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Polyphenol–saliva interactions disrupt mucin-mediated lubrication and induce astringency, yet most models neglect dynamic salivary replenishment. Here, a stepwise artificial saliva (AS) addition model was developed to compare tannic acid (TA) and (−)-epigallocatechin gallate (EGCG), with or without xanthan gum (XG). Four systems (TA–AS, EGCG–AS, TA–XG–AS, EGCG–XG–AS) underwent sequential AS replenishment and were characterized using colloidal, spectroscopic, tribological, and electronic tongue analyses. TA–AS progressively formed larger aggregates and exhibited the highest friction, whereas EGCG–AS generated smaller particles and showed lower friction at intermediate stages. In XG-containing systems, TA–XG–AS formed ternary networks with mucin, stabilizing lubrication and reducing astringency. EGCG–XG–AS primarily enhanced film retention with limited aggregation. Spectroscopy and molecular docking suggested stronger TA–mucin interactions, whereas EGCG interactions were more reversible. Overall, polyphenol structure and XG modulation under dynamic replenishment governed mucin lubrication and astringency attenuation.

Starch microspheres with uniform morphology and controllable particle size show significant application value. In this work, micrometer-sized natural starch microspheres (SMs) were prepared via membrane emulsification for the first time. Transmembrane pressure and the dispersed phase concentration significantly affect the morphology of SMs. The average particle size decreased with an increase in the transmembrane pressure, while a higher dispersed phase concentration yielded a more uniform particle size distribution. Under optimized membrane emulsification conditions (0.2 MPa and 10% dispersed phase concentration), debranched corn starch microspheres (CSM, 7.93 ± 0.12 μm) and debranched amaranth starch microspheres (ASM, 0.95 ± 0.01 μm) were successfully prepared. Gel permeation chromatography (GPC) analysis showed that the SMs had a lower molecular weight dispersity (D̅) than that of debranched starch (from 2.18 to 1.36 for CSM and from 2.04 to 1.59 for ASM), indicating a narrower molecular weight distribution and more densely arranged molecular chains. The crystallinity of conventional starch microspheres was generally lower than that of native starch because the ordered structure of starch molecules was destroyed during the microsphere formation process. Whereas, the SMs prepared in this work exhibited a significant increase in crystallinity compared with native starch (from 18.7 to 58.52% for CSM and from 25.8 to 69.67% for ASM), which was significantly higher than that of starch microspheres reported in previous papers. DSC proved that the gelatinization temperatures of SMs were higher than 90 °C, indicating that our SMs were difficult to gelatinize under conventional conditions. Because of the controllable particle sizes, the SMs prepared in this study had a narrow molecular weight distribution, extremely high crystallinity, and resistance to gelatinization, thus having broad application prospects in food, medicine, and other material fields.

Effects of polysaccharides (pectin, λ-carrageenan, and sodium alginate) on the colloidal behavior and sweetness perception of thaumatin were investigated. Turbidity and zeta potential were measured to map pH-dependent transition regions of polysaccharide-thaumatin complexes. Particle size, secondary structure changes, and molecular docking simulations were analyzed to assess phase behavior and binding interactions of complexes at different conditions. Results showed that polysaccharide type influenced surface charge and complexation strength. At protein-rich mixing ratios, λ-carrageenan-thaumatin and sodium alginate-thaumatin systems exhibited bimodal turbidity profiles, whereas pectin-thaumatin systems showed a single turbidity maximum. FTIR revealed secondary structure redistribution in selected complexes: β-sheet increased from 29.95% (thaumatin) to 33.56% (G11) and 35.19% (H14), while β-turn decreased from 25.22 to 14.65 and 14.16%. Docking of repeating units suggested association with basic surface patches (-6.7/-5.9/-5.5 kcal mol^-1 for pectin/λ-carrageenan/sodium alginate). Sensory analysis showed ratio-dependent sweetness suppression, most evident in the early and late phases of perception, supporting sugar-reduced formulation design.