Zein Matrix Research Articles

Development of multifunctional zein-based films engineered with gallic acid and Ag NPs loaded γ-CD-MOFs for pork preservation

The increasing emphasis on food quality and consumer safety has prompted researchers to explore green manufacturing techniques for packaging materials. In this study, γ-cyclodextrin metal-organic frameworks (γ-CD-MOFs) were prepared as promising nanocarriers for gallic acid (GA) and silver nanoparticles (Ag NPs). These nanocarriers (GA-Ag@CD-MOFs) were further incorporated into a zein matrix to fabricate multifunctional composite films, referred to as MOFs-Zein. Scanning electron microscopy (SEM) and atomic force microscope (AFM) analysis indicated that the fabricated composite film exhibited excellent biocompatibility, with GA-Ag@CD-MOFs uniformly dispersed within the film matrix. Fourier transform infrared spectroscopy (FT-IR) result revealed that the incorporation of GA-Ag@CD-MOFs facilitated the formation of intermolecular hydrogen bonds with the matrix polymer. The addition of GA-Ag@CD-MOFs enhanced the tensile strength of the composite film by 19.70 %, improved the water barrier performance by 57.76 %, and provided almost 100 % UV protection. The exceptional controlled release capability of γ-CD-MOFs for GA empowered the composite films to maintain their robust initial antioxidant capacity even after 100 days of storage. Moreover, the composite films performed high-efficiency antibacterial activity against Escherichia coli O157:H7 and Salmonella enterica. Acute toxicological studies showed no histopathology related toxicity was found in GA-Ag@CD-MOFs treated mice. When applied to fresh pork, the composite films significantly reduced the key quality indicators of raw meat, compared to the control film. Overall, this work presents a promising approach to fabricate the composite films as a sustainable and functional solution for green functional food packaging.

Preparation of zein active films with antimicrobial and antioxidant properties by incorporating gallic acid loaded γ-CD-MOF for pork preservation

The growing concerns over food contamination caused by microorganisms, coupled with the worsening environmental impact of petroleum-based plastics have drawn significant attention to eco-friendly materials in food packaging. Herein, cyclodextrin-metal-organic framework (CD-MOF) was prepared as promising nanocarrier for the natural product gallic acid (GA). Then, the prepared material (GA@CD-MOF) was incorporated into zein matrix to obtain Zein-GA@CD-MOF films. Further studies showed that the composite films possessed great potential for food packaging, offering excellent UV-light blocking, water resistance, and mechanical properties. Notably, Zein-GA@CD-MOF films demonstrated superior antimicrobial activity (44.56%–77.97% against Escherichiacoli O157:H7 and 28.36%–59.49% against Salmonellaenterica) and sustained antioxidant properties for 100 days, which correlated with the sustainable release effect of GA. Furthermore, the exceptional biosafety of GA@CD-MOF has been confirmed through cytotoxicity and hemolysis assays. Pork preservation experiments illustrated that the obtained films could retard protein degradation, microorganism growth, and lipid oxidation, extending the shelf-life by 9 days at 4 °C. These findings suggest that Zein-GA@CD-MOF films has promising application prospects in pork preservation packaging.

New Zein Protein Composites with High Performance in Phosphate Removal, Intrinsic Antibacterial, and Drug Delivery Capabilities.

Herein, poly(N-(4-aminophenyl)methacrylamide)-carbon nano-onions [abbreviated as PAPMA-CNOs (f-CNOs)] integrated gallic acid cross-linked zein composite fibers (ZG/f-CNOs) were developed for the removal/recovery of phosphate from wastewater along with controlled drug delivery and intrinsic antibacterial characteristics. The composite fibers were produced by Forcespinning followed by a heat-pressure technique. The obtained ZG/f-CNOs composite fibers presented several favorable characteristics of nanoadsorbents and drug carriers. The composite fibers exhibited excellent adsorption capabilities for phosphate ions. The adsorption assessment demonstrated that composite fibers process highly selective sequestration of phosphate ions from polluted water, even in the presence of competing anions. The ZG/f-CNOs composite fibers presented a maximum phosphate adsorption capacity (qmax) of 2500 mg/g at pH 7.0. This represents the most efficient phosphate adsorption system among all of the reported nanocomposites to date. The isotherm studies and adsorption kinetics of the adsorbent showed that the adsorption experiments followed the pseudo-second-order and Langmuir isotherm model (R2 = 0.9999). After 13 adsorption/desorption cycles, the adsorbent could still maintain its adsorption efficiency of 96-98% at pH 7.0 while maintaining stability under thermal and chemical conditions. The results mark significant progress in the design of composite fibers for removing phosphates from wastewater, potentially aiding in alleviating eutrophication effects. Owing to the f-CNOs incorporation, ZG/f-CNOs composite fibers exhibited controlled drug delivery. An antibiotic azithromycin drug-encapsulated composite fibers presented a pH-mediated drug release in a controlled manner over 18 days. Furthermore, the composite fibers displayed excellent antibacterial efficiency against Gram-positive and Gram-negative bacteria without causing resistance. In addition, zein composite fibers showed augmented mechanical properties due to the presence of f-CNOs within the zein matrix. Nonetheless, the robust zein composite fibers with inherent stimuli-responsive drug delivery, antibacterial properties, and phosphate adsorption properties can be considered promising multifunctional composites for biomedical applications and environmental remediation.

Highly efficient, eco-friendly, flexible piezoelectric nanogenerators based on MA2CuCl4 NPs embedded into a zein matrix

Eco-friendly, piezoelectric MA2CuCl4-zein nanocomposites (NCs) are fabricated using the sol-gel method in which lead-free halide perovskite MA2CuCl4 nanoparticles (NPs) are successfully embedded in a natural polymer zein matrix without chemical decomposition. The MA2CuCl4-zein NCs are utilized as the piezoelectric layer for piezoelectric nanogenerators (PENGs), and PENGs based on the MA2CuCl4-zein NCs are compared with those based on MA2CuCl4 NPs and on zein. The average output voltage of the PENGs based on the MA2CuCl4-zein NCs under vertical pressure is 48.84 V, which is significantly larger than that of the PENGs with MA2CuCl4 NPs alone and with zein alone by factors of 13.49 and 4.62, respectively. The significantly higher output voltage of the PENGs based on the MA2CuCl4-zein NC thin films is attributed to enhanced piezoelectricity and the surface planarization caused by the zein matrix. The output voltages of the rigid PENG and the flexible TENG based on the MA2CuCl4-zein NC thin films remain stable without degradation after 500 taps and after 500 bends, respectively. The flexible PENGs based on MA2CuCl4-zein NC thin films can be operated using various human motions, such as bending with fingers, the palms of hands, and or the arms, and stepping on the PENGs. The utilization of MA2CuCl4-zein NCs provides insight into developing eco-friendly PENGs that utilize lead-free halide perovskites and natural polymers.

Levofloxacin HCl-Incorporated Zein-Based Solvent Removal Phase Inversion In Situ Forming Gel for Periodontitis Treatment.

Zein is composed of nonpolar amino acids and is a water-insoluble protein used as the matrix-forming agent of localized in situ forming gel (ISG). Therefore, this study prepared solvent removal phase inversion zein-based ISG formulations to load levofloxacin HCl (Lv) for periodontitis treatment using dimethyl sulfoxide (DMSO) and glycerol formal (GF) as the solvents. Their physicochemical properties were determined, including viscosity, injectability, gel formation, and drug release. The topography of dried remnants after drug release was revealed using a scanning electron microscope and X-ray computed microtomography (μCT) to investigate their 3D structure and % porosity. The antimicrobial activities were tested against Staphylococcus aureus (ATCC 6538), Escherichia coli ATCC 8739, Candida albicans ATCC 10231, and Porphyromonas gingivalis ATCC 33277 with agar cup diffusion. Increasing zein concentration or using GF as the solvent notably enhanced the apparent viscosity and injection force of the zein ISG. However, its gel formation slowed due to the dense zein matrix barrier's solvent exchange: the higher loaded zein or utilization of GF as an ISG solvent prolonged Lv release. The SEM and μCT images revealed the scaffold of dried ISG in that their % porosity corresponded with their phase transformation and drug release behavior. In addition, the sustainability of drug diffusion promoted a smaller antimicrobial inhibition clear zone. Drug release from all formulations was attained with minimum inhibitory concentrations against pathogen microbes and exhibited a controlled release over 7 days. Lv-loaded 20% zein ISG using GF as a solvent exhibited appropriate viscosity, Newtonian flow, acceptable gel formation and injectability, and prolonged Lv release over 7 days with efficient antimicrobial activities against various test microbes; thus, it is the potential ISG formulation for periodontitis treatment. Consequently, the Lv-loaded solvent removal zein-based ISGs proposed in this investigation offer promising potential as an efficacious drug delivery system for periodontitis treatment by local injection.

Development and Investigation of Mesoporous Bioactive Glass/Zein Coatings Electrodeposited on Titanium Alloy for Biomedical Applications

The objective of the present work was the development of cathodic electrophoretic deposition (EPD) to obtain composite coatings of mesoporous sol–gel glass (MSGG) particles embedded in a zein matrix on Ti-13Nb-13Zr substrates. To deposit robust and repeatable coatings, a direct current EPD and pulsed direct current EPD as well as the deposition kinetics were investigated, including the deposition yield and deposition rate. The stability of the suspension was determined based on the zeta potential and conductivity. Macroscopically homogeneous coatings with a thickness of about 10 µm and various volume fractions of MSGG were subjected to further examination. Coatings were uniform, exhibiting open porosity and showing excellent adhesion to the substrates. Both zein and MSGG particles revealed an amorphous structure. The coated substrates demonstrated greater resistance to electrochemical corrosion in Ringer's electrolyte in comparison with the virgin (non-coated) substrate. The coatings showed high roughness and moderate hydrophilicity. The incubation of the coated substrates in concentrated 1.5 simulated body fluid (1.5SBF) showed the formation of carbonate hydroxyapatite. The composite coatings showed improved antibacterial properties against gram-negative E. coli and gram-positive S. aureus bacteria compared to pure zein coatings. Electrophoretic MSGG/zein composite coatings should be further investigated in terms of their osteoconductive behavior, to confirm their suitability for medical applications in orthopedics.

Release kinetics of [lidocainium][ibuprofenate] as Active Pharmaceutical Ingredient-Ionic Liquid from a plasticized zein matrix in simulated digestion

An in vitro approach is proposed to study the release of an Active Pharmaceutical Ingredient-Ionic Liquid (API-IL) from a natural biopolymer matrix based on zein, a maize storage protein. Zein can be processed in the molten state with 20 w% [Lidocainium][Ibuprofenate] added as API-IL also acting as plasticizer and potentially co-plasticized by glycerol. The thermal stability of the matrix is checked, as well as the in vivo biological activity of the API-IL confirming anesthetic and anti-inflammatory activities. Model tablets are thermomolded at 130 °C (∅20 mm, 0.2 mm thick) and submitted to simulated digestion based on the INFOGEST static protocol of gastrointestinal food digestion at 37 °C (2 h under gastric conditions followed by 2 h under intestinal ones). The release of the API-IL is evaluated by HPLC-UV to dissociate lidocainium, that shows a progressive release (35 % after 2 h and 60 % after 4 h digestion), from ibuprofenate, that is mainly released under intestinal conditions due to low solubility in acidic conditions. The monitoring of the tablets reveals release mechanisms based on diffusion without noticeable erosion of the matrix. These results demonstrate the interest of this thermoplastic material to provide a relevant drug delivery system.

Antioxidant Effect of Nanoparticles Composed of Zein and Orange (Citrus sinensis) Extract Obtained by Ultrasound-Assisted Extraction.

In the present research, an orange extract (OE) was obtained and encapsulated in a zein matrix for its subsequent physicochemical characterization and evaluation of its antioxidant capacity. The OE consists of phenolic compounds and flavonoids extracted from orange peel (Citrus sinensis) by ultrasound-assisted extraction (UAE). The results obtained by dynamic light scattering (DLS) and scanning electron microscopy (SEM) indicated that zein nanoparticles with orange extract (NpZOE) presented a nanometric size and spherical shape, presenting a hydrodynamic diameter of 159.26 ± 5.96 nm. Furthermore, ζ-potential evolution and Fourier transform infrared spectroscopy (FTIR) techniques were used to evaluate the interaction between zein and OE. Regarding antioxidant activity, ABTS and DPPH assays indicated no significant differences at high concentrations of orange peel extract and NpZOE; however, NpZOE was more effective at low concentrations. Although this indicates that ultrasonication as an extraction method effectively obtains the phenolic compounds present in orange peels, the nanoprecipitation method under the conditions used allowed us to obtain particles in the nanometric range with positive ζ-potential. On the other hand, the antioxidant capacity analysis indicated a high antioxidant capacity of both OE and the NpZOE. This study presents the possibility of obtaining orange extracts by ultrasound and coupling them to zein-based nanoparticulate systems to be applied as biomedical materials functionalized with antioxidant substances of pharmaceutical utility.

Incorporation of gelatin and Fe2+ increases the pH-sensitivity of zein-anthocyanin complex films used for milk spoilage detection

In this study, blueberry anthocyanins, gelatin and Fe2+ were incorporated into zein matrix via electrospinning method to prepare colorimetric indicator films for monitoring milk freshness. Gelatin and Fe2+ were incorporated into the film to improve visual discrimination of indicator films’ color changes in milk with different freshness degrees and in solution with pH 3–7. Results of SEM, FT-IR and XRD showed that there were intermolecular hydrogen bonds among components, which associated with the larger color difference of indicator films. UV–vis spectral analysis showed that blueberry anthocyanin solutions containing both gelatin and Fe2+ displayed the highest intensity absorption peaks. The optimal ability to distinguish the pH (3–7) of solutions was presented by the indicator film incorporating gelatin (1% (w/v)) and Fe2+ (0.07 mg/mL). Gelatin and Fe2+ increased the color-responsive sensitivity of the indicator film to pH. The film could be successfully used to detect the freshness of milk, whose color changes were visually perceivable: from purple black (fresh milk) to royal purple (spoiling milk) and then to violet red (spoiled milk). The color parameters (L*, a*, R, G and B) of the film revealed a high correlation with the pH/acidity of the milk during storage. The successful application of the indicator film embedding gelatin and Fe2+ for monitoring milk quality changes indicated that the addition of special substances could provide great potential for monitoring freshness and preparing intelligent packaging of food.

Improvement in storage stability and resveratrol retention by fabrication of hollow zein-chitosan composite particles

Solid and hollow particles based on zein have been prepared for the encapsulation of bioactive components. Hollow particles have many advantages over their solid counterpart, due to increased surface area, low density, and sustained release, emerged as a promising delivery system for polyphenols. It is necessary to improve the stability of zein particles for the encapsulation of bioactive components. The current work aims to prepare hollow zein particles by employing chitosan coating and explore the potential of the composite particles for the encapsulation and protection of resveratrol, a natural polyphenol. Hollow zein (HZ) and zein-chitosan (HZ-CH) particles were characterized in terms of size, surface charge, morphological structure, particle yield and antioxidant activity. Encapsulation of resveratrol in the zein matrix was studied by the help of fluorescence, infrared and X-ray diffraction techniques. The composite particles were also subjected to storage and in vitro digestion. Particle yield was greater than 90% when the concentrations of chitosan were greater than 0.02%. HZ-CH particles were positively charged and bigger in size as compare to HZ particles. Resveratrol entrapment caused an apparent increase in the size of the particles. The highest encapsulation efficiency and loading capacity of resveratrol were 91% and 14% in the hydrophobic zein shell of HZ-CH particles, respectively. The chitosan coating improved the storage and digestion stability of resveratrol-loaded hollow zein particles and the storage stability of encapsulated resveratrol and exhibited a sustained in vitro release of resveratrol. Therefore, the hollow zein composite particles could be used as an efficient delivery system for resveratrol in the development of functional foods.

Mucoadhesive zein/beta-cyclodextrin nanoparticles for the buccal delivery of curcumin.

Herein, we have developed sprayable dispersions of mucoadhesive nanoparticles (NPs) made of zein, a hydrophobic plant-based protein, for the buccal delivery of curcumin (CUR), a poorly water-soluble polyphenol. NPs were prepared by the liquid-liquid dispersion method using an antisolvent water solution without or with beta-cyclodextrin (CD). NPs were spherical with a monomodal size distribution, a mean size around 140nm and low polydispersity. Excellent colloidal stability of NPs was found at room temperature for up to 1month. CUR entrapment was found to depend mainly on the zein/CUR ratio and related to the ability of CUR to set within hydrophobic pockets in the zein matrix. CD addition generated an increase of NP zeta potential up to +60mV, indicating that positively charged amino acids are prompted to settle on the NP surface. Fluorescence emission spectroscopy indicated that CD interacted with lipophilic amino acids of zein altering interchain interactions and formation of glutamine bridge. Because of zein/CD interactions, mainly occurring at NP periphery, the slowing down of the CUR release rate was observed too. A combination of spectroscopic techniques unequivocally showed that zein NPs strongly interacted with mucin due to electrostatic interactions. Once sprayed on a porcine buccal mucosa, zein/CD NPs securely attached to the tissue resisting repeated washing steps but did not allow CUR transmucosal permeation. Overall, these results point at zein/CD NPs as a novel mucoadhesive platform for the buccal delivery of poorly water-soluble molecules to use as both a food supplement or a drug product to achieve local effects.

Phytochemical-loaded electrospun nanofibers as novel active edible films: Characterization and antibacterial efficiency in cheese slices

The aim of this work was to develop novel active edible electrospun coatings with antimicrobial properties through the encapsulation of essential oils (EOs) from two widely used spices (Laurus nobilis and Rosmarinus officinalis) for inactivating or reducing spoilage and pathogenic microorganisms. Firstly, EOs from dried leaves of both plants were obtained by hydrodistillation and their composition was analysed by Gas Chromatography – Mass Spectrometry (GC – MS). Interestingly, the main component in both extracts, probably as a consequence of the extraction conditions, was 1,8 cineole. Both EOs showed highest antimicrobial activity against Gram-positive than Gram-negative bacteria.Three different concentrations of the 1,8 cineole-rich EOs were incorporated within a zein matrix through electrospinning and solution properties, encapsulation yield, morphological and thermal stability of the edible coatings developed were evaluated. Then, the antibacterial efficiency of EOs-zein nanofibers (ZNF) films against Listeria monocytogenes, S. aureus and mesophilic bacteria counts (MBC) was compared with their counterparts prepared by casting (ZF) when applied directly on an inoculated side of cheese slices. EO obtained from Laurus nobilis showed higher antibacterial activity than Rosmarinus officinalis. The antibacterial effectiveness of the active films increased through storage time, showing a significant reduction of ~2 logarithm units of L. monocytogenes and S. aureus as compared with the control samples, after 28 days at 4 °C, using the highest content of 1,8 cineole-rich EOs and in films prepared by means of the electrospinning process. Interestingly, the growth of aerobic mesophilic bacteria was also inhibited in cheese slices coated with EOs-loaded ZNF based films.

Protein-based halochromic electrospun nanosensor for monitoring trout fish freshness

In the present study, a protein-based halochromic nanosensor was designed to assess the quality of rainbow trout fillets. Zein nanofibers containing alizarin as the indicator dye were electrospun. The sensors were characterised using SEM, FT-IR, DSC, XRD, dye leaching, response time experiments and colorimetric analysis. TVB-N, TVC and pH of fish fillets were also measured over 12 days of storage at 4°C. FT-IR results showed that the alizarin was incorporated in the zein matrix by intermolecular hydrogen bonding. DSC graphs of zein based samples showed that the temperature of dehydration, glass transition and protein unfolding in the halochromic nanofibers were lower than in powdered zein. The amorphous structure of the zein samples was confirmed by XRD analysis. No color changes were occurred in the first 4 days of storage, but later, a light purple color could be observed in the sensor by the naked eye. The color of sensor became magenta by the 10th and 12th day of cold storage indicating spoilage. This fabricated halochromic nanosensor can monitor fish freshness in real time through color changes. The colorimetric results correlated well with microbial and chemical changes in the fish.

Development of Functionalized Carbon Nano-Onions Reinforced Zein Protein Hydrogel Interfaces for Controlled Drug Release.

In the current study, poly 4-mercaptophenyl methacrylate-carbon nano-onions (PMPMA-CNOs = f-CNOs) reinforced natural protein (zein) composites (zein/f-CNOs) are fabricated using the acoustic cavitation technique. The influence of f-CNOs inclusion on the microstructural properties, morphology, mechanical, cytocompatibility, in-vitro degradation, and swelling behavior of the hydrogels are studied. The tensile results showed that zein/f-CNOs hydrogels fabricated by the acoustic cavitation system exhibited good tensile strength (90.18 MPa), compared with the hydrogels fabricated by the traditional method and only microwave radiation method. It reveals the magnitude of physisorption and degree of colloidal stability of f-CNOs within the zein matrix under acoustic cavitation conditions. The swelling behaviors of hydrogels were also tested and improved results were noticed. The cytotoxicity of hydrogels was tested with osteoblast cells. The results showed good cell viability and cell growth. To explore the efficacy of hydrogels as drug transporters, 5-fluorouracil (5-FU) release was measured under gastric and intestinal pH environment. The results showed pH-responsive sustained drug release over 15 days of study, and pH 7.4 showed a more rapid drug release than pH 2.0 and 4.5. Nonetheless, all the results suggest that zein/f-CNOs hydrogel could be a potential pH-responsive drug transporter for a colon-selective delivery system.

Preparation and Characterization of Composites of Hydroxypropyl Tapioca Starch and Zein

AbstractHydroxypropyl tapioca starch and zein composites are prepared and the properties of composites are investigated. Starch granules can readily aggregate in the presence of zein to form large granules more than 30 µm. The total preparation concentration of zein and starch of 45% can be critical, as inferred from the relation between the zein content and the particle size of the composite. An increase of zein content or reaction time allows the starch granules to be adhered with zein, wrapped by zein, or even be embedded in the zein matrix. The characteristic peaks of zein shifting to the lower wavenumber and that of hydrogen bonds moving to higher wavenumbers in the Fourier transform infrared spectroscopy indicate the interaction between zein and starch. Zein reduces the viscosity, increases gelatinization temperature, and decreases gelatinization enthalpy of the composites compared with that of starch. This insight may be helpful in designing and preparing composites of zein and starch with promising properties.

Swelling of Zein Matrix Tablets Benchmarked against HPMC and Ethylcellulose: Challenging the Matrix Performance by the Addition of Co-Excipients.

Zein is an insoluble, yet swellable, biopolymer that has been extensively studied for its applications in drug delivery. Here, we screened the effect of co-excipients on the swelling and drug release of zein tablets. All throughout the study the behavior of zein was benchmarked against that of hydroxypropyl methylcellulose (HPMC) and ethylcellulose (EC). Tablets containing either zein, HPMC, or EC alone or in combination with co-excipients, namely lactose, dicalcium phosphate (DCP), microcrystalline cellulose (MCC), polyvinylpyrrolidone (PVP), or sodium lauryl sulfate (SLS) were prepared by direct compression. Matrix swelling was studied by taking continuous pictures of the tablets over 20 h, using a USB microscope connected to a PC. The overall size change and the axial and radial expansion of the tablets were automatically extrapolated from the pictures by image analysis. Moreover, drug release from tablets containing ternary mixtures of zein, co-excipients and 10% propranolol HCl was also studied. Results showed that zein matrices swelled rapidly at first, but then a plateau was reached, resulting in an initial rapid drug burst followed by slow drug release. HPMC tablets swelled to a greater extent and more gradually, providing a more constant drug release rate. EC did not practically swell, giving a nearly constant drug release pattern. Among the additives studied, only MCC increased the swelling of zein up to nearly three-fold, and thus suppressed drug burst from zein matrices and provided a nearly constant drug release over the test duration. Overall, the incorporation of co-excipients influenced the swelling behavior of zein to a greater extent compared to that of HPMC and EC, indicating that the molecular interactions of zein and additives are clearly more complex and distinct.

Electrospun Nanobelt-Shaped Polymer Membranes for Fast and High-Sensitivity Detection of Metal Ions.

Until now, no polymer nanobelt-shaped materials have been developed as electrochemical, optical, and mass sensors. In this work, we first develop polymer nanobelt-shaped membranes for fast and high-sensitivity detection of metal ions, which are fabricated by a new nanobelt-based processing method with simultaneous zein matrix cross-linking and curcumin cross-linking. Their morphologies, optimal detection pH, ion selectivity, and ion detection sensitivity are systematically analyzed. The limits of detection of electrospun curcumin-loaded zein membranes with a detection time of 0.5 h are as follows: cross-linked nanobelt-shaped membranes (0.3 mg/L) < uncross-linked nanobelt-shaped membranes (1 mg/L) ≈ cross-linked nanofibrous membranes (1 mg/L) < uncross-linked nanofibrous membranes (3 mg/L). The cross-linked nanobelt-shaped membranes are also applied to detect Fe3+ in drinking water and environmental water. Finally, the mechanisms of Fe3+ detection by these membranes are studied and discussed. The results demonstrate that the difference of limit of detection is dependent on if the curcumin sensor is cross-linked or not and the membrane nanostructures (nanobelts or nanofibers). Cross-linking produces stable sensor molecules on the surface and therefore induces low limits of detection. Compared with nanofibers, nanobelts have a higher surface-to-volume ratio and can have more sensor molecules on their surfaces and therefore have lower limits of detection. In addition, the as-prepared membranes had good membrane storage stability (at least 3 months at room temperature). All of these results suggest that cross-linked electrospun nanobelt-shaped membranes by a new nanobelt-based processing method are ideal platforms for sensing. We believe that they will attract increasing attention in scientific and engineering fields such as materials, environmental, and food science.

Bioactive glass combined with zein as composite material for the application in bone tissue engineering

Abstract The present study has focused on the development of new composite scaffolds based on the combination of zein with bioactive glass for the application in bone tissue engineering. Porous polymeric matrices were produced by the salt leaching technique. By incorporating 45S5 bioactive glass particles the lack of bioactivity can be remedied. However, the addition of bioactive glass is influencing the plasticization behavior of the zein matrix during the salt leaching which negatively affects the compression strength as well as the degradation behavior. This paper describes the process during leaching and explains the different behavior of zein with and without the presence of bioactive glass

Microencapsulated chañar phenolics: A potential ingredient for functional foods development

In this work, a Geoffroea decorticans (chañar) extract very rich in polyphenols and with antioxidant and inhibitory activity against pro-inflammatory enzymes, was microencapsulated in a zein matrix using electrospraying to improve its stability and facilitate its handling as food ingredient. The electrosprayed microcapsules were characterized in terms of morphology, encapsulation efficiency, water sorption ability and release properties at different pH and during an in vitro digestion process. The bioactivity of the encapsulated extract in terms of inhibitory activity on enzymes related to the metabolic syndrome were also evaluated and compared to that of the non-encapsulated ingredient. Results showed that microencapsulation did not affect biological activity and effectively protected the bioactive polyphenols during the simulated digestion process. Therefore, this encapsulation structures could be considered a potential ingredient for functional food development.

The combined effects of lysozyme and ascorbic acid on microstructure and properties of zein-based films

Abstract Edible zein-based films containing lysozyme (LY) and ascorbic acid (AA) were developed in the presence of polyethylene glycol 400 (PEG 400), the combined effects of LY and AA on the microstructure, mechanical properties and release properties of developed zein films were investigated in detail. The results of microstructure characterization indicated that zein-based films became compact and smooth, and LY aggregates were well distributed in the zein matrix because of the simultaneous addition of LY and AA. The results of mechanical tests showed that because of the synergistic effects of LY and AA on zein film, elongation at break of zein-based film could be up to 138%, which was 34.5 times higher than that of zein control film. LY release tests showed that when the concentration of AA was less than 3.1 mg·cm − 2 , the release rate of LY significantly decreased by 33.7%, and the total release increased by 80.6%. While the release profiles of AA showed that the release rate and total release of AA from the films containing LY increased by approximately 68.9% and 61.7% than the films without LY. Good antioxidant and sustained antimicrobial activities were found for the developed zein films.