Facile Preparation of Silica/Tannic Acid/Zein Microcapsules Templated from Non-Aqueous Pickering Emulsions and their Application in Cargo Protection.

Microcapsules have attracted significant attention in academia and industry due to their unique properties for protecting and controlling the release of active substances. However, based on water-insoluble biopolymers, developing a straightforward approach to prepare microcapsules with improved biocompatibility and functional shells remains a great challenge. In this study, zein, a water-insoluble protein, is employed to prepare robust microcapsules facilely using oil-in-aqueous ethanol Pickering emulsions as templates. First, the emulsion template is stabilized by hydrophobic silica nanoparticles with in situ surface modification of tannic acid. The zein is then precipitated at the interface in a controlled manner using antisolvent approach to obtain silica/tannic acid/zein (STZ) microcapsules. It is found that the concentration of zein and the presence of tannic acid played a significant role in the formation of STZ microcapsules with well-defined morphology and a robust shell. The uniform deposition of zein on the surface of template droplets is facilitated by the interactions between tannic acid and zein via hydrogen bond and electrostatic force. Finally, the resulting STZ microcapsules showed super resistance to ultraviolet (UV) radiation and high temperature for the unstable, lipophilic, and active substance of ß-carotene.

Protection of α-Tocopherol from UV-Induced Degradation by Encapsulation into Zein Nanoparticles.

Vitamin E is a fat-soluble vitamin with several forms. Among these, α-tocopherol (TOC) is preferentially absorbed and accumulated in humans. In the body, it acts as an antioxidant, helping to protect cells from the damage caused by free radicals. It is an organic chemical compound that undergoes degradation upon irradiation with UV light. To protect this bioactive chemical compound from UV light degradation, encapsulation was carried out using zein as a shell material. Due to the unique phase diagram of TOC in aqueous ethanol, the encapsulation efficiency was >99%. The size of encapsulated particles was ~300 nm or smaller, and the thickness of the shell wall was ~30 nm. The presented procedure offers the most simple and efficient encapsulation process that yields edible products. The investigation of the irradiation effect of UV on TOC revealed that the encapsulation effectively blocks UV light and prevents TOC from being degraded. The presented procedure offers an instantaneous and highly efficient encapsulation process, which yields edible products.

Metformin Loaded Zein Polymeric Nanoparticles to Augment Antitumor Activity against Ehrlich Carcinoma via Activation of AMPK Pathway: D-Optimal Design Optimization, In Vitro Characterization, and In Vivo Study.

Metformin (MET), an antidiabetic drug, is emerging as a promising anticancer agent. This study was initiated to investigate the antitumor effects and potential molecular targets of MET in mice bearing solid Ehrlich carcinoma (SEC) as a model of breast cancer (BC) and to explore the potential of zein nanoparticles (ZNs) as a carrier for improving the anticancer effect of MET. ZNs were fabricated through ethanol injection followed by probe sonication method. The optimum ZN formulation (ZN8) was spherical and contained 5 mg zein and 30 mg sodium deoxycholate with a small particle size and high entrapment efficiency percentage and zeta potential. A stability study showed that ZN8 was stable for up to three months. In vitro release profiles proved the sustained effect of ZN8 compared to the MET solution. Treatment of SEC-bearing mice with ZN8 produced a more pronounced anticancer effect which was mediated by upregulation of P53 and miRNA-543 as well as downregulation of NF-κB and miRNA-191-5p gene expression. Furthermore, ZN8 produced a marked elevation in pAMPK and caspase-3 levels as well as a significant decrease in cyclin D1, COX-2, and PGE2 levels. The acquired findings verified the potency of MET-loaded ZNs as a treatment approach for BC.

Air-Assisted Electrospinning of Dihydromyricetin-Loaded Dextran/Zein/Xylose Nanofibers and Effects of the Maillard Reaction on Fiber Properties.

Dihydromyricetin (DMY) has been encapsulated in delivery systems to address the solubility limitations of DMY in water and improve its bioavailability. Air-assisted electrospinning has been used as a novel technology to load DMY. To evaluate the impact of adding DMY to dextran/zein nanofibers and understand the effects of the Maillard reaction (MR) on the physical and functional properties of DMY-loaded nanofibers, dextran/zein/xylose nanofibers with 0%, 1%, 2%, 3%, and 4% DMY were fabricated, followed by MR crosslinking. Scanning electron microscopy (SEM) observations indicated that the addition of DMY and the MR did not affect the morphology of the nanofibers. X-ray diffraction (XRD) results indicated amorphous dispersion of DMY within the nanofibers and a decreased crystalline structure within the nanofibers following the MR, which might improve their molecular flexibility. The nanofibrous film formed after the MR exhibited both increased tensile strength and elastic modulus due to hydrogen bonding within the nanofibers and increased elongation at break attributed to the increased amorphization of the structure after crosslinking. The nanofibers were also found to exhibit improved heat stability after the MR. The antioxidant activity of the nanofibers indicated a dose-dependent effect of DMY on radical scavenging activity and reducing power. The maintenance of antioxidant activity of the nanofibers after the MR suggested heat stability of DMY during heat treatment. Overall, dextran/zein nanofibers with various DMY contents exhibited tunable physical properties and effective antioxidant activities, indicating that dextran/zein nanofibers offer a successful DMY delivery system, which can be further applied as an active package.

Effect of tannic acid modification on the interface and emulsification properties of zein colloidal particles.

BACKGROUND: Interface modification driven by supramolecular self-assembly has been accepted as a valuable strategy for emulsion stabilization enhancement. However, there has been a dearth of comparative research on the effect of simple complexation and assembly from the perspective of the responsible mechanism. RESULTS: The present study selected zein and tannic acid (TA) as representative protein and polyphenol modules for self-assembly (coined as TA-modified zein particle and TA-zein complex particle) to explore the surface properties and interfacial behavior, as well as the stability of constructed Pickering emulsions to obtain the regulation law of different modification methods on the interfacial behavior of colloidal particles. The results demonstrated that TA-modified zein colloidal particles potentially improved the emulsifying properties. When the TA concentration was 3 mmol L-1 , the optimized TA-modified zein particle was nano-sized (109.83 nm) and had advantageous interfacial properties, including sharply reduced surface hydrophobicity, as well as a low diffusion rate at the oil/water interface. As a result, the shelf life of Pickering emulsion containing 50% oil phase was extended to 90 days. CONCLUSION: Through multi-angled research on the properties of the interfacial membrane, improvement of emulsion stability was a result of the formation of viscoelastic interfacial film that resulted from the decrease of absorption rate between particles and interface. Using refined regulation to investigate the role of different sample preparation methods from a mechanistic perspective. Overall, the present study has provided a reference for TA to regulate the surface properties and interface behavior of zein colloidal particles, enriched the understanding of colloidal interface assembly, and provided a theoretical basis for the quality control of interface-oriented food systems. © 2023 Society of Chemical Industry.

Impact of calcium-reinforcement on stability, bioavailability, and bioactivity of quercetin-loaded zein/alginate-pectin nanoparticles.

BACKGROUND: Cationic calcium ions can crosslink anionic alginate and pectin molecules. It was hypothesized that calcium crosslinking would improve the stability and functionality of biopolymer nanoparticles consisting of zein cores coated by alginate-pectin shells. The effects of calcium ion addition on the structural, physicochemical, and gastrointestinal properties of quercetin-loaded zein/alginate-pectin nanoparticles were therefore investigated. RESULTS: The nanoparticles remained stable to aggregation at calcium ion concentrations of 9 mmol/L or less but aggregated and sedimented at higher concentrations. Calcium ion reinforcement increased the particle dispersion stability even at NaCl concentrations up to 1.4 molL-1. The presence of the calcium ions also reduced quercetin release during the early stages of simulated gastrointestinal digestion but increased its release during the later stages. The relatively high release (56.1%) of quercetin from the calcium-reinforced nanoparticles after digestion resulted in higher intracellular antioxidant activities. The pharmacokinetics of the encapsulated quercetin was measured after its oral administration to rats. The maximal concentration (Cmax) of quercetin in rat plasma for calcium-reinforced nanoparticles was 6.1% higher than non-reinforced nanoparticles; the half-life (t1/2) increased by 17.5%, and the mean retention time (MRT) was 10.0% higher (P < 0.05). CONCLUSION: These results suggest that calcium ion addition improved the performance and bioavailability of nutraceutical-loaded biopolymer nanoparticles. This might find application in the food and beverage industry. © 2024 Society of Chemical Industry.

Preparation and characterization of zein-caseinate-pectin complex nanoparticles for encapsulation of curcumin: pectin extracted by high-speed shearing from passion fruit (Passiflora edulis f. flavicarpa) peel.

BACKGROUND: Pectin extracted by high-speed shearing from passion fruit peel (HSSP) is a potentially excellent wall material for encapsulating curcumin, which has multiple advantages over pectin prepared by heated water extraction. HSSP was used to fabricate complex nanoparticles of zein-sodium caseinate-pectin for encapsulation of curcumin in this study. The influence of heating on the physicochemical properties of the composite nanoparticles was also investigated, as well as the effect of composite nanoparticles on the encapsulation efficiency, antioxidant activity and release characteristics of curcumin. RESULTS: The nanoparticles were formed through electrostatic interactions, hydrogen bonds and hydrophobic interactions between the proteins and HSSP. A temperature of 50 °C was more favorable for generating compact and small-sized nanoparticles, which could effectively improve the encapsulation efficiency and functional properties. Moreover, compared to other pectin used in the study, the nanoparticles prepared with HSSP showed the best functionality with a particle size of 234.28 ± 0.85 nm, encapsulation rate of 90.22 ± 0.54%, free radical scavenging rate of 78.97% and strongest protective capacity in simulated gastric fluid and intestinal release effect. CONCLUSION: Zein-sodium caseinate-HSSP is effective for encapsulating and delivering hydrophobic bioactive substances such as curcumin, which has potential applications in the functional food and pharmaceutical industries. © 2024 Society of Chemical Industry.

Fabrication and characterization of electrospun catechins-loaded nanofibres for fortification of milk.

Catechins in their free form are bitter in taste, and undergo deterioration and oxidation during processing and storage that limit their use as nutraceuticals in foods. Therefore, catechins were electrospun using zein as encapsulating polymer into nanofibres at 15, 18 and 21% w/w concentrations, 16, 20 and 24 kV applied voltage and 0.5 and 1.0 mL/h feed rate. The electrospinning conditions were optimized using Taguchi L18 (21 × 32) design. Encapsulation efficiency as high as 92.8% and mean fibre diameter as low as 95.2 nm were obtained at 18% concentration of zein, 0.5 mL/h feed rate and 20 kV applied voltage. Scanning electron and atomic force micrographs revealed that the nanofibres produced at zein concentration of 18% and above were clean and beadfree, with cylindrical morphology and non-porous topography. The hydrodynamic diameter, zeta potential and polydispersity index of catechins-loaded nanofibres at optimized conditions were 172.3 nm, -26.3 mV and 0.15. FTIR spectroscopy and X-ray diffractometry confirmed that catechins were encapsulated within the nanofibres. The catechins got released from loaded nanofibres in a controlled and sustained manner, while their antioxidant property was retained. The physico-chemical and sensory qualities of milk were not affected after fortification with catechins-loaded nanofibres. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05891-0.

Investigation of the binding interactions mechanism between zein with chrysin by multispectroscopic techniques.

As a natural carrier protein, zein was intensively studied for the construction of a flavonoid delivery system. Chrysin has presented superior tumor-resistant, anti-inflammatory, and anti-oxidation potentials among the flavonoid candidates in clinical practice. However, due to inadequate research, the binding mechanism and structural affinity of zein to chrysin are still indeterminate. Therefore, multispectral methods were employed to explore the molecular interaction of zein and chrysin in this work. These techniques showed that chrysin reduced the intrinsic fluorescence of zein via a static process and that the interaction between zein and chrysin was mainly driven spontaneously by hydrophobic forces. Additionally, the experimental results revealed the changed microenvironment in the vicinity of tyrosine and affected secondary structure in the presence of chrysin, indicating zein's conformation were altered by chrysin. This work provided comprehensive insight into the combination of plant-derived protein (zein) and flavonoids (chrysin) and helped rationalize the protection, transportation, and release of chrysin through a zein-based delivery system.

Electrospun Mucoadhesive Zein/PVP Fibroporous Membrane for Transepithelial Delivery of Propranolol Hydrochloride.

Mucoadhesive drug delivery systems have been extensively studied to effectively reduce the limitations of conventional drug delivery systems. Zein and polyvinyl pyrrolidone (PVP) are appraised for mucoadhesive properties. This study focuses on developing a mechanically stable zein/PVP electrospun membrane for propranolol hydrochloride (PL) transport. Fourier transform infrared, Raman spectra, and swelling studies gave evidence for PVP crosslinking, whereas circular dichroism spectroscopy revealed crosslinking of zein owing to the conformational change from α-helix to ß-sheet. A 10 h thermal treatment of zein/PVP imparted 3.92 ± 0.13 MPa tensile strength to the matrix. Thermally crosslinked electrospun zein/PVP matrix showed 22.1 ± 0.1 g mm work of adhesion in porcine buccal mucosa tissue. Qualitative and quantitative evaluation of cytotoxicity in RPMI 2650 has been carried out. The in vitro drug release profile of PL from thermally crosslinked zein/PVP best fitted with the Korsmeyer-Peppas model. Immunostaining of ß-catenin adherens junctional protein confirmed the absence of paracellular transport through the junctional opening. Still, drug permeation was observed through the porcine buccal mucosa, attributed to the transcellular transport of PL owing to its lipophilicity. The ex vivo permeation of PL through porcine buccal mucosa was also evaluated.

A review of factors affecting the stability of zein-based nanoparticles loaded with bioactive compounds: from construction to application.

Zein-based nanoparticles loaded with bioactive compounds have positive prospects in the food industry, but an important limiting factor for development is colloidal instability. Currently, extensive researches are focused on solving the instability of zein nanoparticles, but since the beginning of the studies, there has not been a summary of the factors affecting the stability of zein-based nanoparticles. In the present work, the factors were reviewed comprehensively from the perspective of carrier construction and application evaluation. The former mainly includes type, quantity, and characteristics of biopolymer, the mass ratio of biopolymer/bioactive compound to zein, blending sequence of biopolymer, and location of encapsulated bioactive compounds. The latter mainly includes pH, heating, ionic strength, storage, freeze-drying, and gastrointestinal digestion. The former is the prerequisite for the success of the latter. The challenge is that stability research is limited to the laboratory level, and it is difficult to ensure that the stability results are suitable for commercial food matrices due to their complexity. At the laboratory level, the future trends are the influence of external energy and the cross-complexity and uniformity of stability research. The review is expected to provide systematic understanding and guidance for the development of zein-based nanoparticles stability.

Salicylic acid functionalized zein for improving plant stress resistance and as a nanopesticide carrier with enhanced anti-photolysis ability.

BACKGROUND: There is a serious global problem of salinization of arable land, causing large reduction in world food production. Use of plant hormones is an effective way to reduce damage caused to crops and salt stress. RESULTS: In this study, PEI-EDA was modified with AM-zein and grafted with plant hormone SA (AM-zein-SA) and used as a nano-pesticide carrier to load emamectin benzoate (EB). The use of AM-zein-SA as a nano-pesticide carrier could reduce the damage caused by salt stress to crops. The structure of AM-zein-SA was characterized by FTIR, UV, fluorescence, Raman, and 1H NMR spectroscopic techniques. AM-zein-SA could effectively improve the resistance of EB to ultraviolet radiations, resistance of cucumber to salt stress, and the absorption of EB by plants. The experimental results showed that AM-zein-SA could effectively improve the anti-UV property of EB by 0.88 fold. When treated with 120 mmol NaCl, the germination rate of cucumber seeds under salt stress increased by 0.93 fold in presence of 6.25 mg/L carrier concentration. The POD and SOD activities increased by 0.50 and 1.21 fold, whereas the content of MDA decreased by 0.23 fold. In conclusion, AM-zein-SA nano-pesticide carrier could be used to improve the salt resistance of crops and the adhesion of pesticides to leaves. CONCLUSION: AM-zein-SA, without undergoing any changes in its insecticidal activity, could simultaneously improve the salt stress resistance and salt stress germination rate of cucumber, reduce growth inhibition due to stress under high-concentration salt, and had a good effect on crops. In addition, EB@AM-zein-SA obviously improved the upward transmission rate of EB, as compared with EB. In this study, SA was grafted onto zein-based nano-pesticide carrier, which provided a green strategy to control plant diseases, insects, and pests while reducing salt stress on crops in saline-alkali soil.

Effects of the maize-derived protein zein, and the milk proteins casein, whey, and α-lactalbumin, on subjective measures of satiety and food intake in normal-weight young men.

Protein is considered to be the most satiating food macronutrient and the satiating effect may be dependent on the source of the protein. The maize-derived protein zein and milk protein casein have been shown previously to lower stomach emptying rate more than dairy whey protein, but the effect of zein on satiety has not been evaluated. The objective was to compare the satiating effects of zein and casein, with whey protein and its protein component α-lactalbumin. The study was a randomised crossover design with thirteen normal-weight men (mean age 27.8 years and mean BMI 24.4 kg/m2) consuming isoenergetic (∼4000 kJ, ∼990 kcal) preload mixed meals enriched with Zein, Casein, whey protein isolate (Whey), α-lactalbumin (ALac), or maltodextrin carbohydrate (Carb). Consumption of an ad libitum standardised test meal of chicken fried rice and water provided 360 min following ingestion of the preload meal was measured, and subjective feelings of appetite (hunger, fullness, desire to eat, and prospective food consumption) were assessed using 100-mm visual analogue scales (VAS). There were no differences among the five preload mixed meals in the amount of chicken fried rice consumed at the ad libitum test meal (mean ± sem: 531.6 ± 35.0 g, p = 0.47) or total (preload + test meal) energy intakes (mean ± sem: 5780.5 ± 146.0 kJ, p = 0.29). The subjective VAS appetite ratings and total area under the curve responses for hunger, fullness, desire to eat, and prospective food consumption, were not different following consumption of all five preload mixed meals (p > 0.05). The findings indicate that the effects of zein and casein on satiety were not different from the satiating effects of whey protein and α-lactalbumin.

Zein Nanoparticles Containing Arginine-Based Surfactants: Physicochemical Characterization and Effect on the Biological Properties.

Cationic surfactants carry antimicrobial activity, based on their interaction and disruption of cell membranes. Nonetheless, their intrinsic toxicity limits their applicability. To overcome this issue, a feasible strategy consists of using solid nanoparticles to improve their delivery. The zein nanoparticles were loaded with four cationic arginine-based surfactants: one single chain Nα-lauroyl-arginine (LAM) and three Gemini surfactants Nα Nω-Bis (Nα-lauroyl-arginine) α, ω-diamide) (C3(LA)2, C6(LA)2 and C9(LA)2). Blank and loaded zein nanoparticles were characterized in terms of size, polydispersity and zeta potential. Furthermore, the antimicrobial activity against bacteria and yeasts and the hemolytic activity were investigated and compared to the surfactants in a solution. Nanoparticles were found to be monodisperse, presenting a size of between 180-341 nm, a pdI of <0.2 and a positive zeta potential of between +13 and +53 mV, remaining stable over 365 days. The nanoencapsulation maintained the antimicrobial activity as unaltered, while the extensive hemolytic activity found for the surfactants in a solution was reduced drastically. Nuclear Magnetic Ressonance (NMR), molecular docking and monolayer findings indicated that zein entraps the surfactants, interfering in the surfactant-membrane interactions. Accordingly, the nanoepcasulation of arginine surfactants improved their selectivity, while the cationic charges were free to attack and destroy bacteria and fungi; the aliphatic chains were not available to disrupt the cellular membranes.

Zein as an Effective Carrier for Hesperidin Delivery Systems with Improved Prebiotic Potential.

Hesperidin is a polyphenol derived from citrus fruits that has a broad potential for biological activity and the ability to positively modify the intestinal microbiome. However, its activity is limited by its low solubility and, thus, its bioavailability-this research aimed to develop a zein-based hesperidin system with increased solubility and a sustained release profile. The study used triple systems enriched with solubilizers to maximize solubility. The best system was the triple system hesperidin-zein-Hpß-CD, for which the solubility improved by more than six times. A significant improvement in the antioxidant activity and the ability to inhibit α-glucosidase was also demonstrated, due to an improved solubility. A release profile analysis was performed in the subsequent part of the experiments, confirming the sustained release profile of hesperidin, while improving the solubility. Moreover, the ability of selected probiotic bacteria to metabolize hesperidin and the effect of this flavonoid compound on their growth were investigated.

Co-Encapsulation of Epigallocatechin-3-Gallate and Vitamin B12 in Zein Microstructures by Electrospinning/Electrospraying Technique.

EGCG is a catechin known for its antioxidant and anti-inflammatory characteristics. Vitamin B12 is an essential vitamin found in animal-derived products, and its deficiency may cause serious health problems such as anemia. The effectiveness of both catechin and vitamin B12 depends on their stability and bioavailability, which can be lost during industrial processes due to degradation when exposed to external factors. A potential solution to this issue is the microencapsulation, which protects the compounds from external agents. The current study aims to microencapsulate EGCG and vitamin B12 in a polymer matrix of biological origin, zein. Microencapsulation was performed using an electrospinning technique, and different concentrations of zein (1-30% w/v) and active compound (0.5-5% w/w) were tested, resulting in the production of micro/nanoparticles, fibers, or the mixture of both. The microstructures were analyzed and characterized in terms of morphology, release profile and kinetics, and encapsulation efficiency. High encapsulation efficiencies were obtained, and the highest were found in the samples with 1% w/w of active substance and 30% w/v of zein. Controlled release studies were conducted in deionized water and in an ethanolic solution, and five kinetic models were applied to the release profiles. The results indicated that the Weibull model was the best fit for the majority of results.

Functional Properties of Corn Byproduct-Based Emulsifier Prepared by Hydrothermal-Alkaline.

As consumers' interest in nature-sourced additives has increased, zein has been treated hydrothermally under alkaline conditions to prepare a nature-sourced emulsifier. The effects of mild hydrothermal-alkaline treatment with different temperatures or alkaline concentrations on the emulsifying properties of zein were investigated. The emulsification activity and stability index of zein hydrolysates increased by 39% and 164%, respectively. The optimal simple stabilized emulsion was uniform and stable against heat treatment up to 90 °C, sodium chloride up to 200 mmol/L, and pH values ranging from 6 to 9. Moreover, it presented excellent storage stability compared to commonly used food emulsifiers. The surface hydrophobicity caused the depolymerization of the tertiary structure of zein and the dissociation of subunits along with exposure of hydrophilic groups. The amino acid composition and circular dichroism results reveal that the treatment dissociated protein subunits and transformed α-helices into anti-parallel ß-sheets and random coil. In conclusion, mild hydrothermal-alkaline treatment may well contribute to the extended functional properties of zein as a nature-sourced emulsifier.

Dragon's Blood Sap Microencapsulation within Whey Protein Concentrate and Zein Using Electrospraying Assisted by Pressurized Gas Technology.

Dragon's blood sap (DBS) obtained from the bark of Croton lechleri (Müll, Arg.) is a complex herbal remedy of pharmacological interest due to its high content in polyphenols, specifically proanthocyanidins. In this paper, electrospraying assisted by pressurized gas (EAPG) was first compared with freeze-drying to dry natural DBS. Secondly, EAPG was used for the first time to entrap natural DBS at room temperature into two different encapsulation matrices, i.e., whey protein concentrate (WPC) and zein (ZN), using different ratios of encapsulant material: bioactive compound, for instance 2:1 w/w and 1:1 w/w. The obtained particles were characterized in terms of morphology, total soluble polyphenolic content (TSP), antioxidant activity, and photo-oxidation stability during the 40 days of the experiment. Regarding the drying process, EAPG produced spherical particles with sizes of 11.38 ± 4.34 µm, whereas freeze-drying produced irregular particles with a broad particle size distribution. However, no significant differences were detected between DBS dried by EAPG or freeze-drying in TSP, antioxidant activity, and photo-oxidation stability, confirming that EAPG is a mild drying process suitable to dry sensitive bioactive compounds. Regarding the encapsulation process, the DBS encapsulated within the WPC produced smooth spherical microparticles, with average sizes of 11.28 ± 4.28 µm and 12.77 ± 4.54 µm for ratios 1:1 w/w and 2:1 w/w, respectively. The DBS was also encapsulated into ZN producing rough spherical microparticles, with average sizes of 6.37 ± 1.67 µm and 7.58 ± 2.54 µm for ratios 1:1 w/w and 2:1 w/w, respectively. The TSP was not affected during the encapsulation process. However, a slight reduction in antioxidant activity measured by DPPH was observed during encapsulation. An accelerated photo-oxidation test under ultraviolet light confirmed that the encapsulated DBS showed an increased oxidative stability in comparison with the non-encapsulated DBS, with the stability being enhanced for the ratio of 2:1 w/w. Among the encapsulating materials and according to the ATR-FTIR results, ZN showed increased protection against UV light. The obtained results demonstrate the potential of EAPG technology in the drying or encapsulation of sensitive natural bioactive compounds in a continuous process available at an industrial scale, which could be an alternative to freeze-drying.

Bioactive zein/chitosan systems loaded with essential oils for food-packaging applications.

BACKGROUND: There has recently been increased interest in biodegradable and sustainable packaging within the food industry. Biopolymer materials based on renewable biomass can be used as alternatives to conventional plastic packaging. A corn protein, zein, possesses excellent film-forming properties because of its hydrophobic nature. It can be used for making edible films and for producing nanofibrous layers. Combination with polysaccharides like chitosan offers promising prospects for the production of delivery systems for the controlled release of active substances. The current trend is to minimize the content of chemical additives; thus essential oils are suitable alternatives to synthetic antimicrobials. RESULTS: This study aimed to develop various zein/chitosan-based film-forming solutions, films, and coatings with antimicrobial substances to prepare active food packaging. Thymol and three essential oils (thyme, cinnamon, oregano) were applied as bioactive ingredients against bacteria, yeasts, and fungi. The incorporation of these natural active compounds led to a decrease in particle size in most film-forming solutions and a reduction of zeta potential compared to controls. Release of the bioactive compound into an aqueous environment was proved by antimicrobial test. A zein/chitosan-based coating with thymol was applied on fresh strawberries. Microbiological analysis over 10 days confirmed the efficient control of bacterial and fungal growth. CONCLUSION: Zein/chitosan (7:1) systems are suitable as bioactive compound carriers to make barriers and to prevent moisture loss, ensuring microbial food quality and prolonging the shelf life of fruits. These systems can serve as sustainable active food packaging. © 2022 Society of Chemical Industry.

Bacterial outer membrane vesicles-cloaked modified zein nanoparticles for oral delivery of paclitaxel.

To improve the aqueous solubility and oral bioavailability of paclitaxel (PTX), a biomimetic system for oral administration of PTX was efficiently developed as an outer membrane vesicle (OMVs) of sodium caseinate (CAS) modified zein nanoparticles (OMVs-Zein-CAS-PTX-NPs) by Escherichia coli. To verify their structure and properties, the designed nanostructures were thoroughly characterized using various characterization techniques. The results indicated that hydrogen bonds and van der Waals forces mainly drove the interaction between PTX and Zein, but the complex is unstable. The physicochemical stability of PTX-loaded zein nanoparticles was improved by the addition of CAS. The biological characteristics of biofilms are reproduced by nanoparticles cloaked with outer membrane vesicles. OMVs-Zein-CAS-PTX-NPs delayed the release of PTX under simulated gastric and intestinal fluids due to OMVs protection. OMVs-Zein-CAS-PTX-NPs exhibited remarkable antitumor ability in vitro and improved the bioavailability of oral administration of PTX in vivo. Therefore, OMVs cloaked in nanoparticles may be a suitable delivery vehicle to provide an efficient application prospect for the oral administration of PTX.