Effects of frequency ultrasound on the properties of zein-chitosan complex coacervation for resveratrol encapsulation

Covalent modulation of zein surface potential by gallic acid to enhance the formation of electrostatic-driven ternary antioxidant complex coacervates with chitosan

Despite existing research on the interaction between zein (Z) and chitosan (CS), the formation and mechanisms of ternary electrostatic coacervates incorporating polyphenols remain unclear. Herein, we covalently and non-covalently modified zein with gallic acid (GA). Comparisons revealed that the covalent coupling of Z with GA (forming Z(GA)) reduced zein's surface potential, enabling them to form tightly bound coacervates with cationic polysaccharide chitosan through electrostatic attraction. Turbidity, ζ-potential, and appearance experiments indicated that the maximum yield of insoluble coacervates was achieved at a Z(GA)/CS mass ratio of 7:1 and pH 6.5. Furthermore, the coacervate properties were evaluated using Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, and microscopic structure analysis. Electrostatic attraction between the -COO- groups of Z(GA) and the -NH3+ groups of CS triggered complex coacervation, which induced structural modifications and enhanced thermal stability. This study fosters the efficient encapsulation and controlled release of nutraceuticals, enhancing human absorption.

Effect of different zein/tea polyphenol/apple pectin coating on nutritional, physicochemical properties of fresh walnut kernel preservation

In this study, zein/apple pectin/tea polyphenol layer-by-layer assembled cling film prepared by solution casting was characterized, and the preservation effect of composite coatings, double, triple, and quadruple multilayer layer-by-layer assembly coatings on fresh walnut kernels at 4 °C was evaluated. As the number of assembly layers increased, the water vapor barrier increased, and the lower the film's UV transmittance. The assembled film's antioxidant and antibacterial activities were significantly higher than composite film. The moisture, color, and texture of the fresh walnut kernels treated with the assembled coatings were less different from 0 d fresh walnut kernels after 40 d of storage at 4 °C. The acid value, peroxide value, and total number of bacterial colonies of the fresh walnut kernels with 4-layer assembled coatings were significantly lower than those of the composite coatings. Overall, zein/apple pectin/tea polyphenol layer-by-layer assembled coating is an effective way to the fresh walnut kernel preservation.

Application of Chitosan and Its Derivatives in Postharvest Coating Preservation of Fruits

Postharvest preservation of fruits is one of the key issues in the current agriculture and food processing industry. Surface coating treatment, a promising technology for postharvest fruit preservation, has gathered significant attention due to its ability to reduce water loss, regulate gas exchange, and inhibit respiration, thereby achieving postharvest fruit preservation. Among them, chitosan-based coating has a wide application prospect due to its superior film-forming capability, high biosecurity, wide range of sources, etc. This review summarizes the structural features, physicochemical properties, modification strategies, and preservation mechanisms of chitosan-based coatings, focusing on their applications in postharvest fruit storage. Unlike prior works, it highlights advanced modifications (e.g., nanocomposite, multifunctional grafting) that enhance antimicrobial activity, mechanical strength, and environmental adaptability. Challenges in fruit preservation-such as microbial resistance and stability-are analyzed, with solutions proposed via material innovation. The discussion on industrial scalability emphasizes chitosan's biodegradability, cost-effectiveness, and alignment with sustainable agriculture, while addressing technical bottlenecks. This work bridges fundamental research and practical use, advancing chitosan-based coatings toward greener, safer, and scalable postharvest solutions.

Recent advances in modification of plant-based proteins for improved encapsulation performance

Encapsulation is a useful technique for protection, stabilization and controlling the release of bioactive compounds and food ingredients particularly sensitive to environmental factors such as heat, light and temperature. A wide variety of biopolymers can be used as wall materials in encapsulation, among which proteins are an essential group. In recent years, with the increasing interest in concepts such as plant-based nutrition and sustainability, the use of plant proteins in encapsulation has also increased. Proteins obtained from plant sources are sustainable, easily accessible, and low cost compared to animal-based counterparts; additionally, they are biodegradable, renewable, and biocompatible. However, there are some limitations regarding their functional properties such as solubility, emulsifying, gelling, and film-forming abilities. Various physical, chemical and enzymatic modification methods are used to improve the functional properties of plant proteins and to expand their use in encapsulation technologies. In this review, plant-based proteins (PBPs) and their use in encapsulation are discussed. Different modification techniques can improve the encapsulation performance of plant proteins; however, process parameters should be optimized. The most commonly studied physical, chemical, enzymatic and combined modification methods are sonication, Maillard conjugation, enzymatic hydrolysis and pH-shifting combined ultrasonication, respectively. The use of combined modification methods is a promising approach for improvement of the encapsulation performance of PBPs.

Enhancing the antifungal efficiency of chitosan nanoparticle via interacting with didymin/flavonoid and its bio-based approaches for postharvest preservation in pear fruit models

In this study, chitosan nanoparticles are used to encapsulate didymin and flavonoids separately using ionic gelation with phytic acid as a cross-linker. Their structural, antioxidant, and antifungal properties were evaluated. Flavonoid (Fs) was extracted from orange peels, while didymin (Did) was qualified in the pure extract using ultra-performance liquid chromatography (UPLC). UV-vis spectroscopy and FTIR confirmed the interaction of the obtained nanoparticles, which aligned with Surflex-dock findings. These nanoparticles showed a more compact structure and excellent thermal stability. The encapsulation efficiency (EE%) of Did-Cn and Fs-Cn nanoparticles was 55.33 ± 3.51 and 47.40 ± 0.56 %, respectively. The antioxidant assay showed that these nanoparticles highly reduced FRAP, DPPH, and ABTS radicals. The growth inhibition of Penicillium expansum was 37.39 ± 1.07 %, that of Aspergillus westerdijkiae was 44.26 ± 1.05 %, and that of Alternaria alternata was completely inhibited, which fits with clicks of the confocal microscope. These results suggest that food packaging or coatings could incorporate these nanoparticles to prevent fungal spoilage, thereby improving food safety. Meanwhile, using such nanoparticles offers a natural, safe, and effective solution for the pharmaceuticals and/or food industries to extend the freshness and shelf life of fruits and perishable items, reducing reliance on synthetic preservatives.

Preparation, characterization, and stability of pectin-whey protein isolate-based nanoparticles with mitochondrial targeting ability

Quercetin (Que) is a polyhydroxy flavonoid with strong inhibitory activity against cancer cells. However, the poor water solubility and low bioavailability of Que. limit its application in the functional food industry. In the present study, the nanoparticle loaded with Que. was prepared with whey isolate protein (WPI) stabilized by triphenylphosphonium bromide (TPP) and pectin (P) as wall materials. The formation mechanism, release of Que., and antitumor activity of nanoparticles were investigated. The results showed that the optimal ratio of WPI: TPP: Que.: P in the preparation of nanoparticles (WPI-TPP-Que-P) was 50:8:1:20 (w/w/w/w). The encapsulation rate of Que. in the WPI-TPP-Que-P was 82.64 % with a particle size of 261.7 nm and a zeta potential of -42.1 mV. Compared with WPI-TPP-Que, the retention rate of WPI-TPP-Que-P increased by 4.03 % after in vitro digestion. The release kinetic result indicated that WPI-TPP-Que-P release was dominated by non-Fickian diffusion. In addition, WPI-TPP-Que-P was taken in and achieved intracellular targeting to mitochondria and promoted apoptosis (apoptosis rate: 83.6 %) by decreasing mitochondrial membrane potential and IL-10 content and improving the content of TNF-α in HepG-2 cells. This study highlights the promising application of P-modified mitochondria-targeted nanocarriers for enhanced Que. delivery.

Animal-free coacervates: The combination of fungal chitosan-gum Arabic for the encapsulation of lipophilic compounds

In this study, fungal chitosan (FC) and gum Arabic (GA) were combined to develop non-animal complex coacervates for encapsulation. Optimal coacervate formation occurred at pH 5 with a 1:4 (FC:GA) weight ratio. Innovative complementary approaches, including rheology coupled with phase-contrast microscopy, revealed that FC-GA coacervates could withstand high shear rates, reverting to their original structure afterward, making them suitable for industrial applications. FTIR, DSC, and TGA analyses confirmed the electrostatic interactions and thermal stability, making them suitable for high-temperature procedures like spray-drying or extrusion. Higher GA concentrations increased coacervate hydrophilicity, while low-dielectric-constant liquids reduced particle size and disrupted coacervates. This study also explored interactions with solvents used in cosmetics, finding that isohexadecane, ethylhexyl stearate, and ethanol improved wetting properties by reducing electrostatic interactions, while polar solvents such as water and glycerol hindered them due to stronger interactions. The coacervates effectively encapsulated α-tocopherol, achieving an 82.6 % of encapsulation efficiency at a 1:1 (w/w) wall material-to-active ratio. These findings highlight the potential of FC-GA coacervates as stable, easy-to-prepare encapsulation materials for high-shear and high-temperature conditions, offering promising applications in the food, cosmetic, and pharmaceutical sectors.

Polysaccharide Hydrogels as Delivery Platforms for Natural Bioactive Molecules: From Tissue Regeneration to Infection Control

Polysaccharide-based hydrogels have emerged as indispensable materials in tissue engineering and wound healing, offering a unique combination of biocompatibility, biodegradability, and structural versatility. Indeed, their three-dimensional polymeric network and high water content closely resemble the natural extracellular matrix, creating a microenvironment for cell growth, differentiation, and tissue regeneration. Moreover, their intrinsic biodegradability, tunable chemical structure, non-toxicity, and minimal immunogenicity make them optimal candidates for prolonged drug delivery systems. Notwithstanding numerous advantages, these polysaccharide-based hydrogels are confronted with setbacks such as variability in material qualities depending on their source, susceptibility to microbial contamination, unregulated water absorption, inadequate mechanical strength, and unpredictable degradation patterns which limit their efficacy in real-world applications. This review summarizes recent advancements in the application of polysaccharide-based hydrogels, including cellulose, starch, pectin, zein, dextran, pullulan and hyaluronic acid as innovative solutions in wound healing, drug delivery, tissue engineering, and regenerative medicine. Future research should concentrate on optimizing hydrogel formulations to enhance their effectiveness in regenerative medicine and antimicrobial therapy.

Ultrasound-Induced Changes in Physicochemical, Microstructural, and Antioxidative Properties of Whey-Protein-Concentrate-Encapsulated 3,3'-Diindolylmethane Nanoparticles

This study determined the impact of ultrasound duration on the encapsulation of 3,3'-diindolylmethane (DIM) using whey protein concentrate (WPC) nanoparticles. Whey-protein-concentrate-based DIM nanoparticles were prepared and treated with different ultrasound times (0-20 min) with 30% amplitude at 4 °C. The results showed that ultrasound treatment significantly decreased the mean particle size (from 265 nm to 218 nm) and the Polydispersity Index (PDI) value (from 0.49 to 0.43) as well as zeta potential values were notably increased. The encapsulation efficiency (EE%) increased with increasing sonication time (0-20 min) from 76% to 88%, respectively. The ultrasound treatment had a significant effect on the apparent viscosity, and a decrease in the viscosity as a function of shear rate was observed with increasing sonication time. The transmission electronic microscopy (TEM) micrographs demonstrated that all of the formulations treated with different sonication times had a smooth and uniform spherical shape and ultrasound treatment led to the reduction of particle size, especially after 20 min of ultrasound. The thermal stability of the WPC-DIM nanoparticles was enhanced with increasing sonication time by increasing peak denaturation temperature and enthalpy. The Fourier transform infrared spectroscopy (FT-IR) spectra analysis revealed that ultrasound treatment had a remarkable effect on the secondary structure of WPC-DIM nanoparticles; electrostatic interactions and hydrogen bonds between DIM and whey protein were strengthened. Moreover, the length of ultrasound treatment exhibited a significant effect on the DPPH (2,2-diphenyl-2-picrylhydrazyl) scavenging activity (from 56% to 62%) and ABTS(2,2'-azinobis(2 ethylbenzothiazoline-6-sulfonate) scavenging activity (from 47% to 68%). In conclusion, the ultrasound treatment successfully improved the physicochemical, microstructural, and antioxidative properties of WPC-DIM nanoparticles; therefore, it is considered an effective method to develop whey-protein-concentrate-based DIM nanoparticles for medical and nutritional applications.

Environmentally friendly pretreatment of chitin using relatively low concentration KOH/urea mixture for enhanced nanofiber preparation

Traditional methods to prepare chitin nanofibers require circular chemical treatment to further purify the chitin from the seller and the morphology of the prepared nanofibers is commonly rod-like one. This study introduces an approach utilizing low-temperature freeze pretreatment of chitin in a relatively low concentration KOH/urea mixture. The crystallinity of β-chitin reduced as the concentration of KOH increased in the pretreatment solvent. The concentration of urea had little effect on the crystallinity of chitin. The pretreated chitin was then oxidized in a 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO)/NaBr/NaClO system to prepare nanofibers. The morphologies of the nanofibers can be regulated by oxidizing the chitin pretreated with different concentration of KOH. The nanofibers obtained by oxidizing chitin pretreated by 3 wt% KOH/ 1 wt% urea mixture showed rod-like morphologies with length about 150 nm. The carboxyl content of nanofibers prepared with KOH/urea mixture freeze treated chitin increased compared to that of nanofibers prepared with solely freeze treated chitin. In addition, the pretreatment solvent can be used to treat α-chitin and can be reused. The freeze KOH/urea mixture pretreatment methods can be extended to treat other biomasses for nanofiberization.

Preparation, in vitro and in vivo evaluation of phloretin-loaded TPGS/Pluronic F68 modified mixed micelles with enhanced bioavailability and anti-aging activity

Phloretin exhibits strong antioxidant and anti-aging properties by inhibiting mitochondrial oxidation of glutamate, succinic acid, and ascorbic acid. However, its clinical application is limited by poor aqueous solubility and low oral bioavailability. To enhance its bioavailability and efficacy, we incorporated phloretin into nano-micelles (phloretin-MM) using the thin film dispersion method. Characterization revealed that the optimal formulation had TPGS and Pluronic F68 in a 4:1 ratio as the excipients, which resulted in spherical micelles with an average particle size of 33.28 nm and an encapsulation efficiency of 71.2 ± 0.48%. The in vitro release profile showed that the phloretin-MM showed significantly higher cumulative release rates than free phloretin across various pH conditions, while the pharmaceutical analysis in rats indicated that phloretin-MM significantly improved the oral bioavailability of phloretin (about 5 folds) in circulation. Additionally, through the analysis of the staining of zebrafish under light microscopy and the average gray value, it can be concluded that phloretin has anti-aging drug effect, and phloretin-MM is better than free phloretin. These findings suggest that TPGS/Pluronic F68-modified phloretin-MM could serve as an excellent nano-drug carrier system, potentially enhancing the solubility, bioavailability, and anti-aging effects of phloretin for broader clinical applications.

Contribution of ultrasound-assisted protein structural changes in marinated beef to the improved binding ability of spices and flavor enhancement

BACKGROUND

Marination is an important part of air-dried beef processing, and traditional methods are inefficient and produce inconsistent results. Ultrasound, as a novel technology, can be combined with traditional marination methods. The study aimed to investigate the improvement of beef flavor by ultrasound-assisted marination. At the same time, the potential relationship between the alteration of meat protein and flavor quality by ultrasound-assisted marinating was further investigated to enable better flavor modulation and research.

RESULTS

Headspace solid-phase microextraction-gas chromatography-mass spectrometry revealed that the spice flavor of beef was significantly enhanced by 500 W ultrasound-assisted marination. Meanwhile, the experimental results demonstrated that the ultrasound-assisted marination promoted the unfolding of beef myofibrillar protein structure, which increased the number of hydrophobic and hydrogen bonding sites, enhanced the electrostatic effect and improved the functional properties of the protein. Ultrasound-assisted marination significantly enhanced the binding ability of beef myofibrillar proteins to flavor compounds compared with conventional marination. An electronic nose confirmed that this resulted in a significant increase in the flavor of the marinated meat.

CONCLUSION

Ultrasound-assisted marination effectively enhanced the flavor of marinated meat, which was closely related to the development of protein conformation. The results of this study have important implications for the food industry and the role of protein unfolding processes in flavor modulation. In particular, the findings can be practically applied to improving meat flavor under ultrasound-assisted marination. © 2024 Society of Chemical Industry.

Co-encapsulation of borage seed oil and peppermint oil blends within ultrasound-assisted soy protein isolate/purity gum ultra complex nanoparticles: Fabrication, structural interaction mechanisms, and in vitro digestion studies

This study aimed at co-encapsulating borage seed oil (BSO)- and peppermint oil (PO) blends in ultrasound-assisted complex nanoparticles stabilized by soy protein isolate (SPI) and purity gum ultra (PGU) in different ratios: SPI/PGU-1:0 (NP1), 0:1 (NP2), 1:1 (NP3), 1:3 (NP4), and 3:1 (NP5). The BSO- and PO-loaded SPI/PGU complex nanoparticles (BP-loaded SPNPs) coded as NP4 (SPI-PGU-1:3) revealed a zeta potential of -33.27 mV, a PDI of 0.14, and the highest encapsulation efficiency (81.38 %). The main interactions observed among SPI, PGU, BSO, PO, and a blend of BSO and PO, as determined by FTIR and molecular docking, involved hydrophobic effects, electrostatic attraction, and H-bonding. These interactions played crucial roles in the production of BP-loaded SPNPs. XRD results validated the alterations in the structure of BP-loaded SPNPs caused by varying proportions of SPI and PGU. The thermal capacity of BP-loaded SPNPs (NP4), as determined by TGA, exhibited the lowest amount of weight loss compared to other BP-loaded SPNPs. Morphological results revealed that NP4 and NP5 exhibited a spherical surface and two distinguishable layers, indicating successful coating of PGU onto the droplet surface. In addition, BP-loaded SPNPs (NP4) exhibited a higher antioxidant effect due to their improved progressive release and prolonged release of co-encapsulated BSO and PO during in vitro digestion. The comprehensive investigation of the co-encapsulation of BSO and PO in complex nanoparticles, dietary supplements, and double-layered emulsified systems provides valuable insights into the development of functional foods.

Monitoring of Specific Phytoestrogens by Dedicated Electrochemical Sensors: A Review

Phytoestrogens are non-steroidal estrogens produced from plants that can bind with the human body's estrogenic receptor site and be used as a substitute for maintaining hormonal balance. They are mainly classified as flavonoids, phenolic acids, lignans, stilbenes, and coumestans; some are resocyclic acids of lactones, which are mycotoxins and not natural phytoestrogen. Phytoestrogens have many beneficial medicinal properties, making them an important part of the daily diet. Electrochemical sensors are widely used analytical tools for analysing various pharmaceuticals, chemicals, pollutants and food items. Electrochemical sensors provide an extensive platform for highly sensitive and rapid analysis. Several reviews have been published on the importance of the biological and medicinal properties of phytoestrogens. However, this review provides an overview of recent work performed through electrochemical measurements with electrochemical sensors and biosensors for all the classes of phytoestrogens done so far since 2019.

Fabrication of novel casein/oligochitosan nanocomplexes for lutein delivery: Enhanced stability, bioavailability, and antioxidant properties

This study aimed to prepare novel nanocomplexes for delivery of lutein using transglutaminase (TGase)-type glycation of casein. The effect of glycated casein nanoparticles on the environmental stability, bioavailability, and antioxidant properties of lutein was investigated. Glycated casein nanoparticles with uniform distribution and small particle size were successfully prepared by ultrasound technology. The structure analysis revealed intermolecular interactions between lutein and glycated casein, with the complexes having a spherical and stable structure. The fabricated nanoparticles exhibited a high encapsulation efficiency (91.89%) and loading capacity (3.06%) for lutein. TGase-type glycation of casein nanoparticles contributed to the strong thermal stability, pH stability, storage stability, and salt stability. Moreover, glycated casein/lutein nanoparticles exhibited resistance to gastric digestion, rapid intestinal release rate, increased lutein bioavailability, and antioxidant activity under simulated digestion. This study provides key support for the development of glycated casein-based nanoparticles as delivery systems and reinforcing stability of hydrophilic nutraceuticals.

Theabrownin/whey protein isolate complex coacervate strengthens C2C12 cell proliferation via modulation of energy metabolism and mitochondrial apoptosis

Theabrownin (TB)-whey protein isolate (WPI) complex coacervates (TW) were firstly prepared to investigate the regulatory effects on skeletal muscle. The binding of TB to WPI reached saturation with the strongest electrostatic interaction at the ratio of 10:1. The formation of TW was driven by electrostatic interactions with the aid of hydrogen bonding and hydrophobic interactions, and the digestion behavior of TW was investigated based on in vitro gastrointestinal and CaCO2 cell models. The regulatory effect of TW on muscle cells was investigated by C2C12 cell assay. Cell cycle analysis showed that TW promoted the transition of skeletal muscle cells from proliferative state to differentiated state. Immunofluorescence and gene expression revealed that TW positively regulated myogenic regulatory factors, contributing to myofiber formation. Moreover, TW activated the intracellular TCA cycling and oxidative phosphorylation, providing energy for skeletal muscle regeneration and repair. Mechanistically, TW inhibited the release of cytochrome C from mitochondria to cytoplasm through the Bcl-2/Cytochrome C/Cleaved-Caspase-3 pathway, exhibiting a protective effect on skeletal muscle cells. In the future, the molecular mechanism of TW enhancing skeletal muscle function should be validated through aging animal models and clinical trials and expand its therapeutic application for muscle health in functional food and dietary supplements.

Role of nanofertilization in plant nutrition under abiotic stress conditions

Plants require nutrients for growth, which they obtain from the soil via the root system. Fertilizers offer the essential nutrients (nitrogen, phosphorus, and potassium, as well as critical secondary elements) required by plants. Soil productivity falls with each crop until nutrients are provided. A wide range of so-called fertilizer products, such as organic fertilizers, argon mineral fertilizers, and mineral fertilizers, can assist farmers in adjusting fertilization methods based on the environment and agricultural conditions (inhibitors, restricted materials, growth mediums, plant bio-stimulants, etc.). Agricultural land is reduced by erosion, pollution, careless irrigation, and fertilization. On the other hand, more agricultural production is needed to meet the demands of expanding industries and the nutritional needs of a growing population. Nano fertilizers have recently started to be manufactured to obtain the highest yield and its quality per unit area. Previous researchers found that nano fertilizers could improve plant nutrient uptake efficiency, lower soil toxicity, mitigate the potential negative effects of excessive chemical fertilizer use, and reduce the frequency of fertilization. To maximize crop yields and optimize nutrient use while reducing the overuse of chemical fertilizers, nano fertilizersNFs are crucial in agriculture. The key component of these fertilizers is that they contain one or more macro- and micronutrients that can be applied regularly in minute doses while not damaging the environment. However, they have a minimal effect on plant growth and agricultural yields when employed in high numbers, like synthetic fertilizers. This article explains the features, relevance and classification of nano-fertilizers, their use in plant development, their advantages and disadvantages, and the results achieved in this field.

A Review on the Driving Forces in the Formation of Bioactive Molecules-Loaded Prolamin-Based Particles

Prolamin-based particles loaded with bioactive molecules have attracted widespread attention from scientists due to their novel properties in chemistry, physics, and biology. In the self-assembly process of biopolymer-based nanocapsules, noncovalent interactions are the main driving forces for reducing bulk materials to the nanoscale and controlling the release of bioactive molecules. This article reviews the types of interaction forces, binding strength, binding active sites, molecular orientation, and binding affinity that affect the release profile of bioactive molecules during the preparation of protein stabilizer particles. Different preparation formulations, the use of different biopolymers, the inherent nature of the loaded bioactive molecules, and external factors (including pH, biopolymer concentration, temperature, salt, ultrasonication, and atmospheric cold plasma treatment) lead to different types and strengths of intra- and intermolecular interactions. Strategies, such as pH, ultrasonication, and atmospheric cold plasma, to change the protein conformation are key to improving the binding strength between proteins and bioactive substances or stabilizers. This review provides some guidance for scientists and technicians dedicated to improving loading efficiency, delaying release, enhancing colloidal stability, and exploring the binding behavior among proteins, stabilizers, and bioactive molecules.

β-Cyclodextrin/dialdehyde glucan-coated keratin nanoparticles for oral delivery of insulin

Successful oral insulin administration can considerably enhance the quality of life (QOL) of diabetes patients who must frequently take insulin injections. However, Oral insulin administration is seriously hampered by gastrointestinal enzymes, wide pH range, mucus and mucosal layers, which limit insulin oral bioavailability to ≤2 %. Herein, we developed a simple, inexpensive and safe dual β-cyclodextrin/dialdehyde glucan-coated keratin nanoparticle (β-CD-K-IN-DG). The resulted β-CD-K-IN-DG not only gave the ultra-high insulin loading (encapsulation efficiency (98.52 %)), but also protected insulin from acid and enzymatic degradation. This β-CD-K-IN-DG had a notable hypoglycemic effect, there was almost 80 % insulin release after 4 h of incubation under hyperglycemic conditions. Ex vivo results confirmed that β-CD-K-IN-DG possessed high mucus-penetration ability. Transepithelial transport and uptake mechanism studies revealed that bypass transport pathway and endocytosis promoted β-CD-K-IN-DG entered intestinal epithelial cells, thus increased the bioavailability of insulin (12.27 %). The improved stability of insulin during in vivo transport implied that β-CD-K-IN-DG might be a potential tool for the effective oral insulin administration.

Study on the interaction mechanism between (-)-epigallocatechin-3-gallate and myoglobin: Multi-spectroscopies and molecular simulation

(-)-Epigallocatechin-3-gallate (EGCG) is remarkably efficacious in inhibiting the browning of red meat. We therefore propose a hypothesis that EGCG forms complexes with myoglobin, thereby stabilizing its structure and thus preventing browning. This study investigated the interaction mechanism between EGCG and myoglobin. EGCG induced static quenching of myoglobin. Noncovalent forces, including hydrogen bonds and van der Waals, primarily governing the interactions between myoglobin and EGCG. The interactions primarily disrupted myoglobin's secondary structure, thus significantly reducing surface hydrophobicity by 53% (P < 0.05). The modification augmented the solubility and thermal stability of myoglobin. The radius of gyration (Rg) value fluctuated between 1.47 and 1.54 nm, and the hydroxyl groups in EGCG formed an average of 2.93 hydrogen bonds with myoglobin. Our findings elucidated the formation of stable myoglobin-EGCG complexes and the myoglobin-EGCG interaction, thus confirming our initial hypothesis.

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.

Fabrication of Citrus bergamia essential oil-loaded sodium caseinate/peach gum nanocomplexes: Physicochemical, spectral, and structural characterization

`The objective of current research was to encapsulate citrus bergamia essential oil (CBEO) in nanocomplexes composed of sodium caseinate (SC) and peach gum polysaccharide (PG) in various ratios (SC/PG-1:0, 0:1, 1:1, 1:3, and 3:1). The nanocomplexes formed by the combination of SC and PG in a ratio of 1:3 exhibited a zeta potential of -21.36 mV and a PDI of 0.25. The CBEO-loaded SC/PG (1:3) nanocomplexes revealed the maximum encapsulation efficiency (82.47 %) and loading capacity (1.85 %). FTIR also confirmed the secondary structure variations in response to different ratios of CBEO-loaded SC/PG nanocomplexes. In addition, the XRD and fluorescence spectroscopy analysis also revealed structural changes among CBEO nanocomplexes. The thermal capability of CBEO-loaded SC/PG (1:3) nanocomplexes via TGA showed the minimum weight loss among other complexes. SEM and CLSM analysis demonstrated the uniform distribution and spherical morphology of CBEO-loaded SC/PG (1:3) nanocomplexes. The antioxidant activity of free CBEO was significantly improved in CBEO-loaded nanocomplexes. Likewise, the inhibitory activity of CBEO-loaded nanocomplexes exhibited significantly higher antibacterial action against S. aureus and E. coli. The aforementioned perspective suggests that SC/PG nanocomplexes have potent potential to serve as highly effective nanocarriers with a broad spectrum of uses in the pharmaceutical and food sectors.

Stability and encapsulation properties of daidzein in zein/carrageenan/sodium alginate nanoparticles with ultrasound treatment

This study aimed to prepare carrageenan/sodium alginate double-stabilized layers of zein nanoparticles loaded with daidzein using ultrasound technology to investigate the effect of ultrasound treatment on the stability of composite nanoparticles and encapsulation of daidzein. Compared with composite nanoparticles without ultrasound treatment, the encapsulation efficiency of nanoparticles was increased (90.36 %) after ultrasound treatment (320 W, 15 min). Ultrasound treatment reduced the particle size and PDI of nanoparticles and improved the stability and solubility of nanoparticles. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) revealed that the nanoparticles treated with ultrasound were smooth spherical and uniformly distributed. Fourier transform infrared spectroscopy (FTIR) results showed that the main forces that form nanoparticles are hydrogen bonding, electrostatic interactions and hydrophobic interactions. Fluorescence and CD chromatography showed that ultrasound treatment alters the secondary structure of zein and maintains nanoparticle stability. Encapsulation of daidzein in nanocarriers with ultrasound treatment can effectively scavenge DPPH and ABTS free radicals, improve antioxidant activity, and realize the slow release of daidzein in the gastrointestinal tract. The results showed that ultrasonication helps the construction of hydrophobic bioactives delivery carriers and provides better protection for unstable bioactives.

Simple and complex coacervation in systems involving plant proteins

Plant-based foods are gaining popularity as alternatives to meat and dairy products due to sustainability and health concerns. As a consequence, there is a renewed interest in the phase behaviour of plant proteins and of mixtures of plant proteins and polysaccharides, in particular in the cases where coacervation is found to occur, i.e., liquid-liquid phase separation (LLPS) into two phases, one of which is rich in biopolymers and one of which is poor in biopolymer. Here we review recent research into both simple and complex coacervation in systems involving plant proteins, and their applications in food- as well as other technologies, such as microencapsulation, microgel production, adhesives, biopolymer films, and more.

Calcium ions induced ι-carrageenan-based gel-coating deposited on zein nanoparticles for encapsulating the curcumin

Zein, curcumin (Cur), and ι-carrageenan (ιCar) were used to prepare core-shell biopolymer nanoparticles (Zein-Cur-ιCar). These nanoparticles consisted of a nutraceutical-loaded protein core (curcumin-loaded zein nanoparticles) and a gelled polysaccharide shell (calcium cross-linked ι-carrageenan). The size, charge, morphology, and interactions of the nanoparticles were characterized by dynamic light scattering, zeta-potential analysis, scanning electron microscopy, and Fourier Transform infrared analysis. Ionic bridging, electrostatic attraction, hydrogen bonding, and hydrophobic attraction were involved in particle formation. The high encapsulation efficiency (93.2%) and loading capacity (6.2%) indicated that curcumin was well encapsulated within nanoparticles with optimized compositions (zein:ι-carrageenan 100:40). These particles had relatively small diameters (351.8 nm) and effectively delayed the light and thermal degradation of curcumin. Moreover, the curcumin within the nanoparticles was released in a sustained manner under simulated gastrointestinal conditions, which may improve its oral bioavailability. In summary, calcium carrageenan-coated zein nanoparticles have potential for the encapsulation, protection, and controlled release of hydrophobic nutrients.

Phellinus linteus polysaccharides: A review on their preparation, structure-activity relationships, and drug delivery systems

Phellinus linteus polysaccharides exhibit antitumor, immunomodulatory, anti-inflammatory, and antioxidant properties, mitigate insulin resistance, and enhance the diversity and abundance of gut microbiota. However, the bioactivities of P. linteus polysaccharides vary owing to the complex structure, thereby, limiting their application. Various processing strategies have been employed to modify them for improving the functional properties and yield. Herein, we compare the primary modes of extraction and purification employed to improve the yield and purity, review the structure-activity relationships, and discuss the application of P. linteus polysaccharides using nano-carriers for the encapsulation and delivery of various drugs to improve bioactivity. The limitations and future perspectives are also discussed. Exploring the bioactivity, structure-activity relationship, processing methods, and delivery routes of P. linteus polysaccharides will facilitate the development of functional foods and dietary supplements rich in P. linteus polysaccharides.

Application of soybean isolate protein (SPI) and soy hull polysaccharide (SHP) complex in fermentation products

We investigated the stability of a soy protein isolate (SPI)/soy hull polysaccharide (SHP) composite and its effect on the quality of fermented products. Sonication contributed to a more stable SPI/SHP composite. Increasing SHP concentrations increased the viscoelasticity of the emulsions and decreased turbiscan stability index (TSI) values, indicating that SHP improved the emulsification and stability of the composite emulsions. The fermented products with SHP had an increased ability to bind to water. Hardness, gelling, chewiness, sourness, and astringency increased with polysaccharide addition. Additionally, SHP promoted acid production by lactic acid bacteria during storage. All groups had viscoelastic behavior (G' ˃ G″, tan δ < 1), with viscosity increasing and subsequently decreasing. TSI values were significantly lower in the treated groups than in the control group. The results revealed that SHP improved the sensory quality and storage stability of fermented products.

Tunability of Pickering particle features of whey protein isolate via remodeling partial unfolding during ultrasonication-assisted complexation with chitosan/chitooligosaccharide

The potential of ultrasonication-driven molecular self-assembly of whey protein isolate (WPI) with chitosan (CS)/chitooligosaccharide (COS) to stabilize Pickering emulsions was examined, based on CS/COS ligands-induced partial unfolding in remodeling the Pickering particles features. Multi-spectral analysis suggested obvious changes in conformational structures of WPI due to interaction with CS/COS, with significantly higher unfolding degrees of WPI induced by COS. Non-covalent interactions were identified as the major forces for WPI-CS/COS conjugates. Ultrasonication enhanced electrostatic interaction between CS's -NH3 groups and WPI's -COO- groups which improved emulsification activity and storability of WPI-COS stabilized Pickering emulsion. This was attributed to increased surface hydrophobicity and decreased particle size compared to WPI-CS associated with differential unfolding degrees induced by different saccharide ligands. CLSM and SEM consistently observed smaller emulsion droplets in WPI-COS complexes than WPI-CS/COS particles tightly adsorbed at the oil-water interface. The electrostatic self-assembly of WPI with CS/COS greatly enhanced the encapsulation efficiency of quercetin than those stabilized by WPI alone and ultrasound further improved encapsulation efficiency. This corresponded well with the quantitative affinity parameters between quercetin and WPI-CS/COS complexes. This investigation revealed the great potential of glycan ligands-induced conformational transitions of extrinsic physical disruption in tuning Pickering particle features.

Tuning the viscoelastic properties of peptide coacervates by single amino acid mutations and salt kosmotropicity

Coacervation, or liquid-liquid phase separation (LLPS) of biomacromolecules, is increasingly recognized to play an important role both intracellularly and in the extracellular space. Central questions that remain to be addressed are the links between the material properties of coacervates (condensates) and both the primary and the secondary structures of their constitutive building blocks. Short LLPS-prone peptides, such as GY23 variants explored in this study, are ideal model systems to investigate these links because simple sequence modifications and the chemical environment strongly affect the viscoelastic properties of coacervates. Herein, a systematic investigation of the structure/property relationships of peptide coacervates was conducted using GY23 variants, combining biophysical characterization (plate rheology and surface force apparatus, SFA) with secondary structure investigations by infrared (IR) and circular dichroism (CD) spectroscopy. Mutating specific residues into either more hydrophobic or more hydrophilic residues strongly regulates the viscoelastic properties of GY23 coacervates. Furthermore, the ionic strength and kosmotropic characteristics (Hofmeister series) of the buffer in which LLPS is induced also significantly impact the properties of formed coacervates. Structural investigations by CD and IR indicate a direct correlation between variations in properties induced by endogenous (peptide sequence) or exogenous (ionic strength, kosmotropic characteristics, aging) factors and the β-sheet content within coacervates. These findings provide valuable insights to rationally design short peptide coacervates with programmable materials properties that are increasingly used in biomedical applications.

Fabrication of compact zein-chondroitin sulfate nanocomplex by anti-solvent co-precipitation: Prevent degradation and regulate release of curcumin

The main purpose of this study was to prepare zein-chondroitin sulfate (ZC) nanocomplex by anti-solvent co-precipitation, and to encapsulate, protect and controlled-release curcumin. As the proportion of chondroitin sulfate (CS) increased, the particle size, turbidity and zeta-potential of the ZC nanocomplexes all increased. When the mass ratio of zein and CS was 10:3, the ZC nanocomplex had small particle size (129 nm) and low polydispersity index (0.3). According to FTIR, FS, CD and XRD results, zein and CS were tightly bound by electrostatic attraction, hydrophobic effect and hydrogen bonding. The ZC nanocomplex was designed to encapsulate curcumin with high encapsulation efficiency (94.7%) and loading capacity (3.8%), and also enhanced the resistance of curcumin to light and thermal degradation by 2.9 and 2.4 times. It also exhibited controlled release capability during simulated gastrointestinal digestion. These results suggested the ZC nanocomplex is a good delivery vehicle to facilitate the application of curcumin.

Effect of ultrasonic assisted grafting on the structural and functional properties of mung bean protein isolate conjugated with maltodextrin through maillard reaction

Four different methods of maillard reaction including ultrasound (150 W, 10 min) assisted, classical wet heating (80 °C, 60min), moderate water bath heating (60°C, 12 to 30 h) and dry state method (60 °C, 79 % relative humidity and 48 h) were used to Mung bean protein isolate - Maltodexrtin conjugates (MPI-MD) preparation. The samples prepared under ultrasound and wet heating were chosen for further analysis according to degree of graft and UV-absorbance at 420 nm. Higher glycosylation at short time and lower browning were obtained under ultrasound treatment. Covalent attachment in conjugates confirmed by SDS-polyacrylamide gel electrophoresis. The structural analysis revealed prominent unfolding effect of ultrasound waves on the protein's molecules. The decrease of α-helix content was related to the exposure of buried amino group residues during reaction. Glycation of MPI under ultrasound caused changes in tertiary structure of protein and leads to decrease in the fluorescence intensity compared with native and wet heating treatments. FTIR spectra confirmed the conjugation of the MPI and MD and suggested that protein structure was changed and ultrasound promoted the graft reaction more than wet heating treatment. Conjugated MPI showed higher emulsification and solubility index than MPI, moreover the effect of ultrasonic waves on ameliorated functional properties was impressive than those for wet heating treatment. Overall, this study showed use of ultrasonication in maillard reaction was a suitable method for producing MPI- MD conjugates and improved the efficiency of graft reaction and functional properties of grafts.

A non-thermal modification method to promote the interaction of zein-alginate oligosaccharides composites for better encapsulation and stability-Cold plasma

This current research explored the application of cold plasma (CP) treatment to modify zein-alginate oligosaccharide (zein-AOS) composites in an ethanol-water solution. Anti-solvent method was used to prepare zein-AOS nanoparticles (NPs), and the objective was to investigate the mechanism by which CP promotes interaction between protein and saccharides. Characterization results indicated that CP treatment improved hydrogen bonding and electrostatic interaction between zein and AOS. The CP zein-AOS NPs underwent dispersion and rearrangement, resulting in smaller aggregates with better dispersibility. Among the various induction conditions tested, the zein-AOS85 NPs (induced at 85 W for 2 min) exhibited superior performance as delivery wall materials, with smaller particle size (234.67 nm), larger specific surface area (9.443 m2/g), and higher surface charge (-35.43 mV). In addition, zein-AOS85 showed high stability when used as delivery wall material, providing more binding sites and self-assembly dynamics for nutrients. Curcumin was used as the nutrient model in this study, and CP was found to enhance hydrogen bonding, electrostatic interaction, and hydrophobic interaction between zein, AOS, and nutrients, resulting in increased encapsulation efficiency (EE) from 63.80 % to 85.17 %. The delivery system also exhibited good pH, ionic strength, storage, and dispersion stability.

Ultrasonic and homogenization: An overview of the preparation of an edible protein-polysaccharide complex emulsion

Emulsion systems are extensively utilized in the food industry, including dairy products, such as ice cream and salad dressing, as well as meat products, beverages, sauces, and mayonnaise. Meanwhile, diverse advanced technologies have been developed for emulsion preparation. Compared with other techniques, high-intensity ultrasound (HIUS) and high-pressure homogenization (HPH) are two emerging emulsification methods that are cost-effective, green, and environmentally friendly and have gained significant attention. HIUS-induced acoustic cavitation helps in efficiently disrupting the oil droplets, which effectively produces a stable emulsion. HPH-induced shear stress, turbulence, and cavitation lead to droplet disruption, altering protein structure and functional aspects of food. The key distinctions among emulsification devices are covered in this review, as are the mechanisms of the HIUS and HPH emulsification processes. Furthermore, the preparation of emulsions including natural polymers (e.g., proteins-polysaccharides, and their complexes), has also been discussed in this review. Moreover, the review put forward to the future HIUS and HPH emulsification trends and challenges. HIUS and HPH can prepare much emulsifier-stable food emulsions, (e.g., proteins, polysaccharides, and protein-polysaccharide complexes). Appropriate HIUS and HPH treatment can improve emulsions' rheological and emulsifying properties and reduce the emulsions droplets' size. HIUS and HPH are suitable methods for developing protein-polysaccharide forming stable emulsions. Despite the numerous studies conducted on ultrasonic and homogenization-induced emulsifying properties available in recent literature, this review specifically focuses on summarizing the significant progress made in utilizing biopolymer-based protein-polysaccharide complex particles, which can provide valuable insights for designing new, sustainable, clean-label, and improved eco-friendly colloidal systems for food emulsion. PRACTICAL APPLICATION: Utilizing complex particle-stabilized emulsions is a promising approach towards developing safer, healthier, and more sustainable food products that meet legal requirements and industrial standards. Moreover, the is an increasing need of concentrated emulsions stabilized by biopolymer complex particles, which have been increasingly recognized for their potential health benefits in protecting against lifestyle-related diseases by the scientific community, industries, and consumers.

Ultrasound-Assisted Encapsulation of Phytochemicals for Food Applications: A Review

The use of phytochemicals as natural food additives is a topic of interest for both academic and food industry communities. However, many of these substances are sensitive to environmental conditions. For this reason, encapsulation is usually performed prior to incorporation into food products. In this sense, ultrasound-assisted encapsulation is an emerging technique that has been gaining attention in this field, bringing important advantages for the production of functional food products. This review article covered applications published in the last five years (from 2019 to 2023) on the use of ultrasound to encapsulate phytochemicals for further incorporation into food. The ultrasound mechanisms for encapsulation, its parameters, such as reactor configuration, frequency, and power, and the use of ultrasound technology, along with conventional encapsulation techniques, were all discussed. Additionally, the main challenges of existing methods and future possibilities were discussed. In general, ultrasound-assisted encapsulation has been considered a great tool for the production of smaller capsules with a lower polydispersity index. Encapsulated materials also present a higher bioavailability. However, there is still room for further developments regarding process scale-up for industrial applications. Future studies should also focus on incorporating produced capsules in model food products to further assess their stability and sensory properties.

Optimization of food-grade colloidal delivery systems for thermal processing applications: a review

Colloidal delivery systems are widely used in the food industry to enhance the dispersibility, stability, efficacy, or bioavailability. However, when exposed to the high temperature, delivery systems are often prone to degradation, which limits its application in thermal processing. In this paper, the effects of thermal processing on the performance of traditional protein-based or starch-based delivery systems are firstly described, including the molecular structure changes of proteins, starches or lipids, and the degradation of embedded substances. These effects are unfavorable to the application of the delivery system in thermal processing. Then, strategies of improving the heat resistance of food grade colloid delivery system and their use in frying, baking and cooking food are mainly introduced. The heat resistance of the delivery system can be improved by a variety of strategies, including the development of new heat-resistant materials, the addition of heat-resistant coatings to the surface of delivery systems, the cross-linking of proteins or starches using cross-linking agents, the design of particle structures, the use of physical means such as ultrasound, or the optimization of the ingredient formula. These strategies will help to expand the application of heat-resistant delivery systems so that they can be used in real thermal processing.

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.

Structural and textural properties of walnut protein gels induced by ultrasound and transglutaminase: encapsulation and release of tea polyphenols

This study investigated the synergy of ultrasonic and transglutaminase (TGase) treatment on the structural, physicochemical, rheological, gelation properties and controlled release properties of dehulled walnut proteins (DWP). The results showed that after ultrasonic-TGase treatment, the surface hydrophobicity was decreased, indicating the involvement of disulfide bonds in gel formation. Scanning electron microscopy (SEM) showed that ultrasonic-TGase treatment resulted in a more uniform and denser microstructure of DWP gels. Ultrasonic-TGase treatment changed the secondary structure of the DWP gels as determined by Fourier transform infrared spectroscopy, with an increase in α-helix, β-turn and random coils and a decrease in β-sheets. In addition, in vitro drug release profiles showed that ultrasonic-TGase treatment promoted the cross-linking of protein molecules and formed a dense network to embed tea polyphenols (TP), thereby slowing down the digestion of TP in simulated gastric fluid and achieving the purpose of slow-release in simulated intestinal fluid. Thus, the synergy of ultrasonic and TGase treatment might be an effective method to improve gel properties and expand the application of protein gels in the food industries.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05756-6.

Protein-polysaccharide nanoconjugates: Potential tools for delivery of plant-derived nutraceuticals

Protein-polysaccharide nanoconjugates are covalently interactive networks that are currently the subject of intense research owing to their emerging applications in the food nanotechnology field. Due to their biocompatibility and biodegradability properties, they have played a significant role as wall materials for the formation of various nanostructures to encapsulate nutraceuticals. The food-grade protein-polysaccharide nanoconjugates would be employed to enhance the delivery and stability of nutraceuticals for their real use in the food industry. The most common edible polysaccharides (cellulose, chitosan, pectin, starch, carrageenan, fucoidan, mannan, glucomannan, and arabic gum) and proteins (silk fibroin, collagen, gelatin, soy protein, corn zein, and wheat gluten) have been used as potential building blocks in nano-encapsulation systems because of their excellent physicochemical properties. This article broadens the discussion of food-grade proteins and polysaccharides as nano-encapsulation biomaterials and their fabrication methods, along with a review of the applications of protein-polysaccharide nanoconjugates in the delivery of plant-derived nutraceuticals.

Co-encapsulation of curcumin and quercetin with zein/HP-β-CD conjugates to enhance environmental resistance and antioxidant activity

In this study, composite nanoparticles consisting of zein and hydroxypropyl beta-cyclodextrin were prepared using a combined antisolvent co-precipitation/electrostatic interaction method. The effects of calcium ion concentration on the stability of the composite nanoparticles containing both curcumin and quercetin were investigated. Moreover, the stability and bioactivity of the quercetin and curcumin were characterized before and after encapsulation. Fluorescence spectroscopy, Fourier Transform infrared spectroscopy, and X-ray diffraction analyses indicated that electrostatic interactions, hydrogen bonding, and hydrophobic interactions were the main driving forces for the formation of the composite nanoparticles. The addition of calcium ions promoted crosslinking of the proteins and affected the stability of the protein-cyclodextrin composite particles through electrostatic screening and binding effects. The addition of calcium ions to the composite particles improved the encapsulation efficiency, antioxidant activity, and stability of the curcumin and quercetin. However, there was an optimum calcium ion concentration (2.0 mM) that provided the best encapsulation and protective effects on the nutraceuticals. The calcium crosslinked composite particles were shown to maintain good stability under different pH and simulated gastrointestinal digestion conditions. These results suggest that zein-cyclodextrin composite nanoparticles may be useful plant-based colloidal delivery systems for hydrophobic bio-active agents.

Polysaccharides, proteins, and their complex as microencapsulation carriers for delivery of probiotics: A review on carrier types and encapsulation techniques

Probiotics provide several benefits for humans, including restoring the balance of gut bacteria, boosting the immune system, and aiding in the management of certain conditions such as irritable bowel syndrome and lactose intolerance. However, the viability of probiotics may undergo a significant reduction during food storage and gastrointestinal transit, potentially hindering the realization of their health benefits. Microencapsulation techniques have been recognized as an effective way to improve the stability of probiotics during processing and storage and allow for their localization and slow release in intestine. Although, numerous techniques have been employed for the encapsulation of probiotics, the encapsulation techniques itself and carrier types are the main factors affecting the encapsulate effect. This work summarizes the applications of commonly used polysaccharides (alginate, starch, and chitosan), proteins (whey protein isolate, soy protein isolate, and zein) and its complex as the probiotics encapsulation materials; evaluates the evolutions in microencapsulation technologies and coating materials for probiotics, discusses their benefits and limitations, and provides directions for future research to improve targeted release of beneficial additives as well as microencapsulation techniques. This study provides a comprehensive reference for current knowledge pertaining to microencapsulation in probiotics processing and suggestions for best practices gleaned from the literature.

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.

Development and Characterization of an Edible Zein/Shellac Composite Film Loaded with Curcumin

The development of functional edible films is promising for the food industry, and improving the water barrier of edible films has been a research challenge in recent years. In this study, curcumin (Cur) was added to zein (Z) and shellac (S) to prepare an edible composite film with a strong water barrier and antioxidant properties. The addition of curcumin significantly reduced the water vapor permeability (WVP), water solubility (WS), and elongation at break (EB), and it clearly improved the tensile strength (TS), water contact angle (WCA), and optical properties of the composite film. The ZS-Cur films were characterized by SEM, FT-IR, XRD, DSC, and TGA; the results indicated that hydrogen bonds were formed among the curcumin, zein, and shellac, which changed the microstructure and improved the thermal stability of the film. A test of curcumin release behavior showed controlled release of curcumin from the film matrix. ZS-Cur films displayed remarkable pH responsiveness, strong antioxidant properties, and inhibitory effects on E. coli. Therefore, the insoluble active food packaging prepared in this study provides a new strategy for the development of functional edible films and also provides a possibility for the application of edible films to extend the shelf life of fresh food.

Particle characteristics and tribo-rheological properties of soy protein isolate (SPI) dispersions: Effect of heating and incorporation of flaxseed gum

To understand the heat treatment and flaxseed gum (FG) on the properties of commercial spray dried soy protein isolate (SPI), SPI dispersions were prepared with mass ratio of 6 %, 9 %, and 12 % in water and the corresponding protein concentrations of 2.2 %, 3.61 % and 5.23 % were reached after centrifugation. The solutions were treated at different temperatures (25, 75 and 100 °C) and the particle characteristics and physical properties of the resulted samples were determined. The influence of different concentrations (0.05 % to 0.3 %) of FG addition was evaluated in the SPI solution at 5 % protein concentration. The results showed that heating caused decrease of particle size of the SPI proteins and 100 °C heat treatment caused decrease of hydrophobicity and viscosity of the protein dispersions, and increase of their physical stability, and the effect was more marked at high protein concentration; while heat treatment at 75 °C caused substantial increase in protein hydrophobicity and viscosity, and decrease of stability. Addition of FG resulted in increase of particle size, absolute value of zeta potential and hydrophobicity of the protein solutions. The viscosity of the solution was decreased with addition of FG, but higher FG concentration could lead to higher viscosity. The physical stability of the mixed system was improved at low FG concentrations, but decreased at concentration higher than 0.2 %, which was more significant after 100 °C heat treatment. FG incorporation could improve the boundary lubrication of the protein solutions.

Interactions between Soybean Trypsin Inhibitor and Chitosan in an Aqueous Solution

Supramolecular structures obtained from protein-polysaccharide association may be applied to encapsulate bioactive compounds or to improve the physical stability and texture properties of colloid-based products. In this study, the interaction of 0.1 wt% soybean trypsin inhibitor (STI) with different concentrations of chitosan (CS) in aqueous solutions was investigated under different pH by the analysis of state diagram, turbidity, zeta potential, spectroscopy, and microstructure; the protective effect of STI-CS complex coacervates on STI stability in simulated gastric juice was also discussed. The results suggested that interactions between STI and CS could form soluble/insoluble complexes mainly through hydrophobic interactions (pH 4.0) or electrostatic interactions (pH 6.0). The CD spectra showed that the secondary structure of STI did not change significantly when CS with the same charge was mixed with STI, and the secondary structure of STI was slightly changed when CS with the opposite charge was mixed with STI. Simulated gastric digestion experiments showed that the complex formed by non-covalent bonding had a protective effect on the active protein. This study provides information about the effect of different CS concentrations and pH values on the formation of complexes of CS and STI in an aqueous solution and provides theoretical references for the construction of supramolecular-structured carrier substances based on CS and STI.

The droplet breakup model and characteristics of pH-shifted peanut protein isolate-high methoxyl pectin stabilised emulsions under ultrasound

The effect of pH on the occurrence states of peanut protein isolate (PPI) and high methoxyl pectin (HMP), and droplet breakup model of the emulsions under ultrasound were studied. Particle size distribution and scanning electron microscopy results showed that PPI-HMP existed a soluble complex at pH 5.0, had no interaction at pH 7.0, and was co-soluble at pH 9.0. Droplet breakup model results revealed that the characteristics of emulsion stabilised by PPI-HMP treated at pH 5.0 was different from that at pH 7.0 and 9.0. The average diameter of the droplet well satisfied the model. According to rheological properties, interface tension, and microstructure, the formation mechanism and characteristics of emulsion stabilised by PPI-HMP treated at pH 5.0 was different from that at pH 7.0 and pH 9.0. The research provided a reference for constructing emulsions using pH-shifted PPI-HMP under ultrasound.