Large and small amplitude oscillatory shear techniques evaluate the nonlinear rheological properties of Ficus pumila polysaccharide -wheat starch gel.

Polysaccharides are used in starch-based product formulations to enhance the final quality of food products. This study examined the interaction mechanisms in Ficus pumila polysaccharide (FPP) and wheat starch (WS) gel systems with varying FPP concentrations using linear and nonlinear rheological analysis. Physicochemical structural analyses showed non-covalent FPP-WS interactions, strengthening hydrogen bonding between molecules and promoting water binding and ordered structure generation during WS gel aging. Small amplitude oscillatory shear analyses revealed that elevated FPP concentrations led to increased storage modulus (G'), loss modulus (G"), critical strains (From 29.02 % to 53.32 %) and yield stresses (From 0.94 Pa to 30.97 Pa) in the WS gel system, along with improved resistance to deformation and short-term regeneration. In the nonlinear viscoelastic region, FPP-WS gels shifted from elastic to viscous behavior. Higher FPP concentrations displayed increased energy dissipation, strain hardening (S>0, e3/e1 > 0) and shear thinning (T<0, v3/v1<0). FPP contributes more nonlinearity in the dynamic flow field as showed by the high harmonic ratio, with a larger I3/I1 values overall. This study highlights FPP's potential in starch gel food processing, and offers a theoretical basis for understanding hydrocolloid-starch interactions.

Structural changes of rice starch-anthocyanins complexes (V-type) and its impact on gut microbiotas and potential metabolic pathways during in vitro fermentation.

This study explored the differences in the in vitro fermentation properties of rice starch (RS) and rice starch-anthocyanins complexes (RS-A). Structural characterization suggested that RS and RS-A complexes showed a V-type crystalline structure. The degree of order (DO) and degree of double helix (DD) values of RS and RS-A complexes were enhanced after fermentation. Moreover, the RS-A complexes could improve the relative abundance of Bacteroidetes, Ruminococcaceae, and up-regulate gut microbiota diversity to maintain gut homeostasis. Relative abundance of potential metabolic pathways, such as energy metabolism, digestion system, and carbohydrate degradation overexpressed in the presence of RS-A complexes. The results demonstrated that the RS-A complexes had slower fermentation rates contributing to the transport of the formed short-chain fatty acid (SCFA) to the end of the colon and that the crystallinity might be a factor influencing the utilization of the starch matrix by the gut microbiota for SCFA formation.

Sulfated modification enhances the immunomodulatory effect of Cyclocarya paliurus polysaccharide on cyclophosphamide-induced immunosuppressed mice through MyD88-dependent MAPK/NF-κB and PI3K-Akt signaling pathways.

The present study investigated the effect of sulfation on the immunomodulatory effect of Cyclocarya paliurus polysaccharide (CP) through a Cyclophosphamide (CTX)-induced immunosuppression mice model. The results showed that sulfated Cyclocarya paliurus polysaccharide (SCP3) had stronger immunomodulatory ability than CP. Administration of SCP3 alleviated immune organ atrophy and restored hematopoiesis in immunosuppressed mice, enhanced splenocyte proliferation, and promoted cytokines and nitric oxide (NO) production in splenocyte supernatants, as well as the number of CD3+, CD4+ and CD8+ T lymphocytes. Meantime, SCP3 significantly improved oxidative stress via increasing the activities of antioxidant enzymes and decreasing the levels of malondialdehyde (MDA) in liver. In addition, SCP3 significantly upregulated the phosphorylation expression of JNK, Erk 1/2, p38 of MAPKs signaling pathway at a dose of 50 mg/kg and accordingly showed increased phosphorylation of Akt, NF-κB (p65), IκB-α, and promoted the degradation of IkB-α. Furthermore, SCP3 significantly increased the expression of the upstream signaling molecule MyD88. All results demonstrated that sulfation can be an effective way to enhance the immunomodulatory effect of polysaccharides. SCP3 has high potential to be a functional food supplement candidate for alleviating chemotherapy drug-induced immunosuppression.