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, Article 104543. https://doi.org/10.1016/j.fochx.2026.104543

Image Credits: AI Generated

DOI: Not provided

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

Salecan is not an ordinary hydrocolloid. Produced by microbial fermentation, it was approved as a novel food additive by the U.S. FDA in 2020 and by China’s National Health Commission in 2021. Structurally, it is a linear, unbranched glucan built from a repeating unit of seven beta-1,3-linked and two alpha-1,3-linked glucose residues, with purity exceeding 90 percent. That linearity matters enormously. Most familiar anionic polysaccharides, from xanthan gum to carrageenan and pectin, carry highly branched backbones and heterogeneous branch distributions, features that create steric hindrance and thermodynamic incompatibility with starch chains. Salecan’s naked backbone can align and entangle directly with starch molecules, while its uniformly distributed carboxyl groups from succinyl and pyruvyl substituents provide consistent negative charge across the entire chain. As a fermentation product, it is also immune to the seasonal and geographic constraints that complicate plant- and seaweed-derived gums.

To test whether Salecan’s behavior depends on starch structure, the research team led by Wanping Xiong and Xianggui Chen at Sichuan University paired two starches that sit at opposite ends of the botanical spectrum. Potato starch, a tuber starch, features large oval granules of 15 to 100 micrometers, negatively charged monophosphate ester groups on its molecular chains, a B-type crystalline pattern and a highly cross-linked granular architecture. Corn starch, the cereal archetype, presents small polygonal granules of 5 to 20 micrometers, a nearly neutral surface, an A-type crystalline pattern and a substantially higher amylose content of 25 to 28 percent with a lower degree of polymerization. Every major structural determinant of polysaccharide-starch interaction therefore differs between the pair, making it an ideal contrast model.

The divergent results began immediately. When Salecan was added at concentrations from 0.5 to 2 percent by starch dry weight, both starches showed delayed gelatinization, with pasting curves shifted to the right and peak times significantly prolonged, findings confirmed by differential scanning calorimetry. But the viscosity story split cleanly along charge lines. In potato starch, Salecan dramatically reduced peak, trough and final viscosity, and at 2 percent addition the consistency coefficient fell by 81.56 percent. The authors attribute this to electrostatic repulsion between the negatively charged potato starch and the anionic polysaccharide, which confines Salecan to the granule surface as a barrier that blocks water ingress and amylopectin leaching. Corn starch behaved in the opposite way: Salecan increased its peak viscosity, breakdown strength and final viscosity, with the consistency coefficient surging by 332.9 percent at 2 percent addition, because the neutral granules allowed Salecan to disperse through the paste and leached amylose supplied abundant hydroxyl groups for hydrogen bonding and chain entanglement.

Rheological measurements reinforced the split. All composite pastes displayed shear-thinning pseudoplastic behavior, but Salecan reduced the apparent viscosity and shear stress of potato starch systems while raising those of corn starch. Frequency sweep tests showed that Salecan depressed the storage and loss moduli of potato gels yet elevated the moduli of corn gels in a concentration-dependent fashion. For food engineers, this duality is a gift. High-viscosity tuber pastes used in sauces, custards and dessert gels become easier to pump and process without sacrificing final gel integrity, while cereal-based soups, gravies and bakery fillings gain viscosity and thermal stability exactly where hot filling and cooling demand them.

The second half of the study tackled retrogradation, the costlier enemy of shelf life, and here Salecan proved a unifying remedy. Storing gels at 4 degrees Celsius for up to 21 days, the researchers tracked gel hardness with texture analysis, water mobility with low-field nuclear magnetic resonance, crystallinity with X-ray diffraction, molecular order with Fourier transform infrared spectroscopy and microstructure with scanning electron microscopy. Every technique converged on the same conclusion: at 1 percent addition, Salecan significantly slowed the aging of both starches, cutting gel hardness by 33.63 percent for potato starch and 31.19 percent for corn starch relative to controls.

The water-migration data are particularly striking. During storage, bound water progressively escapes the starch matrix and becomes free water, a process that culminates in syneresis, the unappetizing pooling of liquid that ruins chilled desserts and fillings. Free water appeared in plain corn starch gel after only three days and in potato starch gel after fourteen days. At 1 percent Salecan, the free water fraction after 21 days fell from 3.75 percent to 0.54 percent in potato gels and from 15.81 percent to 6.31 percent in corn gels. X-ray diffraction showed that Salecan did not change the crystal type formed during aging but significantly lowered relative crystallinity, while infrared ratios revealed suppressed short-range molecular order and reduced double-helix formation at the same optimal dosage. Interestingly, both hardness and structural indices followed a U-shaped dose curve, first falling and then rebounding at high concentrations, because Salecan’s intense water-holding capacity ultimately concentrates amylose in the remaining solvent and promotes renewed association.

The proposed mechanism weaves these observations together. During short-term retrogradation, Salecan’s linear backbone entangles with amylose and sterically blocks chain re-association, delaying initial network formation. During long-term storage, it disrupts the hydrogen-bond reformation needed for double-helix nucleation, impedes the ordered alignment of amylopectin side chains, and physically retains water within the gel network. Scanning electron microscopy captured the microstructural fingerprints of these effects: Salecan produced smaller, more orderly pores and tighter matrix interconnection in potato gels, while in corn gels it preserved a smoother, looser honeycomb structure by resisting the dehydration shrinkage that normally crumples high-amylose networks. No new covalent bonds were detected, confirming that the interactions are dominated by hydrogen bonding and physical entanglement.

Perhaps the most surprising results came from simulated digestion. Freshly gelatinized starch with Salecan was hydrolyzed more slowly by alpha-amylase and amyloglucosidase, because the additive suppresses complete gelatinization and its dense composite network shields enzyme binding sites on starch molecules, a finding that points toward low-glycemic-index versions of instant porridges, steamed rice alternatives and gluten-free breads. Yet after seven days of retrogradation, the pattern inverted: Salecan-containing gels were digested faster than highly crystallized plain retrograded gels, precisely because Salecan had prevented the formation of enzyme-resistant crystalline domains. That inversion doubles as independent mechanistic evidence, confirming from a nutritional angle that Salecan suppresses resistant crystal formation during aging. The authors caution that their structural-dependence conclusions rest on just two contrasting starches, and that broader starch panels will be needed to validate generality. Still, the prospect of a single clean-label, fermentation-produced ingredient that simultaneously tames viscosity where it runs too high, boosts it where it falls short, prevents staling, stops syneresis and reshapes glycemic response is exactly the kind of multifunctional tool the clean-label food industry has been searching for.

Subject of Research: Modulation of potato and corn starch gelatinization, retrogradation and digestibility by the anionic polysaccharide Salecan

Article Title: Structure-dependent modulation of potato and corn starch gelatinization and retrogradation by Salecan

Article References: Xiong, W., Hu, L., Ni, C., Zhao, J., Huang, Y., Yang, X., Chen, P., & Chen, X. (2026). Structure-dependent modulation of potato and corn starch gelatinization and retrogradation by Salecan. Food Chemistry: X, 39, Article 104470. https://doi.org/10.1016/j.fochx.2026.104470

Image Credits: AI Generated

DOI: 10.1016/j.fochx.2026.104470

Keywords: Salecan, starch gelatinization, starch retrogradation, potato starch, corn starch, food hydrocolloids, rheology, X-ray diffraction, water migration, in vitro digestion, low glycemic index, clean label