Fabrication and characterization of quercetin loaded casein phosphopeptides-chitosan composite nanoparticles by ultrasound treatment: Factor optimization, formation mechanism, physicochemical stability and antioxidant activity

Fabrication and characterization of novel TGase-mediated glycosylated whey protein isolate nanoparticles for curcumin delivery

The aim of this study was to fabricate novel transglutaminase (TGase)-mediated glycosylated whey protein isolate (WPI) nanoparticles for the encapsulation and delivery of curcumin. The influences of glycosylation on the physiochemical properties, stability, bioavailability, and antioxidant properties of WPI nanoparticles loaded with curcumin were investigated. Composite nanoparticles exhibited uniform distribution and small particle sizes. The main driving forces for the formation of curcumin nanoparticles were electrostatic interactions, hydrogen bonding, and hydrophobic interactions. The encapsulation and loading efficiency of curcumin after TGase-type glycosylation were significantly increased in comparison to WPI-curcumin nanoparticles. Glycosylated WPI-curcumin nanoparticles had stronger antioxidant properties and stability to resist external environmental changes than WPI-curcumin nanoparticles. In addition, glycosylated WPI-curcumin nanoparticles showed a controlled release and enhanced curcumin bioavailability in vitro gastrointestinal digestion. This study provides novel insights for self-assembled glycosylated protein nanoparticles as delivery systems for protecting hydrophobic nutrients.

Construction of quaternary ammonium chitosan-coated protein nanoparticles as novel delivery system for curcumin: Characterization, stability, antioxidant activity and bio-accessibility

This research aimed to develop a novel, effective, and stable delivery system based on zein (ZE), sodium caseinate (SC), and quaternary ammonium chitosan (HACC) for curcumin (CUR). The pH-driven self-assembly combined with electrostatic deposition methods were employed to construct CUR-loaded ZE-SC nanoparticles with HACC coating (ZE-SC@HACC). The optimized nanocomposite was prepared at ZE:SC:HACC:CUR mass ratios of 1:1:2:0.1, and it had encapsulation efficiency of 89.3%, average diameter of 218.2 nm, and ζ-potential of 40.7 mV. The assembly of composites and encapsulation of CUR were facilitated primarily by hydrophobic, hydrogen-bonding, and electrostatic interactions. Physicochemical stability analysis revealed that HACC coating dramatically enhanced ZE-SC nanoparticles' colloidal stability and CUR's resistance to chemical degradation. Additionally, antioxidant activity and simulated digestion results indicated that CUR-ZE-SC@HACC nanoparticles showed higher free radical scavenging capacity and bio-accessibility of CUR than CUR-ZE-SC nanoparticles and free CUR. Therefore, the ZE-SC@HACC nanocomposite is an effective and viable delivery system for CUR.

Lactobacillus rhamnosus GG coating with nanocomposite ameliorates intestinal inflammation

The steady increase in the prevalence of inflammatory bowel disease (IBD) is regarded as a worldwide health issue. Gut microorganisms could modulate host immune and metabolic status and are associated with health effects. Probiotics, Lactobacillus rhamnosus GG (LGG), are beneficial microorganisms that ameliorate disease and exert advantageous effects on intestinal homeostasis. However, the viability of probiotics will suffer from various risk factors in the digestive tract. In this view, we developed a probiotic coating with nanocomposite using tannic acid (TA) and casein phosphopeptide (CPP) through layer-by-layer technology to overcome the challenges after oral administration. LGG showed an improved survival rate in simulated gastrointestinal conditions after coated. The coating (LGG/TA-Mg2+/CPP) had potent reactive oxygen species (ROS) scavenging ability and improved the survival rate of colorectal epithelial cells after H2O2 stimulation. In DSS-induced colitis, administration of LGG/TA-Mg2+/CPP ameliorated intestinal inflammation and reduced the disruption of barrier function. Furthermore, LGG/TA-Mg2+/CPP increased the abundance and diversity of the gut microbiota. In the mouse model of DSS colitis, LGG/TA-Mg2+/CPP can better activate the EGFR/AKT signaling pathway, thereby protecting the epithelial barrier function of the colon epithelium. In conclusion, the probiotic coating with nanocomposite may become a delivery platform for probiotics applied to IBD.

Chitosan dual gel-like functionalized with flavonoid extract and cinnamaldehyde oil using dual cross-linking agents: Characterization, antioxidant, and antimicrobial effects

This study evaluated antioxidant and antimicrobial properties of chitosan gel (Cs-gel) functionalized with cinnamaldehyde oil (CN) and orange peel-derived flavonoid extract (Fs) using the ionic-gelation method. Results showed that the encapsulation efficiencies of CCF-9 and CCN were 83.14 ± 3.34 and 80.56 ± 1.17%, respectively. The interaction of CN or Fs on Cs-gel indicates the presence of H-bonding formation, as observed by UV-vis spectroscopy, Fourier transform infrared spectrophotometry (FTIR), and Raman-spectroscopy showed a good corroboration with Surflex-dock findings. Scanning electron microscopy also showed the integration that occurred between Cs and both ligands, which was further supported with X-ray diffraction and X-Ray photoelectron spectroscopy spectra. The textural properties of CCF-5 gel showed high hardness, chewiness, and gumminess values, indicating that the integration of Fs and CN altered the microstructure of Cs-gel. Chotison-functionalized based gels exhibited higher antioxidant abilities against DPPH and ABTS free radicals than Cs-gel. The CCF-9 gel showed a good inhibition value of 29.91 ± 1.22 and 93.61 ± 2.12% against Penicillium expansum and Alternaria westerdijkiae, respectively. Additionally, CCF-9 inhibition zones against Staphylococcus aureus, Escherichia coli, and Bacillus cerues were 28.65 ± 0.05, 27.69 ± 0.04, and 26.16 ± 0.02 mm, respectively. These findings demonstrated the potential antioxidant and antimicrobial effects of functionalized chitosan gel indicating its potential as a bioactive additive for food preservation.

Preparation and characterization of bovine serum albumin/chitosan composite nanoparticles for delivery of Antarctic krill peptide

BACKGROUND

Antarctic krill peptide (AKP) has gained considerable interest because of its multiple biological functions. However, its application may be limited by its poor stability and susceptibility to degradation. Encapsulation of AKP using a nanoparticle delivery system is an effective way to overcome these problems. In the present study, bovine serum albumin (BSA) and chitosan (CS) were used as delivery vehicles to encapsulate AKP.

RESULTS

The results revealed that the particle size (83.3 ± 4.4-222.4 ± 32.7 nm) and zeta-potential (35.1 ± 0.7-45.0 ± 2.7 mV) of nanoparticles (NPs) increased with the increasing content of BSA, but the polydispersity index decreased (1.000 ± 0.002 to 0.306 ± 0.011). Hydrogen bonding, hydrophobic and electrostatic interactions were the main forces to form BSA/CS-AKP NPs. X-ray diffraction revealed that AKP was encapsulated by BSA/CS. Scanning electron microscopy images exhibited that the NPs were spherical in shape, uniform in size and tightly bound. BSA/CS-AKP NPs exhibited excellent stability in the pH range (2-5) and after 15 days of storage, and could hinder the release of AKP in simulated gastric environment and promote the release of AKP in simulated intestinal environment. After simulated digestion, the hypoglycemic activity of encapsulated AKP was better than that of unencapsulated AKP.

CONCLUSION

Our results revealed that the BSA/CS showed great potential for protecting and delivering AKP. © 2024 Society of Chemical Industry.

Effect of molecular weight of chitosan on quercetin-loaded chitosan nanoparticles

BACKGROUND

The widespread use of quercetin is limited by its instability, low solubility and poor oral bioavailability. Encapsulation of quercetin using a nanoparticle delivery system is an effective way to overcome these drawbacks.

RESULTS

The effect of the molecular weight (Mw) of chitosan (CS) (100, 200, 500 and 1000 kDa) on quercetin-loaded chitosan nanoparticles (QCNPs) was investigated. The structure, stability, release properties and antioxidant activities of the nanoparticles (QCNP-10, QCNP-20, QCNP-50 and QCNP-100) were assessed. Particle size of QCNPs decreased and polydispersity index increased with the increasing Mw of CS. The main forces involved in the formation of QCNPs were hydrogen bonding and hydrophobic interaction. X-ray diffraction verified that quercetin was loaded into CS nanoparticles. The photostability and thermal stability of QCNPs increased with increasing Mw of CS. QCNP-100 exhibited the lowest release rate in a mixture of water and anhydrous ethanol. The antioxidant activities of QCNPs were enhanced with increasing Mw of CS, and QCNP-100 possessed the highest antioxidant activities, which might be relevant to its smallest particle size.

CONCLUSION

Overall, these results revealed that the Mw of CS affected the properties of QCNPs, and QCNP-100 possessed the smallest particle, best stability, lowest release rate and highest antioxidant activities. © 2024 Society of Chemical Industry.

Fabrication and characterization of curcumin-loaded composite nanoparticles based on high-hydrostatic-pressure-treated zein and pectin: Interaction mechanism, stability, and bioaccessibility

We successfully designed curcumin (Cur)-loaded composite nanoparticles consisting of high-hydrostatic-pressure-treated (HHP-treated) zein and pectin with a pressure of 150 MPa (zein-150 MPa-P-Cur), showing nano-spherical structure with high zeta-potential (-36.72 ± 1.14 mV) and encapsulation efficiency (95.64 ± 1.23 %). We investigated the interaction mechanism of the components in zein-150 MPa-P-Cur using fluorescence spectroscopy, molecular dynamics simulation, Fourier-transform infrared spectrometry and scanning electron microscopy techniques. Compared with zein-P-Cur, the binding sites and binding energy (-53.68 kcal/mol vs. - 44.22 kcal/mol) of HHP-treated zein and Cur were increased. Meanwhile, the interaction force among HHP-treated zein, pectin, and Cur was significantly enhanced, which formed a tighter and more stable particle structure to further improve package performance. Additionally, Cur showed the best chemical stability in zein-150 MPa-P-Cur. And the bioavailability of Cur was increased to 65.53 ± 1.70 %. Collectively, composite nanoparticles based on HHP-treated zein and pectin could be used as a promising Cur delivery system.

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

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

Nanoemulsions Based on Soluble Chenopodin/Alginate Complex for Colonic Delivery of Quercetin

Inflammatory bowel disease (IBD) is an autoimmune disorder caused by uncontrolled immune activation and the subsequent destruction of the colon tissue. Quercetin (Qt) is a natural antioxidant and anti-inflammatory agent proposed as an alternative to mitigate IBD. However, its use is limited by its low oral bioavailability. This study aimed to develop nanoemulsions (NEs) based on a soluble chenopodin/alginate (QPA) complex and Tween 80 (T80), intended for the colonic release of Qt, activated by the pH (5.4) and bacteria present in the human colonic microbiota. NEs with different ratios of QPA/Tw80 (F1-F6) were prepared, where F4Qt (60/40) and F5Qt (70/30) showed sizes smaller than 260 nm, PDI < 0.27, and high encapsulation efficiency (>85%). The stability was evaluated under different conditions (time, temperature, pH, and NaCl). The DSC and FTIR analyses indicated hydrophobic and hydrogen bonding interactions between QPA and Qt. F4Qt and F5Qt showed the greater release of Qt in PBS1X and Krebs buffer at pH 5.4 (diseased condition), compared to the release at pH 7.4 (healthy condition) at 8 h of study. In the presence of E. coli and B. thetaiotaomicron, they triggered the more significant release of Qt (ƒ2 < 50) compared to the control (without bacteria). The NEs (without Qt) did not show cytotoxicity in HT-29 cells (cell viability > 80%) and increased the antioxidant capacity of encapsulated Qt. Therefore, these NEs are promising nanocarriers for the delivery of flavonoids to the colon to treat IBD.

Effect of Amine, Carboxyl, or Thiol Functionalization of Mesoporous Silica Particles on Their Efficiency as a Quercetin Delivery System in Simulated Gastrointestinal Conditions

Quercetin (Q) dietary supplements exhibit poor oral bioavailability because of degradation throughout gastrointestinal digestion (GD), which may be overcome using mesoporous silica particles (MSPs) as an oral delivery system (ODS). This study aimed to elucidate the effect of the functionalization of MSPs with amine-(A-MSP), carboxyl-(C-MSP), or thiol-(T-MSP) groups on their efficiency as a quercetin ODS (QODS). The type and degree of functionalization (DF) were used as factors in an experimental design. The Q-loaded F-MSP (F-MSP/Q) was characterized by gas physisorption analysis, loading capacity (LC), and dynamic light scattering and kinetics of Q release at gastric and intestinal pHs. Antioxidant capacity and Q concentration of media containing F-MSP/Q were evaluated after simulated GD. A-MSP showed the highest LC (19.79 ± 2.42%). C-MSP showed the lowest particle size at pH 1.5 or 7.4 (≈200 nm). T-MSP exhibited the maximum Q release at pH 7.4 (11.43%). High DF of A-MSP increased Q retention, regardless of pH. A-MSP preserved antioxidant capacity of Q-released gastric media (58.95 ± 3.34%). Nonetheless, MSP and F-MSP did not protect antioxidant properties of Q released in intestinal conditions. C-MSP and T-MSP showed essential features for cellular uptake and Q release within cells that need to be assessed.

Nanocarriers for the Delivery of Quercetin to Inhibit the UV-Induced Aggregation of γD-Crystallin

Due to gradual environmental changes like ozone layer depletion and global warming, human eyes are exposed to UV light. Exposure to UV light can be a cause of cataracts, one of the ocular diseases that may cause vision impairment. To date, lens replacement has been the only treatment available for cataracts. In our present study, we carried out an extensive examination of polyphenols as inhibitors for UV-induced aggregation of γD-crystallin. On exposure to UV-C light, γD-crystallin forms fibrils instead of amorphous aggregates. Various polyphenols were tested as inhibitors; out of them, quercetin, baicalein, and caffeic acid were found to be effective. As polyphenols are insoluble in water, nanoencapsulation was used to enhance their bioavailability. CS-TPP and CS-PLGA encapsulating systems were considered, as they form biodegradable nanocapsules. Out of three polyphenols (quercetin, baicalein, and caffeic acid), quercetin forms nanocarriers of smaller sizes, a must for crossing the retinal barrier. Quercetin nanocarriers were considered an effective system that could be used for therapeutic applications. For these nanocarriers, encapsulation efficiency and polyphenol release kinetics were studied. CS-PLGA NPs were found to have a better loading efficiency for quercetin than CS-TPP NPs.

Comparison of milk protein concentrate, micellar casein, and whey protein isolate in loading astaxanthin after the treatment of ultrasound-assisted pH shifting

Milk proteins can be used as encapsulation walls to increase the bioavailability of active compounds because they can bind hydrophobic, hydrophilic, and charged compounds. The objective of this study was to investigate the effects of astaxanthin (ASTA) encapsulation and the functional properties of milk protein and ASTA nanocomposites by an ultrasound-assisted pH-shifting treatment of different milk proteins, including milk protein concentrate (MPC), micellar casein (MCC), and whey protein isolate (WPI). The ultrasound-assisted pH-shifting treatment of milk protein helped to improve the encapsulation rate of ASTA. Therein, MCC showed great improvement of encapsulating ASTA after co-treatment with the raised encapsulated rate of 5.11%, followed by WPI and MPC. Furthermore, the nanocomposites of ASTA with milk protein exhibit improved bioavailability, antioxidant capacity, and storage stability. By comparison, MCC-encapsulated ASTA has the best storage stability, followed by MPC, and WPI-encapsulated ASTA has the least stability over a 28-d storage period. The results of intrinsic fluorescence and surface hydrophobicity showed that milk protein underwent fluorescence quenching after binding to ASTA, which was due to the hydrophobic sites of the protein being occupied by ASTA. In general, the nanocomposites of milk protein and ASTA fabricated by using an ultrasound-assisted pH-shifting treatment have the potential to be better nano-delivery systems for ASTA in functional foods, especially MCC, which showed excellent performance in encapsulation after treatment technique.

A polyglutamic acid/tannic acid-based nano drug delivery system: Antibacterial, immunoregulation and sustained therapeutic strategies for oral ulcers

Oral ulcers are a common inflammatory mucosal ulcer, and the moist and dynamic environment in the oral cavity makes topical pharmacological treatment of oral ulcers challenging. Herein, oral ulcer tissue adhesion nanoparticles were prepared by using esterification reaction between polyglutamic acid and tannic acid, and at the same time doxycycline hydrochloride was loaded into the nanoparticles. The obtained slow drug release effect of the drug-loaded nanoparticles reduced the toxicity of the drug, and by penetrating into the fine crevice region of the wound tissue and adhering to it, they could in-situ release the carried drug more effectively and thus have shown significant antibacterial effects. In addition, tannic acid in the system conferred adhesion, antioxidant and immune regulation activities to the nanocarriers. A rat oral ulcer model based on fluorescent labeling was established to investigate the retention of nanoparticles at the ulcer, and the results showed that the retention rate of drug-loaded nanoparticles at the ulcer was 17 times higher than that of pure drug. Due to the antibacterial and immune regulation effects of the drug-loaded nanoparticles, the healing of oral ulcer wounds was greatly accelerated. Such application of doxycycline hydrochloride loaded polyglutamic acid/tannic acid nanoparticles is a novel and effective treatment strategy for oral ulcer.

Improvement of physicochemical properties, microstructure and stability of lotus root starch/xanthan gum stabilized emulsion by multi-frequency power ultrasound

Multi-frequency power ultrasound was applied as an environmentally friendly technique to control the nanoparticles (LS/XG-NPs) embedded with lotus root starch/xanthan gum, with the aim of enhancing the stability of Pickering emulsions. The present investigation was centered on evaluating the impact of ultrasound technology on various aspects of the emulsions, encompassing their mean particle size, particle size distribution, zeta potential, microstructure, rheological characteristics, and environmental stability. The findings of this study indicate that ultrasonic treatment enhanced the adsorption of LS/XG-NP onto oil droplets surface, resulting in a reduction in their size. Additionally, ultrasonic treatment decreased the viscosity and Brownian motion rate of the emulsion stabilized by LS/XG-NP, leading to increased fluidity. Furthermore, the emulsion's thermal stability and resistance to environmental oxidation were significantly enhanced through ultrasonic treatment. The Pickering emulsions that were prepared using ultrasound demonstrated excellent resistance to acid, alkali (pH 2-8) and salt ions (50-300 mM NaCl) for a period of 30 days during storage. It was worth anticipating that ultrasound-assisted LS/XG-NPs could efficiently retard the volatilization of fishy odor components within fish oil. Taken together, the present research has evinced the efficacy of ultrasound in enhancing the stability of Pickering emulsions coated with LS/XG-NPs. These findings offer significant novel insights into the advancement of ultrasound-assisted Pickering emulsions that are stabilized with starch-based or biopolymeric materials.

Peptides as carriers of active ingredients: A review

Bioactive compounds are highly valuable in the fields of food and medicine, but their application is limited due to easy deterioration after oral or skin administration. In recent years, the use of peptides as delivery systems for bioactive compounds has been intensively researched because of their special physicochemical characteristics. Peptides can be assembled using various preparation methods and can form several composite materials such as hydrogels, micelles, emulsions and particles. The composite material properties are determined by peptides, bioactive compounds and the construction methods employed. Herein, this paper provides a comprehensive review of the peptides used for active ingredients delivery, fabrication methods for creating delivery systems, structures, targeting characteristics, functional activities and mechanism of delivery systems, as well as their absorption and metabolism, which provided theoretical basis and reference for further research and development of functional composites.

High internal phase Pickering emulsions stabilised by ultrasound-induced soy protein-β-glucan-catechin complex nanoparticles to enhance the stability and bioaccessibility of curcumin

AIMS

To evaluate the potential applications of soy protein-glucan-catechin (SGC) complexes prepared with different ultrasound times in stabilising high internal phase Pickering emulsion (HIPPE) and delivering curcumin.

METHODS

The SGC complexes were characterised by particle size, morphology, zeta potential, Fourier transform infra-red, and fluorescence spectroscopy. Formation and stability of curcumin emulsions were monitored by droplet size, microstructure, rheological property, lipid oxidation, and in vitro digestion.

RESULTS

Short-time ultrasound-induced complexes (SGC-U15) exhibited a small size and wettability of ∼82.5°. The chemical stability and bioaccessibility of curcumin was greatly improved by SGC-U15-stabilised HIPPEs, even after 70 days of storage, heating at 100 °C for 30 min, ultraviolet irradiation for 120 min, and in vitro digestion, owing to the formation of elastic gel-like structure at the oil/water interfaces.

CONCLUSION

Our findings may contribute to the design of emulsion-based delivery systems using ultrasound-induced protein-polysaccharide-polyphenol complexes.

Structure relationship of non-covalent interactions between lotus seedpod oligomeric procyanidins and glycated casein hydrolysate during digestion

Procyanidin-amino acid interactions during transmembrane transport cause changes in the structural and physical properties of peptides, which limits further absorption of oligopeptide-advanced glycation end products (AGEs). In this study, glycated casein hydrolysates (GCSHs) were employed to investigate the structure and interaction mechanism of GCSH with lotus seedpod oligomeric procyanidin (LSOPC) complexes in an intestinal environment. LSOPC can interact with GCSH under certain conditions to form hydrogen bonds and hydrophobic interactions to form GCSH-LSOPC complexes. Results showed that procyanidin further leads to the transformation of a GCSH secondary structure and the increase of surface hydrophobicity (H0). The strongest non-covalent interaction between GCSH and (-)-epigallocatechin gallate (EGCG) was due to the polyhydroxy structure of EGCG. Binding site analysis showed that EGCG binds to the internal cavity of P1 to maintain the relative stability of the binding conformation. The antioxidant capacity of GCSH was remarkably elevated by GCSH-LSOPC. This study will provide a new reference for the accurate control of oligopeptide-AGEs absorption by LSOPC in vivo.

Mechanism of ultrasonic combined with different fields on protein complex system and its effect on its functional characteristics and application: A review

In recent years, new food processing technologies (such as ultrasound, high-pressure homogenization, and pulsed electric fields) have gradually appeared in the public 's field of vision. These technologies have made outstanding contributions to changing the structure and function of protein complexes. As a relatively mature physical field, ultrasound has been widely used in food-related fields. However, with the gradual deepening of related research, it is found that the combination of different fields often makes some characteristics of the product better than the product under the action of a single field, which will not only lead to a broader application prospect of the product, but also make the product a better solution in some special fields. There are usually synergistic and antagonistic effects when multiple fields are combined, and these effects will also gradually enlarge the interaction between different components of the protein complex system. In this paper, while explaining the mechanism of ultrasonic combined with other fields affecting the steric hindrance and shielding site of protein complex system, we will further explain the effect of this effect on the function and application of protein complex system.

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

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

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

The health benefits of quercetin are limited by its low bioaccessibility. This could be improved by developing plant-based protein delivery systems. Encapsulating quercetin using untreated and high-intensity ultrasound treated (20 kHz at 139 W for 10, 15 and 20 min) soy protein isolate (SPI) produced composite nanoparticles at around 127-136 nm. Ultrasound treatments on SPI caused structural changes of proteins (e.g. around 6-fold increase of surface hydrophobicity and protein solubility) favorable to encapsulation. The encapsulation efficiency for quercetin complexed with 15 min ultrasound treated SPI (76.5 %) was around 10-fold of that with the native SPI (7.2 %). Quercetin was significantly more in vitro bioaccessible when complexed with the treated SPI (61.1 %-64.5 %), as compared to the free quercetin (10.5 %-13.0 %). Ultrasound treated SPI seems to be a promising nanocarrier to encapsulate hydrophobic bioactive ingredients with higher solubility, stability, and bioaccessibility.

The comparison between zein-anthocyanins complex and nanoparticle systems: Stability enhancement, interaction mechanism, and in silico approaches

This research aimed to compare and characterize the physicochemical properties and interaction mechanism of zein and anthocyanins (ACNs) from experimental and theoretical perspectives. Zein-ACNs complex (ZACP) was prepared by mixing ACNs with different concentrations of zein, and zein-ACNs nanoparticles (ZANPs) were formed using ultrasound-assisted antisolvent precipitation method. The hydrated particle sizes of the two systems were 590.83 nm and 99.86 nm, respectively, and observed to be spherical under transmission electron microscopy (TEM). The multi-spectroscopy approaches confirmed hydrogen bonding and hydrophobic forces were the dominant forces for stabilizing ACNs. The retention of ACNs, color stability and antioxidant activities were also improved in both systems. Furthermore, molecular simulation results were consistent with the multi-spectroscopy findings, which clarified the contribution of van der Waals forces to the binding of zein and ACNs. This study provided a practical approach for stabilizing ACNs and expanding the utilization of plant proteins as stabilization systems.

Effect of Black Tea Powder on Antioxidant Activity and Gel Characteristics of Silver Carp Fish Balls

The effect of black tea powder on the antioxidant activity and gel characteristics of fish balls from silver carp were investigated after freezing storage for 7 days. The results show that black tea powder with different concentrations of 0.1%, 0.2% and 0.3% (w/w) could significantly increase the antioxidant activity of fish balls (p < 0.05). In particular, at the concentration of 0.3%, the antioxidant activity was the strongest among these samples, where the reducing power, DPPH, ABTS and OH free radical scavenging rate were up to 0.33, 57.93%, 89.24% and 50.64%, respectively. In addition, black tea powder at the level of 0.3% significantly increased the gel strength, hardness and chewiness while greatly reducing the whiteness of the fish balls (p < 0.05). ESEM observation found that the addition of black tea powder could promote the crosslinking of proteins and reduced the pore size of the gel network structure of the fish balls. The results suggest that black tea powder could be used as a natural antioxidant and gel texture enhancer in fish balls, which we found to be much related to the phenolic compounds of black tea powder.

Industrial Application of Protein Hydrolysates in Food

Protein hydrolysates, which may be produced by the protein in the middle of the process or added as an ingredient, are part of the food formula. In food, protein hydrolysates are found in many forms, which can regulate the texture and functionality of food, including emulsifying properties, foaming properties, and gelation. Therefore, the relationship between the physicochemical and structural characteristics of protein hydrolysates and their functional characteristics is of significant importance. In recent years, researchers have conducted many studies on the role of protein hydrolysates in food processing. This Review explains the relationship between the structure and function of protein hydrolysates, and their interaction with the main ingredients of food, to provide reference for their development and further research.

Ultrasound-assisted development and characterization of novel polyphenol-loaded pullulan/trehalose composite films for fruit preservation

A novel food packaging film was developed by incorporating a tea polyphenols-loaded pullulan/trehalose (TP@Pul/Tre) into a composite film with ultrasound-assisted treatment of dual-frequency (20/35 kHz, 40 W/L) for 15 min to assess the physicochemical and mechanical properties of a composite film. The optimized ultrasound-assisted significantly increases elongation at break, tensile strength, and improves the composite film's UV/water/oxygen barrier properties. Structure analysis using attenuated total reflectance-Fourier transform infrared, X-ray diffraction and thermal stability revealed that these improvements were achieved through ultrasound-enhanced H-bonds, more ordered molecular arrangements, and good intermolecular compatibility. Besides, the ultrasound-assisted TP@Pul/Tre film has proven to have good antibacterial performance against Escherichia coli and Staphylococcus aureus, with approximately 100 % lethality at 4 h and 8 h, respectively. Moreover, the ultrasound-assisted TP@Pul/Tre film effectively delayed moisture loss, oxidative browning, decay, and deterioration in fresh-cut apples and pears, thereby extending their shelf life. Thus, ultrasound has proved to be an effective tool for improving the quality of food packaging films, with a wide range of applications.

Chitosan-Polyphenol Conjugates for Human Health

Human health deteriorates due to the generation and accumulation of free radicals that induce oxidative stress, damaging proteins, lipids, and nucleic acids; this has become the leading cause of many deadly diseases such as cardiovascular, cancer, neurodegenerative, diabetes, and inflammation. Naturally occurring polyphenols have tremendous therapeutic potential, but their short biological half-life and rapid metabolism limit their use. Recent advancements in polymer science have provided numerous varieties of natural and synthetic polymers. Chitosan is widely used due to its biomimetic properties which include biodegradability, biocompatibility, inherent antimicrobial activity, and antioxidant properties. However, due to low solubility in water and the non-availability of the H-atom donor, the practical use of chitosan as an antioxidant is limited. Therefore, chitosan has been conjugated with polyphenols to overcome the limitations of both chitosan and polyphenol, along with increasing the potential synergistic effects of their combination for therapeutic applications. Though many methods have been evolved to conjugate chitosan with polyphenol through activated ester-modification, enzyme-mediated, and free radical induced are the most widely used strategies. The therapeutic efficiency of chitosan-polyphenol conjugates has been investigated for various disease treatments caused by ROS that have shown favorable outcomes and tremendous results. Hence, the present review focuses on the recent advancement of different strategies of chitosan-polyphenol conjugate formation with their advantages and limitations. Furthermore, the therapeutic applicability of the combinatorial efficiency of chitosan-based conjugates formed using Gallic Acid, Curcumin, Catechin, and Quercetin in human health has been described in detail.

Improving effect of oleic acid-mediated sodium caseinate-based encapsulation in an ultrasound field on the thermal stability and bioaccessibility of quercetin

The simultaneous improvement of quercetin (QUE) processing stability and bioavailability has always presented a technical challenge during food processing. This study constructed a water-soluble carrier consisting of oleic acid (OA) and sodium caseinate (NaCas) in an ultrasonic field and investigated the effect of its encapsulation on improving the thermal stability and bioaccessibility of QUE. The results showed that the OA and NaCas generated uniform, stable water-soluble particles with a poly dispersity index (PDI) below 0.3 and an absolute value of Zeta potential above 30 mV in optimized conditions (a protein concentration of 4 mg/mL, ultrasonic power of 300 W, and ultrasonic time of 5 min). OA-NaCas mass ratio of 1:40, 1:15, 1:8, and 1:4 was selected for QUE loading to compare its encapsulation effect at different mass ratios. Compared with the NaCas without OA, the QUE embedding rate reached 95 % at OA-NaCas mass ratios of 1:15 and 1:8. In addition, the transmission electron microscopy (TEM) images confirmed that QUE was embedded in OA-NaCas particles, forming regular, spherical OA-NaCas-QUE particles at mass ratios or 1:15 and 1:8. Next, when heated at 80 °C for 120 min, the OA-NaCas (OA:NaCas, 1:15, 1:8, and W/W) particles significantly improved the QUE retention rate. The simulated in vitro gastrointestinal digestion experiments showed that the QUE bioaccessibility increased from 25 % to more than 60 % when it was encapsulated in OA-NaCas (OA:NaCas, 1:15, 1:8, and W/W) particles. These results indicated that the OA-NaCas complex was suitable as a hydrophilic delivery carrier of fat-soluble polyphenols.

Ultrasound-alkaline combined extraction improves the release of bound polyphenols from pitahaya (Hylocereus undatus 'Foo-Lon') peel: Composition, antioxidant activities and enzyme inhibitory activity

In this study, ultrasound-assisted alkaline hydrolysis was used to extract polyphenols from pitahaya peel. The effects of sonication time, ultrasonic density, NaOH concentration and the liquid-material ratio on the total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity of the extracts were studied. The composition and content difference of the extracts were analyzed and the inhibitory effect of α-amylase and α-glucosidase was measured. The results of single-factor analysis showed that when the sonication time was 45 min, the ultrasonic density was 32 W/L, the NaOH solution concentration was 6 M and the liquid-material ratio was 30 mL/g, the release of phenolic compounds was the largest and the antioxidant activity was the strongest. An UPLC-QTOF-MS/MS method was used to analyze the components and contents of the extracts. We found that there was a great difference in the component content of the free polyphenol extract and the bound polyphenol extract. From the results, we concluded that there was a strong correlation between the type and content of phenolic compounds and antioxidant activities, indicating that phenolic compounds were the main compounds of these biological activities. Moreover, the bound polyphenol extracts showed a significant inhibitory effect on α-amylase and α-glucosidase was stronger than that of the free polyphenol extracts. In addition, scanning electron microscopy showed that ultrasound-assisted extraction is crucial to the destruction of the cell wall and the release of bound polyphenols. Therefore, the pitahaya peel has the potential for therapeutic, nutritional, and functional food applications, and ultrasound-assisted alkaline hydrolysis is an effective means to release phenolic compounds.