Physicochemical and digestive properties of corn starch nanoparticles incorporated different polyphenols.

The corn starch nanoparticles were prepared by incorporating three kinds of polyphenols, including quercetin, proanthocyanidins and tannin acid. The physicochemical and digestive properties of corn starch nanoparticles were researched. The quercetin showed a higher complexation index than proanthocyanidins and tannin acid when they complexed with corn starch. The mean size of corn starch quercetin, proanthocyanidins and tannin acid were 168.5 nm, 179.1 nm and 188.6 nm, respectively. XRD results indicated that all the corn starch-polyphenols complex showed V-type crystalline structure, the crystallinity of corn starch-quercetin complex was 19.31 %, which showed more formation of amylose-quercetin single helical formed than the other two starch-polyphenol complexes. In vitro digestion revealed that polyphenols could resist digestion and quercetin increased the content of resistant starch from 23.32 % to 35.24 % and polyphenols can form complexes with starch through hydrophobic interactions or hydrogen bonding. This study indicated the hydrophobic polyphenols had a more significant effect on the digestibility of corn starch. And the cell toxicity assessments demonstrated that all nanoparticles were nontoxic and biocompatible.

Preparation and characterization of carvacrol/ε-polylysine loaded antimicrobial nanobilayer emulsion and its application in mango preservation.

Carvacrol is well-known natural antimicrobial compounds. However, its usage in fruit preservation is restricted owing to poor water solubility. Our study aims to address this limitation by combining carvacrol with whey protein isolate (WPI) to form nanoemulsion and enhancing antimicrobial properties and stability of nanoemulsion through ε-polylysine addition, thereby improving their application in fruit preservation. The results indicated that the nanoemulsion exhibited a double-layer structure. The physicochemical properties and storage stability were found to be favorable under the conditions of WPI (0.3 wt% v/v), Carvacrol (0.5 % v/v), and ε-polylysine (0.3 wt% v/v). In addition, the nanoemulsion had inhibitory effects on Staphylococcus aureus, Escherichia coli, and Aspergillus niger at concentrations of minimal inhibition concentration (32, 32, and 200 µg/mL, respectively). In addition, during a 7-day storage period, the nanoemulsion effectively preserved mangoes. Therefore, nanoemulsion could serve as a candidate for control of postharvest mangoes spoilage and extend its period of storage.

Hydroxyl group-induced enhancement of antioxidant activity of resveratrol over pterostilbene by binding to lactoferrin.

The reduced antioxidant capacity of trans-resveratrol (Res) than the second generation of Res, namely pterostilbene (Pte), severely prohibits its in-depth intriguing radical-scavenging applications in food formulations. Herein, a unique chemical structure-dependent strategy was proposed to specifically enhance the radical scavenging activity of Res over Pte, relying on the two more hydroxyl groups on the A-benzene ring of Res, thus facilitating its binding with lactoferrin (LF) to form stable complexes through more hydrogen bonds. We prepared LF-Res and LF-Pte complexes, revealed their binding mechanisms by multispectral analysis and molecular docking/dynamics simulations, further evaluated their antioxidant properties via ABTS and DPPH assays and a model of inhibiting apple browning, eventually elucidated their structure-binding-property relationships. This contribution offers a new approach to restore the antioxidant capability of Res, also paves the way to precisely regulate the fascinating bioactivities of hydrophobic compounds by protein-binding in a chemical structure-, especially hydroxyl group-dependent manner.

Recent advances in dietary androgen receptor inhibitors.

As a nuclear transcription factor, the androgen receptor (AR) plays a crucial role not only in normal male sexual differentiation and growth of the prostate, but also in benign prostatic hyperplasia, prostatitis, and prostate cancer. Multiple population-based epidemiological studies demonstrated that prostate cancer risk was inversely associated with increased dietary intakes of green tea, soy products, tomato, and so forth. Therefore, this review aimed to summarize the structure and function of AR, and further illustrate the structural basis for antagonistic mechanisms of the currently clinically available antiandrogens. Due to the limitations of these antiandrogens, a series of natural AR inhibitors have been identified from edible plants such as fruits and vegetables, as well as folk medicines, health foods, and nutritional supplements. Hence, this review mainly focused on recent experimental, epidemiological, and clinical studies about natural AR inhibitors, particularly the association between dietary intake of natural antiandrogens and reduced risk of prostatic diseases. Since natural products offer multiple advantages over synthetic antiandrogens, this review may provide a comprehensive and updated overview of dietary-derived AR inhibitors, as well as their potential for the nutritional intervention against prostatic disorders.

Comparison of interactions between alpha-lactalbumin and three protopanaxadiol ginsenosides: Impacts on the structure and antitumor properties.

In this research, interactions between α-lactalbumin (ALA) and three protopanaxadiol ginsenosides [20(S)-Rg3, 20(S)-Rh2, and 20(S)-PPD] were compared to explore the effects of similar ligand on structure and cytotoxicity of ALA. Multi-spectroscopy revealed the binding between ALA and ginsenoside changed the conformation of ALA, which related to different structures and solubility of ligands. Scanning electron microscope illustrated that all ALA-ginsenoside complexes exhibited denser structures via hydrophobic interactions. Additionally, the cytotoxic experiments confirmed that the cytotoxicity of ginsenoside was enhanced after binding with ALA. Molecular docking showed all three ginsenosides were bound to the sulcus depression region of ALA via hydrogen bonding and hydrophobic interaction. Furthermore, molecular dynamics simulation elucidated the precise binding sites and pertinent system properties. Among all three composite systems, 20(S)-Rh2 had optimal binding affinity. These findings enhanced understanding of the synergistic utilization of ALA and ginsenosides as functional ingredients in food, medicine, and cosmetics.

Nuclear Receptors-Mediated Endocrine Disrupting Effects of Non-Phthalate Plasticizers: A Review.

In 2021, the global market for non-phthalate plasticizers reached $3.1 billion, and it is projected to grow by 25.8% by 2025. These plasticizers have gained substantial attention as substitutes for phthalates in various industrial applications due to their potential health and environmental risks, particularly in agroecosystems where they have emerged as contaminants. Furthermore, recent studies have demonstrated that non-phthalate plasticizers can exert endocrine-disrupting effects through mechanisms mediated by nuclear receptors. This review aims to summarize the present understanding of the molecular mechanisms by which non-phthalate plasticizers modulate the activity of nuclear receptors, including estrogen receptor, androgen receptor, glucocorticoid receptor, and peroxisome proliferator-activated receptors. Furthermore, the potential health impacts of exposure to conventional phthalate plasticizers are discussed, with a particular emphasis on developmental and reproductive toxicity, metabolic disorders, and carcinogenesis. Overall, this review underscores the significance of evaluating the endocrine-disrupting effects of non-phthalate plasticizers and lays the foundation for the development of safer alternatives within the plastic industry.

Mixed whey and pea protein based cold-set emulsion gels induced by calcium chloride: Fabrication and characterization.

The cold-set gels of oil-in-water emulsions stabilized by mixtures of whey protein isolate (WPI) and pea protein isolate (PPI) with mass ratios of 10:0, 7:3, 5:5, 3:7, and 0:10 were investigated to evaluate the possibility of pea protein to replace milk protein. Particle size and surface charge of emulsions increased and decreased with raised PPI content, respectively. The redness and yellowness of emulsion gels were strengthened with elevated pea protein percentage and independent of calcium concentration applied. Considerable differences in water holding capacity were observed between samples with different mixed proteins and high percentage of pea protein gave better water retaining ability. Gradual decreases in hardness and chewiness of emulsion gels were observed at three calcium levels with the increased PPI proportion. FT-IR spectra indicated no new covalent bonds were generated between samples with different whey and pea protein mass ratios. As PPI concentration elevated, the network structure of emulsion gels gradually became loose and disordered. The established cold-set calcium-induced whey/pea protein composite gels may have the potential to be utilized as a new material to encapsulate and deliver environment sensitive bio-active substances.

Lycopene-loaded emulsions stabilized by whey protein covalently modified with pectin or/and chlorogenic acid: Enhanced physicochemical stability and reduced bio-accessibility.

Lycopene-loaded emulsions were formulated with whey protein isolate (WPI) covalently modified with high methoxylated pectin (HMP) or/and chlorogenic acid (CA) prepared by dry heating or/and alkali grafting. Covalent WPI products were confirmed by SDS-PAGE and degree of graft/CA binding equivalent values. The α-helix and ß-sheet percentage, surface hydrophobicity and fluorescence intensity of WPI decreased significantly (p < 0.05) upon binding. Both binary and ternary complexes enhanced the stability of the emulsions, and lycopene retained more after UV irradiation, thermal treatment, storage, compared with emulsions stabilized by WPI, with the best protection by both ternary complexes. In vitro simulated digestion results showed that free fatty acids were released in the order of WPI > WPI-HMP > WPI-CA > WPI-HMP-CA ≈ WPI-CA-HMP. Bio-accessibility analysis showed the same trend as the fatty acid release rate. These results may provide a theoretical basis for applications of conjugating protein with polysaccharide or/and polyphenol emulsions.

In vitro and in silico assessment of endocrine disrupting effects of food contaminants through pregnane X receptor.

As a promiscuous xenobiotic receptor, pregnane X receptor (PXR) has been confirmed to participate in numerous physiological process. In addition to the conventional estrogen/androgen receptor, PXR also serves as an alternative target for environmental chemical contaminants. In this work, the PXR-mediated endocrine disrupting effects of typical food contaminants were explored. Firstly, the time-resolved fluorescence resonance energy transfer assays confirmed the PXR binding affinities of 2,2',4,4',5,5'-hexachlorobiphenyl, bis(2-ethylhexyl) phthalate, dibutyl phthalate, chlorpyrifos, bisphenol A, and zearalenone, with IC50 values ranging from 1.88 to 4284.00 nM. Then their PXR agonist activities were assessed by PXR-mediated CYP3A4 reporter gene assays. Subsequently, the regulation of gene expressions of PXR and its targets CYP3A4, UGT1A1, and MDR1 by these compounds was further investigated. Intriguingly, all the tested compounds interfered with these gene expressions, confirming their endocrine disrupting effects via PXR-mediated signaling. The compound-PXR-LBD binding interactions were explored by molecular docking and molecular dynamics simulations to unravel the structural basis of their PXR binding capacities. The weak intermolecular interactions are key players in stabilizing these compound-PXR-LBD complexes. During the simulation process, 2,2',4,4',5,5'-hexachlorobiphenyl remained stable while the other 5 compounds underwent relatively severe disturbances. In conclusion, these food contaminants might exhibit endocrine disrupting effects via PXR.

Formation, stability and in vitro digestion of curcumin loaded whey protein/ hyaluronic acid nanoparticles: Ethanol desolvation vs. pH-shifting method.

Curcumin (CUR) was encapsulated in whey protein isolate/hyaluronic acid (WPI/HA) electrostatic nanoparticles at pH 5.4, 4.4, 3.4 and 2.4 using ethanol desolvation (DNP) or pH-shifting (PSNP) method. The prepared nanoparticles were characterized and compared for physiochemical properties, structure, stability, and in vitro digestion. PSNPs had smaller particle size, more uniform distribution, and higher encapsulation efficiency than DNPs. Main driving forces involved for fabricating the nanoparticles were electrostatic forces, hydrophobic forces, and hydrogen bonds. PSNP exhibited better resistance towards salt, thermal treatment, and long-term storage while DNPs showed stronger protection for CUR against thermal degradation and photodegradation. Stability of nanoparticles increased with decreasing pH values. In vitro simulated digestion exhibited that DNPs had lower release rate of CUR in SGF and higher antioxidant activity of its digestion products. Data may provide a comprehensive reference for selection of loading approach when constructing nanoparticles based on proteins/polysaccharides electrostatic complexes.

Target-based screening for natural products against Staphylococcus aureus biofilms.

As a notorious food-borne pathogen, Staphylococcus aureus can readily cause diseases in humans via contaminated food. Biofilm formation on various surfaces can increase the capacity of viable S. aureus cells for self-protection due to the stubborn structure of the biofilm matrix. Increased disease risk and economic losses caused by biofilm contamination in the food industry necessitate the urgent development of effective strategies for the inhibition and removal of S. aureus biofilms. Natural products have been extensively used as important sources of "eco-friendly" antibiofilm agents to avoid the side effects of conventional strategies on human health and the environment. This review discusses biofilm formation of S. aureus in food industries and focuses on providing an overview of potential promising target-oriented natural products and their mechanisms of S. aureus biofilm inhibition or removal. Hoping to provide valuable information of attractive research targets or potential undeveloped targets to screen potent natural anti-biofilm agents in food industries.

Dietary phytochemicals as modulators of human pregnane X receptor.

As a promiscuous xenobiotic sensor, pregnane X receptor (PXR) plays a crucial role in drug metabolism. Since dietary phytochemicals exhibit the potential to modulate human PXR, this review aims to summarize the plant-derived PXR modulators, including agonists, partial agonists, and antagonists. The crystal structures of the apo and ligand-bound forms of PXR especially that of PXR complexed with binary mixtures are summarized, in order to provide the structural basis for PXR binding promiscuity and synergistic activation of PXR by composite ligands. Furthermore, this review summarizes the characterized agonists, partial agonists, and antagonists of human PXR from botanical source. Contrary to PXR agonists, there are only a few antagonists obtained from botanical source due to the promiscuity of PXR. It is worth noting that trans-resveratrol and a series of methylindoles have been identified as partial agonists of PXR, both in activating PXR function, but also inhibiting the effect of other PXR agonists. Since antagonizing PXR function plays a crucial role in the prevention of drug-drug interactions and improvement of therapeutic efficacy, further research is necessary to screen more plant-derived PXR antagonists in the future. In summary, this review may contribute to understanding the roles of phytochemicals in food-drug and herb-drug interactions.

Anti-biofilm activity of biochanin A against Staphylococcus aureus.

Biofilm-forming Staphylococcus aureus can easily accumulate on various food contact surfaces which induce cross-contamination and are difficult to eliminate in the food industry. This study aimed to evaluate the anti-biofilm effects of natural product biochanin A against S. aureus. Results showed that biochanin A effectively eradicated established S. aureus biofilms on different food-contact materials. Fluorescence microscopic analyses suggested that biochanin A disintegrated the established biofilms by dissociate extracellular polymeric substance (EPS) in matrix. In addition, biochanin A at the sub-MIC concentration also effectively inhibited the biofilm formation by regulating the expression of biofilm-related genes (icaA, srtA, eno) and suppressing the release of EPS in biofilm matrix. Molecular docking also demonstrated that biochanin A conducted strong interactions with biofilm-related proteins (Ica A, Sortase A, and Enolase). These findings demonstrated that biochanin A has the potential to be developed as a potent agent against S. aureus biofilm in food industries. KEY POINTS: • Anti-biofilm effect of biochanin A against S. aureus was revealed for the first time. • Biofilm of S. aureus on various food-contact surfaces were efficiently eradicated. • Biochanin A prevented S. aureus biofilm formation via reducing EPS production.

Insights into the Mechanisms of Reuterin against Staphylococcus aureus Based on Membrane Damage and Untargeted Metabolomics.

Reuterin is a dynamic small-molecule complex produced through glycerol fermentation by Limosilactobacillus reuteri and has potential as a food biopreservative. Despite its broad-spectrum antimicrobial activity, the underlying mechanism of action of reuterin is still elusive. The present paper aimed to explore the antibacterial mechanism of reuterin and its effects on membrane damage and the intracellular metabolome of S. aureus. Our results showed that reuterin has a minimum inhibitory concentration of 18.25 mM against S. aureus, based on the 3-hydroxypropionaldehyde level. Key indicators such as extracellular electrical conductivity, membrane potential and permeability were significantly increased, while intracellular pH, ATP and DNA were markedly decreased, implying that reuterin causes a disruption to the structure of the cell membrane. The morphological damage to the cells was confirmed by scanning electron microscopy. Subsequent metabolomic analysis identified significant alterations in metabolites primarily involved in lipid, amino acid, carbohydrate metabolism and phosphotransferase system, which is crucial for cell membrane regulation and energy supply. Consequently, these findings indicated that the antibacterial mechanism of reuterin initially targets lipid and amino acid metabolism, leading to cell membrane damage, which subsequently results in energy metabolism disorder and, ultimately, cell death. This paper offers innovative perspectives on the antibacterial mechanism of reuterin, contributing to its potential application as a food preservative.

Characterization of coacervation behavior between whey protein isolate and propylene glycol alginate: A morphology, spectroscopy, and thermodynamics study.

The interactions between whey protein isolate (WPI) and propylene glycol alginate (PGA) were investigated as a function of pH and the mass ratio. The results showed that WPI and PGA formed a soluble and uniform complex at a mass ratio of 2:1 and pH 4.0 through forces such as electrostatic attraction and hydrogen bonding. Isothermal titration calorimetry confirmed that the contribution of positive enthalpy (ΔH) and entropy (ΔS) were the beneficial indicator in the process of combining WPI and PGA under the same mass ratio but different pH. Fourier transform infrared spectroscopy, fluorescence spectroscopy and circular dichroism confirmed that hydrogen bonding was also one of the interaction forces in addition to electrostatic interactions between WPI-PGA complex. The freeze-dried WPI-PGA complex showed the same amorphous structure as WPI. These formed WPI-PGA complexes provided insights for interaction mechanism of proteins and polysaccharides as well as a theoretical basis for the food industry.

Pea protein based nanocarriers for lipophilic polyphenols: Spectroscopic analysis, characterization, chemical stability, antioxidant and molecular docking.

The current research aims to construct and assess pea protein isolate (PPI) nanocarriers for lipophilic polyphenols of curcumin (CUR), quercetin (QUE) and resveratrol (RES), respectively. Fluorescence analysis demonstrated that the binding affinity declined in sequence of QUE > CUR > RES and about one polyphenol compound was bound to protein. Thermodynamic parameters revealed that hydrophobic interaction was mainly responsible for complexation between CUR/RES and PPI, while hydrogen bonding for QUE with PPI. All nanoparticles showed particle size of 154-159 nm. Three lipophilic polyphenols were successfully encapsulated into PPI, with loading capacity of RES > QUE > CUR. Complexation of three polyphenols did not change the secondary structure of PPI. Results of FTIR, DSC and XRD confirmed that polyphenols changed from crystalline to amorphous state after combination with PPI. SEM pictures exhibited regular spherical microstructure of nanocomplexes. PPI shielded polyphenols from sensitive environment of ultraviolet light and thermal treatment. ABTS and DPPH radical scavenging activity of polyphenols were considerably improved through complexation with PPI. Molecular docking studies showed binding energy with 11S legumin in sequence of QUE > RES > CUR, and stronger hydrogen bonds were built between QUE and the protein than the other two polyphenols. Data in the present work may provide helpful information for encapsulation of lipophilic polyphenols with pea protein and the potential application in food science, pharmaceutical and cosmetics industries in the future.

Polysaccharides from Hericium erinaceus Fruiting Bodies: Structural Characterization, Immunomodulatory Activity and Mechanism.

Five fractions from crude Hericium erinaceus polysaccharides (HEPs), including HEP-1, HEP-2, HEP-3, HEP-4 and HEP-5, were obtained through column chromatography with a DEAE Cellulose-52 column and Sephadex G-100 column. The contents of total carbohydrates and uronic acid in HEPs were 53.36% and 32.56%, respectively. HEPs were mainly composed of Fuc, Gal and Glu in a molar ratio of 7.9:68.4:23.7. Its chemical structure was characterized by sugar and methylation analysis, along with 1H and 13C NMR spectroscopy. HEP-1 contains the backbone composed of (1→6)-linked-galactose with branches attached to O-2 of some glucose. The immunological activity assay indicated that HEP-1 significantly promoted the production of nitric oxide, interleukin-6, interleukin-10, interferon-γ and tumor necrosis factor-α and the phosphorylation of signaling molecules. Collectively, these results suggested that HEP-1 could improve immunity via NF-κB, MAPK and PI3K/Akt pathways. Hericium erinaceus polysaccharides might be explored as an immunomodulatory agent for use in dietary supplements.

Characterization and antibacterial activity study of α-Lactalbumin-carvacrol complex.

Food contamination and poisoning caused by bacteria will endanger human health, and the development of natural antibacterial agents is a pressing issue. We prepared ALA-Car complex and demonstrated its formation by multi-spectroscopy techniques and localized surface plasmon resonance experiments. Computer simulations have shown that van der Waals forces dominate the interaction between ALA and Car. The minimum inhibitory concentration (MIC) of Car toward Gram-negative Escherichia coli was decreased from 336 µg/mL to 224 µg/mL after binding to ALA. It had little effect on the MIC of Gram-positive Staphylococcus aureus (224 µg/mL), but further proved Car had a weaker antibacterial activity than the ALA-Car complex by the spread plate method. Overall, this work demonstrated that the ALA-Car complex had significantly higher antibacterial activities than Car, further advancing the development of natural antibacterial agents.

Selenium nanoparticles: Enhanced nutrition and beyond.

Selenium is a trace nutrient that has both nutritional and nutraceutical functions, whereas narrow nutritional range of selenium intake limits its use. Selenium nanoparticles (SeNPs) are less toxic and more bioavailable than traditional forms of selenium, suggesting that SeNPs have the potential to replace traditional selenium in food industries and/or biomedical fields. From the perspective of how SeNPs can be applied in health area, this review comprehensively discusses SeNPs in terms of its preparation, nutritional aspect, detoxification effect of heavy metals, nutraceutical functions and anti-pathogenic microorganism effects. By physical, chemical, or biological methods, inorganic selenium can be transformed into SeNPs which have increased stability and bioavailability as well as low toxicity. SeNPs are more effective than traditional selenium form in synthesizing selenoproteins like glutathione peroxidases. SeNPs can reshape the digestive system to facilitate digestion and absorption of nutrients. SeNPs have shown excellent potential to adjunctively treat cancer patients, enhance immune system, control diabetes, and prevent rheumatoid arthritis. Additionally, SeNPs have good microbial anti-pathogenic effects and can be used with other antimicrobial agents to fight against pathogenic bacteria, fungi, or viruses. Development of novel SeNPs with enhanced functions can greatly benefit the food-, nutraceutical-, and biomedical industries.

Influence of ultrasound and enzymatic cross-linking on freeze-thaw stability and release properties of whey protein isolate hydrogel.

This study investigated the effect of ultrasound and enzymatic cross-linking on the freeze-thaw (FT) stability and release properties of whey protein isolate hydrogels. We evaluated the FT stability by the changes in the microstructure, riboflavin retention, syneresis, water holding capacity (WHC), and texture of gels subjected to 3 FT cycles. High-intensity ultrasound (HUS) and transglutaminase (TGase)-mediated cross-linking improved the FT stability of whey protein isolate hydrogels loaded with riboflavin (WPISAR), as demonstrated by a more uniform and denser porous structure, significantly higher riboflavin retention, WHC, and textural properties, and lower syneresis after 3 FT cycles than those of untreated hydrogels. Furthermore, HUS- and TGase-mediated cross-linking decreased protein erosion and swelling ratio of WPISAR in simulated gastrointestinal fluids (SGIF) and reduced the riboflavin release rate in SGIF both with and without the addition of digestive enzymes. After 3 FT cycles, faster riboflavin release occurred due to a more porous structure induced by ice crystal formation compared with their unfrozen counterparts as detected by confocal laser scanning microscopy. High-intensity ultrasound- and TGase-mediated cross-linking alleviated the FT-induced faster riboflavin release rate in SGIF. High-intensity ultrasound- and TGase-treated gel samples showed that both diffusion and network erosion were responsible for riboflavin release regardless of FT. These results suggest that HUS- and TGase-mediated cross-linking improved the FT stability of WPISAR with a high riboflavin retention, and might be a good candidate as a controlled-release vehicle for riboflavin delivery to overcome undesired FT processing.