Improved in vitro bioaccessibility of quercetin by nanocomplexation with high-intensity ultrasound treated soy protein isolate

On the modification of plant proteins: Traditional methods and the Hofmeister effect

With increasing consumer health awareness and demand from some vegans, plant proteins have received a lot of attention. Plant proteins have many advantages over animal proteins. However, the application of plant proteins is limited by a number of factors and there is a need to improve their functional properties to enable a wider range of applications. This paper describes the advantages and disadvantages of traditional methods of modifying plant proteins and the appropriate timing for their use, and collates and describes a method with fewer applications in the food industry: the Hofmeister effect. It is extremely simple but efficient in some respects compared to traditional methods. The paper provides theoretical guidance for the further development of plant protein-based food products and a reference value basis for improving the functional properties of proteins to enhance their applications in the food industry, pharmaceuticals and other fields.

Improvement of physicochemical properties and quercetin delivery ability of fermentation-induced soy protein isolate emulsion gel processed by ultrasound

This study aimed to investigate the effects of ultrasonic treatment at different powers on the physicochemical properties, microstructure and quercetin delivery capacity of fermentation-induced soy protein isolate emulsion gel (FSEG). The FSEG was prepared by subjecting soy protein isolate (SPI) emulsion to ultrasonic treatment at various powers (0, 100, 200, 300, and 400 W), followed by lactic acid bacteria fermentation. Compared with the control group (0 W), the FSEG treated with ultrasound had higher hardness, water holding capacity (WHC) and rheological parameters. Particularly, at an ultrasonic power of 300 W, the FSEG had the highest hardness (101.69 ± 4.67 g) and WHC (75.20 ± 1.07%) (p < 0.05). Analysis of frequency sweep and strain scanning revealed that the storage modulus (G') and yield strains of FSEG increased after 300 W ultrasonic treatment. Additionally, the recovery rate after creep recovery test significantly increased from 18.70 ± 0.49% (0 W) to 58.05 ± 0.54% (300 W) (p < 0.05). Ultrasound treatment also resulted in an increased β-sheet content and the formation of a more compact micro-network structure. This led to a more uniform distribution of oil droplets and reduced mobility of water within the gel. Moreover, ultrasonic treatment significantly enhanced the encapsulation efficiency of quercetin in FSEG from 81.25 ± 0.62 % (0 W) to 90.04 ± 1.54% (300 W). The bioaccessibility of quercetin also increased significantly from 28.90 ± 0.40% (0 W) to 42.58 ± 1.60% (300 W) (p < 0.05). This study enriches the induction method of soy protein emulsion gels and provides some references for the preparation of fermented emulsion gels loaded with active substances.

Preparation, characterization, stability, and controlled release of chitosan-coated zein/shellac nanoparticles for the delivery of quercetin

Quercetin, an essential flavonoid compound, exhibits diverse biological activities including anti-inflammatory and antioxidant effects. Nevertheless, due to its inadequate solubility in water and vulnerability to degradation, pure quercetin is constrainedly utilized in pharmaceutical formulations and functional foods. Considering the existing scarcity of nanoparticles consisted of zein and hydrophobic biopolymers, this study developed a quercetin-loaded nanoencapsulation based on zein, shellac, and chitosan (QZSC). When the mass ratio of zein to chitosan was 4:1, the encapsulation efficiency of QZSC reached 74.95%. The ability of QZSC for scavenging DPPH radicals and ABTS radicals increased from 59.2% to 75.4% and from 47.0% to 70.2%, respectively, compared to Quercetin. For QZSC, the maximum release amount of quercetin reached 59.62% in simulated gastric fluid and 81.64% in simulated intestinal fluid, achieving controlled and regulated release in vitro. In summary, this study offers a highly promising encapsulation strategy for hydrophobic bioactive substances that are prone to instability.

Quercetin Exhibits Preferential Binding Interaction by Selectively Targeting HRAS1 I-Motif DNA-Forming Promoter Sequences

I-Motif (iM) DNA structures represent among the most significant noncanonical nucleic acid configurations. iM-forming DNA sequences are found in an array of vital genomic locations and are particularly frequent in the promoter islands of various oncogenes. Thus, iM DNA is a crucial candidate for anticancer medicines; therefore, binding interactions between iM DNA and small molecular ligands, such as flavonoids, are critically important. Extensive sets of spectroscopic strategies and thermodynamic analysis were utilized in the present investigation to find out the favorable interaction of quercetin (Que), a dietary flavonoid that has various health-promoting characteristics, including anticancer properties, with noncanonical iM DNA structure. Spectroscopic studies and thermal analysis revealed that Que interacts preferentially with HRAS1 iM DNA compared with VEGF, BCL2 iM, and duplex DNA. Que, therefore, emerged as a suitable natural-product-oriented antagonist for targeting HRAS1 iM DNA. The innovative spectroscopic as well as mechanical features of Que and its specific affinity for HRAS1 iM may be useful for therapeutic applications and provide crucial insights for the design of compounds with remarkable medicinal properties.

Formulation and characterization of choline oleate-based micelles for co-delivery of luteolin, naringenin, and quercetin

Flavonoids have diverse beneficial roles that potentiate their application as nutraceutical agents in nutritional supplements and as natural antimicrobial agents in food preservation. To address poor solubility and bioactivity issues, we developed water-soluble micellar formulations loaded with single and multiple flavonoids using the biocompatible surface-active ionic liquid choline oleate. The food preservation performance was investigated using luteolin, naringenin, and quercetin as model bioactive compounds. The micellar formulations formed spherical micelles with particle sizes of <150 nm and exhibited high aqueous solubility (>5.15 mg/mL). Co-delivery of multiple flavonoids (luteolin, naringenin, and quercetin in LNQ-MF) resulted in 84.85% antioxidant activity at 100 μg/mL. The effects on Staphylococcus aureus and Salmonella enterica were synergistic with fractional inhibitory concentration indices of 0.87 and 0.71, respectively. LNQ-MF hindered the growth of S. aureus in milk (0.83-0.89 log scale) compared to the control. Co-delivered encapsulated flavonoids are a promising alternative to chemical preservatives.

Preparation of core-shell hordein/pectin nanoparticles as quercetin delivery matrices: Physicochemical properties and colon-specific release analyses

Quercetin (Que) is a hydrophobic flavanol that has the potential to prevent colon diseases. This study aimed to design hordein/pectin nanoparticle as a colon-specific delivery system for quercetin. The encapsulation efficiency, physicochemical stability and release properties of the nanoparticles were estimated. The FTIR and secondary structure analysis indicated that hydrogen bonds, hydrophobic interactions and electrostatic attractions were formed in the quercetin-loaded hordein/pectin nanoparticles (Que-hordein/pectin NPs). In comparison to Que-hordein NPs, Que-hordein/pectin NPs exhibited better colloidal stability (physical, UV light, heating and salt). Furthermore, the release properties studies showed that pectin coating restrained the premature release of Que from hordein NPs in gastric fluid and intestinal fluid. In-vitro release, when the Que-hordein/pectin NPs were exposed to simulated colonic fluid (SCF) for 6 h, quercetin was greatly released from the hordein/pectin NPs (15.29 ± 1.17% - 80.60 ± 1.78%). In-vivo release, the concentration of Que (μg/g) in Que-hordein/pectin NPs was 2.18 times higher than Que-hordein NPs in colon tissue after 6 h of oral administration. This study suggests that Que-hordein/pectin NPs have promising applications in the specific delivery and release of quercetin to the colon.