Dandelion polysaccharides improve the emulsifying properties and antioxidant capacities of emulsions stabilized by whey protein isolate

Structure characterization of polysaccharide isolated from Ribes nigrum L. and it's bioactivity against gout

Gout mainly caused by the increase of uric acid level in serum poses a threat to human health. Inhibition on the activity of xanthine oxidase (XOD) usually an effective method for treating gout, so finding XOD inhibitors without side effects is crucial. In this study, two heteropolysaccharides were extracted from blackcurrant by microwave-assisted aqueous two-phase technology, and the top phase (PRNP-1) and bottom phase (PRNP-2) polysaccharides at high purity (>86%) were obtained after column chromatography separation. Methylation and NMR analyses confirmed the potential structural backbone of PRNP-1 may be composed of →3)-α-L-Araf-(1 → 3)-β-D-Galp-(1 → 4)-β-D-Manp-(1 → 5)-α-Araf-(1 → 4)-α-D-GalpA-(1 → 3,6)-β-D-Glup-(1→, while PRNP-2 exhibited a differing repeating unit of →4)-β-D-Manp-(1 → 3)-α-D-Araf-(1 → 3)-β-D-Galp-(1 → 5)-α-Araf-(1 → 4)-α-D-GalpA-(1 → 3,6)-β-D-Glup-(1→. Compared to PRNP-1 (4.87 × 104 kDa), PRNP-2 with low molecular weight (2.30 × 104 kDa) exhibited better dispersivity, homogeneity, water solubility and thermal stability, as well as XOD inhibitory activity. Both PRNP-1 and PRNP-2 demonstrated a competitive, reversible inhibition towards XOD and quenched its fluorescence through forming polysaccharide-XOD complexes. Molecular docking and molecular dynamics simulation assays revealed that PRNP-2 exhibited a better binding capacity with XOD than PRNP-1. PRNPs markedly decreased the serum concentration of uric acid and creatinine, and XOD activity in hyperuricemia mice model. Therefore, PRNPs may be the potential natural therapeutic agents for the treatment of gout.

A comparative study of ultrasound and thermal processing: Effects on goat milk stability and protein structure

Ultrasonic treatment has been shown to improve the functional properties and quality of proteins; however, the effects of ultrasound on the proteins in goat milk and the quality of goat milk are not clear. In this study, we aimed to analyze the thermal stability of whole, raw goat milk in terms of protein structure aspect. Goat milk was subjected to ultrasound treatments (400 W for 10 min, 500 W for 10 min, and 600 W for 10 min), and untreated and heat-treated samples served as controls. The results demonstrated that ultrasonic treatment led to a more uniform distribution of fat globules and protein particles, reduced agglomeration, and fostered a more compact and ordered protein network structure. Additionally, it enhanced the stability of goat milk. After ultrasonic treatment, the composition and structure of goat milk protein changed. The exposure of more hydrophobic groups enhanced the intermolecular forces, thereby making the protein conformation more stable. These findings indicate that ultrasonic processing not only improved the structure of goat milk proteins but also increased their thermal stability. This study highlights the potential of ultrasonic treatment as an effective method for enhancing the stability and quality of goat milk.

Pickering emulsion gel stabilized by milk fat globule membrane/pectin enhanced probiotic stability

The milk fat globule membrane (MFGM) has been shown to improve probiotic survival in the gastrointestinal tract. However, emulsions stabilized through electrostatic interactions between MFGM and polysaccharides for probiotic encapsulation remain unexplored. This study established optimal conditions for creating MFGM-Pectin (CP) emulsions. At pH 4.0, a MFGM/CP ratio of 1 produced the smallest particle size and the highest zeta potential, ideal for emulsion stabilization. We evaluated the effects of varying complex concentrations and oil phase ratios on emulsion properties. The results indicate that CP significantly affects the apparent viscosity, oxidative stability, centrifugal stability, storage stability, and antioxidant activity of MFGM-CP emulsions. Furthermore, the encapsulation of LGG within the emulsion improved its survival and storage stability in simulated gastrointestinal fluids. These findings suggest that MFGM is a promising material for probiotic encapsulation and provide a foundation for developing MFGM-based products containing probiotics or other active ingredients.

Improvement of curcumin loading properties and bioaccessibility of beta-lactoglobulin-hyaluronic acid nanocomplexes conjugated via ultrasound-assisted Maillard reaction

Curcumin (Cur) has many potential applications in the food industry. However, it suffers from poor water solubility, low plasma and tissue uptake and susceptibility to oxidation. In this study, β-lactoglobulin (β-LG)-hyaluronic acid (HA) binary covalent complexes were prepared by ultrasound-assisted Maillard reaction and used as the carrier to deliver Cur. Results of SDS-PAGE, degree of grafting, and SEM showed that β-LG was successfully grafted to HA, and the degree of grafting increased from 15.30 ± 0.28 % to 29.70 ± 0.45 % under ultrasound treatment. There was a decrease in α-helix and β-sheet contents, and an increase in random coil content, and the amide I bands, and tryptophan motifs in the covalent secondary and tertiary structures of the nanocomplexes. Encapsulation by β-LG-HA could form the controlled release of Cur, resulting in a decreased release rate in the oral and gastric phases and an increased release rate in the intestinal phase, as demonstrated in an in vitro digestion simulation. Furthermore, the β-LG-HA-Cur nanocomplex exhibited the superior antioxidant and enzyme inhibition of α-amylase and α-glucosidase. The inhibition rates of α-amylase and α-glucosidase could reach 48.91 ± 0.81 % and 49.88 ± 0.61 %, respectively. This study will help to understand the ultrasound-assisted Maillard reaction covalent binding of protein- polysaccharides complexes, demonstrate the potential for Cur delivery, and develop functional dairy products with hypoglycemic activity.

Insights into the soybean protein isolate hydrolysates: Performance characterization, emulsion construction and in vitro digestive behavior

In this experiment, the co-constructed O/W emulsions of different soy protein hydrolysates (SPHs) and gum arabic (GA) were investigated. SPHs were prepared by hydrolyzing soy protein isolate (SPI) using different enzymes, and investigated the effects of enzyme types and hydrolysis time on the physicochemical properties of SPHs. Moreover, SPI/GA and SPHs/GA were prepared and used as hydrophilic emulsifiers to construct O/W emulsions. The results showed that the optimal hydrolysis times for bromelain, pepsin and trypsin were 2 h (BSPH2), 3 h (PSPH3) and 3 h (TSPH3), respectively. Compared with SPI/GA emulsions, SPHs/GA emulsions had smaller particle size, more negative charge, higher interfacial adsorbed protein, and more stable emulsion systems. During the digestion process, SPHs/GA emulsions were effective in realizing the release of bioactives. In conclusion, enzymatic hydrolysis can be an effective modification technique, and SPHs/GA can be used as an effective emulsifier for the emulsion system.

The phytochemical and pharmacological profile of dandelion

Dandelion (Taraxacum genus), a perennial herb belonging to the Asteraceae family is widely distributed in hillside grasslands, roadsides, fields, and river beaches in middle and low-altitude areas. It has a long history of traditional Chinese medicine usage as a heat-clearing and detoxifying agent, often consumed as tea or vegetable. Multiple pharmacological studies have demonstrated the antiviral, antibacterial, anti-inflammatory, immune-regulating, antioxidant, anti-tumor, and other effects of the Taraxacum genus. Bioactive compounds associated with these effects include triterpenes and their saponins, phenolic acids, sterols and their glycosides, flavonoids, organic acids, volatile oils, and saccharides.

Structural characterization and hypoglycemic effect of polysaccharides of Polygonatum sibiricum

Polygonatum sibiricum polysaccharide (PSP) was extracted and purified from raw material obtained from P. sibiricum. The structural features of PSP were investigated by Congo red, circular dichroism spectrum, high-performance gel permeation chromatography, scanning electron microscope, atomic force microscope, ultraviolet spectroscopy, and Fourier transform infrared spectroscopy analysis. In vitro simulations were conducted to investigate the kinetics of PSP enzyme inhibition. Moreover, a type II diabetes mouse model (T2DM) with streptozotocin-induced insulin resistance was established, and the indexes of lipid quadruple, insulin resistance index, oral glucose tolerance (OGTT), organ index, and pancreatic morphology of model mice were measured. The results showed that PSP mainly consists of monosaccharides, such as mannose, glucose, galactose, xylose, and arabinose. It also has a β-glycosidic bond of a pyranose ring and an irregular reticulated aggregated structure with a triple helix. In vitro enzyme inhibition assays revealed that PSP acts as a reversible competitive inhibitor of α-glucosidase and α-amylase. Furthermore, PSP was found to reduce insulin resistance index, increase OGTT and serum insulin levels, decrease free fatty acid content to improve lipid metabolism, and lower glycated serum protein content to enhance glucose metabolism in T2DM mice, thereby leading to a reduction in blood glucose concentration. Additionally, PSP exhibited reparative effects on the damaged liver tissue cells and pancreatic tissue in T2DM mice. The experiment results provide a preliminary basis for the therapeutic mechanism of PSP about type II diabetes and a theoretical reference for application in food and pharmaceutical development.

Protein extraction from chlorella pyrenoidosa microalgae: Green methodologies, functional assessment, and waste stream valorization for bioenergy production

C. pyrenoidosa, a species of microalgae, has been recognized as a viable protein source for human consumption. The primary challenges in this context are the development of an efficient extraction process and the valorization of the resultant waste streams. This study, situated within the paradigm of circular economy, presents an innovative extraction approach that achieved a protein extraction efficiency of 62 %. The extracted protein exhibited remarkable oil-water emulsifying performances, such as uniform morphology with high creaming stability, suggesting a sustainable alternative to conventional emulsifiers. Additionally, hydrothermal liquefaction technique was employed for converting the residual biomass and waste solution from the extraction process into biocrude. A biocrude yield exceeding 40 wt%, characterized by a carbon content of 73 % and a higher heating value of 36 MJ/kg, were obtained. These findings demonstrate the promising potential of microalgae biorefinery, which is significant for paving toward circular economy and zero-waste society.