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This study aimed to develop complex coacervates utilizing lactoferrin (LF) and chia seed mucilage (CSM) for promoting intestinal delivery of quercetin (Q) and fortification of set yogurt. Three cross-linkers, including calcium chloride (CC), transglutaminase (TG), and polyphenolic complex (HP), were used to further reinforce the coacervate network. Cross-linked coacervates had higher values of coacervate yield, encapsulation efficiency, and loading capacity. They efficiently preserved Q under gastric condition (⁓87%–99%), with CSM-TG-Q-LF being most effective for intestinal delivery of Q. Moreover, digested pellets of the cross-linked coacervates displayed better antioxidant activity than the uncross-linked coacervates with CSM-TG-Q-LF pellets showing maximum bioactivity. The Q-loaded coacervates demonstrated superior assembly in the yogurt matrix compared to the unencapsulated Q. Moreover, the coacervate systems, especially CSM-TG-Q-LF significantly improved the textural properties of yogurt and the stability of Q in it. Therefore, CSM-TG-LF is a promising carrier to promote intestinal delivery and food application of hydrophobic molecules. [Display omitted] • Complex coacervates were formed using lactoferrin (LF) and chia seed mucilage (CSM) • Crosslinkers improved the coacervation process and encapsulation efficiency • Coacervation enhanced the solubility & gastrointestinal stability of quercetin (Q) • CSM-TG-Q-LF was superior in intestinal delivery of Q with enhanced bioactivity • Complex coacervates, especially CSM-TG-Q-LF, improved the texture of set yogurt [ABSTRACT FROM AUTHOR]

To further enhance the stability of rice bran oil body (RBOB) emulsions, this study examined the impact of various concentrations of quercetin (QU) on the microstructure, rheological properties, oxidative stability, and digestive properties of RBOB emulsions. The results indicated that by incorporating QU concentration, the particle size of RBOB emulsions could be significantly reduced to 300 nm; QU could improve the surface hydrophobicity, the emulsifying activity index and emulsification stability index of RBOB emulsions of 550, 0.078 m2/g and 50.78 min, respectively; the storage stability of RBOB emulsions was further improved; the higher concentration of QU could delay the oxidation of RBOB emulsions, among which, the 500 μmol/L concentration inhibited the strongest effect of oil oxidation. It also improved the thermal stability of RBOB emulsions. After gastrointestinal digestion, the free fatty acids release rate of RBOB emulsions with QU addition decreased to 14.68%, and RBOB emulsions were slowly hydrolyzed. Therefore, adding QU to RBOB helps to improve its stability and delay digestion. [Display omitted] • Quercetin reduced the emulsion particle size of rice bran oil body (RBOB). • The stability of RBOB emulsion was better at 500 μmol/L quercetin. • Changes in surface charge and tension affect the stabilization of RBOB emulsions. • The rate of oil oxidation in RBOB emulsions was retarded. [ABSTRACT FROM AUTHOR]

This research develops diacylglycerol (DAG) based Pickering emulsions with enhanced oxidative stability stabilized by self-assembled quercetin/DAG/β-cyclodextrin (β-CD) complexes (QDCCs) using a one-step agitation method. Influence of DAG content (5%, 15%, 40%, and 80%, w /w) on the self-assembly behavior, interfacial properties, and emulsifying ability of complex particles was investigated. SEM, XRD and ATR-FTIR studies confirmed the formation of ternary composite particles. QDCCs in 80% DAG oil had the highest quercetin encapsulation efficiency (6.09 ± 0.01%), highest DPPH radical scavenging rate and ferric reducing antioxidant property (FRAP). β-CD and quercetin adsorption rates in emulsion with 80% DAG oil were 88.4 ± 2.53% and 98.34 ± 0.15%, respectively. Pickering emulsions with 80% DAG had the smallest droplet size (8.90 ± 1.87 μm) and excellent oxidation stability. This research develops a novel approach to regulate the physicochemical stability of DAG-based emulsions by anchoring natural antioxidants at the oil-water interface through a one-pot self-assembly method. [Display omitted] • Pickering emulsion were formed by self-assembled quercetin/DAG/β-CD complexes. • Impact of DAG content in the oil phase on emulsion stability was revealed. • Formation of complexes was predominantly driven by intermolecular hydrogen bonds. • Anchoring antioxidants at the interface enhanced lipid oxidative stability of emulsions. [ABSTRACT FROM AUTHOR]

To verfy their difference from isolated fatty acids, the absolute kinetics of peroxidation was studied for seven triglyceride-based oils of olive (OLI-1, OLI-2), high-oleic sunflower (SUN-HO), high-oleic and high-linoleic safflower (SAF-HO, SAF-HL) grapeseed (GRA) and borage (BOR), by oxygen uptake monitoring, using 2,6-di- tert -butyl-4-methoxyphenol and 2,2,5,7,8-pentamethyl-6-chromanol as reference inhibitors. Propagation constants (k p /M−1 s−1 at 303 K in PhCl) were respectively 34.8 ± 2.3, 35.1 ± 1.8, 40.6 ± 5.5, 36.0 ± 7.7, 160.8 ± 5.1, 145.1 ± 24.5, 275.1 ± 63.8, while oxidizability responded to empirical equation k p (2 k t)-½/M-½s-½ = 1.63 × 10−3[allyl >CH 2 /M] + 1.82 × 10−2[bisallyl >CH 2 /M], based on fatty acids residues assessed by GC–MS. Peroxidation kinetics was markedly different from that of isolated fatty acids. The H-bond basicity of all oils was measured by FT-IR affording Abraham's βH 2 values in the range 0.55 ± 0.03. H-bonding explained the protection of oils measured for seven reference phenolic antioxidants, except for the catechols quercetin and caffeic acid phenethyl ester, which were 2-to-4-folds more effective than expected, supporting a proposed different mechanism. • k p and 2 k t constants for triglycerides differ from those of their main fatty acids. • MUFA-rich triglycerides oxidize 40-folds faster than their isolated MUFAs. • A linear empirical equation predicted oxidizability from FAME analysis (r 2 = 0.992). • Protection and k i nh for antioxidants were explained by H-bonding to triglycerides. • Catechols quercetin and CAPE gave exceptional protection via different mechanisms. [ABSTRACT FROM AUTHOR]

In this study, a combination of whey protein (hydrophilic coating) and polydopamine (crosslinking agent) was used to improve the stability and functionality of quercetin-loaded zein nanoparticles. There are two key benefits of the core-shell nanoparticles formed. First, the ability of the polydopamine to bind to both zein and whey protein facilitates the formation of a stable core-shell structure, thereby protecting quercetin from any pro-oxidants in the aqueous surroundings. Second, neutral and hydrophilic whey proteins were used for the surface coating of the nanoparticles to further enhance the sustained and slow release of quercetin, facilitating its sustained release into the body at a slow and steady rate. The results of this study will promote the innovative development of precise nutritional delivery systems for zein and provide a theoretical basis for the design and development of dietary supplements based on hydrophobic food nutrient molecules. [Display omitted] • Mussel-inspired polydopamine-mediated zein/whey protein nanoparticle was designed. • Polydopamine-induced zein-based NPs protected QUE against environment stress. • The zein-based NPs improved antioxidant and antimicrobial activity of QUE. • The study offers new insights into the design of novel polyphenols delivery system. [ABSTRACT FROM AUTHOR]

The effects of ethanol on the physicochemical, structural and in vitro digestive properties of Tartary buckwheat starch-quercetin/rutin complexes (e-TBSQ and e-TBSR) were investigated. Ethanol restricted the gelatinization of Tartary buckwheat starch (TBS), which resulted an increase in ∆H, G' and G" as well as a decrease in apparent viscosity of e-TBSQ and e-TBSR. The particle size, scanning electron microscopy and X-ray diffraction results showed that ethanol influenced the morphological structure of TBS granules and the starch crystalline structure in e-TBSQ and e-TBSR changed from B-type to V-type when the ethanol concentration was 25%. Saturation transfer difference-nuclear magnetic resonance results revealed that ethanol weakened the binding ability of quercetin/rutin to TBS in e-TBSQ and e-TBSR, leading to a change in the binding site on the quercetin structural unit. The residual ungelatinized TBS granules in e-TBSQ and e-TBSR induced a high slowly digestible starch content, and thus displayed a "resistant-to-digestion". [Display omitted] • Ethanol addition caused starch granules agglomeration with limiting gelatinization. • Ethanol at 25% altered starch granule morphology and induced V-type crystal formation. • Ungelatinized starch granules provided a rigid frame and higher G' for complex gels. • Ethanol induced the binding site changes of the quercetin unit in the complexes. • Ungelatinized starch granules conferred resistant-to-digestion to the complexes. [ABSTRACT FROM AUTHOR]

In this study, the electrospinning technique was used to co-encapsulate Quercetin (Qu) and Lactiplantibacillus plantarum 1–24-LJ in PVA-based nanofibers, and the effect of bioactive films on fish preservation was evaluated at the first time. The findings indicated that both Lpb. plantarum 1–24-LJ and Qu were successfully in the fibers, and co-loaded fibers considerably outperformed single-loaded fiber in terms of bacterial survival and antioxidant activity. Following fish preservation using the loaded fibers, significant reductions were observed in TVB-N, TBARS, and microbial complexity compared to the control group. Additionally, the co-loaded fibers more effectively reduced the counts of H 2 S-producing bacteria and Pseudomonas. In the future, fibers with both active substances and LAB hold promise as a novel approach for fish preservation. [Display omitted] • Co-loading of flavonoids quercetin (Qu) and Lpb. plantarum by electrospinning technology. • Qu and Lpb. plantarum synergize provide strong antioxidant and hyper-bacterial activity. • Qu or/and Lpb. plantarum films inhibit the growth of spoilage bacteria. • Active films improved fish's physiology, raised sensory appeal and extended storage time. [ABSTRACT FROM AUTHOR]

This study synthesized composite samples incorporating four representative polyphenolic structures, gallic acid (GA), quercetin (QC), resveratrol (RES), and magnolol (MN), with rice starch using various preparation processes, including the addition of polyphenols and alteration of temperature and pH, via co-gelatinization. Subsequently, the complexation rates, starch digestion properties, and polyphenol release during in vitro digestion were examined. The results indicated that both the preparation process and structural variations of polyphenols affected starch digestion and polyphenol release by modulating the complexation. All polyphenols displayed inhibitory effects on rice starch digestion, with GA being the most efficient polyphenol. Additionally, rice starch exhibited a protective effect against RES during in vitro digestion, as rice starch-coated RES reduced the damage from stomach acids. Overall, these findings may help optimize the processing conditions for the synthesis of polyphenol-rice starch-based food products. [Display omitted] • All four polyphenols complexed with rice starch via non-covalent bonding. • Polyphenols affect digestibility of complex by affecting combination. • The combination rate was positively correlated with the preparation temperature. • Inhibition of polyphenol on rice starch digestion was related to complexation rate. • Rice starch demonstrated notable resistance to RES during in vitro digestion. [ABSTRACT FROM AUTHOR]

Advanced targeted nanoparticles (NPs) were designed to enhance the targeted delivery of resveratrol (RES) and quercetin (QUE) by utilizing carboxymethyl chitosan (CTS) and Jiuzao glutelin isolate (JGI) conjugates. Briefly, RES and QUE were encapsuled within CTS-JGI-2 (CTS/JGI, m/m, 2:1). The carrier's targeting properties were further improved through the incorporation of folic acid (FA) and polyethylenimine (PEI). Moreover, the stability against digestion was enhanced by incorporating baker yeast cell walls (BYCWs) to construct RES-QUE/FA-PEI/CTS-JGI-2/MAT/BYCW NPs. The results demonstrated that FA-PEI/CTS-JGI-2/MAT/BYCW NPs could improve cellular uptake and targeting property of RES and QUE through endocytosis of folic acid receptors (FOLRs). Additionally, RES-QUE successfully alleviated LPS- and DSS-induced inflammation by regulating NF-κB/IkBa/AP-1 and AMPK/SIRT1signaling pathways and reducing the secretion of inflammatory mediators and factors. These findings indicate FA-PEI/CTS-JGI-2/MAT/BYCW NPs hold promise as an oral drug delivery system with targeted delivery capacities for functional substances prone to instability in dietary supplements. [Display omitted] • Nanoparticles were constructed using JGI and CTS Maillard reaction conjugate. • The targeting of RES and QUE was achieved through the incorporation of FA and PEI. • The stability of RES and QUE against digestion was enhanced by BYCW. • Encapsulation of RES and QUE in the FA-PEI/CTS-JGI-2/MAT/BYCW resulted in higher anti-inflammatory activities. [ABSTRACT FROM AUTHOR]

Cyclodextrin-based metal-organic framework (CD-MOF) has been widely used in various delivery systems due to its excellent edibility and high drug loading capacity. However, its typically bulky size and high brittleness in aqueous solutions pose significant challenges for practical applications. Here, we proposed an ultrasonic-assisted method for rapid synthesis of uniformly-sized nanoscale CD-MOF, followed by its hydrophobic modification through ester bond cross-linking (Nano-CMOF). Proper ultrasound treatment effectively reduced particle size to nanoscale (393.14 nm). Notably, carbonate ester cross-linking method significantly improved water stability without altering its cubic shape and high porosity (1.3 cm3/g), resulting in a retention rate exceeding 90% in various media. Furthermore, the loading of quercetin did not disrupt cubic structure and showcased remarkable storage stability. Nano-CMOF achieved controlled release of quercetin in both aqueous environments and digestion. Additionally, Nano-CMOF demonstrated exceptional antioxidant (free radical scavenging 82.27%) and biocompatibility, indicating its significant potential as novel nutritional delivery systems in food and biomedical fields. [Display omitted] • Ultrasound-assisted hydrothermal method was developed for fabricating nanoscale CD-MOF. • CD-MOF cross-linked by ester bonds (Nano-CMOF) had a cubic structure and higher water stability. • Nano-CMOF as a carrier for quercetin enhanced its stability and antioxidant activity. • Nano-CMOF achieved controlled release of quercetin and had great biocompatibility. [ABSTRACT FROM AUTHOR]

• FAs and NaCas could form hydrophilic complexes through host–guest recognition. • FAs-NaCas complexes exhibited outstanding encapsulation efficiency for QUE. • FA ligands did not affect the binding mode between QUE and NaCas. • FA ligands enhanced the binding affinity of NaCas to QUE. • FA ligands improved the processing adaptability and absorbability of QUE. Quercetin (QUE) sufferred from poor processing adaptability and absorbability, hindering its application as a dietary supplement in the food industry. In this study, fatty acids (FAs)-sodium caseinate (NaCas) ligand complexes carriers were fabricated to improve the aqueous dispersibility, storage/thermal stability, and bioaccessibility of QUE using an ultrasound method. The results indicated that all six selected common dietary FAs formed stable hydrophilic complexes with NaCas and the FAs-NaCas complexes achieved an encapsulation efficiency greater than 90 % for QUE. Furthermore, the introduction of FAs enhanced the binding affinity between NaCas and QUE, but did not change the binding mode (static bursting) and types of intermolecular forces (mainly hydrogen bonding). In addition, a distinct improvement was discovered in the storage stability (>2.37-fold), thermal processing stability (>32.54 %), and bioaccessibility (>2.37-fold) of QUE. Therefore, the FAs-NaCas ligand complexes could effectively protect QUE to minimize degradation as fat-soluble polyphenol delivery vehicles. [ABSTRACT FROM AUTHOR]

A simple fluorescent quenching probe based on polyethylene glycol-400 capped sulfur quantum dots (PEG-SQDs) was fabricated to determine quercetin (QT) quantitatively. As anticipated, the PEG-SQDs exhibited favourable luminescent properties, stability and low cytotoxicity. QT effectively quenched the fluorescence of the PEG-SQDs through static quenching and the inner filter effect. Moreover, the PEG-SQDs showed rapid QT detection within a linear range of 0.100-45.0 μM, with a limit of detection of 0.014 μM (3σ/k). This fluorescent probe successfully detected QT in human serum, quercetin supplement capsules and red wine, achieving a standard recovery of 92.6 %-105 %., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

To solve the challenges posed by increasing meat consumption, it is imperative to develop polysaccharide composite edible scaffolds for cell-cultured meat production using novel food production technologies. This study developed some non-animal-origin polysaccharide composite scaffolds for cell-cultured meat production, based on chitin‑sodium alginate and crosslinked with quercetin. The results indicated that the chitin‑sodium alginate-quercetin (CH-SA-QR) scaffolds exhibited a porous and loose structure, and excellent mechanical support capability and cell adhesion sites. Meanwhile, QR1 and QR1.5 scaffolds were screened by immunofluorescence staining, RT-qPCR, and SEM imaging results to facilitate the proliferation and differentiation of cells and enhance the generation of myotube fusion and extracellular matrix protein. Importantly, the texture of the fried cultured meat was similar to traditional beef or even more tender, while the color appearance of the cultured meat was different from beef, but more similar to fried meat cutlets. These results suggest that cultured meat produced based on CH-SA-QR scaffolds could provide consumers with more choices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The study was the first to evaluate the synergistic interaction of luteolin + quercetin, luteolin + 3-O-methylquercetin, and quercetin + 3-O-methylquercetin mixtures on α-glucosidase and the binding mechanisms were explored using both experimental and theoretical approaches. The results showed that three flavonoid mixtures exhibited a mixed type of inhibition and demonstrated the most potent synergistic effects on α-glucosidase inhibition at 6:4 ratio, with interaction index (γ) of 0.85, 0.78 and 0.73, respectively. The three mixtures had a great influence on α-glucosidase secondary structures. Molecular simulation further demonstrated that three flavonoid mixtures formed hydrophobic interactions and hydrogen bonds with amino acid residues at different sites of α-glucosidase. Collectively, luteolin + quercetin, luteolin + 3-O-methylquercetin and quercetin + 3-O-methylquercetin were found to inhibit α-glucosidase in a synergistic manner and can be potentially used for the development of hypoglycemic food products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study investigates the potential of a quercetin-based emulsion system to moderate starch digestion and manage blood glucose levels, addressing the lack of in vivo research. By enhancing quercetin bioaccessibility and targeting release in the small intestine, the emulsion system demonstrates significant inhibition of starch digestion and glucose spikes through both in vitro and in vivo experiments. The system inhibits α-amylase and α-glucosidase via competitive and mixed inhibition mechanisms, primarily involving hydrogen bonds and van der Waals forces, leading to static fluorescence quenching. Additionally, this system downregulates the protein expression and gene transcription of SGLT1 and GLUT2. These findings offer a novel approach to sustaining glucose equilibrium, providing a valuable foundation for further application of quercetin emulsion in food science. [Display omitted] • Emulsion-loaded quercetin retarded starch digestion better than unloaded quercetin. • Quercetin emulsion reversibly and competitively inhibit α-amylase activity. • Quercetin emulsion has a reversible and mixed inhibitory effect on α-glucosidase. • Quercetin emulsion interacts with amylase mainly through hydrogen bonding. • Quercetin emulsion inhibits glucose transport by SGLT1 and GLUT2. [ABSTRACT FROM AUTHOR]

This study aimed to prepare soy protein isolate-xanthan gum complexes (SPI-XG) at pH 7.0 and as emulsifiers to prepare Pickering emulsions for delivering quercetin (Que). The results showed that SPI-XG exhibited a gel network structure in which protein particles were embedded. Fourier transform infrared spectroscopy (FTIR) and molecular docking elucidated that SPI-XG formed through hydrogen bonding, hydrophobic, and electrostatic interactions. Three-phase contact angle (θo/w) of SPI-XG approached 90° with biphasic wettability. SPI-XG adsorbed at the oil-water interface to form an interfacial layer with a gel network structure, which prevented droplet aggregation. Following in vitro simulated digestion, Que displayed higher bioaccessibility in SPI-XG stabilized Pickering emulsions (SPI-XG PEs) than SPI stabilized Pickering emulsions. In conclusion, SPI-XG PEs were a promising system for Que delivery. [Display omitted] • SPI-XG was used to stabilize Pickering emulsions for quercetin delivery. • SPI-XG was formed by hydrogen bonding, hydrophobic, and electrostatic interactions. • Gel network structure maintained SPI-XG Pickering emulsions stability. • SPI-XG Pickering emulsions showed higher quercetin bioaccessibility. [ABSTRACT FROM AUTHOR]

This study explored the mechanism of interaction of pH-shifting combined ultrasonication and its effect on soybean lipophilic proteins (SLP) and the potential of modified SLP as the carrier for vitamin E (VE) and quercetin (QU). The spectroscopy results revealed that both VE and QU changed the SLP conformation and exposed hydrophobic groups. The loading rates of VE and QU by SLP with alkaline pH-shifting combined with ultrasonication (300 w,20 min) were 86.91% and 75.99%, respectively. According to the antioxidant analysis, with an increase in the ultrasonication power, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging capacity of the samples increased, where the DPPH and ABTS radical scavenging capacity of sample SQV-6 were 70.90% and 63.43%, respectively. The physicochemical properties, microstructure, and stability of the SLP–VE–QU complex improved significantly. Overall, the present findings broadened the application of simple structural carriers for co-encapsulating functional factors. [Display omitted] • SLP was modified by pH-shifting combined with ultrasonication. • Using modified SLP to co-encapsulate of active substances with different solubility. • The modified treatment increased the solubility of SLP. • The reaction mechanism of the complex has been clarified. [ABSTRACT FROM AUTHOR]

Quercetin is a flavonoid that occurs in many types of fruit and vegetables and is stable for no longer than 4.5 h in the investigated pH range (6.0–8.0), even at 4 °C in the dark. At higher temperatures, the degradation/oxidation process is much faster. Simple but effective proliposomal encapsulation was used to protect the quercetin from environmental conditions such as pH. With this approach, 65 to 90% of pure quercetin and quercetin-rich onion extract was kept after >60 days under conditions that favoured its oxidation (pH 7.4). In addition, the encapsulated quercetin decreases the lipid peroxidation induced by pulsed UV light by >50%. At a mass ratio of 1:100 quercetin to lipids (w /w), the liposomes remained intact in solutions for six months. Quercetin in lipid bilayers simultaneously protects the unsaturated lipids from peroxidation. [Display omitted] • Quercetin auto-oxidizes at all studied temperatures at pH 7.4. • Seven degradants of quercetin were identified by UPLC-MS/MS. • Liposomal encapsulation protects quercetin up to 90% at pH 7.4 for 60 days. • At ratio 1:100 quercetin/lipids, liposome structure is intact for 6 months. • At ratio 1:20 quercetin/lipids, liposomal features are less favourable. [ABSTRACT FROM AUTHOR]

Quercetin and its glycosides (QG), vitally natural flavonoid, have been popular for health benefits. However, the absorption and metabolism affect their bioavailability, and the metabolic transformation alters their biological activities. This review systematically summarizes the bioavailability and pathways for the absorption and metabolism of quercetin/QG in vivo and in vitro, the biological activities and mechanism of quercetin/QG and their metabolites in treating glucolipid metabolism are discussed. After oral administration, quercetin/QG are mainly absorbed by the intestine, undergo phase II metabolism in the small intestine and liver to form conjugates and are metabolized into small phenolic acids by intestinal microbiota. Quercetin/QG and their metabolites exert beneficial effects on regulating glucolipid metabolism disorders, including improving insulin resistance, inhibiting lipogenesis, enhancing thermogenesis, modulating intestinal microbiota, relieving oxidative stress, and attenuating inflammation. This review enhances understanding of the mechanism of quercetin/QG regulate glucolipid metabolism and provides scientific support for the development of functional foods. Systematically summarized the bioavailability, absorption and metabolism of quercetin and its glycosides, and their effects and mechanism of regulating glucolipid metabolism disorders. [Display omitted] • Factors affected the bioavailability of quercetin and its important glycosides (QG) were reported. • Elucidated the absorption, metabolism, and excretion pathway of quercetin/QG. • Quercetin/QG and their metabolites played a crucial role in attenuating glucose and lipid metabolism disorders. [ABSTRACT FROM AUTHOR]

Kombucha was fermented by the pure cultured tea fungus, and the changes of functional compounds and their transformation were explored. After fermentation, the contents of total polyphenols, total flavonoids, quercetin, kaempferol and catechins respectively enhanced by 77.14%, 69.23%, 89.11%, 70.32% and 45.77% compared with the control, while flavonol glycosides reduced by 38.98%. The bioavailability of polyphenols and flavonoids respectively increased by 29.52% and 740.6%, and DPPH and ABTS respectively increased by 43.81% and 35.08% compared with the control. Correlation analysis showed that microorganisms and the antioxidant activity were highly positive correlation with total polyphenols, total flavonoids, EGC, EC, EGCG, ECG, quercetin and kaempferol, and negative correlation with kaempferol-3-glucoside. The constructed models confirmed that organic acids were more likely to damage the structure of tea leaves, and enzymes (polygalacturonidase and tannase) and solvents (acids, alcohols and esters) had a synergistic effect on the biotransformation of functional compounds. Graphical abstract [Display omitted] • Improving the contents of main functional compounds in kombucha by the tea fungus • Increasing the bioavailability of total polyphenols and total flavonoids in kombucha • Revealing the relationship of the compounds with antioxidant activity and tea fungus • Exploring the biotransformation mechanism of polyphenols and flavonoids [ABSTRACT FROM AUTHOR]

Dual-compartmental emulsions, containing multiple chambers, possess great advantages in co-encapsulation of different cargoes. Herein, we reported a stable dual-compartmental emulsion by regulating the ratio of Marsupenaeus japonicus ferritin (MF) and chitooligosaccharide (COS), enabling efficient co-encapsulation of different compounds. The adsorption behavior of MF/COS complex over droplet interface varied at different ratios, thereby exerting an influence on the emulsion properties. Remarkably, emulsions stabilized by MF/COS complex at a ratio of 2:1 exhibited superior stability, as evidenced by no significant creaming or demulsification during storage or heat treatment. The mechanism is that MF/COS 2:1 complex can enhance the formation of thicker interfacial layer and dense continuous phase network structure. Additionally, curcumin and quercetin can be co-encapsulated into the emulsions and their retention rates were significantly improved than those in oils, implying the potential of the resulting dual-compartmental emulsions in co-encapsulation and delivery of bioactive compounds. [Display omitted] • Stable dual-compartmental emulsion is obtained by regulating MF/COS ratio. • MF/COS 2:1 emulsion exhibits superior storage and thermal stability. • The stabilization mechanism of MF/COS emulsion is illustrated. • The dual-compartmental emulsion can be used for encapsulating curcumin and quercetin. • The dual-compartmental emulsion shows protective effect on the loaded bioactive molecules. [ABSTRACT FROM AUTHOR]

Quercetin (QCT) is a flavonoid with significant health benefits, necessitating sensitive detection methods for food safety and quality control. This study presents a novel UiO-66-TCPP ratiometric fluorescent probe for the quantitative and visual detection of QCT. Under optimal conditions, the fluorescence intensity of UiO-66-TCPP decreased linearly with increasing QCT concentration, with a detection limit of 26 nM. The probe demonstrated high specificity, showing no significant interference from various substances and QCT analogues. Practical applicability was confirmed by testing artificially contaminated juice samples, achieving recovery rates between 98.0% and 104.8%. Furthermore, a paper-based sensor was developed by incorporating UiO-66-TCPP onto Whatman#1 chromatography paper. This sensor exhibited stable fluorescence and a reliable, sensitive visual response to QCT concentrations, detectable via a smartphone-based color recognizer application. The UiO-66-TCPP ratiometric fluorescent probe provides a sensitive, specific, and practical method for detecting QCT in food matrices, offering significant potential for both laboratory and on-site applications. • A ratiometric fluorescent probe, namely UiO-66-TCPP, was synthesized for the detection of quercetin. • A paper-based sensor utilizing UiO-66-TCPP was fabricated for convenient on-site detection. • The ratiometric fluorescent probe exhibited remarkable sensitivity, with a detection limit as low as 26 nM. [ABSTRACT FROM AUTHOR]

[Display omitted] • Quercetin-loaded zein/shellac nanoparticles with chitosan coatings (QZSC) were prepared. • QZSC with a ratio of 4:1 of zein and chitosan demonstrated superior physical properties. • The nanoparticles exhibit excellent environmental stability. • The chitosan-coated zein/shellac matrix enhanced the antioxidant capability of quercetin. • The QZSC are capable of controlled release in the simulated gastrointestinal solutions. 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. [ABSTRACT FROM AUTHOR]

• Coordination chemistry of three structurally analogous flavonols was studied. • A novel synthesis method for flavonol–Cu(II) coordination compounds is introduced. • Consistent binding patterns of Cu ions with flavonols mainly at 4,5 sites observed. • Binding affinity of the flavonols for Cu ions is: myricetin > quercetin > kaempferol. This study explores the coordination dynamics between dietary polyphenols, specifically kaempferol, quercetin, and myricetin, and Cu ions in aqueous environments. A novel synthesis method for flavonol–Cu(II) coordination compounds is introduced, effectively reducing interference from free metal ions. Our results reveal consistent binding patterns of Cu ions with flavonols (2:1 ratio of flavonol to Cu(II)), predominantly at the 4,5 sites. Various analytical techniques are used to validate these coordination ratios and sites. The binding affinity of the flavonols for Cu ions follows a descending sequence: myricetin > quercetin > kaempferol. Notably, coordination with Cu ions enhances the free-radical scavenging activities of these flavonols. These findings hold substantial importance for food chemistry, biology, and medicine, providing crucial insights into the way dietary flavonols form stable structures in environments similar to human body fluids and their interactions with metal ions, opening new possibilities for their application and understanding in diverse scientific domains. [ABSTRACT FROM AUTHOR]

[Display omitted] • The quercetin was detected using the electrochemical sensing method. • The PrV@g-CN composite was prepared by the hydrothermal method. • The synergetic effect between the PrVO 4 and g-CN enhanced the detection of Qc. • The PrV@g-CN shows a linear range of 0.05–252.0 µM and LOD 0.002 µM of towards Qc. • The proposed sensor was applied for Qc detection in green and black tea samples. Flavonoids or phenolic compounds are part of the daily intake of every human being. Though they are positive traders for metabolism, excessive intakes bring about detrimental impacts on human health. Herein, the anti-cancer capacitive nature quercetin (Qc) was electrochemically detected through the rare earth metal-based sphere like praseodymium vanadate (PrVO 4) entrapped graphitic carbon nitride (g-CN) as electrode modifiers. The nanocomposite was prepared by the one-pot hydrothermal method and characterized by phase compositional and morphology-based techniques. The existing synergistic nature between the PrV@g-CN (praseodymium vanadate@graphitic carbon nitride) makes them have an enhanced electrochemical response towards the Qc than the individual material. The obtained cyclic voltammogram and differential pulse voltammogram profile show one major oxidation peak which is attributed to the conversion of quercetin to quercetin-o-quinone. The PrV@g-CN/GCE (GCE- glassy carbon electrode) shows a good electrochemical active surface area (A = 110 cm2) and linear range between 0.05 and 252.00 μM with a LOD (limit of detection) of 0.002 µM. Moreover, the PrV@g-CN/GCE exhibits good current retention (94.76 %) around 14 days and appreciable repeatability (RSD- 0.5 %) and reproducibility (RSD- 1.3 %) towards the Qc. The real-time implementation of the proposed sensor exhibits a good recovery range towards the black tea (95.00–98.10 %) and green tea (97.80–99.60 %). [ABSTRACT FROM AUTHOR]

• The formation of HAs and AGEs in roasted eel was determined. • The intervention mechanism of quercetin and l -ascorbic acid on HAs/AGEs was studied. • The effect of key lipids on HAs and AGEs generation was analyzed. Eel is a commercially important marine fish, frequently featured as sushi or roasted preparations. This study determined the formation of heterocyclic amines (HAs) and advanced glycation end products (AGEs) in roasted eel and evaluated the inhibitory mechanism of quercetin and l -ascorbic acid on their formation. The results indicate a respective reduction of 75.07% and 84.72% in total HAs, alongside a decline of 23.03% and 39.14% in AGEs. Additionally, fundamental parameters of roasted eel, lipid oxidation indicators and precursors were measured to elucidate the mechanisms and impact of natural antioxidants on HAs and AGEs formation in roasted eel. Furthermore, endeavors were made to probe into the molecular mechanisms governing the influence of key differential lipids on the generation of HAs and AGEs through lipid-mics analysis. This research emphasizes the potential of natural antioxidants in preventing harmful substances formation during eel thermal processing, which is helpful to food manufacturers for healthier food production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Quercetin conjugation changed the structure and antigenic epitopes of Bra c p. • Quercetin conjugation with Bra c p alleviated allergic reactions in mice. • Quercetin conjugation with Bra c p regulated mice purine metabolism. • Quercetin conjugation with Bra c p modulated the calcium signaling pathway. • Quercetin conjugation with Bra c p regulated the proportion of Tregs to normal. Profilin family members are highly conserved food allergens that can cause widespread cross-allergic reactions. Our previous research has demonstrated that the covalent conjunction with quercetin can disrupt the conformational epitopes of a profilin allergen, Bra c p. In this study, we further investigated the intrinsic molecular mechanisms using molecular dynamics simulations. Moreover, the allergenic potential of Bra c p and its conjugate with quercetin was assessed in BALB/c mice. The results showed that continuous interaction with quercetin increased the molecular motion of Bra c p, causing changes to its α-helices and exposing hydrophobic residues which altered antigenic epitopes. Additionally, mice treated with Bra c p-quercetin conjugate showed reduced allergic reactions compared to those treated with Bra c p alone by regulating purine metabolism, calcium signaling, and CD4+CD25+ Tregs proportion. Quercetin conjugation decreases the allergenicity of Bra c p, providing a scientific foundation for reducing the profilin allergens in food. [ABSTRACT FROM AUTHOR]

[Display omitted] • Winemaking byproduct treated with endo -1,4-β- d -glucanases released polyphenols and COS. • COS- and polyphenol-rich solution supports growth of beneficial Bifidobacterium and Lactobacillus. • Marc hydrolysate shows superior in vitro faecal fermentability over glucose and inulin. • Winemaking byproduct is valorised into functional components by enzyme processing. Grape marc, the main winemaking byproduct, is an excellent source of bioactive polyphenols, such as anthocyanins, resveratrol and quercetin. An enzyme-catalysed treatment of marc was developed using endo -1,4-β- d -glucanase to release polyphenol O- glucosides and simultaneously generate the optimal concentration of water-soluble cello-oligosaccharides (COS), including cellopentaose, cellotriose, and cellobiose from the marc matrix. The prebiotic properties of marc hydrolysate rich in COS was assessed using human probiotic monocultures of Lactobacillus spp. and Bifidobacterium spp. strains, and in vitro human faecal fermentation. The COS-rich hydrolysate showed excellent prebiotic effect in both studies, successfully supporting the growth of beneficial probiotic strains, and was highly fermentable by faecal microbiota producing gas and short chain fatty acids. Acetate and propionate production were the highest when faecal bacteria fermented COS-rich solution compared with standard substrates. For the first time, COS was shown to be fermented by faecal microbiota, demonstrating the potential benefits of valorised grape marc. [ABSTRACT FROM AUTHOR]

• Oxidation of flavonols substantially amplifies their antioxidant properties. • Amplification arises from converting the pyrane ring into a hydroxyl-furanone ring. • 2-benzoyl-2-hydroxy-3(2H)-benzofuranones emerge as a novel type of antioxidants. Quercetin oxidation leads to the formation of a metabolite, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone, whose antioxidant potency was recently reported to be a 1000-fold higher than that of its precursor. The formation of similar metabolites (BZF) is limited to certain flavonols (FL), among which are myricetin, fisetin, and morin. Here we addressed the consequences of inducing the auto-oxidation of these flavonols in terms of their antioxidant properties (assessed in ROS-exposed Caco-2 cells). The mixtures that result from their oxidation (FLox) exhibited antioxidant activities 10-to-50-fold higher than those of their precursors. Such amplification was fully attributable to the presence of BZF in each FLox (established by HPLC-ESI-MS/MS and chemical subtraction techniques). An identical amplification was also found when the antioxidant activities of BZF, isolated from each FLox, and FL were compared. These findings warrant the search of these BZF in edible plants and their subsequent evaluation as a new type of functional food ingredients. [ABSTRACT FROM AUTHOR]

• Degraded konjac glucomannan (KGM60) delayed loaded quercetin release from microgel. • KGM60 enhanced phenolic metabolites production from quercetin-loaded microgel. • Combined effect of KGM60 and quercetin reduced BCFA but increased SCFA levels. • Quercetin-loaded KGM60-containing microgel modulated gut microbiota profiles. Alginate microgels co-encapsulating degraded Konjac glucomannan (KGM60) underwent in vitro fecal fermentation and their effects on human microbiota and metabolites were investigated. KGM60 delayed quercetin release and enhanced phenolic metabolites production. Microgels co-encapsulating KGM60 and quercetin increased linear short chain fatty acid but decreased branched chain fatty acid production. Microgels encapsulated with quercetin with or without KGM60 decreased Firmicutes while increased Bacteroidetes over 24 h of fermentation, at genus level promoted Bacteroides growth at 24 h and decreased the abundance of Negativibacillus, Ruminococcus _NK4A214, and Christensenellaceae R_7. Faecalibacterium and Collinsella levels were exclusively promoted by microgels encapsulating KGM60 with or without quercetin, highlighting prebiotic effect of KGM60. Only microgels co-encapsulating both KGM60 and quercetin enhanced Dialister while inhibited Lachnoclostridium , indicating synergism between KGM60 and quercetin. Our study indicates that co-encapsulating KGM60 and quercetin in alginate microgel is effective in modulating human gut microbiota and metabolites production potentially beneficial to gut health. [ABSTRACT FROM AUTHOR]

• Inulin crystallite dispersion in different ratios was used as encapsulating agent. • Quercetin-inulin microparticles with three crystallinity indexes were formulated. • Crystallinity slightly modified the quercetin released during in vitro digestion. • The crystallinity of the microparticles did not influence the Q bioaccessibility. • The encapsulated quercetin was released in the colonic phase to exert its effect. Encapsulation of quercetin (Q) with inulin (In) by spray-drying was performed applying a Box-Behnken design where the effect of the inlet air temperature, percentage of inulin crystallite dispersion and Q content were studied on the crystallinity index (CI). Three microparticle systems with CI between 2 % and 20 % (Q-In-2 %, Q-In-12 % and Q-In-20 %) were selected to study the CI effect on Q release during an in vitro digestion. The higher the CI of microparticles, the higher the encapsulation efficiency (76.4 %, Q-In-20 %). Surface quercetin was steadily released during the oral, gastric, and intestinal phases of the digestion. The CI of the microparticles did not influence the Q bioaccessibility values (23.1–29.7 %). The highest Q delivery occurred during the simulated colonic phase (44.4–66.4 %) due to the action of the inulinase. The controlled crystallization in spray-dried microparticles is a promising strategy for the designing of polyphenol-based microparticles with specific delivery properties. [ABSTRACT FROM AUTHOR]

• Facile one-pot method to synthesize Nano-Zr-MOF. • Possessing good dispersion and optical properties. • Real-time detection of quercetin and Hg2+ by synergistic effect. In this study, a nanoscale Zr-based metal–organic framework (nano-Zr-MOF) was prepared by one-pot method using meso -tetra(4-carboxyphenyl)porphyrin as organic ligand and Zr4+ as metal unit. The nanoscale structure endows it with excellent dispersion in water. The nano-Zr-MOF exhibited intense red fluorescence, which could be significantly quenched by the addition of quercetin, probably due to its electron-rich framework. The high selectivity for quercetin detection was verified with analogues and common ions as interfering agents. Moreover, the nano-Zr-MOF could be used as a highly selective and sensitive sensor for the detection of Hg2+. The detection limits for quercetin and Hg2+ were 0.026 μM and 0.039 μM, respectively. This fluorometric method was successfully applied to detect quercetin in red wine and food samples with satisfactory recoveries ranging from 83.7–112.3% and 81.8–115.9%, respectively. The recovery in detection of Hg2+ in lake water were ranging from 97.1–109.2%. [ABSTRACT FROM AUTHOR]

[Display omitted] • 51 polyphenols were identified by UHPLC-HRMS in M. alba fruits from 13 cvs. • PCA suggested how polyphenols are synthesized during ripening. • 1-DNJ and anthocyanins were quantified for the first time on M. alba Italian cvs. • Fruits revealed different antioxidant and α-glucosidase inhibition activity. • Supervised models indicated which compounds are involved in biological activities. Morus alba L. fruits are considered functional foods with an important nutritional value for their high content of polyphenols. Therefore, the type and level of phytochemicals of the soroses from 13 M. alba cultivars grown in Italy were characterized due to the lack of data available about their nutraceutical properties. Mature M. alba fruits exhibited variable polyphenol, flavonoid, anthocyanin, proanthocyanins, and 1-deoxynojirimycin contents which resulted in different antioxidant and α-glucosidase inhibitory activities. Regression models built on UHPLC-HRMS results revealed a strong correlation between the expression of quercetin derivatives, cyanidin 3- O -glucoside, caffeoyl methyl quinates, and 5,5′-dehydrodivanillic acid, and the biological activity of each fruit. On another note, principal component analysis revealed that the quantity of caffeoyl/dicaffeoyl methyl quinate, caffeoylquinic acids, and quercetin derivatives decreased during ripening. The results on the compositional and functional characterization of mature M. alba fruits might improve their consumption and economic value in Italy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Luteolin, Naringenin, and Quercetin-loaded formulation (LNQ-MF) was developed. • Formulations encapsulated as spherical micelle with particle size of <150 nm. • LNQ-MF showed better aqueous solubility, release rate and antioxidant activity. • LNQ-MF demonstrated synergistic effect against S. aureus and S. enterica. • LNQ-MF hindered the growth of S. aureus in milk compared with the control. 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. [ABSTRACT FROM AUTHOR]

• WPI and HA co-constructed the emulsion gel system as an innovative delivery carrier. • HA promoted gel formation through hydrophobic interactions and hydrogen bonding. • The WPI-HA emulsion gels exhibited excellent rheological and structural properties. • The encapsulation efficiency and bioaccessibility of quercetin were improved. Quercetin (Que), a health-promoting polyphenol, has limited applicability in food products due to its susceptibility to degradation in the gastrointestinal tract. To overcome this problem, Que-loaded emulsion gels were produced using whey protein isolate (WPI) and hyaluronic acid (HA) by combining heating and CaCl 2 treatment. The effects of HA addition on the structural and rheological properties of the emulsion gels were evaluated, and the protective effect of the gel on Que under simulated digestion was investigated in vitro. Microstructural observations indicated that HA leads to a more compact and uniform network structure, which significantly enhances the textural and rheological properties of emulsion gels. In vitro digestion experiments revealed that WPI-HA emulsion gels exhibited a higher Que bioaccessibility (55.01%) compared to that produced by WPI alone (21.26%). This innovative delivery carrier has potential applications in food products to accomplish sustained nutrient release along with improved stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • A mixture containing 73% RES and 27% QUE (OPM) maximised the antioxidant capacity. • OPM upregulated the expression of HO-1, SOD, and CAT in L929 fibroblasts. • OPM decreased the ROS generation in H 2 O 2 -challenged L929 fibroblasts. • OPM increased the antioxidant capacity (DPPH and FRAP) of chamomile tea by 39–59%. • Slow pasteurisation did not change the total phenolics, FRAP, . OH scavenging activity, and human plasma protection against oxidation. Designing functional foods as delivery systems may become a tailored strategy to decrease the risk of noncommunicable diseases. Therefore, this work aims to optimise a combination of t- resveratrol (RES), chlorogenic acid (CHA), and quercetin (QUE) based on antioxidant assays and develop a functional tea formulation enriched with the optimal polyphenol combination (OPM). Experimental results showed that the antioxidant capacity of these compounds is assay- and compound-dependent. A mixture containing 73% RES and 27% QUE maximised the hydroxyl radical scavenging activity and FRAP. OPM upregulated the gene expressions of heme oxygenase-1, superoxide dismutase, and catalase and decreased the reactive oxygen species generation in L929 fibroblasts. Adding OPM (100 mg/L) to a chamomile tea increased FRAP:39%, DPPH:59%; total phenolic content: 57%, iron reducing capacity: 41%, human plasma protection against oxidation: 67%. However, pasteurisation (63 °C/30 min) decreased only the DPPH. Combining technology, engineering, and cell biology was effective for functional tea design. [ABSTRACT FROM AUTHOR]

[Display omitted] • The pH-cycle led to shellac micelles with co-encapsulated curcumin and quercetin. • Curcumin and quercetin at a 4:1 mass ratio demonstrated synergistic bioactivities. • Nanocapsules were smaller than 50 nm and stable during 4-week storage at 4 °C. • After simulated digestions, nanoscapsule structure and cytotoxicity were retained. • Nanoencapsulation improved the bioaccessibility and cytotoxicity post-digestions. Synergistic bioactivity of dietary polyphenols can enhance functional food development to prevent chronic diseases like cancer. In this study, physicochemical properties and cytotoxicity of curcumin and quercetin co-encapsulated in shellac nanocapsules at different mass ratios were investigated and compared to nanocapsules with one polyphenol and their unencapsulated counterparts. At curcumin and quercetin mass ratio of 4:1, encapsulation efficiency was approximately 80% for both polyphenols, and the nanocapsules showed the highest synergistic antioxidant properties and cytotoxicity for HT-29 and HCT-116 colorectal cancer cells. The nanocapsules had discrete structures smaller than 50 nm and remained stable during 4-week refrigerated storage, and the encapsulated polyphenols were amorphous. After simulated digestions, 48% of the encapsulated curcumin and quercetin were bioaccessible, the digesta retained nanocapsule structures and cytotoxicity, and the cytotoxicity was higher than nanocapsules with only one polyphenol and free polyphenol controls. This study provides insights on utilizing multiple polyphenols as promising anti-cancer agents. [ABSTRACT FROM AUTHOR]

[Display omitted] • 150 MPa high-pressure homogenization produced nano-sized quercetin-loaded liposomes. • Liposomes were oblong in shape (ca. 30 nm) and had a 42% encapsulation efficiency. • Advanced analytical techniques are required to characterize nano-sized liposomes. • Loaded liposomes exhibited higher antitumor action compared to free quercetin. Quercetin-loaded nano-liposomes were prepared by high-pressure homogenization (HPH) at different pressures (up to 150 MPa) and number of passes (up to 3) to define the best processing conditions allowing the lowest particle size and the highest encapsulation efficiency (EE). The process at 150 MPa for 1 pass was the best, producing quercetin-loaded liposomes with the lowest particle size and 42% EE. Advanced techniques (multi-detector asymmetrical-flow field flow fractionation and analytical ultracentrifugation combined with transmission electron microscopy) were further used for the characterization of the liposomes which were oblong in shape (ca. 30 nm). Results highlight the need for several techniques to study nano-sized, polydisperse samples. The potential of quercetin-loaded liposomes against colon cancer cells was demonstrated. Results prove that HPH is an efficient and sustainable method for liposome preparation and highlight the remarkable role of process optimisation as well as the powerfulness of advanced methodologies for the characterisation of nano-structures. [ABSTRACT FROM AUTHOR]

Investigation of edible oil stability involves interactions between additive polyphenols and the inherent tocopherols. The work aimed to identify endogenous polyphenols to produce the synergistic effect with α-tocopherol in olive oil and to find the right action ratio. Caffeic acid and quercetin were selected from the 15 main endogenous phenolic compounds in olive oil. Quercetin had the strongest synergistic effect with α-tocopherol at 2:1 in the olive oil model. The rate of 2:1 also was the turning point of the change of synergism. Furthermore, the addition of quercetin and α-tocopherol at 2:1 to olive oil resulted in lower POV, K232, K270, and secondary oxidation products such as (E, E)-2,4-decadienal and 2-pentylfuran than the olive oil model with a single antioxidant in three months of accelerated oxidation. The dynamic changes of antioxidants during oxidation in olive oil indicated that their synergistic effect was the repair and regeneration of α-tocopherol by quercetin., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Pancreatic lipase inhibitors can reduce blood lipids by inactivating the catalytic activity of human pancreatic lipase, a key enzyme involved in triglyceride hydrolysis, which helps control some dyslipidemic diseases. The ability of Eucommia ulmoides tea to improve fat-related diseases is closely related to the natural inhibitory components of pancreatic lipase contained in the tea. In this study, fifteen pancreatic lipase inhibitors were screened and identified from Eucommia ulmoides tea by affinity-ultrafiltration combined UPLC-Q-Exactive Orbitrap/MS. Four representative components of geniposidic acid, quercetin-3-O-sambuboside, isochlorogenic acid A, and quercetin with high binding degrees were further verified by nanoscale differential scanning fluorimetry (nanoDSF) and enzyme inhibitory assays. The results of flow cytometry showed that they could significantly reduce the activity of pancreatic lipase in AR42J cells induced by palmitic acid in a concentration-dependent manner. Our findings suggest that Eucommia ulmoides tea may be a promising resource for pancreatic lipase inhibitors of natural origin., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

• A MCPE was applied as a green method for determination of quercetin. • The proposed method is simple, fast, low cost, and environmentally friendly. • Optimization process was accomplished by chemometric multivariate methods. • The method is applicable in food and fruit juice samples with satisfactory results. • Validation of proposed method was performed by HPLC-UV with satisfactory results. This study was conducted for quantitative determination of quercetin in food and fruit juice samples based on a green, fast, and accurate method namely, micro-cloud point extraction (MCPE). The proposed MCPE is essentially a miniaturized form of traditional cloud point extraction (CPE) in which only a few microliters of micellar extracting phase is sufficient for determination. Factors influencing the extraction efficiency, such as amount of Triton X-114 (5%, v/v), effect of pH, amount of Na 2 SO 4 salt (5%, w/v) and time of centrifugation were investigated and optimized by experimental design. Under the optimized condition, the calibration range was found to be linear over 10–100 ng mL−1 with the limit of detection of 2.2 ng mL−1. The relative standard deviation of 2.8%, was obtained on a 30 ng mL−1quercetin standard solution (n = 3). Finally, the proposed method was successfully applied for the determination of quercetin in onion, tomato, apple and orange juice samples. [ABSTRACT FROM AUTHOR]

Highlights • A simple method with magnetic separation was developed to determine quercetin. • The Fe 3 O 4 @MIPs can be easily collected from the complex matrix in a very short time. • The Fe 3 O 4 @MIPs have a good selectivity and with a good recovery for the template. Abstract Magnetic molecularly imprinted polymers (M-MIPs) with core–shell structure were prepared through the surface molecular imprinting technique by using quercetin as the template molecule. The resultant Fe 3 O 4 @MIPs were characterized using X-ray diffraction, Fourier transform infrared spectrum, transmission electron microscopy, and vibrating sample magnetometer. The Fe 3 O 4 @MIPs possessed high adsorption capacity and specific recognition for quercetin. The maximum adsorption capacity of Fe 3 O 4 @MIPs towards quercetin was 10.52 mg/g, and could reach binding equilibrium within 30 min. The selectivity and specific recognition ability of Fe 3 O 4 @MIPs were evaluated according to their recognition to quercetin and its analogues. The Fe 3 O 4 @MIPs were successfully applied as selective sorbents to extract and determine quercetin from apple samples with a relatively high recoveries (89.2–93.6%) and relative standard deviations of <5%. The obtained Fe 3 O 4 @MIPs have potential application for quercetin determination in real samples. [ABSTRACT FROM AUTHOR]

Highlights • Quercetin reduced the glycemic potential of both baked and steamed bread. • A model to describe the digestibility of bread with/without quercetin was developed. • The digestion rate of bread was significantly reduced by the addition of quercetin. • Quercetin was more bioaccessible from quercetin-fortified bread than supplement. Abstract Quercetin, a plant-extracted flavonol, is a potent inhibitor of carbohydrate digestive enzymes. This study aimed to examine: (1) the extent to which quercetin altered the starch digestion and the glycemic potential of the fortified western baked bread as well as oriental steamed bread, (2) the matrix effects of bread on the potential bioaccessibility and bioavailability of quercetin. The starch digestion of bread was quantitatively evaluated by determination of starch digestion rate (k) via a developed mathematical model. Results showed a significant reduction of k for the 1.5, 3, and 6% quercetin-fortified baked and steamed bread compared to the controls by up to 18.3%. The predicted GIs of the baked bread samples with quercetin were significantly reduced in comparison to control bread. Moreover, the potential bioaccessibility of quercetin incorporated in bread products was significantly higher than that of quercetin supplement probably as a result of the protective effects from food matrix. [ABSTRACT FROM AUTHOR]

Highlights • In non-treated Tartary buckwheat flour, most of the rutin was extracted in 20 min. • By hydrothermal treatments at 25, 40 and 60 °C, most of the rutin was degraded. • After hydrothermal treatments at 80 and 95 °C, rutin was retained in flour. • Buckwheat flour-water mixture produced at 95 °C contained 12 mg rutin/g dry matter. Abstract The aim was to determine conditions under which rutin can be retained during production of Tartary buckwheat (Fagopyrum tataricum) dough. Tartary buckwheat flour was hydrothermally treated by mixing with water at 25, 40, 60, 80 and 95 °C, with unprocessed Tartary buckwheat flour as control. With hydrothermal treatments at 25, 40 and 60 °C, most of the rutin was transformed to quercetin. However, for hydrothermal treatments at 80 and 95 °C, rutin was retained due to denaturation of the rutin-degrading enzymes during hydrothermal treatment. This is the first report to describe a temperature threshold for denaturation of rutin-degrading enzymes in any buckwheat material. Tartary buckwheat dough produced at 95 °C contained 12 mg rutin/g dry matter. Based on these characteristics, dough from hydrothermally treated Tartary buckwheat is a promising, rutin-rich functional food material. [ABSTRACT FROM AUTHOR]

Highlights • Cereals and pulses are complementary dietary commodities. • Cereals and pulse flavonoids are structurally different. • Combined cereal flavones and pulse flavonols show enhanced absorption. • Effect due to suppression of phase II metabolism and ABC transporter function. • Strategic combinations of cereal and pulses could enhance biological benefits. Abstract Predominant flavonoids in cereals and pulses are structurally different and may positively interact to enhance bioactivity in combined diet. This work investigated the effects of combined cereal 3-deoxyflavonoids (apigenin, naringenin) and pulse flavonols (quercetin), along with natural extracts, on their bioavailability and underlying mechanisms using Caco-2 monolayer model. Membrane permeability, phase II metabolism, and ATP binding cassette (ABC) membrane transporter expression and function were measured. Apparent absorption of quercetin and apigenin increased (p < 0.05) 3.3× and 1.5×, respectively, while both compounds were significantly less metabolized in combined treatments. Combinations with naringenin had insignificant effect, suggesting a role for flavonoid C2 C3 conjugation. Both natural extracts and apigenin-quercetin combinations synergistically (3–40 fold) downregulated ABC transporter expression, and inhibited P-glycoprotein activity, suggesting direct binding and inhibition of ATPase. Combination of conjugated cereal and pulse flavonoids enhances their potential bioavailability through synergistic inhibition of membrane transporter and phase II enzyme function. [ABSTRACT FROM AUTHOR]

Highlights • 27 out of 54 antioxidants generate H 2 O 2 in water, saline and cell culture media. • The most active were: propyl gallate, epigallocatechin gallate and quercetin. • H 2 O 2 generated contributes to the cytotoxicity of these compounds in vitro. • Generation of H 2 O 2 in tea can be prevented by addition of a lemon slice. Abstract Studies of 54 antioxidants revealed that 27 of them, mainly polyphenols, generated hydrogen peroxide (H 2 O 2) when added to Dulbecco's modified Eagle's medium (DMEM), other media used for culture of mammalian and yeast cells and phosphate-buffered saline. The most active antioxidants were: propyl gallate (PG), (−)-epigallocatechin gallate (EGCG) and quercetin (Q). Chelex treatment and iron chelators decreased H 2 O 2 generation suggesting that transition metal ions catalyze antioxidant autoxidation and H 2 O 2 production. Green tea also generated H 2 O 2 ; tea prepared on tap water generated significantly more H 2 O 2 than tea prepared on deionized water. Ascorbic acid decreased H 2 O 2 production although it generated H 2 O 2 itself, in the absence of other additives. Lemon added to the tea significantly reduced generation of H 2 O 2. Hydrogen peroxide generated in the medium contributed to the cytotoxicity of PG, EGCG and Q to human prostate carcinoma DU-145 cells, since catalase increased the survival of the cells subjected to these compounds in vitro. [ABSTRACT FROM AUTHOR]

Highlights • Flavonoids provide cytoprotective against HR–induced oxidative stress in HTR-8/SVneo. • Flavonoids are effective against the production of reactive oxygen species. • Their protective effect is brought about via the reduction of caspase 3/7 activation. • Increasing the intake of in flavonoids rich food may benefit early pregnancy. Abstract This study aimed to investigate the cytoprotective effects of flavonoids, their metabolites alone or in combination against hypoxia/reoxygenation induced oxidative stress in the transformed human first trimester trophoblast cell line (HTR-8/SVneo). Oxidative stress was achieved with hypoxia followed by reoxygenation and the following assays were performed: MTT, CellTox™ Green Cytotoxicity, CellTiter-Glo®, NADP/NADPH-Glo™, ROS-Glo™/H 2 O 2 , GSH/GSSG-Glo™ and Caspase-Glo® 3/7 assays. HTR-8/SVneo cells, pre-treated for 24 h with flavonoids or their metabolites were protected significantly from oxidative stress. Flavonoids were associated with ROS modulation, reducing the generation of superoxide/hydrogen peroxide. The activities of caspases 3/7 were also significantly reduced significantly in HTR-8/SVneo cells pre-treated with flavonoids. This study has shown for the first time that 24 h pre-treatment with flavonoids, their metabolites alone or in combination, protected against HR-induced oxidative stress in the trophoblast cell line. These data indicate that dietary flavonoids may be beneficial to placental health and invasion during early gestation. [ABSTRACT FROM AUTHOR]

Highlights • Pinoresinol was detected for the first time in cold-pressed grape seed oils. • Total phenolic content ranged between 0.83 mg/kg to 15.16 mg/kg. • Good correlation between total phenolic content and inhibitory power of PTP-1B. • Pinoresinol, p -coumaric acid and quercetin give the major contribute to inhibition. • Ethyl esters of gallic and caffeic acid were detected for the first time. Abstract This paper investigates the phenolic composition of 17 monocultivar commercial cold-pressed grape seed oils. Chromatographic profiles showed the presence of more than 28 molecules, 11 of which were successfully identified by HPLC-DAD-MS-TOF and HPLC-FLD analysis. Pinoresinol, ethyl caffeate and ethyl gallate were detected for the first time in these oils. The total phenolic content ranged between 0.83 mg/kg for Viognier sample to 15.16 mg/kg for Merlot org sample. The detected ethyl esters can be suggested as markers to evaluate the intensity of fermentation in grape seeds before oil extraction, and to control the sensorial quality of the produced oils. In addition, the inhibitory power of these phenolic extracts against Protein Tyrosine Phosphatase 1B enzyme (PTP-1B), overexpressed in type-two diabetes, was investigated for the first time. Data highlighted a good correlation between total phenolic content and inhibitory power, with pinoresinol, p -coumaric acid and quercetin making the greater contributions. [ABSTRACT FROM AUTHOR]

Highlights • Actinidia arguta is a promising new crop well adapted to European weather conditions. • A total of 31 polyphenolic compounds were identified in fruits by LC-MS-PDA-Q/TOF method. • Mainly glycosylated and acetylated forms of quercetin and kaempferol were present in A. arguta. • Anticholinergic effect of A. arguta fruits can be depend on phenolic compounds, especially flavonols. • A. arguta fruits showed strong nutritional potential to improve human health. Abstract This study discusses polyphenolic compounds identified and quantified in Actinidia arguta fruits by LC-MS-PDA-Q/TOF method and in vitro anticholinergic activity. Notably, of 31 compounds, including 16 flavonols, 7 flavanols, 7 phenolic acids, and 1 anthocyanin were identified or tentatively identified on the basis of their retention times, accurate mass measurements and subsequent mass fragmentation data, or by comparison with reference substances and literature. Among the detected compounds, 27 were reported for the first time in A. arguta fruits. The content of total polyphenols equal 845.54 mg/100 g dry weight (dw), and flavanols predominat (92% of total phenolic compounds). Flavonol derivatives, mainly glycosylated and acetylated forms of quercetin (22.64 mg/100 g dw) and kaempferol (18.40 mg/100 g dw) were quantified. The total content of phenolic acids was 29.63 mg/100 g dw, and neochlorogenic acid predominant. This anticholinergic activity effect of A. arguta fruits can be explained by the Pearson’s correlation found between flavonols (r = 0.709 and 0.678), phenolic acids (r = 0.513 and 0.487), flavan-3-ols (r = 0.466 and 0.443) and anthocyanins (r = 0.312 and 0.301) for acetylcholinesterase (AChE) or butylcholinoesterase (BuChE), respectively. The data compiled from the quantitative polyphenol indicate that A. arguta fruits could be regarded as a promising source of bioactive functional food. [ABSTRACT FROM AUTHOR]