pH-driven encapsulation of curcumin in self-assembled casein nanoparticles for enhanced dispersibility and bioactivity

Microfluidization based nano/sub-micron curcumin formulations for food and nutraceuticals: Physico-functional characteristics and safety aspects

Curcumin is extensively used natural polyphenol with tremendous health benefits that are compromised due to its low water solubility, rapid degradation of its metabolites and low-bioavailability. It degrades during processing or in gastrointestinal tract and alkaline conditions leading to low bioavailability. These limitations have attracted many researchers' attention to improve its bioaccessibility and stability through several techniques by reducing its particle size. Microfluidization has progressed as a promising technique to achieve the micro and nano-sized curcumin. This review discusses microfluidics-based attempts to formulate submicron and nano-sized curcumin formulations for food and functional food applications. It highlights challenges associated with obtaining nano-sized curcumin, and subsequent improvement in the bioaccessibility/bioavailability through microfluidization. Further, the safety of such processed formulations as well as that of microfluidization and critical research gaps has also been discussed. This review shall provide a fresh perspective on effective utilization of microfluidized curcumin formulations for food & nutraceuticals applications.

Influence of the maturity on the characteristics of orange-derived extracellular vesicles and their delivery performance for curcumin

Plant-derived extracellular vesicles have considerable potential as natural pharmaceutical and nutraceutical delivery systems. However, the impact of plant maturity on the physicochemical and structural properties of isolated extracellular vesicles is currently unknown. In this work, extracellular vesicles isolated from oranges at different maturity stages were first characterized and compared. Afterwards, polyphenol-load orange juices were successfully prepared by incorporating polyphenols (mainly curcumin) into extracellular vesicles originated from orange juices. Encapsulation in vesicles was found to increase the solubility, stability, bioaccessibility, and antioxidant activity of curcumin, but the effects depended on the maturity of oranges. Specifically, the vesicles from unripe and ripe orange juices were more effective for curcumin delivery than those from overripe orange juice. Conclusively, this study has provided important new information about the optimum maturity for isolating fruit-derived extracellular vesicles. Moreover, the extracellular vesicle-based delivery systems developed in this study may facilitate the design of more effective functional foods and beverages.

pH shifting treatment of egg yolk granules /salted ovalbumin mixed gels: Reassembled of egg yolk granules effects on heat-induced amorphous aggregates

In this study, we propose three methods of acidic pH shifting of egg yolk granules (EYGs) to investigate effects of EYGs structure on properties of EYGs-salted ovalbumin (SO) gels. Different pH parameters affect protein unfolding behavior, as well as assembly of high-density lipoprotein (HDL) and phosvitin during acidification. The main mechanism was a change in the microenvironment of hydrophobic amino acid residues and new hydrogen bonds, which induced the reassembly. Besides, low-content EYGs increased the mixed gel network structure density, cohesiveness (0.12-0.14) and chewiness (29.46-49.11). While mixed gels with high content EYGs had higher hardness and recovery rate, and were more tightly bound to water molecules. EYGs-4-6 exhibited greater hydrogen bonding forces, which could lead to a more rigid network and greater potential for use as an active filler. Our study tracked the trajectory of pH-shifting preparations of reassembled EYGs while providing new insight into nutritional value of SO gel.

Effects of colloidal delivery systems for curcumin encapsulation and delivery

The types of colloidal delivery systems impact curcumin encapsulation properties, including stability, spray-dried powder properties, business-concerned properties, and loading capacity. Therefore, it is crucial to comprehensively compare the curcumin encapsulation properties of different colloidal delivery systems. Four systems (sodium caseinate, β-cyclodextrin, liposome, soy protein isolate) were used to encapsulate curcumin. Powder characterization revealed that curcumin-loaded sodium caseinate exhibited high curcumin loading capacity (5.10 %), free radical scavenging rate (89.8 %), re-dispersibility, and transmittance of re-dispersed solution (92 %), while curcumin-loaded β-cyclodextrin demonstrated satisfactory hygroscopicity (5.3 %) and D90 particle size (215.5 nm). Stability tests indicated that curcumin-loaded sodium caseinate exhibited superior physicochemical stability except for photo stability, whereas curcumin-loaded β-cyclodextrin exhibited good photo stability. Physicochemical stability of the other two systems was unsatisfactory. In summary, curcumin encapsulation performance varied significantly among systems, with sodium caseinate emerging as a high-performance curcumin nanocarrier with potential for beverage industry applications.

Enhancing the Viability of Spray-Dried Limosilactobacillus fermentum Using Quercetin-Integrated Encapsulation: Physicochemical, Metabolic, and Transcriptomic Insights

The application of spray drying for the production of probiotic microcapsules offers many attractive advantages, yet now there are concerns regarding probiotic survivability. This study explores the impact of quercetin (Que) in a whey protein isolate (WPI) and trehalose (TR) encapsulation matrix to improve probiotic survival during spray drying. Results showed that probiotic survival increased by 4.95-fold (p < 0.05) with Que supplementation than the probiotics capsulated using WPI and TR. Physicochemical characteristics analysis indicated that adding Que resulted in slight changes in the moisture and water activity of probiotic microcapsules and improved the gastrointestinal digestion resistance and storage stability. The particle size of the spray-dried microcapsules varied from 9.84 to 11.17 µm. Cell membrane analysis demonstrated that the probiotics encapsulated with the WPI-Que-TR complex exhibited higher integrity and fluidity than WPI-TR-coated probiotics. Moreover, introducing Que reduced the ratio of saturated to unsaturated fatty acids and increased the pyruvate kinase activity of probiotics, contributing to the maintenance of cell activity. Transcriptomic results suggested that Que upregulated genes associated with fatty acid synthesis and energy supply while downregulating certain genes involved in amino acid biosynthesis, enabling probiotics to exist better in harsh conditions. Therefore, those results indicated that the co-microencapsulation of probiotics and hydrophobic active substance-Que-was realized, and the mechanism by which Que affects probiotic activity during spray drying has been revealed, which provides a scientific foundation for co-encapsulating probiotics with hydrophobic actives. PRACTICAL APPLICATION: In a rapidly growing market, the demand for dry probiotics has surged, highlighting the need for mass production. Spray drying, with its low energy costs and sustainable process, is a promising method for microencapsulating bacteria in protective substrates, enhancing their resistance during storage, processing, and digestion. Que can improve the survival rate of probiotics during spray drying, offering a novel approach for incorporating flavonoids in the creation of probiotic microcapsules with activity and stability.

Baicalin-loaded peony seed polypeptide nanoparticles via a pH-driven method: Characterization, release kinetics, and in vitro anti-inflammatory effects

Baicalin (BA), a flavonoid with diverse bioactivities, faces clinical application challenges due to its poor solubility, low bioavailability, and limited stability. This study reports on the development of BA-loaded peony seed polypeptide nanoparticles (BA-PSP NPs) using a pH-driven method to overcome these limitations. These nanoparticles (NPs) were spherical, 88.20 ± 2.19 nm in size, with a zeta potential of -35 mV, demonstrating excellent stability under thermal, pH, salt ion, and storage conditions. Physicochemical assays confirmed that BA was encapsulated in an amorphous state within the peony seed peptide matrix, with an encapsulation efficiency of 81.37 ± 0.57 %. The nanosystem effectively protected BA from degradation in simulated gastrointestinal environments. In vitro assays revealed that BA-PSP NPs exerted a superior anti-inflammatory effect compared to free BA mediated via inhibiting pro-inflammatory factor secretion (IL-1β, IL-6, and TNF-α) and promoting anti-inflammatory factor production (IL-10) in LPS-induced RAW264.7 cells, as well as validated via qPCR for corresponding mRNA regulation. This study develops pH-driven self-assembled peony seed peptide nanoparticles as green and safe colon-targeted carriers, effectively encapsulating polyphenols with enhanced stability and bioavailability, thereby providing technical support for functional food development and precision nutraceutical delivery systems.

A 3D bioprinted gelatin/quaternized chitosan/decellularized extracellular matrix based hybrid bionic scaffold with multifunctionality for infected full-thickness skin wound healing

Skin wound repair, a highly integrated and overlapping process, is susceptible to infection, hyperoxia and excessive inflammation, which can delay wound healing or even lead to chronic wounds. In this study, a GQL/dGQue bilayered multifunctional scaffold, epidermis composed of gelatin (G), quaternized chitosan (Q) and lignin (L), and dermis composed of skin-derived decellularized extracellular matrix (d), gelatin and quercetin (Que), with bionic skin structure, was constructed by 3D bioprinting technology. The results showed that lignin effectively improved the mechanical properties (Young's modulus above 90 MPa) and regulated the appropriate degradation (about 84 % for 15 d) of the scaffold, as well as endowed it with good UV shielding properties. In addition, GQL/dGQue showed prominent antibacterial activity of 90.76 ± 4.94 % and 90.34 ± 4.14 % against E. coli and S. aureus, respectively, good free radical scavenging (87.22 ± 1.71 %) and significant anti-inflammatory properties. In vivo studies demonstrated that GQL/dGQue scaffold could effectively prevent wound infection and mitigate inflammation, thereby accelerating vascularization and regeneration of hair follicle and sebaceous gland with a remarkable wound closure of 98.29 ± 1.77 % at 21 d. Therefore, the GQL/dGQue bilayered multifunctional scaffold has a considerable potential to apply in skin tissue engineering for clinical wound repair.

Eco-friendly nano colloids for enhanced black gram (Vigna mungo) seed viability: experimental and computational analysis

An experiment was designed to fabricate Polyvinylpyrrolidone-coated zein-zipped herbal molecules infused nano colloids (PZCA-NCs) for extending Vigna mungo seeds storability. PZCA-NCs was synthesized and characterized in Fourier Transform Infrared Spectroscopy (FTIR), X-Ray diffraction (XRD), Particle size analyser, Zeta Potential, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Energy-dispersive X-ray spectroscopy (EDAX). The bio-efficacy of PZCA-NCs on seed storability was tested under accelerated ageing. The sphere-shaped PZCA-NCs possess a 151 nm size with 44.5mV zeta potential at an encapsulation of 73.44% curcumin and 69.0% azadirachtin. The spectra of FTIR, UV -Vis, XRD, and TGA confirmed the functionality, composition, and stability of PZCA-NCs. The dialysis diffusion method was utilised to study the maximum cumulative release of biomolecules 6.1ppm (88.4%) azadirachtin and 64.57ppm (88.2%) curcumin at pH 7.4. Density functional theory (DFT) was used to determine the binding mode of molecules and examine ligand interactions in PZCA-NCs. PZCA-NCs treated seeds at 25 mL/kg enumerated higher germination, vigour index, α-amylase, dehydrogenase, and catalase and peroxidase activity under ageing. Seeds storage pathogen infection was reduced with an increase in the concentration of PZCA-NCs coating. The bioassay results on insect activity evidenced that PZCA-NCs at 15.76 mL/kg killed 50% and 40 mL/kg killed 100% of the storage insect Callosobruchus maculatus. Toxicity study on Macrophomina phaseolina showed that PZCA-NCs at 35 mL resulted in 0.8 cm mycelia growth with 91.11% inhibition zone, while at 45 mL had zero growth of fungal mycelia with 100% inhibition. The study concludes that PZCA-NCs act as an efficient seed invigoration material to extend the vitality of Vigna mungo seeds during ageing.

Enhanced solubility, stability, bioaccessibility, and antioxidant activity of curcumin with hydrolyzed pea protein-based nano-micelles: pH-driven method vs ethanol-induced method

Pea protein nano-micelles gained with partial hydrolysis by a proteolytic enzyme (Protamex) were employed as nanocarriers to encapsulate and stabilize liable and hydrophobic curcumin (CUR) with two various methods (pH-driven method (PDM) and ethanol-induced method (EIM)). Both CUR-loaded pea protein hydrolysates (PPHs) nano-micelles by PDM and EIM exhibited spherical shapes, and uniform particle size distributions. Highest CUR loading amount (3.21 %) was gained with PPHs by PDM. The interaction between PPHs nano-micelles and curcumin was comprehensively examined with optical spectroscopy. These outcomes obviously demonstrated the water solubility, storage stability against UV light and heating, bioaccessibility and in vitro antioxidant activity of CUR can be pronouncedly enhanced with PPHs-based nanocarriers. Interestingly, PPHs-CUR nano-micelles fabricated with PDM have higher loading amount, light stability, and better bioaccessibility as well as antioxidant activity than those by EIM. These results clearly show that PDM may be a better method than EIM and provide useful information in nutraceuticals encapsulation with vegetable proteins-based delivery systems.

Formation of bovine serum albumin-galangin nanoparticles and their potential to inhibit reactive oxygen species-induced inflammation: Ethanol desolvation versus pH-shifting method

The pH-shifting method, as an ecofriendly approach, is a promising alternative to the desolvation method, yet systematic comparison of their properties is still lacking. In this study, BSA-galangin nanoparticles (BSA-GA NP) were designed for alleviating reactive oxygen species (ROS)-mediated macrophage inflammation by the 2 separate methods. Compared with the desolvation method, BSA exhibited a higher loading capacity for GA under the pH-shifting method, which was attributed to the exposure of the binding site leading to enhanced affinity for GA and a more compact particle structure. Further analyses evidenced that the electron arrangement and crystal structure of GA changed with different methods. The content of the random coil of BSA was elevated after the pH-shifting method. Additionally, the smaller size rendered the pH-shifting treated BSA-GA NP easier to be taken up by macrophages, and the enhanced specific surface area conferred excellent ROS scavenging and anti-inflammatory performances. This study may provide new insights into the choice of loading methods.

An Improved pH-Driven Method for Upcycling Polyphenols from Plants or Byproducts into Foods

The incorporation of polyphenols into food systems provides various health benefits, yet their stability and bioactivity are often compromised by processing conditions. In this study, we advanced the pH-driven method for processing highly pH-sensitive polyphenols, such as quercetin, by optimizing operating conditions, including minimizing oxygen exposure and reducing operating times. As a result, an improved post-pH-driven (PPD) method was developed to encapsulate pH-sensitive quercetin into nanoemulsions with an encapsulation efficiency exceeding 95%, indicating that this method could be broadly applicable for incorporating various polyphenols. For example, it has been successfully applied to upcycle plant polyphenols from peanut skin into nanoemulsions, serving as a representative food model. The PPD method demonstrated superior performance compared to a conventional water-based method, achieving 1.8 times higher remaining percentage of total polyphenolic content. Additionally, the PPD-based nanoemulsions exhibited significantly enhanced antioxidant properties, with DPPH and ABTS radical scavenging activities increasing by 3.7 and 2.8 times, respectively, compared to the water-based method. These findings underscore the potential of the PPD method as a versatile and efficient approach for developing polyphenol-powered foods by upcycling plant byproducts and improving processing efficiency.

Harnessing pH for sustainable and effective synthesis of phenolic compound-loaded nanoparticles directly from raw plants

While considerable efforts have been made to develop phenolic compound-loaded nanoparticles for applications in foods, pharmaceuticals, and agriculture, current production methods fall short in sustainability, efficiency, and cost-effectiveness. This study introduces a pH-based "raw-to-nano" strategy to produce phenolic compound-loaded nanoparticles directly from raw plants. Curcumin-loaded nanoparticles were first formulated from raw turmeric, with an average size of 141.3 ± 2.8 nm and a surface charge of -23.3 ± 0.7 mV. Nanoparticles are stabilized by electrostatic interactions at pH 7, but stability decreases under acidic conditions (pH < 5), which could limit certain applications in acidic beverages. Based on pH effects and microstructures, a core-shell model is proposed, where acidic polysaccharides coat the surface, and insoluble branched starches form the inner phase, trapping hydrophobic curcumin molecules. This strategy successfully applies to other plants like ginger, paprika, and thyme, enabling versatile nanoparticle synthesis for practical applications in various aspects.

Characterization, in vitro elderly digestion, and organoids cell uptake of curcumin-loaded nanoparticles

Curcumin, a bioactive compound, showed versatile in anti-inflammatory and anti-cancer ability, while their biological fate in elderly is unclear. In this study, curcumin-loaded nanoparticles based on octyl succinate hydrate (OSA) starch and sodium caseinate were prepared and the in vitro elderly digestion and absorption fate was investigated. The loading capacity of curcumin-loaded nanoparticles prepared from OSA starch (HI), sodium caseinate (SC) and OSA starch‑sodium caseinate (HS) were all higher than 15%. Curcumin release behavior of the three nanoparticles during in vitro digestion conformed to first-order kinetics. Meanwhile, the transport efficiency of curcumin for HI, SC, and HS increased significantly than the free curcumin (near 1-fold), and the permeability were 1.9, 2.0, and 2.0 times, respectively. The gene expressions of TNF-α, SREBP2 and NPC1L1 in the organoids were enhanced than control group. This study provided scientific reference and guidance for encapsulation of curcumin and digestion and absorption properties in elderly.

Advances of curcumin in nervous system diseases: the effect of regulating oxidative stress and clinical studies

In recent years, researchers have highly observed that neurological disorders (NSDs) with the aging of the population are a global health burden whose prevalence is increasing every year. Previous evidence suggested that the occurrence of neurological disorders is correlated with predisposing factors such as inflammation, aging, and injury. Particularly, the neuronal cells are susceptible to oxidative stress, leading to lesions caused by high oxygen-consuming properties. Oxidative stress (OS) is a state of peroxidation, which occurs as a result of the disruption of the balance between oxidizing and antioxidizing substances. The oxidative intermediates such as free radicals, hydrogen peroxide (H2O2), and superoxide anion (O2-) produced by OS promote disease progression. Curcumin, a natural diketone derived from turmeric, is a natural antioxidant with a wide range of neuroprotective, anti-inflammatory, anti-tumor, anti-aging, and antioxidant effects. Fortunately, curcumin is recognized for its potent antioxidant properties and is considered a promising candidate for the prevention and treatment of neurological diseases. Consequently, this review elucidates the mechanisms by which curcumin mitigates oxidative stress and emphasizes the potential in treating nervous system disorders, including depression, Alzheimer's disease, Parkinson's disease, epilepsy, subarachnoid hemorrhage, and glioblastoma. We aim to provide a new therapeutic option for the management of neurological diseases.

Encapsulation of polyphenols in protein-based nanoparticles: Preparation, properties, and applications

Polyphenols have a variety of physiological activities, including antioxidant, antimicrobial, and anti-inflammatory properties. However, their applications are often limited because due to the instability of polyphenols. Encapsulation technologies can be employed to overcome these problems and increase the utilization of polyphenols. In this article, the utilization of protein-based nanoparticles for encapsulating polyphenols is reviewed due to their good biocompatibility, biodegradability, and functional attributes. Initially, the various kinds of animal and plant proteins available for forming protein nanoparticles are discussed, as well as the fabrication methods that can be used to assemble these nanoparticles. The molecular interaction mechanisms between proteins and polyphenols are then summarized. Applications of protein-based nanoparticles for encapsulating polyphenols are then discussed, including as nutrient delivery systems, in food packaging materials, and in the creation of functional foods. Finally, areas where further research is need on the development, characterization, and application of protein-based polyphenol-loaded nanoparticles are highlighted.

Perilla oil emulsions stabilized by casein-dextran sulfate nanocomplexes with and without curcumin

Protein-polysaccharide nanocomplexes are potential particulate emulsifiers to improve physical and chemical stability of emulsions containing polyunsaturated fatty acids. This study prepared nanocomplex dispersions with 2.0 % w/v sodium caseinate and 0-0.4 % w/v dextran sulfate (DS) with and without 0.1 % w/v curcumin. The dispersions exhibited a Z-average diameter of 124.61-182.46 nm, a polydispersity index of 0.37-0.52, and a zeta potential between -30.1 and -34.9 mV, with a curcumin encapsulation efficiency of higher than 75 %. These nanocomplexes were used to emulsify 60 % v/v perilla oil (PO) through shear homogenization and sonication. Emulsions showed discrete droplets in light and confocal laser scanning microscopy. The creaming index decreased as DS concentration increased, remaining below 6 % after 30 days of storage Emulsions had >70 % DS, >80 % caseinate, and 100 % curcumin adsorbed on the oil droplet surface. For oxidative stability at 55 °C for 15 days, emulsions prepared with 2.0 % w/v caseinate and 0.4 % w/v DS, with and without curcumin, showed a maximum of 40 % reduction in the peroxide value and 71 % reduction in the thiobarbituric reactive substances value from those of bulk PO. The present study showed the significance of casein-DS nanocomplexes for the physical and chemical stability of PO emulsions.

A capsule-based scaffold incorporating decellularized extracellular matrix and curcumin for islet beta cell therapy in type 1 diabetes mellitus

The transplantation of islet beta cells offers an alternative to heterotopic islet transplantation for treating type 1 diabetes mellitus (T1DM). However, the use of systemic immunosuppressive drugs in islet transplantation poses significant risks to the body. To address this issue, we constructed an encapsulated hybrid scaffold loaded with islet beta cells. This article focuses on the preparation of the encapsulated structure using 3D printing, which incorporates porcine pancreas decellularized extracellular matrix (dECM) to the core scaffold. The improved decellularization method successfully preserved a substantial proportion of protein (such as Collagen I and Laminins) architecture and glycosaminoglycans in the dECM hydrogel, while effectively removing most of the DNA. The inclusion of dECM enhanced the physical and chemical properties of the scaffold, resulting in a porosity of 83.62% ± 1.09% and a tensile stress of 1.85 ± 0.16 MPa. In teams of biological activity, dECM demonstrated enhanced proliferation, differentiation, and expression of transcription factors such as Ki67, PDX1, and NKX6.1, leading to improved insulin secretion function in MIN-6 pancreatic beta cells. In the glucose-stimulated insulin secretion experiment on day 21, the maximum insulin secretion from the encapsulated structure reached 1.96 ± 0.08 mIU ml-1, representing a 44% increase compared to the control group. Furthermore, conventional capsule scaffolds leaverage the compatibility of natural biomaterials with macrophages to mitigate immune rejection. Here, incorporating curcumin into the capsule scaffold significantly reduced the secretion of pro-inflammatory cytokine (IL-1β, IL-6, TNF-α, IFN-γ) secretion by RAW264.7 macrophages and T cells in T1DM mice. This approach protected pancreatic islet cells against immune cell infiltration mediated by inflammatory factors and prevented insulitis. Overall, the encapsulated scaffold developed in this study shows promise as a natural platform for clinical treatment of T1DM.

Encapsulation of three different types of polyphenols in casein using a customized pH-driven method: Preparation and characterization

Phenolic compounds represent natural compounds endowed with diverse biological functionalities. However, their inherent limitations, characterized by poor water solubility and low oral bioavailability, limit their broader applications. Encapsulation delivery systems are emerging as a remedy, able to ameliorate these limitations by enhancing the stability and solubility of phenolic compounds. In this study, a novel, customized pH-driven approach was developed by determining the optimal deprotonation and protonation points of three different types of polyphenols: ferulic acid, resveratrol, and rhein. The polyphenols were successfully encapsulated in a casein carrier. The solubility, stability, LogD, and LogS curves of the three polyphenols at different pH values were analyzed to identify the optimal deprotonation points for ferulic acid (pH 9), resveratrol (pH 11), and rhein (pH 10). Based on these findings, three different nanoparticles were prepared. The encapsulation efficiencies of the three phenolic compounds were 95.86%, 94.62%, and 94.18%, respectively, and the casein nanoparticles remained stable at room temperature for seven days. FTIR spectroscopy, fluorescence spectroscopy, and molecular docking study substantiated the encapsulation of phenolic compounds within the hydrophobic core of casein-based complexes, facilitated by hydrogen bonding interactions and hydrophobic interactions. Furthermore, the analysis of antioxidant activity elucidated that casein nanoparticles heightened both the water solubility and antioxidant efficacy of the phenolic compounds. This customized encapsulation technique, by establishing a transitional pH value, resolves the challenges of chemical instability and facile degradation of polyphenols under alkaline conditions in the application process of pH-driven methods. It presents novel insights for the application of polyphenols in the domains of food and biomedical fields.

Gastrointestinal digestion behavior and bioavailability of greenly prepared highly loaded myofibrillar-luteolin vehicle

In this study, the highly loaded myofibrillar protein (MP)-luteolin (Lut) complexes were noncovalently constructed by using green high-pressure homogenization technology (HPH) and high-pressure micro-fluidization technology (HPM), aiming to optimize the encapsulation efficiency of flavonoids in the protein-based vehicle without relying on the organic solvent (i.e. DMSO, ethanol, etc.). The loading efficiency of Lut into MPs could reach 100 % with a concentration of 120 μmol/g protein by using HPH (103 MPa, 2 passes) without ethanol adoption. The in vitro gastrointestinal digestion behavior and antioxidant activity of the complexes were then compared with those of ethanol-assisted groups. During gastrointestinal digestion, the MP digestibility of complexes, reaching more than 70.56 % after thermal treatment, was higher than that of sole protein. The release profile of Lut encapsulated in ethanol-containing and ethanol-free samples both well fitted with the Hixson-Crowell release kinetic model (R2 = 0.92 and 0.94, respectively), and the total phenol content decreased by ≥ 40.02 % and ≥ 62.62 %, respectively. The in vitro antioxidant activity (DPPH, ABTS, and Fe2+) of the digestive products was significantly improved by 23.89 %, 159.69 %, 351.12 % (ethanol groups) and 13.43 %, 125.48 %, 213.95 % (non-ethanol groups). The 3 mg/mL freeze-dried digesta significantly alleviated lipid accumulation and oxidative stress in HepG2 cells. The triglycerides and malondialdehyde contents decreased by at least 57.62 % and 67.74 % after digesta treatment. This study provides an easily approached and environment-friendly strategy to construct a highly loaded protein-flavonoid conjugate, which showed great potential in the formulation of healthier meat products.

Nanofillers in Novel Food Packaging Systems and Their Toxicity Issues

Background: Environmental concerns about petroleum-based plastic packaging materials and the growing demand for food have inspired researchers and the food industry to develop food packaging with better food preservation and biodegradability. Nanocomposites consisting of nanofillers, and synthetic/biopolymers can be applied to improve the physiochemical and antimicrobial properties and sustainability of food packaging. Scope and approach: This review summarized the recent advances in nanofiller and their applications in improved food packaging systems (e.g., nanoclay, carbon nanotubes), active food packaging (e.g., silver nanoparticles (Ag NPs), zinc oxide nanoparticles (ZnO NPs)), intelligent food packaging, and degradable packaging (e.g., titanium dioxide nanoparticles (e.g., TiO2 NPs)). Additionally, the migration processes and related assessment methods for nanofillers were considered, as well as the use of nanofillers to reduce migration. The potential cytotoxicity and ecotoxicity of nanofillers were also reviewed. Key findings: The incorporation of nanofillers may increase Young's modulus (YM) while decreasing the elongation at break (EAB) (y = -1.55x + 1.38, R2 = 0.128, r = -0.358, p = 0.018) and decreasing the water vapor (WVP) and oxygen permeability (OP) (y = 0.30x - 0.57, R2 = 0.039, r = 0.197, p = 0.065). Meanwhile, the addition of metal-based NPs could also extend the shelf-life of food products by lowering lipid oxidation by an average of approx. 350.74% and weight loss by approx. 28.39% during the longest storage period, and significantly increasing antibacterial efficacy against S. aureus compared to the neat polymer films (p = 0.034). Moreover, the migration process of nanofillers may be negligible but still requires further research. Additionally, the ecotoxicity of nanofillers is unclear, as the final distribution of nanocomposites in the environment is unknown. Conclusions: Nanotechnology helps to overcome the challenges associated with traditional packaging materials. Strong regulatory frameworks and safety standards are needed to ensure the appropriate use of nanocomposites. There is also a need to explore how to realize the economic and technical requirements for large-scale implementation of nanocomposite technologies.

Enhanced bioavailability of curcumin amorphous nanocomposite prepared by a green process using modified starch

Curcumin (Cur), a bioactive compound extracted from plants, has attracted widespread attention due to its multiple pharmacological activities. However, the low bioavailability due to the inherent limitations in water solubility, chemical stability, and permeability poses great challenges for realizing its clinical potentials. In the current study, octenyl succinic anhydride-modified starch (OSA-S), a renewable and biodegradable biopolymer, was employed to fabricate Cur amorphous composite nanoparticles (Cur/OSA-S NPs) through a solvent-free pH-driven method with the aim to enhance Cur's bioavailability by improving its solubility and stability. Cur/OSA-S NPs, with mean sizes of about 128.9 ± 8.6 nm, encapsulation efficiencies of about 90.0 %, and the drug loading capacities around 51.0 ± 0.2 %, were successfully prepared. Cur was found to be dispersed within the composite nanoparticles in amorphous state as confirmed by the XRD and DSC characterizations. In addition, Cur/OSA-S NPs offers excellent storage, thermal and light stability, excellent re-dispersibility, and approximately 92 times better solubility than the original Cur. Furthermore, studies of dissolution and the parallel artificial membrane permeability assay (PAMPA) confirmed enhanced dissolution rates and in vitro permeabilities of Cur/OSA-S NPs. Cancer cell viability and uptake experiments revealed that Cur/OSA-S NPs possessed more potent inhibitory effects on cancer cell proliferation compared to the raw Cur. The results obtained from the current study demonstrated the effectiveness of OSA-S for manufacturing Cur amorphous composite nanoparticles with enhanced solubility, stability, and permeability, which might be valuable for further development of Cur based products for treatment of various diseases.

Synthesis of polymeric nanoparticles by double emulsion and pH-driven: encapsulation of antibiotics and natural products for combating Escherichia coli infections

The design, development, and obtaining of nanostructured materials, such as polymeric nanoparticles, have garnered interest due to loading therapeutic agents and its broad applicability. Polymeric nanoparticle synthesis employs advanced techniques such as the double emulsion approach and the pH-driven method, allowing the efficient incorporation of active compounds into these matrices. These loading methods ensure compound stability within the polymeric structure and enable control of the release of therapeutic agents. The ability of loaded polymeric nanoparticles to transport and release therapeutic agents on target manner represents a significant advancement in the quest for effective therapeutic solutions. Amid escalating concerns regarding antimicrobial resistance, interventions using polymeric nanostructures stand out for the possibility of carrying antimicrobial agents and enhancing antibacterial action against antibiotic-resistant bacteria, making a new therapeutic approach or complement to conventional treatments. In this sense, the capability of these polymeric nanoparticles to act against Escherichia coli underscores their relevance in controlling bacterial infections. This mini-review provides a comprehensive synthesis of promising techniques for loading therapeutic agents into polymeric nanoparticles highlighting methodologies and their implications, addressing prospects of combating bacterial infections caused by E. coli. KEY POINTS: • The double emulsion method provides control over size and release of bioactives. • The pH-driven method improves the solubility, stability, and release of active. • The methods increase the antibacterial action of those encapsulated in PNPs.

Structures and interactions forming stable shellac-casein nanocomplexes with a pH-cycle

Casein forms diverse structures with functionalities tunable by complexation with surfactants, and shellac is an emerging surfactant. In the present work, molecular and mesoscopic structures of shellac and micellar casein and the underlying interactions after treatment with a pH-cycle were investigated. Dispersions with 0.5 % w/v shellac and various shellac:casein mass ratios were prepared at pH 12.0 to dissolve shellac and dissociate casein micelles, followed by neutralization to pH 7.0 to form complexes. Both covalent and non-covalent (hydrogen bonding, electrostatic, and hydrophobic) interactions contributed to the complex formation. The formed complexes had an average diameter of ~80 nm. The complexation of shellac and casein prevented the precipitation of protonated shellac during neutralization, and dispersions with casein:shellac mass ratios of 2:1 and above were absent of precipitates at pH 7.0. The formed nanocomplexes may have applications for preparing novel colloidal systems and loading lipophilic bioactive compounds.

Nanoencapsulation and delivery of bioactive ingredients using zein nanocarriers: approaches, characterization, applications, and perspectives

Zein has garnered widespread attention as a versatile material for nanosized delivery systems due to its unique self-assembly properties, amphiphilicity, and biocompatibility characteristics. This review provides an overview of current approaches, characterizations, applications, and perspectives of nanoencapsulation and delivery of bioactive ingredients within zein-based nanocarriers. Various nanoencapsulation strategies for bioactive ingredients using various types of zein-based nanocarrier structures, including nanoparticles, nanofibers, nanoemulsions, and nanogels, are discussed in detail. Factors affecting the stability of zein nanocarriers and characterization methods of bioactive-loaded zein nanocarrier structures are highlighted. Additionally, current applications of zein nanocarriers loaded with bioactive ingredients are summarized. This review will serve as a guide for the selection of appropriate nanoencapsulation techniques within zein nanocarriers and a comprehensive understanding of zein-based nanocarriers for specific applications in the food, pharmaceutical, cosmetic, and agricultural industries.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01489-6.

Self-assembled nanoparticles of acid-induced fish (Cyprinus carpio L.) scale gelatin: Structure, physicochemical properties, and application for loading curcumin

This work expands the functionality of fish scale gelatin (FSG) as a carrier of hydrophobic bioactive substances. The hydrophobicity of FSG was enhanced to promote its interaction with hydrophobic curcumin and to increase its bioavailability. This results in a remarkable increase in the curcumin loading capacity of acid-hydrolyzed FSG (HFSG) from 1.08 ± 0.08 μg/mg (0 h) to 9.15 ± 0.21 μg/mg (3 h). The amino acid composition indicated that acid hydrolysis effectively increased the ratio of hydrophobic amino acids of FSG. Acid hydrolysis facilitated the transformation of the α-helical conformation into a β-sheet structure. Hydrophobic interactions between HFSG and curcumin were strengthened by moderate acid hydrolysis. A sustained-release profile emerged for the curcumin-loaded HFSG during simulated gastrointestinal digestion, thereby improving the bioaccessibility and bioavailability of curcumin. These findings contribute to the application of acid hydrolysis in modifying FSG for enhanced hydrophobicity and curcumin loading capacity in the food industry.

Self-assembled pea vicilin nanoparticles as nanocarriers for improving the antioxidant activity, environmental stability and sustained-release property of curcumin

BACKGROUND

The application of curcumin (Cur) in the food industry is usually limited by its low water solubility and poor stability. This study aimed to fabricate self-assembled nanoparticles using pea vicilin (7S) through a pH-shifting method (pH 7-pH 12-pH 7) to develop water-soluble nanocarriers of Cur.

RESULTS

Intrinsic fluorescence, far-UV circular dichroism spectra and transmission electron microscopy analysis demonstrated that the structure of 7S could be unfolded at pH 12.0 and refolded when the pH shifted to 7.0. The assembled 7S-Cur exhibited a high loading ability of 81.63 μg mg-1 for Cur and homogeneous particle distribution. Cur was encapsulated in the 7S hydrophobic nucleus in an amorphous form and combined through hydrophobic interactions and hydrogen bonding, resulting in the static fluorescence quenching of 7S. Compared with free Cur, the retention rates of Cur in 7S-Cur were approximately 1.12 and 1.70 times higher under UV exposure at 365 nm or heating at 75 °C for 120 min, respectively, as well as 7S-Cur showing approximately 1.50 times higher antioxidant activity. During simulated gastrointestinal experiments, 7S-Cur exhibited a better sustained-release property than free Cur.

CONCLUSION

The self-assembled 7S nanocarriers prepared using a pH-shifting method effectively improved the antioxidant activity, environmental stability and sustained-release property of Cur. Therefore, 7S isolated from pea protein could be used as potential nanocarriers for Cur. © 2023 Society of Chemical Industry.

Encapsulation of rutin in protein nanoparticles by pH-driven method: impact of rutin solubility and mechanisms

BACKGROUND

The use of rutin in the food industry is limited by its poor solubility. Encapsulation can be used as an effective way to improve polyphenol solubility. Proteins with high safety, biocompatibility and multiple binding sites are known as the most promising encapsulating carriers. Therefore, the improvement of rutin solubility by pH-driven encapsulation of rutin in soy protein isolate (SPI) nanoparticles, as well as the form of rutin after encapsulation and rutin-protein binding index were investigated.

RESULTS

SPI had a high encapsulation efficiency (87.5%) and loading amount (10.6%) for rutin. When the mass ratio of protein to rutin was 5:1, the highest concentration of rutin in solution was 3.27 g L-1 , which was a 51.57-fold increase compared to the original rutin. At this situation, rutin transformed from crystalline to amorphous form. During the formation of nanoparticles, SPI was in a dynamic change of unfolding and refolding. Rutin deprotonated in alkaline conditions increasing its solubility and bound to protein to form nanoparticles during the process of returning to neutral. Hydrophobic interactions and hydrogen bonding promoted the formation of the nanoparticles and there were at least 1-2 binding sites between rutin and each SPI molecule.

CONCLUSION

The results suggested that encapsulation of rutin in protein nanoparticles can effectively increase the solubility of rutin. This study may provide important information for the effective utilization of polyphenol functional foods. © 2023 Society of Chemical Industry.

Comparative study of dietary phenols with Tartary buckwheat protein (2S/13S): impact on structure, binding sites and functionality of protein

BACKGROUND

This research was to investigate the interaction mechanism between 2S albumin and 13S globulin (2S and 13S, the most important storage proteins in Tartary buckwheat seeds) and three phenols (rutin, quercetin and myricetin) regarding the structural and antioxidant properties of their complexes.

RESULTS

There are differences in the binding affinity of phenols for 2S and 13S. Rutin had a higher binding affinity for 2S, myricetin had a higher binding affinity for 13S, and 13S exhibited a higher affinity toward phenols than did 2S. Binding with phenols significantly changed the secondary and tertiary structures of 2S and 13S, decreased the surface hydrophobic value and enhanced the antioxidant capacity. Molecular docking and isothermal titration calorimetry showed that the binding processes were spontaneous and that there were hydrogen bonds, hydrophobic bonds and van der Waals force interactions between phenols and proteins.

CONCLUSION

These findings could provide meaningful guidance for the further application of buckwheat protein complex. © 2023 Society of Chemical Industry.

Ellagic acid-loaded soy protein isolate self-assembled particles: Characterization, stability, and antioxidant activity

The limited water solubility and bioactivity of lipophilic phytochemicals may be enhanced by delivery systems. Ellagic acid (EA) has antioxidant and anti-inflammatory properties, but low solubility and instability limit its use in the food industry. In this study, the pH-shift method was applied to encapsulate EA with soy protein isolate (SPI). The interaction, encapsulation, and protective potential of the EA-loaded soy SPI complexes (SPI-EA) were investigated. The fluorescence spectra results suggest that the reaction between SPI and EA is spontaneous, with hydrophobic interactions predominating. Binding of EA molecules quenches the intrinsic fluorescence of SPI, mainly static quenching, with a binding site involved in the binding process. The ultraviolet (UV)-visible spectroscopy of the SPI-EA complexes included the characteristic absorption peaks of both SPI and EA, and the scanning electron microscopy images further indicated that the EA had been successfully embedded in SPI. Fourier transform infrared spectroscopy illustrates that EA has significantly changed the secondary structure of the SPI, primarily in the form of a decreased content of α-helix structures and an increased content of β-sheet and random coil structures. The encapsulation efficiency of EA was concentration-dependent, up to 81.08%. The addition of EA reduces the size of SPI particles (d < 155 nm). In addition, the SPI-EA complex showed up to 81.05% and 96.46% 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity. TGA showed that the degradation temperature of SPI-EA complex could be extended up to 300°C. And by encapsulation of EA, the loss of EA under the action of UV light, heat treatment, and high concentration of salt ion sensitive environment can be reduced. PRACTICAL APPLICATION: Ellagic acid (EA), a natural bioactive with low water solubility and stability, can be enhanced by forming an inclusion complex with soy protein isolate (SPI). SPI-EA complex has broad potential applications in the food, beverage, and pharmaceutical industries. Multiple spectral analyses have contributed to our understanding of the formation and interaction mechanisms of the SPI-EA complex under pH-driven conditions. Stability assays have also aided in the development of dietary resources for EA.

Curcumin in Cancer Prevention: Insights from Clinical Trials and Strategies to Enhance Bioavailability

Cancer remains a leading cause of death worldwide, and current cancer drugs often have high costs and undesirable side effects. Additionally, the development of drug resistance can reduce their effectiveness over time. Natural products have gained attention as potential sources for the treatment and prevention of various diseases. Curcumin, an extract from turmeric (Curcuma longa), is a natural phenolic compound with diverse pharmacological properties, including antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, antiprotozoal, antidiabetic, antivenom, antiulcer, anticarcinogenic, antimutagenic, anticoagulant, and antifertility activities. Given the increasing interest in curcumin for cancer prevention, this review aims to comprehensively examine clinical trials investigating the use of curcumin in different types of cancer. Additionally, effective techniques and approaches to enhance the bioavailability of curcumin are discussed and summarized. This review article provides insights into the properties of curcumin and its potential as a future anticancer drug.

Fabrication and characterization of curcumin-loaded nanoparticles using licorice protein isolate from Radix Glycyrrhizae

Licorice was widely used in food and herbal medicine. In its extract industry, a substantial amount of licorice protein was produced and discarded as waste. Herein, we extracted Licorice Protein Isolate (LPI) and explored its potential as a curcumin nanocarrier. Using a pH-driven method, we fabricated LPI-curcumin nanoparticles with diameters ranging from 129.30 ± 3.21 nm to 75.03 ± 1.19 nm, depending on the LPI/curcumin molar ratio. The formation of LPI-curcumin nanoparticles was primarily driven by hydrophobic interactions, with curcumin entrapped in LPI being in an amorphous form. These nanoparticles significantly enhanced curcumin properties in terms of solubility, photochemical stability, and stability under varying pH, storage, and physiological conditions. Moreover, the loaded curcumin exhibited a 2.58-fold increase in cellular antioxidant activity on RAW 264.7 cells and a 1.86-fold increase in antitumor activity against HepG2 cells compared to its free form. These findings suggested that LPI could potentially serve as a promising novel delivery material.

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.

Konjac glucomannan/carboxymethyl chitosan film embedding gliadin/casein nanoparticles for grape preservation

Constructing biopolymer-based packaging films with fantastic water resistance and mechanical properties for food preservation is highly desirable and challenging. In this work, Gliadin/Casein nanoparticles (GCNPs) were prepared by pH-driven method and embedded into konjac glucomannan/carboxymethyl chitosan (KC) film matrix to improve the water resistance and mechanical properties of KC film. Gliadin and Casein showed good compatibility and co-assembled to form compact GCNPs clusters through hydrogen bonding and hydrophobic interaction verified by FT-IR spectroscopy, and fluorescence spectroscopy. The particle size and zeta potential of GCNPs was 269.7 nm and -7.6 mV, respectively. The effect of GCNPs on the mechanics, water barrier, thermal stability, and UV-shielding of KC-GCNPs film was investigated. SEM images revealed that GCNPs uniformly distributed into KC film matrix and significantly improved the mechanics (tensile strength: 75.6 MPa, elongation at breaking: 36.7 %), water barrier ability (water contact angle: 91.3°, water vapor permeability: 0.994 g mm/m2 day kPa, water solubility: 52.0 %), thermal stability and UV blocking property of KC-GCNPs film. Furthermore, KC-GCNPs film could also be applied to extend the shelf life of grapes. This paper demonstrated the great potential of GCNPs as functional nanofillers in enhancing the physicochemical properties of KC film.

Post pH-driven encapsulation of polyphenols in next-generation foods: principles, formation and applications

To meet the needs of a growing global population (∼10 billion by 2050), there is an urgent demand for sustainable, healthy, delicious, and affordable next-generation foods. Natural polyphenols, which are abundant in edible plants, have emerged as promising food additives due to their potential health benefits. However, incorporating polyphenols into food products presents various challenges, including issues related to crystallization, low water-solubility, limited bioavailability, and chemical instability. pH-driven or pH-shifting approaches have been proposed to incorporate polyphenols into the delivery systems. Nevertheless, it is unclear whether they can be generally used for the encapsulation of polyphenols into next-generation foods. Here, we highlight a post pH-driven (PPD) approach as a viable solution. The PPD approach inherits several advantages, such as simplicity, speed, and environmental friendliness, as it eliminates the need for heat, organic solvents, and complex equipment. Moreover, the PPD approach can be widely applied to different polyphenols and food systems, enhancing its versatility while also potentially contributing to reducing food waste. This review article aims to accelerate the implementation of the PPD approach in the development of polyphenol-fortified next-generation foods by providing a comprehensive understanding of its fundamental principles, encapsulation techniques, and potential applications in plant-based foods.

The bioengineered and multifunctional nanoparticles in pancreatic cancer therapy: Bioresponisive nanostructures, phototherapy and targeted drug delivery

The multidisciplinary approaches in treatment of cancer appear to be essential in term of bringing benefits of several disciplines and their coordination in tumor elimination. Because of the biological and malignant features of cancer cells, they have ability of developing resistance to conventional therapies such as chemo- and radio-therapy. Pancreatic cancer (PC) is a malignant disease of gastrointestinal tract in which chemotherapy and radiotherapy are main tools in its treatment, and recently, nanocarriers have been emerged as promising structures in its therapy. The bioresponsive nanocarriers are able to respond to pH and redox, among others, in targeted delivery of cargo for specific treatment of PC. The loading drugs on the nanoparticles that can be synthetic or natural compounds, can help in more reduction in progression of PC through enhancing their intracellular accumulation in cancer cells. The encapsulation of genes in the nanoparticles can protect against degradation and promotes intracellular accumulation in tumor suppression. A new kind of therapy for cancer is phototherapy in which nanoparticles can stimulate both photothermal therapy and photodynamic therapy through hyperthermia and ROS overgeneration to trigger cell death in PC. Therefore, synergistic therapy of phototherapy with chemotherapy is performed in accelerating tumor suppression. One of the important functions of nanotechnology is selective targeting of PC cells in reducing side effects on normal cells. The nanostructures are capable of being surface functionalized with aptamers, proteins and antibodies to specifically target PC cells in suppressing their progression. Therefore, a specific therapy for PC is provided and future implications for diagnosis of PC is suggested.

Co-Encapsulation of Multiple Polyphenols in Plant-Based Milks: Formulation, Gastrointestinal Stability, and Bioaccessibility

Plant-based milk is particularly suitable for fortification with multiple nutraceuticals because it contains both hydrophobic and hydrophilic domains that can accommodate molecules with different polarities. In this study, we fortified soymilk with three common polyphenols (curcumin, quercetin, and resveratrol) using three pH-driven approaches. We compared the effectiveness of these three different approaches for co-encapsulating polyphenols. The gastrointestinal fate of the polyphenol-fortified soymilks was then studied by passing them through a simulated mouth, stomach, and small intestine, including the stability and bioaccessibility of polyphenols. All three pH-driven approaches were suitable for co-encapsulating multiple polyphenols at a high encapsulation efficiency, especially for the curcumin and resveratrol. The polyphenol-loaded delivery systems exhibited similar changes in particle size, charge, stability, and bioaccessibility as they passed through the mouth, stomach, and intestinal phases. The bioaccessibility of the co-encapsulated polyphenols was much greater than that of crystallized polyphenols dispersed in water. The poor bioaccessibility of the crystallized polyphenols was attributed to their low solubility in water, which made them more difficult to solubilize within mixed micelles. This study underscores the feasibility of pH-driven approaches for encapsulating a variety of polyphenols into the same plant-based delivery system. These fortified plant-based milks may therefore be designed to provide specific health benefits to consumers.

Flavor-food ingredient interactions in fortified or reformulated novel food: Binding behaviors, manipulation strategies, sensory impacts, and future trends in delicious and healthy food design

With consumers gaining prominent awareness of health and well-being, a diverse range of fortified or reformulated novel food is developed to achieve personalized or tailored nutrition using protein, carbohydrates, or fat as building blocks. Flavor property is a critical factor in the acceptability and marketability of fortified or reformulated food. Major food ingredients are able to interact with flavor compounds, leading to a significant change in flavor release from the food matrix and, ultimately, altering flavor perception. Although many efforts have been made to elucidate how food matrix components change flavor binding capacities, the influences on flavor perception and their implications for the innovation of fortified or reformulated novel food have not been systematically summarized up to now. Thus, this review provides detailed knowledge about the binding behaviors of flavors to major food ingredients, as well as their influences on flavor retention, release, and perception. Practical approaches for manipulating these interactions and the resulting flavor quality are also reviewed, from the scope of their intrinsic and extrinsic influencing factors with technologies available, which is helpful for future food innovation. Evaluation of food-ingredient interactions using real food matrices while considering multisensory flavor perception is also prospected, to well motivate food industries to investigate new strategies for tasteful and healthy food design in response to consumers' unwillingness to compromise on flavor for health.

Solubilization mechanism of self-assembled walnut protein nanoparticles and curcumin encapsulation

BACKGROUND

Native walnut protein is an alkali-soluble protein that seriously limits the application of walnut protein. The pH-shifting method could improve the solubility of walnut proteins and enable the encapsulation of active ingredients. The present study aimed to prepare water-soluble nanoparticles of curcumin using walnut protein and evaluate the process of walnut protein self-assembly, interaction between walnut protein and curcumin, encapsulation properties, and stability of nanoparticles.

RESULTS

The solubility of native walnut protein was poor, but the solubility of walnut protein nanoparticles (WPNP) formed by walnut protein after pH-shifting significantly improved to 91.5 ± 1.2%. This is because, during the process of pH changing from 7 to 12 and back to 7, walnut protein first unfolded under alkaline conditions and then refolded under pH drive, finally forming an internal hydrophobic and external hydrophilic shell-core structures. The quenching type of walnut protein and curcumin was static quenching, and the quenching constant was 2.0 × 10¹⁴  mol^-1  L^-1  s^-1 , indicating that the interaction between walnut protein and curcumin was non-covalent. Adding curcumin resulted in the formation of nanoparticles with small particle size compared with the no-load. The loading capacity of curcumin-loaded walnut protein nanoparticles (WPNP-C) was 222 mg g^-1 walnut protein isolate. Under the same mass, the curcumin equivalent concentration in aqueous solution of WPNP-C was 17 000 times higher than that of the native curcumin.

CONCLUSION

The solubility of the self-assembled WPNP significantly increased after pH-shifting treatment. The walnut protein carrier could improve the stability of the encapsulated curcumin. Therefore, walnut proteins could be used as water-soluble carriers for hydrophobic drugs. © 2023 Society of Chemical Industry.

Research Progress of Protein-Based Bioactive Substance Nanoparticles

Bioactive substances exhibit various physiological activities-such as antimicrobial, antioxidant, and anticancer activities-and have great potential for application in food, pharmaceuticals, and nutraceuticals. However, the low solubility, chemical instability, and low bioavailability of bioactive substances limit their application in the food industry. Using nanotechnology to prepare protein nanoparticles to encapsulate and deliver active substances is a promising approach due to the abundance, biocompatibility, and biodegradability of proteins. Common protein-based nanocarriers include nano-emulsions, nano-gels, nanoparticles, and nano complexes. In this review, we give an overview of protein-based nanoparticle fabrication methods, highlighting their pros and cons. Additionally, we discuss the applications and current issues regarding the utilization of protein-based nanoparticles in the food industry. Finally, we provide perspectives on future development directions, with a focus on classifying bioactive substances and their functional properties.

Ultrasound-assisted pH-shifting to construct a stable aqueous solution of paprika oleoresin using egg yolk low-density lipoprotein as a natural liposome-like nano-emulsifier

In this study, a stable aqueous solution of paprika oleoresin (PO, the natural colorant extracted from the fruit peel of Capsicum annuum L) was constructed. The solubility of PO in an alkline aqueous solution (pH 10.95-11.10) increased rapidly. However, the aqueous solution of PO (pH 12.00) was unstable, obvious stratification was observed, and the color retention rate was only 52.99% after 28 days of storage. Chicken egg yolk low-density lipoprotein (LDL) was added combined with ultrasonic treatment to improve the stability of LDL-PO solution. The method could decrease the turbidity by 17.5 %, reduce the average particle size of the LDL-PO solution (13.9%), and enhance the interaction and combination of LDL and PO. The prepared PO aqueous solution was used in yogurt, egg white gel, fish balls and soymilk, and it could significantly improve the color of products and provided potential health benefits.

Laccase-Induced Gelation of Sugar Beet Pectin-Curcumin Nanocomplexes Enhanced by Genipin Crosslinking

Research on the use of polysaccharides as hydrophobic bioactive carriers instead of proteins is still scarce. Sugar beet pectin (SBP) contains a small amount of protein and is a potential carrier for loading curcumin. In this work, SBP encapsulation, genipin crosslinking, and laccase-induced gelation were used to develop novel jelly food and improve the stability of curcumin without the incorporation of oil. By mixing the SBP solution (40 mg/mL) with curcumin powder (25 mg/mL SBP solution), an SBP-curcumin complex (SBP-Cur) was fabricated with a loading amount of 32 mg/g SBP, and the solubility of curcumin improved 116,000-fold. Fluorescence spectroscopy revealed that hydrophobic interactions drove the complexation of curcumin and SBP. Crosslinked by genipin (10 mM), SBP-Cur showed a dark blue color, and the gel strength of laccase-catalyzed gels was enhanced. Heating and UV radiation tests suggested that the genipin crosslinking and gelation strategies substantially improved the stability of curcumin. Because of the unique UV-blocking capacity of blue pigment, crosslinked samples retained 20% more curcumin than control samples. With the enhanced stability of curcumin, the crosslinked SBP-curcumin complexes could be a functional food ingredient used in functional drinks, baked food, and jelly food.

Construction of a Ternary Composite Colloidal Structure of Zein/Soy Protein Isolate/Sodium Carboxymethyl Cellulose to Deliver Curcumin and Improve Its Bioavailability

This work presents the fabrication of ternary nanoparticles (Z/S/C NPs) comprising zein (Z), soy protein isolate (SPI) and carboxymethylcellulose sodium (CMC-Na) through a pH-driven method. The results showed that the smallest particle size (71.41 nm) and the most stable zeta potential, measuring -49.97 mV, were achieved with the following ratio of ternary nanoparticles Z/SPI/CMC-Na (2:3:3). The surface morphology of the nanoparticles was further analyzed using transmission electron microscopy, and the synthesized nanoparticles were utilized to encapsulate curcumin (Cur), a hydrophobic, bioactive compound. The nanoparticles were characterized using a particle size analyzer, infrared spectroscopy, and X-ray diffraction (XRD) techniques. The results revealed that the formation of nanoparticles and the encapsulation of Cur were driven by electrostatic, hydrogen-bonding and hydrophobic interactions. The drug loading efficiency (EE%) of Z/S/C-cur nanoparticles reached 90.90%. The Z/S/C ternary nanoparticles demonstrated enhanced storage stability, photostability and simulated the gastrointestinal digestion of Cur. The release of Cur and variations in the particle size of nanoparticles were investigated across different stages of digestion. The biocompatibility of the Z/S/C ternary nanoparticles was assessed by conducting cell viability assays on HepG2 and L-O2 cells, which showed no signs of cytotoxicity. These results suggested that the ternary composite nanoparticles have potential in delivering nutritional foods and health-promoting bioactive substances.

Effects of curcumin, phycocyanin, or modified lycopene colorants on the physicochemical and sensory properties of whey protein-cellulose nanocrystal packaging films

To utilize natural hydrophobic/hydrophilic colorants to manufacture good quality and attractive packaging films, we investigated the effects of natural colorants (curcumin, phycocyanin, modified lycopene, and their mixed colorants) on the physicochemical and sensory properties of whey protein isolate-cellulose nanocrystal packaging film. Owing to the improvement in hydrophobicity and spatial density, moisture content (MC) and water vapor permeability (WVP) of films containing curcumin were reduced by 16.91% and 8.49%, respectively, in contrast to that, MC and WVP increased by 10.75% and 4.09%, respectively, in film containing modified lycopene. Mechanical testing, infrared spectra, and X-ray diffraction revealed the retention of structural properties of protein matrix. Rate-All-That-Apply evaluation indicated that films containing colorants enriched tactile and visual sensory characteristics. The eye tracking testing of packed foods showed that preferential attraction depends on the color of the food itself. Thus, a consumer-oriented multi-colored packaging film with good performance was achieved.

Effects of Different Molecular Weight Oxidized Dextran as Crosslinkers on Stability and Antioxidant Capacity of Curcumin-Loaded Nanoparticles

Curcumin is a polyphenolic compound that has been widely investigated for its health benefits. However, the clinical relevance of curcumin is limited due to its low water solubility and inefficient absorption. Therefore, curcumin is often encapsulated in nanocarriers to improve its delivery and function. In this study, composite nanoparticles composed of stearic acid-modified chitosan (SA-CS) and sodium caseinate (NaCas) were formed using sodium periodate-oxidized dextran with different molecular weights as a crosslinking agent. The effects of oxidized dextran (Odex) with different molecular weights on the composite nanoparticles were compared. The optimal SA-CS/NaCas/Odex composite nanoparticle (NPO) was obtained using an Odex (150 kDa)-to-SA-CS mass ratio of 2:1. Its size, polydispersity index (PDI), and zeta potential (ZP) were 130.2 nm, 0.149, and 25.4 mV, respectively. The particles were highly stable in simulated gastric fluid (SGF) in vitro, and their size and PDI were 172.3 nm and 0.263, respectively. The encapsulation rate of NPO loaded with curcumin (Cur-NPO) was 93% under optimal ultrasonic conditions. Compared with free curcumin, the sustained release of Cur-NPO significantly reduced to 17.9%, and free-radical-scavenging ability improved to 78.7%. In general, the optimal prepared NPO exhibited good GI stability and has potential applications in the formulation of orally bioactive hydrophobic drugs.

Co-delivery of curcumin and quercetin in shellac nanocapsules for the synergistic antioxidant properties and cytotoxicity against colon cancer cells

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.

Lactoferrin-Based Ternary Composite Nanoparticles with Enhanced Dispersibility and Stability for Curcumin Delivery

Curcumin has been reported to exhibit free radical antioxidant, anti-inflammatory, and anticancer activities, which are beneficial for nutraceutical applications. However, its application for this purpose is limited by its poor water solubility, stability, and bioavailability. These problems can be overcome using food-grade colloidal particles that encapsulate, protect, and deliver curcumin. These colloidal particles can be assembled from structure-forming food components that may also exhibit protective effects, such as proteins, polysaccharides, and polyphenols. In this study, lactoferrin (LF), (-)-epigallocatechin gallate (EGCG), and hyaluronic acid (HA) were used to fabricate composite nanoparticles using a simple pH-shift method. We showed that curcumin could be successfully loaded into these LF-EGCG-HA nanoparticles (d = 145 nm). The encapsulation efficiency (86%) and loading capacity (5.8%) of curcumin within these nanoparticles were relatively high. Encapsulation improved the thermal, light, and storage stabilities of the curcumin. Moreover, the curcumin-loaded nanoparticles exhibited good redispersibility after dehydration. The in vitro digestion properties, cellular uptake, and anticancer effects of the curcumin-loaded nanoparticles were then explored. Compared to free curcumin, the bioaccessibility and cellular uptake of the curcumin were significantly improved after encapsulation in the nanoparticles. Furthermore, the nanoparticles significantly promoted the apoptosis of colorectal cancer cells. This study suggests that food-grade biopolymer nanoparticles can be used to improve the bioavailability and bioactivity of an important nutraceutical.

Collagen hydrolysates improve the efficiency of sodium alginate-encapsulated tea polyphenols in beads and the storage stability after commercial sterilization

This study showed that sodium alginates (SA)-based beads reinforced with collagen hydrolysates (CHs) significantly increased an encapsulation rate of tea polyphenols (TP) from 34.54 % to 85.06 % when the mass ratio of SA: CHs increased from1.5:0 to 1.5:0.5. And after the 30-day storage at 37 °C, the retention rate of TP in beads with CHs at the solutions with pH = 4.0 or pH = 7.0 increased from 61.10 % to 80.21 %, or from 67.72 % to 80.47 % after sterilization at 98 °C or 121 °C for 30 min, respectively. Also, the addition of CHs at 0.5 % resulted in a greater retention of the polyphenolic compositions values of TP determined by UPLC-Orbitrap-MS system. Additionally, the DPPH and ABTS+ free-radical scavenging capacities and ferric-reducing antioxidant power of beads with CHs after sterilization at 98 °C or 121 °C for 30 min were significantly higher than which without CHs. Physical phenomena based on ζ-potential, particle size, fluorescence, UV spectroscopy and confocal laser scanning microscope showed that tightly non-covalent complexes of CHs in combination to TP could be uniformly and stably distributed in the network of SA solution for encapsulating TP in SA-based beads. These findings provided suggestions for the co-encapsulation design and development of hydrophilic nutritive compounds based on CHs in SA-based beads.

Structural, Binding and Functional Properties of Milk Protein-Polyphenol Systems: A Review

Polyphenols (PP) are linked to health benefits (e.g., prevention of cancer, cardiovascular disease and obesity), which are mainly attributed to their antioxidant activity. During digestion, PP are oxidised to a significant degree reducing their bio-functionality. In recent years, the potential of various milk protein systems, including β-casein micelles, β-lactoglobulin aggregates, blood serum albumin aggregates, native casein micelles and re-assembled casein micelles, to bind and protect PP have been investigated. These studies have yet to be systematically reviewed. The functional properties of the milk protein-PP systems depend on the type and concentration of both PP and protein, as well as the structure of the resultant complexes, with environmental and processing factors also having an influence. Milk protein systems protect PP from degradation during digestion, resulting in a higher bioaccessibility and bioavailability, which improve the functional properties of PP upon consumption. This review compares different milk protein systems in terms of physicochemical properties, PP binding performance and ability to enhance the bio-functional properties of PP. The goal is to provide a comprehensive overview on the structural, binding, and functional properties of milk protein-polyphenol systems. It is concluded that milk protein complexes function effectively as delivery systems for PP, protecting PP from oxidation during digestion.