Metal Nanogap Memory: Performances and Switching Mechanism.

The nanogap memory (NGM) device, emerging as a promising nonvolatile memory candidate, has attracted increasing attention for its simple structure, nano/atomic scale size, elevated operating speed, and robustness to high temperatures. In this study, nanogap memories based on Pd, Au, and Pt were fabricated by combining nanofabrication with electromigration technology. Subsequent evaluations of the electrical characteristics were conducted under ambient air or vacuum conditions at room temperature. The investigation unveiled persistent challenges associated with metal NGM devices, including (1) prolonged SET operation time in comparison to RESET, (2) the potential generation of error bits when enhancing switching speeds, and (3) susceptibility to degradation during program/erase cycles. While these issues have been encountered by predecessors in NGM device development, the underlying causes have remained elusive. Employing molecular dynamics (MD) simulation, we have, for the first time, unveiled the dynamic processes of NGM devices during both SET and RESET operations. The MD simulation highlights that the adjustment of the tunneling gap spacing in nanogap memory primarily occurs through atomic migration or field evaporation. This dynamic process enables the device to transition between the high-resistance state (HRS) and the low-resistance state (LRS). The identified mechanism provides insight into the origins of the aforementioned challenges. Furthermore, the study proposes an effective method to enhance the endurance of NGM devices based on the elucidated mechanism.

Physicochemical and antimicrobial properties of soy protein isolate films incorporating high internal phase emulsion loaded with thymol.

Oil-in-water (O/W) high internal phase (HIP) emulsion was prepared to investigate its effects on the physicochemical properties and antimicrobial properties of soy protein isolate (SPI)-based films. The particle size and migration degree of oil droplets in the SPI film-forming solution with HIP emulsion and the films were lower than those with conventional O/W emulsion or oil. The SPI-based emulsion films with HIP emulsion containing 30 % oil had the lowest water vapor permeability (1.15 × 10-10 g·m-1·s-1·Pa-1), glass transition temperature (40.93 °C) and tensile strength (4.47 MPa), and the highest transparency value (12.87) and elongation at break (160.83 %). The antimicrobial test of the SPI-based emulsion films loaded with thymol showed that the thymol encapsulation efficiency, sustained release effect, and growth inhibition effect on microbes were higher for the films with HIP emulsion than those for the films with O/W emulsion or oil.

Characteristics of hairtail surimi gels treated with myofibrillar protein-stabilized Pickering emulsions.

BACKGROUND: Hairtail (Trichiurus haumela) surimi exhibits poor gelation properties and a dark gray appearance, which hinder its utilization in high-quality surimi gel products. The effect of Pickering emulsions stabilized by myofibrillar proteins (MPE) on the gel properties of hairtail surimi has been unclear. In particular, the impact of MPE under NaCl and KCl treatments on the quality of hairtail surimi gels requires further elucidation. RESULTS: Pickering emulsions stabilized by myofibrillar proteins and treated with NaCl or KCl (Na-MPE, K-MPE) were added to hairtail surimi in amounts of 10-70 g kg-1. The addition of 50 g kg-1 Na-MPE and K-MPE improved the gel strength, textural properties, whiteness, and water-holding capacity (WHC) of hairtail surimi. The relative content of ß-turn and ß-sheet in the surimi gels increased and the relative content of random coils and α-helix decreased with the addition of oil. The addition of Na-MPE and K-MPE did not affect the secondary structure of surimi gels but stimulated the gelation of hairtail surimi gels. Hairtail surimi containing K-MPE demonstrated similar performance in terms of hardness, microstructure, and WHC compared with the addition of Na-MPE. CONCLUSION: The quality of hairtail surimi gels can be improved by the addition of Na-MPE or K-MPE. The K-MPE proved to be an effective option for enhancing the properties of hairtail surimi gels at 50 g kg-1 to replace Na-MPE. © 2024 Society of Chemical Industry.

The selective adsorption mechanism of V-type starches for key off-odors of sea cucumber intestinal peptides.

The off-odors of sea cucumber intestinal peptide (SCIP) severely limit its application. In this study, the V-type starches were derived from high amylose maize starch to adsorb odors of SCIP and the adsorption mechanism was explored. The inclusion complexes formed by V-type starches and volatile compounds of SCIP were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The electronic nose results revealed a decreasing trend in response values of SCIP, with significant differences before and after deodorization (p < 0.05). Furthermore, 82 volatiles were identified from SCIP, and six were determined as key volatiles using gas chromatography-mass spectrometry. The V6- and V7-type starches with smaller cavity sizes selectively adsorb butyric acid, isobutyric acid and nonaldehyde, and V8-type starches with a larger cavity size selectively adsorb trimethylamine. This study proved that using V-type starches for deodorization could effectively improve SCIP flavor.

Comparative effects of W/O and O/W emulsions on the physicochemical properties of silver carp surimi gels.

The comparative effects of water-in-oil (W/O) and oil-in-water (O/W) emulsions on the physicochemical characteristics of silver carp surimi gels were investigated. The breaking force of surimi gels was 188.72 g, which decreased with increasing W/O emulsion but remained constant by adding O/W emulsion. The hardness decreased with increasing W/O emulsion, while the other parameters to TPA maintained constant whether the W/O or O/W emulsion was added. The yellowness value of surimi gels was 1.30, which increased with increasing W/O emulsion while remained constant after adding O/W emulsion. The water-holding capacity of surimi gels was invariant when emulsions increased. After emulsions added to surimi gels, no changes in the surimi protein interactions were found in electrophoretic patterns and Fourier transform infrared spectra. The increasing W/O emulsion enlarged the droplet size of oil and then destroyed the surimi gel network structure, while the oil droplets were evenly dispersed with increasing O/W emulsion.

Structural properties and emulsification of myofibrillar proteins from hairtail (Trichiurus haumela) at different salt ions.

The structural properties and emulsification of myofibrillar proteins (MPs) are susceptibly affected by salt ions. The effect of different salt ions on the structural properties and emulsification of MPs from hairtail (Trichiurus haumela) remains unclear. Hairtail MPs were analyzed under different ion treatments of Na+, K+, Ca2+ and Mg2+. MPs at K+ and Na+ treatment showed a similar trend on salt effect due to the unfolding of proteins under salt ions. However, the excessive electrostatic effect of divalent ions could enhance protein aggregation, especially at Ca2+ and Mg2+. The ß-sheet of MPs at different salt ions interconverted with α-helix and random coil at ionic strengths from 0.1 mol/L to 1.0 mol/L. The surface hydrophobicity and active sulfhydryl content of MPs increased with the improvement of ionic strengths at 0-0.8 mol/L. Under Ca2+ and Mg2+ treatments, the turbidity of MPs was low compared to that under the treatment of Na+ and K+. Additionally, the emulsification of hairtail MPs treated with different ions was improved at an ionic strength of 0.6 mol/L. This study can contribute to using salts in constructing fish protein-based emulsions for manufacturing emulsified surimi products and promoting the development and utilization of hairtail proteins.

Antioxidant characteristics of hydrolysate from low-value sea cucumber: In vitro and in vivo activities of Caenorhabditis elegans.

The antioxidant activity in vitro and in vivo of Actinopyga miliaris hydrolysate (AMH) was investigated. The proportion of oligopeptides with 150-1000 Da in AMH was 65.48%. The IC50 values of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), hydroxyl radical scavenging ability, and ferric ion reducing power of AMH were 0.37, 3.43, and 24.15 mg/mL, respectively. Compared with the control group, the body length of Caenorhabditis elegans fed with 8 mg/mL AMH extended from 632.08 µm to 1009.57 µm, and the swallowing frequency and head-swing frequency increased significantly. After being fed with AMH, the lifespan of C. elegans can be prolonged even under stress conditions, primarily due to superoxide dismutase activity, catalase activity, reduced glutathione content, and total antioxidant capacity in C. elegans increased, whereas reactive oxygen species level was reduced. The results showed that AMH had in vitro and in vivo antioxidant activity, which can alleviate oxidative damage and prolong life of C. elegans.

Preparation and characterization of soy protein isolate films by pretreatment with cysteine.

The effect of cysteine concentration on the viscosity of soy protein isolate (SPI)-based film-forming solution (FFS) and physicochemical properties of SPI films was investigated. The apparent viscosity of FFS decreased after adding 1 mmol/L cysteine but did not change after adding 2-8 mmol/L cysteine. After treatment with 1 mmol/L cysteine, the film solubility decreased from 70.40% to 57.60%, but the other physical properties did not change. The water vapor permeability and contact angle of SPI films increased as cysteine concentration increased from 4 mmol/L to 8 mmol/L, whereas the film elongation at break decreased. Based on scanning electron microscopy and X-ray diffraction results, cysteine crystallization could be aggregated on the surface of SPI films treated with 4 or 8 mmol/L cysteine. In conclusion, pretreatment with approximately 2 mmol/L cysteine could reduce the viscosity of SPI-based FFS, but did not change the physicochemical properties of SPI films.

Ultrasonic treatment regulates the properties of gelatin emulsion to obtain high-quality gelatin film.

Gelatin emulsion was an important process for preparing gelatin films. A gelatin film with water resistance and ductility could be prepared using gelatin emulsion, whereas the prepared gelatin film has several defects (e.g., low tensile strength and poor thermal stability). This study aimed to modify gelatin emulsion through ultrasonic treatment, then gelatin film was prepared by the modified gelatin emulsion. The results showed that: under the condition of ultrasonic treatment for 12 min at 400 w, zeta potential and viscosity of gelatin emulsion were the largest; thickness, water vapor permeability (WVP) and water solubility (WS) of corresponding gelatin film were the lowest, and the tensile strength (TS), elongation at break (EAB), denaturation temperature (Tm) and enthalpy value (ΔH) of corresponding gelatin film were the highest. The above result suggested that ultrasonic treatment can be used to prepare a gelatin film with better quality by regulating the properties of gelatin emulsion, and a certain correlation was found between the properties of gelatin emulsion and the properties of gelatin film.

Characteristics and potential application of myofibrillar protein from golden threadfin bream (Nemipterus virgatus) complexed with chitosan.

The strategies to broaden the applications of proteins involve their modification with polysaccharides. However, the characteristics and application of myofibrillar proteins (MPs) from golden threadfin bream (Nemipterus virgatus) complexed with chitosan (CS) are still unclear. Therefore, the characteristics of MPs complexed with CS and their application were investigated at different MP/CS ratios (100:0-80:20 (w/w)). The turbidity of MP/CS complexes was small at the MP/CS ratio of 95:5 (w/w). Besides, CS addition induced changes in MP structure to make it hydrophilic. Secondary structure analysis showed that α-helix and ß-turn interconverted with ß-sheet and random coil after the addition of CS. Additionally, the thermal stability of MP/CS mixtures enhanced after the addition of CS and the MP/CS mixtures at the ratio of 95:5 (w/w) had a relatively compact structure. High internal phase emulsions (HIPEs) prepared at the MP/CS ratio of 95:5 (w/w) were relatively stable compared to those at the other ratios. Consequently, MP/CS mixtures at suitable ratios possess the potential ability to prepare HIPEs. These results exhibit that MP/CS mixtures may be applied for constructing food-graded emulsion delivery systems with a high internal phase in the food industry.

Effects of pre-emulsion prepared using sucrose esters with different hydrophile-lipophile balances on characteristics of soy protein isolate emulsion films.

The preparation of emulsion films using pre-emulsification has received extensive attention due to the enhancement of oil binding capacity. However, the different effects of water in oil (W/O) and oil in water (O/W) pre-emulsions on the physicochemical properties of films are still unclear. Therefore, the soy protein isolate (SPI) based emulsion films were prepared by W/O or O/W pre-emulsion using sucrose esters with different hydrophile-lipophile balances to investigate the properties of SPI emulsion (SPIE) films. The viscosity, storage moduli, and loss moduli of film-forming solutions (FFSs) with O/W pre-emulsion were higher than those of FFSs with W/O pre-emulsion. The oil droplets of FFSs with W/O pre-emulsion were large and uneven, and the oil droplet size increased after drying. Phase separation and macroporous network appeared in cross-sectional of SPIE films with W/O pre-emulsion according to scanning electron microscope images. Meanwhile, the SPIE films with W/O pre-emulsion demonstrated higher oil concentration and hydrophobicity on the upper surface compared with the SPIE films with O/W pre-emulsion. Low tensile strength, glass transition temperature, and high elongation at break and transparency value of SPIE films with O/W pre-emulsions were founded. The water vapor permeability of SPIE films with W/O pre-emulsion increased with the addition of oil, whereas the opposite trend appeared in that with O/W pre-emulsion. In conclusion, the structure and porosity of emulsion films could be affected by the pre-emulsion types, which can determine the application ranges.

Characteristics and in vitro digestion of resveratrol encapsulated in Pickering emulsions stabilized by tea water-insoluble protein nanoparticles.

This study focused on the characteristics and in vitro digestion of resveratrol encapsulated in Pickering emulsions stabilized by tea water-insoluble protein nanoparticles (TWINs). The absolute value of zeta potential of Pickering emulsions stabilized by TWIPNs (TWIPNPEs) encapsulating resveratrol was above 40 mV. Resveratrol encapsulated in TWIPNPEs was located at a hydrophobic environment of emulsion droplets. Additionally, the encapsulation efficiency (EE) of TWIPNPEs at TWIPN concentrations of 3.0% and 4.0% was above 85%. The resveratrol encapsulated in TWIPNPEs at a TWIPN concentration of 4.0% was still greater than 80% after UV irradiation to reduce the susceptibility of resveratrol for photodegradation. Moreover, the bioavailability of resveratrol in TWIPNPEs was improved in the simulated in vitro digestion. The bioavailability of resveratrol in TWIPNPEs in the simulated system was two times higher than unencapsulated resveratrol. This research could be useful for the encapsulation and application of nutraceuticals like resveratrol based on TWIPNPEs.

Physicochemical properties of soybean ß-conglycinin-based films affected by linoleic acid.

To explore the interaction between lipids and proteins during emulsion film formation, the linoleic acid concentration effects on the physicochemical properties of soybean ß-conglycinin (7S) films were studied. The viscosity and size of oil droplets in the film-forming solution gradually increased with the increasing linoleic acid concentration. As the linoleic acid concentration increased, the number of oil droplets on the film surfaces and elongation at break of films gradually increased, whereas the tensile strength decreased. The films containing 20% linoleic acid had the highest water vapor permeability value, which was decreased by increasing or decreasing the linoleic acid concentration. According to the molecular dynamics simulation and chemical interactions, 7S could be adsorbed at the linoleic acid interface and bind stably, resulting in the decreased ionic and hydrogen bonds but the increased hydrophobic interactions and covalent bonds among proteins in the films.

Unique roles in health promotion of dietary flavonoids through gut microbiota regulation: Current understanding and future perspectives.

Advances in understanding the biological effects of dietary flavonoids and flavonoid-rich foods have been reported. Improving knowledge about their beneficial effects, and mechanisms of action, is crucial for better utilization. However, mechanisms responsible for their health benefits are still unclear. Previous research considered has suggested that gut microbiota might be linked to the metabolism of dietary flavonoids. To understand the bioactivities of dietary flavonoids/flavonoid-rich foods better, and the role of microbiota, we explored systematically 1) types of dietary flavonoids and associated health benefits, 2) low bioaccessibilities and metabolic characteristics, 3) gut microbiota role in regulation, and 4) crosstalk between regulation mechanisms. Current challenges and future perspectives were also considered, offering new research directions and identifying trends in the development of flavonoid-rich food products.

Advancement of Protein- and Polysaccharide-Based Biopolymers for Anthocyanin Encapsulation.

Although evidence shows that anthocyanins present promising health benefits, their poor stability still limits their applications in the food industry. Increasing the stability of anthocyanins is necessary to promote their absorption and metabolism and improve their health benefits. Numerous encapsulation approaches have been developed for the targeted release of anthocyanins to retain their bioactivities and ameliorate their unsatisfactory stability. Generally, choosing suitable edible encapsulation materials based on biopolymers is important in achieving the expected goals. This paper presented an ambitious task of summarizing the current understanding and challenges of biopolymer-based anthocyanin encapsulation in detail. The food-grade edible microencapsulation materials, especially for proteins and polysaccharides, should be employed to improve the stability of anthocyanins for effective application in the food industry. The influence factors involved in anthocyanin stability were systematically reviewed and highlighted. Food-grade proteins, especially whey protein, caseinate, gelatin, and soy protein, are attractive in the food industry for encapsulation owing to the improvement of stability and their health benefits. Polysaccharides, such as starch, pectin, chitosan, cellulose, mucilages, and their derivatives, are used as encapsulation materials because of their satisfactory biocompatibility and biodegradability. Moreover, the challenges and perspectives for the application of anthocyanins in food products were presented based on current knowledge. The proposed perspective can provide new insights into the amelioration of anthocyanin bioavailability by edible biopolymer encapsulation.

Physicochemical, Sensory and Digestive Properties of Eel Burgers at Different Baking Temperatures.

The effect of baking temperature on the physicochemical, sensory and digestive properties of eel burgers was investigated. The moisture content of eel burgers gradually decreased with increased baking temperature, whereas the water-holding capacity remained unchanged. The breaking force of eel burgers baked at 160°C was significantly higher than that at other baking temperatures. With increased baking temperature from 100 to 220°C, amide I in the Fourier transform infrared spectroscopy of eel burgers shifted from 1,645 to 1,633 cm-1, and the peak intensity of 1,744 cm-1 initially increased and then decreased. When the baking temperature exceeded 160°C, the band intensity of protein aggregate increased gradually with increased baking temperature. Scanning electron microscopy result indicated that the muscle fibers in eel burgers contracted significantly with increased baking temperature, and a honeycomb-like network structure appeared in eel burgers baked at 220°C. The sulfur compounds in the eel burgers baked at 130°C were lower than those of the sample baked at 100°C, but it increased gradually with further increased baking temperature. The aftertaste astringency, richness, saltiness, and overall acceptability of eel burgers increased with increased baking temperature. The eel burgers baked at 130-160°C could be easily digested according to the in vitro digestibility and confocal laser confocal microscopy of gastrointestinal digests. In conclusion, the texture properties, barbecue aroma, and digestibility of eel burgers could be controlled by the baking temperature.

Effect of ionic strength on the structural properties and emulsion characteristics of myofibrillar proteins from hairtail (Trichiurus haumela).

Myofibrillar proteins (MPs) are susceptibly affected by ionic strength. The effect of ionic strength on the structure and emulsifying properties of MPs from hairtail (Trichiurus haumela) is still unclear. Therefore, the effect of ionic strength on the structural properties and emulsification of myofibrillar proteins from hairtail was analyzed. The increase in ionic strength led to the increase in endogenous fluorescence intensity of MPs. The α-helix content in MPs first increased and then decreased from ionic strength of 0 to 1.0 mol/L and ß-sheet content exhibited the oppositive trend, indicating that α-helix in MP transformed into ß-sheet. The surface hydrophobic groups of MPs increased; however, the contact angle decreased with the increase in ionic strength of 0-0.8 mol/L and a slight rebound at 1.0 mol/L. Sulfhydryl content and electrophoretic analysis further exhibited the change of MP structure at ionic strengths of 0-1.0 mol/L. Besides, the droplet size of MP emulsions was small and evenly distributed at 0.6 mol/L. Additionally, the creaming index of MP emulsions had better stability prepared at 0.6 mol/L than the other ionic strength conditions. The apparent viscosity of MP emulsions increased with the increase in ionic strength of 0-0.8 mol/L and decreased slightly at 1.0 mol/L. The rheological behavior of MP emulsions exhibited gel-like behavior without the effect of temperatures at 20-80 °C. These results can broaden the potential application of MPs from hairtail on the emulsion-type seafood products and delivery system in the food industry.

Pickering Emulsions Stabilized by Tea Water-Insoluble Protein Nanoparticles From Tea Residues: Responsiveness to Ionic Strength.

Tea water-insoluble protein nanoparticles (TWIPNs) can be applied to stabilize Pickering emulsions. However, the effect of ionic strength (0-400 mmol/L) on the characteristics of Pickering emulsions stabilized by TWIPNs (TWIPNPEs) including volume-averaged particle size (d4,3), zeta potential, microstructure and rheological properties is still unclear. Therefore, this work researched the effect of ionic strength on the characteristics of TWIPNPEs. The d4,3 of TWIPNPEs in the aquatic phase increased with the increase in ionic strength (0-400 mmol/L), which was higher than that in the SDS phase. Furthermore, the flocculation index of TWIPNPEs significantly (P < 0.05) increased from 24.48 to 152.92% with the increase in ionic strength. This could be verified from the microstructure observation. These results indicated that ionic strength could promote the flocculation of TWIPNPEs. Besides, the absolute values of zeta potential under different ionic strengths were above 40 mV in favor of the stabilization of TWIPNPEs. The viscosity of TWIPNPEs as a pseudoplastic fluid became thin when shear rate increased from 0.1 to 100 s-1. The viscoelasticity of TWIPNPEs increased with increasing ionic strength to make TWIPNPEs form a gel-like Pickering emulsion. the possible mechanism of flocculation stability of TWIPNPEs under different ionic strengths was propose. TWIPNs adsorbed to the oil-water interface would prompt flocculation between different emulsion droplets under the high ionic strength to form gel-like behavior verified by CLSM. These results on the characteristics of TWIPNPEs in a wide ionic strength range would provide the theoretical basis for applying Pickering emulsions stabilized by plant proteins in the food industry.

Encapsulation and release kinetics of ethylene into "pre-formed" V-type starch and granular cold-water-soluble starch.

Ethylene gas was loaded into "pre-formed" V-type starch (V6, V7 and V8) by molecular encapsulation, and granular cold-water-soluble starch (GCWSS) was chosen as a control. The formation, structural characteristics and morphological properties of inclusion complexes (ICs) were investigated using X-ray diffraction, scanning electron microscopy, and 13C solid-state nuclear magnetic resonance spectroscopy. The V6a-type starch represented the most effective structure in encapsulating ethylene gas among different "pre-formed" V-type starches. The Avrami equation was used to describe the release kinetic properties of ethylene gas from ICs under various conditions of temperatures and relative humidities (RHs). The release of ethylene from ICs conformed to diffusion-limited release mechanisms (temperature) and first-order kinetics (RH). This could be caused by the differences in starch structure and association mechanisms between ethylene and starch single helices. Accelerated ripening experiments showed that ethylene-starch ICs could ripen bananas within 5 days, suggesting that this molecular encapsulation technology can provide precise control and targeted application of ethylene gas in the ripening of vegetables and fruits.

Characteristics of Pickering emulsions stabilized by tea water-insoluble protein nanoparticles at different pH values.

This study aimed to explore the characteristics of Pickering emulsions stabilized by tea water-insoluble protein nanoparticles (TWIPNs) at different pH values. The characteristics of TWIPNs at different pH values were analysed first. The average hydrodynamic diameter of TWIPNs in the suspension was smaller than 400 nm at pH 7-11. TWIPNs at pH 3 could not be used to stabilize Pickering emulsions. The flocculation index (FI) of fresh TWIPN-stabilized Pickering emulsions (TWIPNPEs) at pH 5 was higher than those of TWIPNPEs at pH 7-11 (FI < 5%), indicating that bridging flocculation led to the aggregation of small emulsion droplets. The zeta potential of TWIPNPEs at pH 7-11 did not change after 7 d. In addition, the TWIPNPEs showed gel-like properties under neutral and alkaline conditions. These results will be helpful for broadening the application of TWIPNPEs at different pH values.