Protein/Arabinoxylans Gels: Effect of Mass Ratio on the Rheological, Microstructural and Diffusional Characteristics

Wheat bran arabinoxylan (WBAX) gels entrapping standard model proteins at different mass ratios were formed. The entrapment of protein affected the gel elasticity and viscosity values, which decreased from 177 to 138 Pa. The presence of protein did not modify the covalent cross-links content of the gel. The distribution of protein through the network was investigated by confocal laser scanning microscopy. In mixed gels, protein aggregates forming clusters were detected at protein/polysaccharide ratios higher than 0.25. These clusters were not homogeneously distributed, suggesting that WBAX and protein are located in two different phases. The apparent diffusion coefficient (Dm) of proteins during release from mixed gels was investigated for mass ratios of 0.06 and 0.12. For insulin, Dm increased significantly from 2.64 × 10−7 to 3.20 × 10−7 cm2/s as the mass ratio augmented from 0.06 to 0.12. No significant difference was found for Dm values of ovalbumin and bovine serum albumin released from the mixed gels. The results indicate that homogeneous protein/WBAX gels can be formed at low mass ratios, allowing the estimation of Dm by using an analytical solution of the second Fick’s law

Exploring antioxidant potential and phenolic compound extraction from Vitis vinifera L. using ultrasound-assisted extraction

The research investigates the extraction of antioxidant phenolic compounds from grape pomace, a wine fermentation byproduct. Ultrasound-assisted extraction (UAE), varying parameters such as solute:solvent ratio, power, and time were utilized. UAE was specifically applied to Vitis vinifera L. using high-intensity ultrasound with ratios of 1:18 and 1:42 g:mL, 250 and 400 W power levels, and extraction times of 15 and 20 minutes. Total phenolic content was quantified via the Folin–Ciocalteau reagent, and total flavonoids were determined using quercetin as a standard. Antioxidant capacity was evaluated through ABTS, FRAP, and DPPH Radical Scavenging Assays, with Trolox equivalent antioxidant capacity (TEAC) for comparison. Results indicated a total phenolic content of 50 to 80 μmol GAE/g d.w., with no significant differences among treatments. Total flavonoid concentration ranged from 2.5 to 4 μmol QE/g d.w. Importantly, the solute:solvent ratio impacted antioxidant capacity, with higher ratios showing increased ABTS radical capacity. Treatment 1, with the highest flavonoid content, exhibited the greatest antioxidant capacity against DPPH radicals. This study underscores the intrinsic correlation between cumulative bioactive compound content and the inherent antioxidant capacity of grape pomace extracts. This highlights the potential application of these extracts as antioxidant reservoirs, poised for integration into functional foods and biomedical nutraceuticals

Water Extractable Arabinoxylan Aerogels Prepared by Supercritical CO2 Drying

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