Enhancing mucoadhesion: Exploring rheological parameters and texture profile in starch solutions, with emphasis on micro-nanofiber influence.

This comprehensive analysis explores the rheological parameters and texture profile analysis (TPA) to effect starch solutions for mucoadhesion and assess the impact of micro-nanofibers (MNFs) on these parameters. The surface chemistry of all six samples was examined through the Fourier transform infrared (FTIR) technique. The spectrum of FTIR was recorded in the range of 500-4000 cm-1. The viscosity of different pHs (2-11) and temperatures (20-70 °C) of verious starches, potato, corn, and rice, decreased with the increasing of shear rate, exhibiting shear thinning behavior, which conformed to pseudoplastic fluid.The combination of chitosan and collagen MNFs significantly changed rheological properties, and the sample with the addtion of 1500 µL CC-MNF exhibited a greater viscosity of 59.8 mPa·s at a shear rate of 1.49 s-1. Potato starch emerged as a strong candidate for mucoadhesion due to its low hardness (4.62 ± 0.31 N), high adhesion (0.0322 ± 0.0053 mJ), cohesiveness (0.37 ± 0.03 Ratio), low chewiness (0.66 ± 0.12 mJ), and gumminess (1.69 ± 0.23 N). The inclusion of MNFs, especially collagen/chitosan MNFs showed the potential to further enhance adhesion.

Identification of Hyperuricemia Alleviating Peptides from Yellow Tuna Thunnus albacares.

The development of food-derived antihyperuricemic substances is important for alleviating hyperuricemia (HUA) and associated inflammation. Here, novel peptides fromThunnus albacares (TAP) with strong antihyperuricemic activity were prepared. TAP was prepared by alkaline protease (molecular weight <1000 Da), with an IC50 value of xanthine oxidase inhibitory activity of 2.498 mg/mL, and 5 mg/mL TAP could reduce uric acid (UA) by 33.62% in human kidney-2 (HK-2) cells (P < 0.01). Mice were fed a high-purine diet and injected with potassium oxonate to induce HUA. Oral administration of TAP (600 mg/kg/d) reduced serum UA significantly by 42.22% and increased urine UA by 79.02% (P < 0.01) via regulating urate transporters GLUT9, organic anion transporter 1, and ATP-binding cassette subfamily G2. Meantime, TAP exhibited hepatoprotective and nephroprotective effects, according to histological analysis. Besides, HUA mice treated with TAP showed anti-inflammatory activity by decreasing the levels of toll-like receptor 4, nuclear factors-κB p65, NLRP3, ASC, and Caspase-1 in the kidneys (P < 0.01). According to serum non-targeted metabolomics, 91 differential metabolites between the MC and TAP groups were identified, and purine metabolism was considered to be the main pathway for TAP alleviating HUA. In a word, TAP exhibited strong antihyperuricemic activity both in vitro and in vivo.

Isolation and differential structure characteristics of calcium-binding peptides derived from Pacific cod bones by hydroxyapatite affinity.

Calcium-chelating peptides were found in Pacific cod bone, but their binding structure and properties have not been elucidated. Novel calcium-binding peptides were isolated by hydroxyapatite affinity chromatography (HAC), and their binding structure and properties were investigated by isothermal titration calorimetry (ITC), multispectral techniques, and mass spectrometry. Based on multiple purifications, the calcium binding capacity (CBC) of Pacific cod bone peptides (PBPs) was increased from 1.71 ± 0.15 µg/mg to 7.94 ± 1.56 µg/mg. Peptides with a molecular weight of 1-2 kDa are closely correlated with CBC. After binding to calcium, the secondary structure of peptides transitioned from random coil to ß-sheet, resulting in a loose and porous microstructure. Hydrogen bonds, electrostatic interaction, and hydrophobic interaction contribute to the formation of peptide­calcium complexes. The F21 contained 42 peptides, with repeated "GE" motif. Differential structure analysis provides a theoretical basis for the targeted preparation of high CBC peptides.

A comprehensive review of calcium and ferrous ions chelating peptides: Preparation, structure and transport pathways.

Calcium and iron play crucial roles in human health, deficiencies of which have globally generated public health risks. The poor solubility, low bioavailability and gastrointestinal irritation of existing commercial mineral supplements limit their further application. As an emerging type of mineral supplement, mineral chelating peptides have drawn plenty of attention due to their advantages in stability, absorptivity and safety. A majority of calcium and ferrous ions chelating peptides have been isolated from food processing by-products. Enzymatic hydrolysis combined with affinity chromatography, gel filtration and other efficient separation techniques is the predominant method to obtain peptides with high calcium and ferrous affinity. Peptides with small molecular weight are more likely to chelate metals, and carboxyl, amino groups and nitrogen, oxygen, sulfur atoms in the side chain, which can provide lone-pair electrons to combine with metallic ions. Unidentate, bidentate, tridentate, bridging and α mode are regarded as common chelating modes. Moreover, the stability of peptide-mineral complexes in the gastrointestinal tract and possible transport pathways were summarized. This review is to present an overview of the latest research progress, existing problems and research prospects in the field of peptide-mineral complexes and to provide a more comprehensive theoretical basis for their exploitation in food industry.

Contribution of secondary bonds to the storage stability of ready-to-eat sea cucumber.

To explore the contribution of secondary bonds on storage stability of RSC, urea, n-propanol and sodium nitrite (NaNO2) were used for the breakdown of hydrogen bonds, hydrophobic bonds, side-chain groups, respectively. The impact of the breakdown of secondary bonds before and after storage on texture properties and microstructure were investigated. The breakdown of hydrogen bonds, especially before storage, significantly reduced the hardness (from 3.12 to 2.21 N), chewiness (from 1.82 to 1.05 mJ), and springiness (from 2.57 to 1.57 mJ) of RSC, while the breakdown of hydrophobic bonds and side-chain groups had a slight effect. Similarly, degradation of collagen fibers by breaking hydrogen bonds before storage was more serious than other groups. Furthermore, moisture content and water activity decreased and the degradation degree of collagen in RSC body wall increased with hydrogen bonds breaking. The results showed that hydrogen bonds were essential for the storage stability of RSC.