated for 6 or 12 hours in water, bromelain, papain, or ginger extract, then cooked. A key measurement was the myofibrillar fragmentation index, or MFI, which rises as myofibrils are broken into smaller pieces. All three enzymes raised MFI in both meats, and chicken fragmented faster and more extensively than pork. But the temporal patterns differed: papain and bromelain kept fragmenting the tissue as marination lengthened, while ginger produced its most pronounced relative increase in fragmentation during the first 6 hours, then plateaued, behaving as a milder, self-limiting tenderizer.

That restraint proved technologically important. Excessive proteolysis can wreck the protein network that holds water in meat, and the cooking yield data showed exactly that trade-off. Papain-treated chicken consistently lost the most weight during cooking, indicating that aggressive enzymatic breakdown destabilized the protein matrix during heating. Ginger-treated samples of both species, meanwhile, achieved the highest or near-highest cooking yields after 12 hours of marination, statistically comparable to the water controls and significantly better than papain or bromelain. Water-holding capacity told a complementary story: in chicken, moderate proteolysis after 6 hours improved water entrapment, while prolonged treatment eroded it, and pork showed a blunted response overall, consistent with its tougher myofibrillar scaffolding.

Color measurements added another dimension. In raw chicken, ginger-marinated samples retained redness better than controls or samples treated with the other enzymes, an effect the authors link to the antioxidant phenolic compounds that ride along in the crude ginger extract and help protect myoglobin from oxidation. After cooking, enzymatic marination produced large treatment-dependent color shifts in both meats, with papain causing the most dramatic alterations. Ginger-treated samples partially preserved reddish tones after cooking, particularly in pork, suggesting that the extract modulates pigment chemistry as well as protein structure.

The final test was whether any of this registers on the palate. A 25-member sensory panel, untrained but experienced in meat evaluation, compared cooked samples marinated for 6 hours in water or ginger extract under blind conditions. Ginger marination lifted scores across the board in both meats, with statistically significant gains in odor intensity, flavor, and overall acceptability in pork, and marked improvements in odor, flavor, sapidity, chewiness, and juiciness in chicken. Notably, the ginger-derived aroma was positively received and introduced no off-notes, while metallic or ferrous perceptions actually declined in the treated samples. The sensory gains tracked the instrumental data: controlled myofibrillar modification and preserved water retention translated directly into juicier, more tender eating.

The broader significance of the study lies in its demonstration that enzyme effects cannot be divorced from muscle biology. The same extract that excels on chicken may underperform on pork, and the same treatment that improves tenderness at 6 hours may degrade water retention at 12. For a meat industry under pressure to replace synthetic additives with natural, clean-label ingredients, crude ginger extract emerges as a promising middle path, a tenderizer strong enough to restructure muscle protein yet gentle enough to preserve cooking performance, color, and flavor. As the authors conclude, the response of meat to plant proteases depends on the enzyme, the muscle, and the clock, and ginger, it turns out, keeps remarkably good time.

Subject of Research: Proteolytic activity of ginger extract on myofibrillar proteins and meat quality

Article Title: Proteolytic Activity of Zingiber officinale Extract: Interaction With Myofibrillar Proteins of Different Origins and Functional Effects in Meat Systems

Article References: Crinò, A., Fabrizi, C., Menci, A., & Liburdi, K. (2026). Proteolytic Activity of Zingiber officinale Extract: Interaction With Myofibrillar Proteins of Different Origins and Functional Effects in Meat Systems. Food Science & Nutrition, 14(10), Article e72459. https://doi.org/10.1002/fsn3.72459

Image Credits: AI Generated

DOI: 10.1002/fsn3.72459

Keywords: ginger, zingibain, plant proteases, meat tenderization, myofibrillar proteins, papain, bromelain, chicken breast, pork loin, marination, water-holding capacity, sensory analysis

The research team prepared pork leg meat by removing connective tissue and grinding lean and fat portions together at a ratio of 8.5 to 1.5. Into this base emulsion they mixed a seasoned formulation containing sugar, fish sauce, glycerol, spices, salt, and water, then varied the gelatin concentration from 0 to 2.5 percent by weight. Each formulation was printed into a rectangular slab mimicking pork jerky using a food-grade extrusion printer operating at 25 degrees Celsius with a 1.55-millimeter nozzle, 100 percent infill, and a printing speed of 30 millimeters per second. The printed products were then hot-air dried, baked, and analyzed for everything from gel strength to moisture distribution.

Rheological measurements revealed why gelatin matters so much. In dynamic frequency sweeps, the storage modulus G-prime exceeded the loss modulus G-double-prime in every formulation, meaning the material behaved predominantly as a solid-like viscoelastic gel. That solid-like character is exactly what a printed layer needs: it allows the extruded strand to support the weight of subsequent layers without collapsing. Gel strength rose significantly with gelatin content, climbing from 119.62 grams in the untreated paste to 154.48 grams at the highest dosage, a change the authors attribute to hydrogen bonds forming between gelatin molecules and the myofibrillar proteins that make up 50 to 55 percent of pork’s total protein.

But more gelatin is not always better. When the concentration reached 2 percent, the researchers observed clogging and adhesion at the nozzle, likely because undissolved gelatin particles or overly viscous aggregates disrupted the uniformity of the paste and jammed the extrusion process. The sweet spot turned out to be 1 percent gelatin, which produced the best layer adhesion, the highest printing fidelity, and no structural collapse. Confocal laser scanning microscopy confirmed the story visually: without gelatin the protein network was loose and porous with large voids, while moderate gelatin addition produced a densely cross-linked, compact matrix. At 2.5 percent, however, the network showed signs of stacking and compression, as excess macromolecular gelatin crowded the native pork proteins.

Water is the hidden variable in printed meat. Using low-field nuclear magnetic resonance, the team identified three water populations in the gels — bound water, immobilized water, and free water — corresponding to relaxation peaks at roughly 0.01 to 10, 10 to 100, and 100 to 1000 milliseconds. At the optimal 1 percent gelatin level, all three relaxation times reached their shortest values, indicating the tightest integration of water into the protein network, while the free-water fraction peaked at 1.09 percent, providing just enough lubrication for smooth extrusion. Water-holding capacity climbed in a dose-dependent manner, reaching 80 percent at 1 percent gelatin, and the baking loss rate fell to its minimum of 48.63 percent at the same concentration — a meaningful economic gain, since every percentage point of moisture lost during cooking is weight and value lost from the product.

Fourier-transform infrared spectroscopy added a conformational dimension to the findings. The alpha-helix content of the proteins, which was only 17 percent in the unmodified paste, rose to 23 percent as gelatin increased to 1.5 percent, while the proportion of disordered random coils initially declined. Because alpha-helical content reflects hydrophobic groups and sulfhydryl groups being folded back into the protein interior, this shift signals a more ordered, elastic gel. The authors note that gel performance peaks at a certain degree of helical unfolding or re-formation, and their data pinpoint 1 percent gelatin as the concentration that achieves that balance.

The most novel part of the study, however, descends to the molecular scale. Because myofibrillar proteins contain fluorescent tryptophan and tyrosine residues, the team could use fluorescence spectroscopy as a molecular spy. When oleic acid or palmitic acid — the two predominant fatty acids in pork — were added to purified myofibrillar protein, the intrinsic fluorescence dimmed progressively, with quenching efficiencies of 51.70 percent for oleic acid and 50.74 percent for palmitic acid in the binary systems. Stern-Volmer analysis showed that the quenching constants decreased as temperature rose from 328.15 to 338.15 kelvin, the signature of static quenching: the fatty acids form stable, non-fluorescent ground-state complexes with the protein rather than merely colliding with it.

Gelatin rewired these interactions in revealing ways. In the ternary systems containing gelatin, quenching efficiencies dropped to 33.81 percent for the oleic acid combination and 41.5 percent for palmitic acid, showing that gelatin partially shields the protein’s fluorescent residues from fatty acid binding. Binding constants and the number of binding sites both increased in the presence of gelatin, with the effect stronger for palmitic acid than for oleic acid. Thermodynamic analysis of enthalpy and entropy changes showed that oleic acid alone binds myofibrillar protein through hydrophobic interactions, an endothermic process that strengthens with heat. Add gelatin, however, and the dominant forces shift to van der Waals interactions and hydrogen bonds — the same forces that govern palmitic acid binding with or without gelatin. Synchronous fluorescence spectra reinforced the picture, showing blue shifts of up to 4 nanometers that indicate the amino acid microenvironments became less polar and more hydrophobic, with gelatin exerting a stronger influence on tyrosine than on tryptophan.

What makes this study compelling is the way it connects the molecular ledger to the printed object on the plate. Gelatin’s thermally reversible triple-helix gelation and strong shear-thinning behavior give the paste the flow profile needed for smooth extrusion and the rapid re-gelling needed for self-supporting layers, while its protein nature lets it weave directly into the myofibrillar network in a way that polysaccharide hydrocolloids such as carrageenan and gellan gum cannot. By modulating how fatty acids bind to the protein matrix — softening quenching, increasing binding capacity, and steering oleic acid toward hydrogen-bonded association — gelatin stabilizes the entire lipid-protein-water architecture that determines whether a printed pork product holds its shape, retains its moisture, and survives the oven. For a field racing toward personalized nutrition, cultured-meat scaffolds, and printed meals for dysphagia patients, the message is that printability is not just a rheology problem; it is a molecular recognition problem, and the right hydrocolloid can solve both at once.

Subject of Research: Gelatin modulation of 3D printing properties and fatty acid–myofibrillar protein interactions in pork mince

Article Title: Study on the modulation of the properties of 3D printing pork mince and interaction mechanisms with myofibrillar proteins and fatty acids by gelatin

Article References: Wu, L., Wang, A., & Cui, Q. (2026). Study on the modulation of the properties of 3D printing pork mince and interaction mechanisms with myofibrillar proteins and fatty acids by gelatin. Food Chemistry: X, 39, Article 104543. https://doi.org/10.1016/j.fochx.2026.104543

Image Credits: AI Generated

DOI: 10.1016/j.fochx.2026.104543

Keywords: 3D food printing, gelatin, pork mince, myofibrillar proteins, oleic acid, palmitic acid, fluorescence spectroscopy, rheology, water-holding capacity, protein conformation, food hydrocolloids, static quenching

The experiment was designed around a deceptively simple question: what is the minimum radiation dose that kills pathogens without compromising meat quality? The team inoculated raw beef bottom round with five of the most notorious foodborne pathogens: Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, and Escherichia coli. Samples were then treated with electron beam doses ranging from 1 to 9 kilograys using a linear accelerator operating at 10 megaelectronvolts, with the meat held at minus 2 degrees Celsius during treatment to mimic realistic cold-chain conditions. The results were striking: Salmonella, Listeria, Staphylococcus, and E. coli all fell below the detection limit of less than one log colony-forming unit per gram at doses of 3 kilograys or higher.

One microbe, however, proved remarkably stubborn. Bacillus cereus, a spore-forming bacterium, required doses of at least 7 kilograys before it too dropped below detectable levels. The reason lies in the extraordinary architecture of bacterial spores. These dormant structures are wrapped in multiple protective layers, including a cortex, an outer membrane, protein coats, and an exosporium. The outer coat contains pigments that absorb ultraviolet radiation, while the spore core maintains an extremely low water content and is packed with pyridine-2,6-dicarboxylic acid and small acid-soluble proteins that bind directly to DNA, shielding the genetic material from radiation-induced damage.

The physics of why radiation kills bacteria in the first place comes down to water. When high-energy electrons strike the moisture-rich interior of a microbial cell, they trigger radiolysis, splitting water molecules and generating a cascade of reactive oxygen species. These highly reactive chemicals, including hydroxyl radicals, attack cellular components indiscriminately, causing base modifications in DNA, strand breaks, and cross-linking that prevent cell division and ultimately destroy the organism. The researchers note that meats with higher moisture content may actually generate more of these lethal radicals, potentially enhancing the antimicrobial effect. Refrigerated storage at 4 degrees Celsius compounded the kill effect, with viable counts in irradiated samples continuing to decline over two weeks of storage while control samples remained unchanged.

Crucially, the radiation doses that annihilated pathogens did not gut the meat’s nutritional value. Proximate composition, measured through standardized methods for moisture, crude protein, crude fat, and ash, showed no significant differences between irradiated samples up to 3 kilograys and untreated controls. The researchers attribute this to the nature of the analytical methods themselves, which measure total mass regardless of chemical denaturation, and to the protective conditions of the experiment. Vacuum packaging limits oxygen migration and suppresses radiation-induced oxidation, while the meat’s abundant proteins can soak up free radical ions, stabilizing them before they cause substantial mass loss detectable by total-mass-based techniques.

Not every quality parameter emerged unscathed. Water-holding capacity, the meat’s ability to retain its own moisture, decreased significantly at doses of 2 and 3 kilograys. The mechanism traces back to those same reactive oxygen species: they react with amino acids and peptide bonds, driving protein oxidation that reduces surface hydrophilicity. Radiation also appears to reshape the secondary structure of myofibrillar proteins, increasing amorphous random coils and beta-turns, promoting partial unfolding and aggregation. These structural changes can alter hydrogen and disulfide bonds, reduce the activity of proteolytic enzymes such as calpains, and limit the degradation of cytoskeletal proteins, all of which shrink the spaces between muscle fibers where water is normally held.

Texture, by contrast, barely budged. Shear force, measured with a V-blade texture analyzer cutting perpendicular to the muscle fibers, declined only slightly and not significantly with increasing dose. The researchers suggest that radiation-generated radicals can abstract hydrogen atoms from proteins, forming carbon-centered radicals that initiate oxidation chain reactions. These may promote actomyosin depolymerization and degrade contractile proteins such as actin and myosin, along with structural proteins like titin and nebulin, which could explain the modest tenderizing trend. Oxidation of the myosin heavy chain is thought to reduce calcium-ATPase activity and weaken protein contractility, subtly softening the meat’s structural integrity without producing a statistically meaningful change.

Color chemistry told a more nuanced story. At week zero, samples treated with 3 kilograys displayed the lowest lightness and the highest redness, a dose-dependent shift the authors link to oxidative transformations of myoglobin, the heme protein responsible for meat’s characteristic hue. Reactive oxygen species can oxidize the heme iron from its ferrous to ferric state, or generate a highly oxidized intermediate called ferrylmyoglobin, which catalyzes further oxidation through pseudo-peroxidase activity. Radiation may also disrupt calcium homeostasis in muscle cells, impairing mitochondrial function and amplifying radical production. The Fenton reaction, in which hydrogen peroxide reacts with ferrous iron to produce hydroxyl radicals, may sustain metmyoglobin formation during storage, gradually browning the meat over time.

Two classic spoilage indicators, thiobarbituric acid reactive substances and volatile basic nitrogen, crept upward with dose and storage time, though neither showed statistically significant differences from controls at the outset. TBARS, a proxy for lipid oxidation, rose gradually during weeks one and two, with the 3-kilogray samples showing the highest levels, likely reflecting the accumulation of secondary lipid oxidation products such as aldehydes. Volatile basic nitrogen, a marker of protein breakdown, increased significantly with dose from week two onward, consistent with radiation-induced deamination, decarboxylation, and peptide bond cleavage that release ammonia and other nitrogen-containing volatiles. The delayed onset suggests these protein modifications accumulate silently before manifesting as measurable spoilage chemistry.

The study’s context is the booming raw pet food market, where uncooked meat poses real zoonotic risks to both animals and the humans handling it, particularly the immunocompromised. With Korea permitting radiation sterilization up to 10 kilograys for feed, and the United States allowing up to 50 kilograys for pet food, the finding that 3 kilograys suffices for non-spore-forming pathogens leaves a wide safety margin. The authors conclude that electron beam irradiation at 3 kilograys effectively secures microbial safety in raw beef while inducing only limited and acceptable physicochemical changes, positioning the technology as a practical non-thermal sterilization strategy. Whether consumer skepticism about irradiated food, which has long hampered adoption despite mandatory radura labeling in many countries, can be overcome by this kind of hard evidence remains the next frontier.

Subject of Research: Effects of electron beam irradiation on microbial inactivation and physicochemical quality of raw beef

Article Title: Physicochemical and microbial changes in Raw beef meat induced by radiation

Article References: Beak, U.-B., & Kim, H.-Y. (2026). Physicochemical and microbial changes in Raw beef meat induced by radiation. Food Science of Animal Resources, 46(1), Article 56. https://doi.org/10.1007/s44463-026-00060-1

Image Credits: AI Generated

DOI: 10.1007/s44463-026-00060-1

Keywords: electron beam irradiation, raw beef, food safety, microbial inactivation, Salmonella, Listeria monocytogenes, Bacillus cereus, reactive oxygen species, water-holding capacity, lipid oxidation, myoglobin, non-thermal sterilization

The team’s choice of almond protein isolate was deliberate. Almonds already have a reputation in the plant-milk world for mild flavor and smooth texture, avoiding the beany off-notes and allergenic baggage that complicate soy. The isolate is roughly 97 percent protein, most of it the water-soluble globulin amandin, which makes up 65 to 70 percent of the total. Crucially, almond protein shares an isoelectric point with casein, in the pH 4.5 to 5.5 range, and retains about 70 to 80 percent solubility even at pH 4. That means it can undergo heat- and acid-driven structural changes at almost exactly the point where yogurt fermentation ends, mimicking the acid coagulation that builds dairy gels. The researchers hypothesized that varying the almond protein concentration within a xanthan gum-stabilized millet matrix would tune protein–polysaccharide interactions and dictate whether the final gel held together or fell apart.

The experimental design was straightforward but rigorous. Millet milk was prepared by soaking, blending, and filtering proso millet grains, then supplemented with almond protein isolate at 0, 0.5, 1, 1.5, and 2 percent weight per volume, alongside 0.5 percent xanthan gum, 3 percent inulin as a prebiotic, and 3 percent sucrose. After hydration, pasteurization at 90 degrees Celsius for 30 minutes, and inoculation with a vegan starter culture containing Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, L. acidophilus, and Bifidobacterium animalis subsp. lactis, the mixtures were fermented to pH 4.6 and chilled. The resulting yogurts were then put through an unusually complete battery of tests: proximate composition, fermentation kinetics, electron microscopy, infrared spectroscopy, zeta potential, free sulfhydryl measurement, selective-solvent interaction analysis, colorimetry, water-holding capacity, texture profiling, rheology, and a trained sensory panel.

The compositional results alone tell a striking story. Millet milk starts with a meager 1.23 percent crude protein, and the unsupplemented control yogurt contained just 0.38 percent. Adding almond protein raised protein content in a concentration-dependent manner, reaching 2.23 percent at the 2 percent dose, roughly a six-fold increase over the control. Fat stayed below 0.5 percent across all formulations, comfortably meeting the European Union criterion for a fat-free claim. But the more consequential effects appeared during fermentation. Yogurts with 1 percent almond protein or more acidified faster and reached the pH 4.6 endpoint earlier than the control, and viable lactic acid bacteria counts climbed from 5.29 log CFU per gram in the control to 7.00 log CFU per gram at the highest dose. The likely explanation is nitrogen: the o-phthaldialdehyde assay showed that trichloroacetic acid-soluble amino groups rose significantly during fermentation, from 2.39 to 3.42 millimolar glycine equivalents in the 2 percent formulation, providing the peptides and free amino acids that fuel bacterial metabolism and acid production.

Microscopy revealed exactly why the control yogurt failed. Under focused ion beam scanning electron microscopy, the unsupplemented sample showed a fragmented, poorly connected structure of irregular particles that remained fluid and flowed when the cup was inverted. At 0.5, 1, and 1.5 percent almond protein, however, the gels formed compact, homogeneous networks with honeycomb-like pores, smooth cohesive surfaces, and the ability to hold their shape upside down. At 2 percent, the picture reversed: pores collapsed, fractures appeared, the surface turned rough and aggregated, and visible syneresis, or water separation, set in. The lesson is that gel quality is not a simple dose–response curve. Moderate protein supplementation builds a continuous network, while too much pushes the system past the point where electrostatic repulsion can keep protein molecules from clumping into a coarse, grainy mass.

The molecular explanation lies in the balance of intermolecular forces. Selective buffer experiments showed that electrostatic interactions were the dominant force in most almond-supplemented yogurts, rising from 0.17 milligrams per milliliter at 0.5 percent protein to 0.49 at 1.5 percent before falling back to 0.27 at 2 percent, where hydrogen bonding took over. Zeta potential measurements reinforced this interpretation: all formulations were negatively charged, consistent with the anionic xanthan gum, but the potential became less negative as protein increased, dropping sharply to minus 26.0 millivolts at 2 percent. That collapse in electrostatic repulsion coincided with the aggregation and structural failure seen under the microscope. Free sulfhydryl content did decline during fermentation, indicating some disulfide bonding, but the values were far below those reported for soy yogurt, reflecting almond protein’s limited cysteine content. Disulfide bridges helped, but the electrostatic glue between charged protein regions and anionic polysaccharides was the real architect of the gel.

Physical performance tracked the molecular story closely. Water-holding capacity, the single best indicator of physical stability in set yogurt, jumped from a dismal 17.65 percent in the control to 99.00 percent at 0.5 percent almond protein and 97.92 percent at 1 percent, then slid to 89.47 percent at 1.5 percent and crashed to 59.77 percent at 2 percent. Firmness in the back-extrusion test rose from 0.19 newtons to 21.46 newtons across the same range, and the consistency index climbed from 4.56 to 437.18 newton-seconds. Notably, the 0.5 and 1 percent formulations landed nearest the firmness and consistency values typical of dairy set yogurt, around 2 to 3 newtons and 50 to 60 newton-seconds, while the two highest doses produced gels far harder than anything a consumer would recognize as spoonable. Rheology confirmed the pattern: storage modulus exceeded loss modulus in every sample, confirming solid-like behavior, but the 2 percent gel reached moduli of 10,000 pascals, orders of magnitude above the 1 to 100 pascal range of conventional yogurt.

Perhaps the most counterintuitive finding came from the three-interval thixotropy test, which measures how well a gel rebuilds itself after being sheared apart. The 1 percent formulation showed a significantly higher recovery rate than the 1.5 and 2 percent samples, and the 2 percent gel recovered worst of all. Pearson correlation analysis made the point explicit: firmness and storage modulus were negatively correlated with structural recovery, meaning that stiffer gels bounced back more poorly after mechanical deformation. Strength, in other words, is not the same as resilience. A dense, rigid network built on excessive protein aggregation and hydrogen bonding cannot absorb stress the way a balanced, electrostatically stabilized, porous network can. For product developers, this decoupling of hardness from quality is a critical design principle: the goal is not the strongest gel but the most organized one.

The sensory panel of twenty trained tasters agreed. The millet yogurts outscored a commercial soy set yogurt on appearance, and the 0.5 and 1 percent formulations earned the highest texture scores, consistent with their yogurt-like firmness and rheology. Almond protein improved taste and flavor across the board, but the 1 percent sample achieved the highest overall acceptability at 4.85 on the nine-point hedonic scale, a judgment that weighed color, water retention, microstructural uniformity, texture, and flavor together. The authors conclude that heat-induced protein unfolding and fermentation-driven acidification enabled almond protein to mediate protein–polysaccharide interactions that convert a weakly gelling cereal matrix into a self-supporting, low-fat, soy-free set yogurt whose gelation pattern resembles conventional dairy yogurt. They caution that the detailed molecular events of aggregation were not directly observed and will require further characterization. Even so, the study offers a practical recipe for the next generation of plant-based yogurts: a climate-hardy grain, a mild tree nut protein, and a dose window narrow enough that precision, not abundance, makes the gel.

Subject of Research: Using almond protein isolate to modulate protein–polysaccharide gel networks and improve the physicochemical stability of millet-based set yogurt

Article Title: Modulating protein–polysaccharide gel networks via almond protein to improve physicochemical stability of millet-based set yogurt

Article References: Min, E. S., Han, J. H., Lee, H. J., Park, S. M., Choi, B. J., & Han, S. G. (2026). Modulating protein–polysaccharide gel networks via almond protein to improve physicochemical stability of millet-based set yogurt. Food Chemistry: X, 39, Article 104535. https://doi.org/10.1016/j.fochx.2026.104535

Image Credits: AI Generated

DOI: 10.1016/j.fochx.2026.104535

Keywords: plant-based yogurt, almond protein isolate, proso millet, protein–polysaccharide interactions, xanthan gum, gel network, water-holding capacity, rheology, lactic acid fermentation, food texture, syneresis, dairy alternatives

The chemistry behind phosphate functionality is more intricate than most shoppers would ever suspect. Food-grade phosphates are derived from rock phosphorus, which is converted into phosphoric acid, purified to food grade, and neutralized with strong alkali before being melted and polymerized. Only about one percent of the world’s phosphoric acid ends up in food and beverages; the vast majority goes into fertilizer. The resulting phosphate salts fall into structural families, including ring, linear, and combined forms, and their behavior in meat depends heavily on chain length. Short-chain pyrophosphates excel at dissociating actomyosin and extracting myofibrillar proteins, which is critical for water retention and emulsion formation in comminuted products. Longer-chain tripolyphosphates and polyphosphates, by contrast, offer superior cold-water solubility and metal-ion sequestration, making them better suited for brine systems where they help control warmed-over flavor and discoloration. Monophosphates buffer well but bind calcium poorly and dissolve reluctantly in cold water, which is why manufacturers typically blend phosphate types to balance buffering behavior, brine stability, extraction efficiency, and oxidative control.

These structural differences translate directly into product quality. Phosphates influence meat color by reducing surface light scattering from moisture exudation and by shifting the equilibrium among myoglobin forms, the pigments responsible for the red, purple, and brown hues of muscle tissue. Studies on Spanish-style chorizo showed that phosphate addition altered lightness and yellowness values while changing moisture dynamics during drying. In emulsion-type sausages stored for thirty days at refrigeration temperatures, phosphate inclusion stabilized hardness and reduced purge loss, while higher phosphate levels increased emulsion stability and cooking yield. Texture effects extend to whole-muscle products as well: phosphate-enhanced chicken breast and beef showed improved tenderness, with shear force responding significantly to salt concentration. Interestingly, the review notes that phosphate addition is not universally beneficial, as sous-vide cooked lamb loins with high moisture content and phosphate actually exhibited increased hardness and shear force, likely because swollen tissue and excessive protein denaturation demanded greater compression forces.

Flavor presents a subtler picture. At recommended addition levels of 0.3 to 0.5 percent, phosphates generally leave flavor perception largely unchanged, though certain types can impart bitterness or an alkaline, soapy aftertaste at higher concentrations. Tetrapotassium pyrophosphate scored lower on flavor in goat meat studies than tetrasodium pyrophosphate. More importantly, phosphates protect flavor indirectly by sequestering the metal ions that drive lipid oxidation, thereby suppressing warmed-over flavor and other storage-related off-notes in cooked, refrigerated meats. Consumer studies of enhanced Australian beef fajitas found that phosphate-treated samples earned higher flavor and overall liking scores, an effect the researchers attributed to the strong correlation between juiciness and perceived flavor intensity. In this sense, phosphates act less as flavorings and more as guardians of the flavor that meat naturally possesses.

The health case for reduction rests on a crucial biochemical distinction. Phosphorus is an essential mineral, with roughly 85 percent of the body’s supply stored in bones and teeth, and homeostasis is tightly regulated by the kidneys, intestine, parathyroid hormone, fibroblast growth factor-23, and vitamin D. But the inorganic phosphates added to processed foods behave very differently from the organic phosphorus bound in meat and dairy. Inorganic phosphate additives exhibit approximately 90 to 100 percent bioavailability, producing rapid intestinal absorption and elevated serum phosphate levels. High dietary phosphate intake has been associated with disturbed mineral metabolism, particularly in people with chronic kidney disease, and elevated serum phosphate may stimulate secretion of parathyroid hormone and FGF-23, promoting altered calcium metabolism, vascular calcification, bone demineralization, and increased cardiovascular risk. Epidemiological analyses have even linked high serum phosphate to cardiovascular mortality within the upper normal physiological range. Emerging evidence also suggests excessive phosphate may perturb gut microbiota composition and intestinal barrier function, though the authors caution that this area requires further investigation.

Regulatory frameworks reflect this ambivalence. The U.S. Food and Drug Administration classifies phosphate food additives as generally recognized as safe when used according to good manufacturing practices, though specific applications in meat products carry quantity limits. European legislation permits phosphates in meat preparations, minced meat, and processed meat products but prohibits them in fresh meat, capping the permitted maximum at 5 grams per kilogram expressed as phosphorus pentoxide in the finished product. The Joint FAO/WHO Expert Committee on Food Additives has set a maximum tolerable daily intake of 70 milligrams of phosphorus per kilogram of body weight, based on the lowest dose that caused nephrocalcinosis in rats. Estimated daily phosphorus intakes across European Union populations, ranging from about 265 milligrams per day in infants to roughly 1,767 milligrams in adults, currently fall within tolerable limits, but the cumulative contribution of processed foods to long-term exposure remains a genuine public health concern.

So what can replace a molecule that simultaneously adjusts pH, extracts protein, binds water, stabilizes emulsions, and chelates prooxidants? The review’s central conclusion is sobering: no single ingredient fully replicates the multifunctional portfolio of phosphates. Dietary fibers from citrus, wheat, bamboo, and oats bind water effectively through their porous structures and hydrophilic functional groups, and citrus fiber has partially replaced sodium phosphate in emulsified bologna while maintaining acceptable cooking yield and texture. Native and modified starches improve water retention and viscosity, with pregelatinized and resistant starches enhancing gel formation and reducing purge loss, though starch does little for myofibrillar protein extraction. Proteins from milk, blood plasma, soy, and peas stabilize emulsions through interfacial activity and gelation, compensating for reduced phosphate-induced protein solubilization, though allergen labeling and flavor consequences must be weighed. Alkaline salts such as sodium bicarbonate mimic the pH-shifting effect, and studies on enhanced beef showed bicarbonate improved tenderness and juiciness, but overuse risks soapy flavors and excessive alkalinity. Transglutaminase, the enzyme that cross-links proteins covalently, strengthens gel structure without directly raising water-holding capacity.

Processing technologies offer a complementary path. High-pressure processing at moderate levels of 100 to 300 megapascals unfolds muscle proteins and enhances gelation and water binding without any additives, though the capital cost of pressure equipment remains a barrier for smaller plants. Ultrasound generates cavitation that improves mass transfer and myofibrillar protein extraction, boosting the functionality of low-phosphate systems. Vacuum tumbling optimizes brine penetration and protein extraction, potentially allowing reduced phosphate levels when salt concentration and temperature are carefully controlled. Adjusting sodium chloride levels and ionic strength can partially compensate for missing phosphate by enhancing protein solubilization, although sodium reduction targets complicate that lever. The most promising industrial strategy, the authors argue, is a hurdle-based approach that combines multifunctional ingredients with optimized processing, pairing affordable technologies like vacuum tumbling with fiber, starch, or protein systems so that small-scale manufacturers are not locked out by expensive equipment.

The bottom line from the Korean research team, supported by the Korea Food Research Institute, is that strategic phosphate reduction is technologically achievable but demands product-specific reformulation rather than one-to-one substitution. Partial replacement is generally more feasible than complete elimination, particularly in emulsified meat systems where phosphate functionality is most deeply embedded. Future research, the review concludes, should focus on elucidating the fundamental mechanisms of protein-water interactions, developing clean-label multifunctional ingredient systems, validating long-term storage quality and sensory performance, and aligning reformulation efforts with evolving regulations. As consumers increasingly scrutinize ingredient lists and sustainability pressures mount on finite phosphate reserves, the humble sausage may soon owe its juiciness to citrus fiber, high pressure, and clever engineering rather than a sprinkle of sodium tripolyphosphate, a shift that would reshape one of the food industry’s oldest chemical partnerships.

Subject of Research: Strategies for reducing and replacing phosphate additives in processed meat products

Article Title: Strategies for replacing phosphates in meat processing

Article References: Kim, T.-K., Lee, M. H., Shin, D.-M., Kim, Y.-J., Jung, S., & Choi, Y.-S. (2026). Strategies for replacing phosphates in meat processing. Food Science of Animal Resources, 46(1), Article 65. https://doi.org/10.1007/s44463-026-00069-6

Image Credits: AI Generated

DOI: 10.1007/s44463-026-00069-6

Keywords: phosphates, meat processing, clean label, water-holding capacity, phosphate substitutes, food additives, emulsified meat products, high-pressure processing, dietary fiber, transglutaminase, food safety, sustainability

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 motivation behind the work stems from a growing unease within the food industry about the additives long used to keep processed meats from going rancid. Synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) work by stabilizing free radicals and thereby slowing lipid oxidation, the chemical cascade that turns fats stale and unpalatable. Yet BHA has been classified by the U.S. National Toxicology Program as reasonably anticipated to be a human carcinogen, and recent network toxicology analyses have suggested potential liver, kidney, and nerve toxicity associated with both compounds. As consumers increasingly demand clean-label products, food scientists have turned to plant materials rich in bioactive compounds, including buckwheat, green tea, and licorice, in search of safer preservative strategies.

Magnolia denudata emerged as a promising candidate because its flowers are packed with polyphenols and flavonoids, two families of plant secondary metabolites renowned for their ability to quench reactive radicals. The blossoms also contain distinctive phenolic compounds such as rutin, chlorogenic acid, magnolol, and honokiol, which previous research has linked to antibacterial, anti-inflammatory, and antioxidant activity. To prepare the extract, the team harvested fully bloomed flowers in April 2024 from trees on the Chungbuk National University campus, dried them at room temperature, and soaked them in an 80 percent ethanol solution for one week in a shaking water bath at 37 degrees Celsius. After filtration, vacuum concentration, and freeze-drying, the process yielded a dry extract at 5.33 percent of the original flower weight, with a coefficient of variation below 2 percent across three independent batches.

Laboratory characterization confirmed the extract’s potency. In the DPPH radical scavenging assay, a standard test in which a stable purple radical turns yellow upon neutralization by antioxidants, the extract achieved a scavenging rate of 44.48 percent. That figure compares favorably with other edible spring flowers, exceeding forsythia at 40.4 percent and rhododendron at 34.5 percent, and narrowly outperforming cherry blossom at 43.3 percent. The extract contained 132.91 milligrams of gallic acid equivalents per gram in total polyphenols and 42.44 milligrams of naringin equivalents per gram in total flavonoids, values consistent with earlier analyses of the species and pointing to a dense concentration of the molecular machinery responsible for radical interception.

With the extract characterized, the researchers formulated emulsified chicken breast sausages containing ground chicken, pork backfat, ice, salt, and sugar, adding the freeze-dried extract powder at 0.1, 0.15, and 0.2 percent by weight. A negative control received no additives, while a positive control contained 0.1 percent ascorbic acid, a well-established antioxidant benchmark. The emulsions were stuffed into tubes, cooked in an 80 degree Celsius water bath for 30 minutes, and stored under refrigeration at 4 degrees Celsius for two weeks while the team tracked an array of quality indicators, from proximate composition and color to pH, lipid oxidation, and protein breakdown.

The proximate analysis revealed a clear concentration-dependent pattern. Sausages containing the extract held significantly more moisture than either control, with moisture rising as the dose increased from 0.1 to 0.2 percent. The researchers attribute this to insoluble dietary fibers such as cellulose and lignin in the flower material, which bind water within the emulsion matrix. Correspondingly, protein content declined relative to the untreated control, an effect the authors liken to earlier observations with mustard powder, where fiber-driven moisture gain dilutes the relative protein fraction. Fat and ash contents shifted only modestly, with the highest-dose group showing the lowest fat percentage, likely a dilution effect of its greater water content.

Two processing metrics told perhaps the most commercially compelling story. Cooking yield, the proportion of weight retained after heat treatment, ranged from 82.81 to 86.26 percent and was significantly higher in every extract-treated group than in either control, climbing steadily with concentration. Water-holding capacity followed a similar trajectory, with the 0.15 and 0.2 percent groups significantly outperforming the untreated control. The mechanism, the researchers suggest, is twofold: the insoluble fibers physically trap water, while the abundant polyphenols inhibit protein oxidation, preserving the structural integrity of the meat matrix and its ability to bind moisture. For manufacturers, higher yields and better water retention translate directly into reduced cooking losses and juicier products.

During refrigerated storage, the extract’s preservative effects became even more pronounced. Thiobarbituric acid reactive substances, or TBARS, the standard proxy for fat oxidation measured as malonaldehyde equivalents, were significantly lower in all extract-treated sausages than in the untreated control at every time point, with the 0.2 percent group showing the slowest rise over the two weeks. Volatile basic nitrogen, a marker of protein degradation driven by microbial activity, was also significantly reduced in the highest-dose group throughout storage. The authors point to the flower’s essential oil chemistry as a plausible explanation: previous analyses identified 3-carene, comprising 77.07 percent of magnolia flower oil, as active against spoilage bacteria such as Brochothrix thermosphacta and Pseudomonas fluorescens, while beta-elemene shows effectiveness against foodborne pathogens including Staphylococcus aureus. Slower microbial growth means fewer alkaline amines and ammonia compounds, which in turn kept pH values more stable in the treated sausages than in the controls.

Color measurements added nuance to the picture. Redness increased with extract concentration, consistent with the pigmented nature of polyphenols and flavonoids, while lightness was lowest in the mid-dose group. Yellowness rose in the lower-dose treatments, likely reflecting the extract’s inherent brownish hue, though the 0.2 percent group showed no significant difference from the untreated control, an optical effect the authors attribute to pigment dilution by the higher moisture content. A trained sensory panel of ten evaluators, however, flagged a trade-off at the highest dose: bitterness scores climbed with concentration, consistent with the known astringency of concentrated polyphenols, and overall preference was lowest for the 0.2 percent sausages. The ascorbic acid control retained the highest overall acceptability, while the 0.1 and 0.15 percent treatments scored in between.

The findings position Magnolia denudata extract as a functional, natural antioxidant capable of enhancing cooking yield, water retention, and oxidative and microbial stability in emulsified chicken products, with 0.2 percent emerging as the most effective functional dose. The remaining challenge is sensory: preserving the extract’s preservative benefits while tempering the bitterness that concentrated polyphenols impart. The authors suggest that future formulation strategies, perhaps blending the extract with masking ingredients or adjusting processing techniques, could reconcile function with flavor. As meat consumption in South Korea continues its climb toward a projected 60 kilograms per person by 2027, and as regulators and consumers alike push industry away from synthetic additives, a springtime flower long prized for its perfume may find a second career quietly protecting the sausages in the refrigerated aisle.

Subject of Research: Use of Magnolia denudata flower extract as a natural antioxidant to improve quality and storage stability of emulsified chicken sausages

Article Title: Effects of Magnolia denudata extract on quality and storage characteristics of emulsified chicken sausage

Article References: Ku, B., Kim, M., Kang, J., Han, H., Park, G., Lee, S.-H., & Choi, J. (2026). Effects of Magnolia denudata extract on quality and storage characteristics of emulsified chicken sausage. Food Science of Animal Resources, 46(1), Article 70. https://doi.org/10.1007/s44463-025-00026-9

Image Credits: AI Generated

DOI: 10.1007/s44463-025-00026-9

Keywords: Magnolia denudata, natural antioxidants, chicken sausage, lipid oxidation, TBARS, volatile basic nitrogen, polyphenols, flavonoids, water-holding capacity, cooking yield, food preservation, meat science

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