A research team led by Shaoning Cui and Han Du set out to test whether cellulose nanocrystals, or CNCs, could slow the retrogradation of pea starch. CNCs are rigid, rod-like crystalline fragments of cellulose, typically 100 to 500 nanometers long and 10 to 50 nanometers wide, produced by dissolving away the amorphous portions of microcrystalline cellulose with sulfuric acid. Unlike flexible polysaccharides such as chitosan or alginate, which behave like soft polymer chains, CNCs behave more like microscopic reinforcing bars. Their surfaces are studded with hydroxyl groups that can form hydrogen bonds with neighboring molecules, and their stiff geometry prevents them from tangling with one another. The team hypothesized that these rods would fight retrogradation in two ways at once: by competitively binding water that starch chains need to mobilize, and by physically blocking the realignment of amylose and amylopectin chains as the gel ages.

To test the idea, the researchers hydrolyzed wheat-straw-derived microcrystalline cellulose with 65 percent sulfuric acid under sonication, then purified the resulting rods by repeated centrifugation and dialysis. Transmission electron microscopy confirmed the classic whisker morphology, while dynamic light scattering revealed a zeta potential of −36.9 millivolts, a negative surface charge imparted by sulfate ester groups that keeps the particles stably dispersed in water. X-ray diffraction showed that the acid treatment had stripped out the disordered regions of the parent cellulose, raising the crystallinity index from 62.26 percent to 88.71 percent. These intrinsic properties—a high aspect ratio, strong surface charge, and near-perfect crystallinity—turned out to be critical to everything that followed.

The team then blended CNCs into pea starch at concentrations ranging from 2 to 8 percent by weight and subjected the mixtures to a battery of analytical tests spanning seven orders of magnitude in scale, from molecular vibrations to whole-gel texture. Rapid viscosity analysis showed that even small doses of CNCs changed how the starch behaved during cooking. At 4 percent CNCs, the peak viscosity of the paste dropped from 505 to 487 pascal-seconds, a sign that the nanorods were crowding the swelling granules and competing for water. More tellingly, the setback viscosity—a measure of how much the paste thickens as it cools and the chains begin to reassociate—fell steadily from 187 pascal-seconds in the pure starch to 159 pascal-seconds at 8 percent CNCs, indicating that the nanorods were already interfering with the earliest stages of chain reordering.

The most visually striking evidence came from simple refrigeration experiments. When gels were stored at 4 degrees Celsius for five and seven days, the untreated pea starch gel expelled progressively more water, a phenomenon called syneresis that anyone who has opened a container of old pudding will recognize. By day seven, the control gel had lost 30.63 percent of its weight as expelled water. The gel fortified with 8 percent CNCs lost only 27.49 percent, a reduction of more than three percentage points, and the effect grew stronger with increasing CNC loading. Low-field nuclear magnetic resonance revealed what was happening at the molecular level: the fraction of free, mobile water in the gels fell dose-dependently from 33.09 percent in the control to 27.79 percent at 8 percent CNCs after a week of storage, while the relaxation time of weakly bound water shortened, showing that the nanorods were literally pinning water molecules in place within the gel network.

Scanning electron microscopy provided the structural explanation. In the freeze-dried retrograded gels, the CNCs appeared as rigid rods uniformly distributed throughout the starch matrix, bridging adjacent fragments and pore walls like tiny struts in a scaffold. Gels containing the nanorods showed thickened fragment walls, smoother surfaces, and more homogeneous pore distributions than the untreated control, forming what the authors describe as a concrete-like supportive framework. The hydroxyl-rich surfaces of the rods competitively bind water while simultaneously forming hydrogen bonds with amylose and amylopectin chains, reinforcing the three-dimensional network and denying the starch chains the mobility they need to crystallize.

Spectroscopic and thermal measurements confirmed that the interaction is non-covalent but powerful. Fourier transform infrared spectroscopy showed no new absorption peaks and no peak shifts, only a pronounced broadening of the hydroxyl stretching band near 3300 wavenumbers—a fingerprint of extensive hydrogen bonding between the nanorods and the starch chains. Differential scanning calorimetry quantified the energetic consequence: after seven days of refrigeration, the retrogradation enthalpy of pure pea starch was 1.46 joules per gram, but only 0.60 joules per gram at 8 percent CNCs, cutting the degree of retrogradation nearly in half, from 14.07 percent to 7.23 percent. X-ray diffraction delivered perhaps the most dramatic number of all: the relative crystallinity of the stored gels fell from 34 percent to 16 percent across the CNC range, a 52.94 percent reduction, while the characteristic B-type crystal polymorph of the starch remained unchanged, confirming that the nanorods suppressed crystal growth without altering its fundamental nature.

Texture analysis tied the physics back to the eating experience. After a week of cold storage, the untreated pea starch gel had hardened to 93.76 grams of resistance, while every CNC-fortified gel was measurably softer, with springiness preserved near 1.0 throughout. Interestingly, the relationship between CNC concentration and gel properties was not strictly linear. The inhibitory effect rose with loading and then plateaued between 6 and 8 percent, and above that threshold the nanorods began to agglomerate, losing their ability to disperse and undermining the very interfacial contact on which the mechanism depends. This non-linear, dispersion-governed behavior distinguishes rigid rod-like CNCs from both flexible hydrocolloids and spherical nanoparticles, and it establishes a practical formulation window for food developers.

The implications reach beyond the laboratory. Because CNCs are derived from abundant agricultural byproducts and work through physical rather than chemical modification, they sidestep the toxicity concerns of chemical starch additives and the limited controllability of enzymatic treatments. A dosing guideline of 6 to 8 percent CNCs could extend the refrigerated shelf life of pea-based noodles, jellies, and meat analogues without any synthetic preservatives. The authors caution that their study covered only one week of storage at 4 degrees Celsius, leaving room-temperature stability, freeze-thaw cycling, digestibility, and real-food matrices for future work. But the core message stands: the answer to keeping plant-based foods fresh may lie in scattering billions of impossibly small cellulose rods through the gel, where they lock up water, brace the network, and quietly stop starch from turning back against itself.

Subject of Research: Using cellulose nanocrystals to inhibit the retrogradation of high-amylose pea starch in food gels

Article Title: Effects of cellulose nanocrystals on the physicochemical and retrogradation properties of pea starch

Article References: Cui, S., Cui, S., Xie, W., Li, H., Li, F., Ge, S., Fu, Z., & Du, H. (2026). Effects of cellulose nanocrystals on the physicochemical and retrogradation properties of pea starch. Food Chemistry: X, Article 104569. https://doi.org/10.1016/j.fochx.2026.104569

Image Credits: AI Generated

DOI: 10.1016/j.fochx.2026.104569

Keywords: pea starch, cellulose nanocrystals, starch retrogradation, food chemistry, amylose, syneresis, nanomaterials, gelatinization, X-ray diffraction, LF-NMR, plant-based foods, shelf life

The research team, led by Yuqian Zheng and Sheng Li, set out to resolve a question that has lingered in food science: while HHP is known to alter the short-term behavior of starch, and polyphenols are known to bind starch through non-covalent interactions, the combined effect of these two interventions on long-term retrogradation remained poorly understood. The researchers treated corn starch with 600 megapascals of pressure for 15 minutes, blended it with three grape polyphenol preparations at concentrations ranging from 0.1 to 2.0 percent, gelatinized the mixtures, and then stored the resulting gels at 4 degrees Celsius for 14 days to track how their structure, texture, and water distribution evolved.

The three polyphenols were deliberately chosen to represent different corners of grape chemistry. Grape seed oligomeric proanthocyanidins, or GSOP, are oligomeric mixtures built from catechin, epicatechin, and their gallate derivatives. Grape seed polyphenols, or GSP, are a broader commercial extract whose components were characterized by liquid chromatography-mass spectrometry. Grape skin anthocyanins, or GSA, were extracted from the variety Vitis amurensis cv. Beibinghong, with malvidin-3-glucoside as the dominant pigment. Because anthocyanins carry hydrophobic methoxy groups that the other two preparations lack, the comparison offered a natural test of how molecular structure shapes function.

Fourier transform infrared spectroscopy provided the first molecular clues. After two weeks of storage, all samples showed increased short-range molecular ordering, but the polyphenol-containing samples displayed a notably narrower hydroxyl stretching band between 3100 and 3700 inverse centimeters, signaling a more homogeneous hydrogen-bonding environment. The ratio associated with ordered double-helical structures dropped by 14.46 percent in the 1.5 percent GSOP sample, 16.03 percent in the 2 percent GSP sample, and 16.48 percent in the 0.5 percent GSA sample relative to pressurized starch alone. The authors interpret this as evidence that polyphenol aromatic rings can slip into the hydrophobic cavity of amylose single helices while their hydroxyl groups form intermolecular hydrogen bonds, together restricting the alignment and reassociation of starch chains.

X-ray diffraction told a complementary story. The original A-type crystalline pattern of corn starch vanished entirely during storage, replaced by peaks near 17 and 20 degrees two-theta that mark the formation of V-type crystals, the signature of inclusion complexes between leached amylose and small guest molecules. Crucially, the increase in relative crystallinity over the storage period was significantly smaller in every polyphenol-treated sample than in pressurized starch alone, confirming that the additives retarded the growth of long-range ordered domains even as they permitted local molecular rearrangement. Scanning electron microscopy revealed the structural consequences: polyphenol gels developed heterogeneous, layered networks with visible cavities, in contrast to the compact, contracted architecture of the control.

Texture measurements translated these molecular events into something tangible. Gel hardness rose in all samples over 14 days, as expected from the slow recrystallization of amylopectin, but the polyphenol-containing gels hardened far less, indicating a slower transition from disorder to order and reduced water exudation. Low-field nuclear magnetic resonance added a fourth dimension by tracking water itself. Four water populations were identified, from tightly bound water to highly mobile freezable water, and the polyphenol samples retained significantly higher transverse relaxation times for weakly bound water, meaning water molecules kept more of their mobility. Magnetic resonance imaging visualized this directly, showing more uniform proton density across the polyphenol gels after storage. Notably, GSA was less effective at restraining water migration than GSOP and GSP, a difference the authors attribute to its methoxy-substituted structure, which interacts more weakly with starch and water.

With the anti-retrogradation mechanism established, the team turned to application. The best-performing starch-polyphenol systems were substituted for 30 percent of the wheat flour in a standard cookie dough formulation, and the results were striking. Infrared analysis of the amide I band showed that the dough containing grape seed polyphenols increased its beta-sheet content by 38.73 percent and its alpha-helix content by 47.55 percent relative to the control, indicating a more stable gluten network. At the same time, dough hardness fell sharply, springiness dropped by roughly 45.65 percent, and chewiness in the GSP group declined by approximately 56.57 percent, producing a softer, more cohesive matrix that requires less oral processing.

Rheology reinforced the picture. In frequency sweeps from 0.1 to 10 hertz, the storage modulus of the formulated doughs fell below that of the control while the loss modulus rose, shifting the material toward a less elastic, more viscous character. Creep-recovery tests showed that the polyphenol doughs resisted deformation under constant stress yet recovered their shape more completely once the stress was removed, a balance the authors consider favorable for bolus cohesion during swallowing. Low-field NMR of the doughs mirrored the gel findings, with a higher proportion of bound water and less mobile free water, conditions that maintain lubrication without sacrificing structural integrity.

The dysphagia connection was formalized through the International Dysphagia Diet Standardization Initiative framework, the global standard that classifies texture-modified foods from Level 0 to Level 7. In fork pressure tests, all the composite gels crushed under a force of roughly 17 kilopascals, comparable to the pressure the tongue exerts during swallowing, and failed to spring back. In fork drip tests they held their position on the tines without flowing through the gaps, and in spoon tilt tests every polyphenol formulation slid off intact, unlike the sticky control. Taken together, the composite gels met the qualitative criteria for IDDSI Level 4, the category of smooth, pureed foods that hold their shape under gravity but require no chewing.

The authors are careful to mark the limits of the work. The precise molecular arrangement of the amylose-polyphenol complexes has not been directly verified, and future studies using molecular dynamics simulations, solid-state carbon-13 NMR, or synchrotron X-ray scattering are needed. The observed effects may also reflect the combined influence of pressure pretreatment and subsequent thermal gelatinization rather than HHP alone, and neither swallowing safety nor consumer acceptability was tested. Even so, the study offers a compelling proof of concept: two gentle interventions, one physical and one derived from an agricultural byproduct, can simultaneously extend the storage stability of starch foods and tune their texture toward the needs of people who struggle to swallow. If the molecular mechanisms hold up under closer scrutiny, grape polyphenols may find a second life far from the winery, inside the texture-modified foods of an aging world.

Subject of Research: Regulation of corn starch retrogradation and dough functionality by grape polyphenols and high hydrostatic pressure treatment for dysphagia food development

Article Title: Regulation of corn starch long-term retrogradation and dough functionality by grape polyphenols and HHP treatment with potential implications for dysphagia food development

Article References: Zheng, Y., Qin, X., Wang, W., Wen, X., Ren, P., Ren, F., Liu, T., & Li, S. (2026). Regulation of corn starch long-term retrogradation and dough functionality by grape polyphenols and HHP treatment with potential implications for dysphagia food development. Food Chemistry: X, 39, Article 104515. https://doi.org/10.1016/j.fochx.2026.104515

Image Credits: AI Generated

DOI: 10.1016/j.fochx.2026.104515

Keywords: corn starch, starch retrogradation, grape polyphenols, high hydrostatic pressure, dysphagia, IDDSI, cookie dough, food texture, V-type complexes, water migration, food chemistry, shelf life

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