Preparation and Formation Mechanism Study of Antibiofilm Coating Based on Phase Transition of Glutenin.

The surface of food processing equipment is easily affected by biofilm-forming bacteria, leading to cross-contamination and food safety hazards. The critical issue is how to endow the surface of contact materials with antibacterial and antibiofilm abilities. A sustainable, stable, and antibiofilm coating was prepared by phase transition of glutenin. The disulfide bonds in glutenin were reduced by tris(2-carboxyethyl)phosphine, triggering the phase transition of glutenin. Hydrophobic interactions and intermolecular disulfide bonds may be the primary forces. Furthermore, the phase-transited products formed a nanoscale coating on the surface of stainless steel and glass under their own adhesion force and gravity. The coating exhibited good stability in harsh environments. More importantly, after 3 h of direct contact, the colony of Escherichia coli and Staphylococcus aureus decreased by one logarithm. The amount of biofilm was observed to be significantly decreased through optical microscopy and scanning electron microscopy. This article provides a foundational module for developing novel coatings.

Deciphering the interactions between altertoxins and glutenin based on molecular dynamic simulation: inspiration from detection.

BACKGROUND: Mycotoxin contamination of food has been gaining increasing attention. Hidden mycotoxins that interact with biological macromolecules in food could make the detection of mycotoxins less accurate, potentially leading to the underestimation of the total exposure risk. Interactions of the mycotoxins alternariol (AOH) and alternariol monomethyl ether (AME) with high-molecular glutenin were explored in this study. RESULTS: The recovery rates of AOH and AME (1, 2, and 10 µg kg-1) in three types of grains (rice, corn, and wheat) were relatively low. Molecular dynamics (MD) simulations indicated that AOH and AME bound to glutenin spontaneously. Hydrogen bonds and π-π stacking were the primary interaction forces at the binding sites. Alternariol with one additional hydroxyl group exhibited stronger binding affinity to glutenin than AME when analyzing average local ionization energy. The average interaction energy between AOH and glutenin was -80.68 KJ mol-1, whereas that of AME was -67.11 KJ mol-1. CONCLUSION: This study revealed the mechanisms of the interactions between AOH (or AME) and high-molecular glutenin using MD and molecular docking. This could be useful in the development of effective methods to detect pollution levels. These results could also play an important role in the evaluation of the toxicological properties of bound altertoxins. © 2024 Society of Chemical Industry.

Normal Force-Induced Highly Efficient Mechanical Sterilization of GaN Nanopillars.

Bacterial residue is one of the main causes of diseases and economic losses. In recent years, microfabrication technology has inspired the introduction of microstructures on the surfaces of relevant materials to provide antibacterial effects. This antibacterial method has become a popular research topic due to its safety, effectiveness, and stability. However, its exact mechanism is still under debate. In this study, normal force was introduced to bacteria on GaN nanopillars to investigate the mechanical sterilization effects and a computer simulation was conducted. The results show that the normal force induces highly efficient mechanical sterilization of the nanopillars, and their surfaces impede the attachment of bacteria. This study provides insights into the antibacterial effect of nanopillars and offers a potential antibacterial tool with high efficiency.

Purification and Identification of Pine Nut (Pinus yunnanensis Franch.) Protein Hydrolysate and Its Antioxidant Activity in Vitro and in Vivo.

In this study, the pine nut (Pinus yunnanensis Franch.) protein was hydrolyzed by alkaline protease and trypsin to prepare pine nut protein hydrolysate (PNPH). The chemical, intracellular and in vivo antioxidant capacity of PNPH were evaluated. PNPH owned the ability of scavenging free radicals, and it could protect the HepG2 cells from oxidative damage by preserving cell viability. Moreover, PNPH could reduce the malondialdehyde (MDA) content and improved the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in serum, heart and liver of aging mice induced by D-galactose. Further, the PNPH was stepwise purified and identified, and 15 peptides were identified from purified fraction in PNPH. The three-dimension structures of identified peptides were predicted. Among all identified peptides, peptide 3, 7, 8 and 11 were presumed to possess good antioxidant activity. Overall, PNPH and purified peptides isolated from PNPH have potential application prospects in the field of natural antioxidants and anti-aging functional foods.

Ratiometric determination of Cr(VI) based on a dual-emission fluorescent nanoprobe using carbon quantum dots and a smartphone app.

A simple dual-colour fluorescent nanoprobe has been designed composed of blue and yellow emission carbon quantum dots (CQDs). This system is inexpensive and easy to operate and was successfully employed for on-site measurements based on a smartphone app. The designed nanoprobe exhibited increased selectivity for Cr(VI), leading to a double stable response of the two CQDs. The dual-emission nanoprobe showed blue-violet fluorescence upon UV irradiation, and the fluorescent emission peaks were located at 418 nm and 552 nm. The blue light emission of CQDs was quenched with increasing Cr(VI) concentration due to the inner filter effect, whereas the yellow light emission was enhanced due to the aggregation-induced emission effect. The different responses of the dual emissions to Cr(VI) resulted in a fluorescent colour variation, thus enabling facile macroscopic visualization. With a smartphone, the change in the fluorescence colour could be observed more apparently than that of a single fluorescence nanoprobe, and the response increased linearly so that the nanoprobe could be applied to instantaneous measurements. Furthermore, the dual-emission nanoprobe was successfully employed for analysing food and water samples. Accurate concentrations were obtained by constructing a calibration plot using a fluorescence spectrometer and a smartphone app; the recoveries were 81.6% to 107.7%, and the relative standard deviation was below 3.6%. Therefore, this smartphone-integrated dual-emission detection system is promising as a new portable method for the on-site measurement of Cr(VI) ions. * Y-CQDs: yellow emission carbon quantum dots. B-CQDs: blue emission carbon quantum dots. B/Y-CQDs: a mixture of B-CQDs and Y-CQDs.

Raman silent region - based method for detection of pesticides with cyano group.

Based on the fact that not all chemical substances possess good Raman signals, this article focuses on the Raman silent region signals of pesticides with cyano group. Under the optimized conditions of methanol-water (1:1, v/v) as the solvent, irradiation at 302 nm light source for 20 min, and the use of 0.5 mol/L KI as the aggregating agent, Surface-enhanced Raman spectroscopy (SERS) method for azoxystrobin detection was developed by the Raman silent region signal of 2230 cm-1, and verified by detecting the spiked grapes with different concentrations of azoxystrobin. Other four pesticides with cyano group also could be identified at the peak of 2180 cm-1, 2205 cm-1, 2125 cm-1, and 2130 cm-1 for acetamiprid, phoxim, thiacloprid and cymoxanil, respectively. When azoxystrobin or acetamiprid was mixed respectively with chlorpyrifos without cyano group, their SERS signals in the Raman silent region of chlorpyrifos were not interfered, while mixed with cymoxanil in different ratios (1:4, 1:1 and 4:1), respectively, each two pesticides with cyano group could be distinguished by the changes in the Raman silent region. In further, four pesticides with or without cyano group were mixed together in 1:1:1:1 (acetamiprid, cymoxanil, azoxystrobin chlorpyrifos), and each pesticide still could be identified even at 0.5 mg/L. The results showed that the SERS method combined with UV irradiation may provide a new way to monitor the pesticides with C≡N performance in the Raman silent region without interference from the food matrix.

Interaction behavior, mechanisms and hazardous changes of microplastics on single and binary component pesticide in the environment and food: Diethofencarb and pyrimethanil.

In order to investigate the adsorption behavior and mechanism of microplastics (MPs) on multiple coexisting pesticides in practical systems, as well as their hazardous changes upon binding, diethofencarb and pyrimethanil were selected to be studied with four MPs. The adsorption rate of both pesticides would be faster in the binary-component case, conforming to pseudo-second-order kinetics, with adsorption sites and chemical adsorption dominating. And the more hydrophobic the pesticide, the faster the adsorption rate and the higher the adsorption capacity. Diethofencarb belonged to monolayer adsorption, whereas pyrimethanil belonged to monomolecular combined with multilayer adsorption, depending on the size of pesticides. And the adsorption process was both competitive and synergistic when pesticides coexist. In addition, the adsorption process was a spontaneous heat absorption process. Electrostatic forces have little effect on adsorption, while the adsorption capacity can be altered by the adsorption sites and hydrophobicity of MPs. The salting-out effect also facilitated the adsorption process. As for changes in hazard, the bioluminescence of A. fischeri wasn't significantly inhibited, lacking of acute environmental toxicity. However, in vitro digestion experiments demonstrated a significant increase in bioavailability of diethofencarb and pyrimethanil in combination with MPs. These findings suggest the stronger adsorption behaviors and higher loading capacities between pesticides and MPs could lead more serious hazards to the human body, which deserves further attention.

Monitoring of COS, SO2, H2S, and CS2 gases by Al24P24 nanoclusters: a DFT inspection.

Through utilizing density functional theory (DFT), the current work investigates the potential uses of Al24P24 fullerene for detecting CS2, H2S, SO2, and COS. The interaction order for the stability of these gases was SO2 > H2S > COS > CS2. The moment of electric dipole and molecules' adsorption energy seems correlated. Al24P24 fullerene is regarded as an electronic sensor of the Ф-type for detecting SO2 and CS2. According to the findings, CS2 and SO2 might act as Al24P24 fullerenes when H2S is present. Nevertheless, we cannot presume it to be a COS and H2S sensor of Ф-type. At room temperature, the fullerene of Al24P24 has a quick recovery time of 0.50 µs and 0.17 s in CS2 and SO2 desorption from the surface. It can thus be inferred that it has the ability to function in moist media.

The chemical recognition of hydrogen fluoride via B24N24 nanocage: quantum chemical approach.

CONTEXT: Ab initio calculations were employed in this investigation to scrutinize the adsorption characteristics of a linear chain (HF)n on a BN nanocage (B24N24), wherein the chain lengths varied (n = 1, 2, 3, and 4). The overarching aim was to assess the efficiency of this setup in detecting and adhering to (HF)n under both liquid and gaseous scenarios. This study encompassed an array of aspects, encompassing adsorption energy, optimal configuration determination, work function analysis, and charge exchange assessment. Furthermore, an exploration was conducted into the impact of HF linear chain dimensions on electrical attributes and adsorption energy. According to the values of adsorption energy, the dimer form of HF adsorbed onto BN nanocages displayed the highest stability. METHODS: This scrutiny was undertaken utilizing density functional theory (DFT), employing the B3LYP functional and the 6-31 + + G(d,p) basis set. Notably, the choice of the 6-31 + + G(d,p) basis set is particularly apt for delving into nanostructure analyses. The HOMO-LUMO energy gap was significantly reduced by (HF)n upon adsorption onto the nanocage, falling from 6.48 to 5.43 eV and enhancing electrical conductivity as a result. Additionally, BN nanocages may be used as sensors to find (HF)n among other environmental pollutants.

Rapid magnetization and removal of microplastics from environment and food based on magnetic metal-organic framework Fe3O4@SiO2@MIL-53(Al).

Microplastics (MPs) are now not only emerging as pollutants in the environment, but their current state of contamination in food is also a cause for concern. It is necessary to focus how to control, reduce, and even remove MPs. In this study, a magnetic metal-organic framework (MOF) material, Fe3O4@SiO2@MIL-53(Al), was synthesized and applied to simulate the magnetization and removal of four types of MPs. Fe3O4@SiO2@MIL-53(Al) was characterized by various means to demonstrate its successful synthesis as a core-shell nanomaterial. The conditions of the method were optimized by examining the effect of time, the mass ratio of material to MPs, temperature, and pH on the removal effect. The removal rates of four MPs were 54.10-94.17%, and the maximum adsorption capacities of Fe3O4@SiO2@MIL-53(Al) that can be adsorbed were 10511.45-44390.24 mg g-1. Notably, the material can effectively magnetize and remove MPs from liquid food containing alcohol with highest efficiency of 97.10 ± 1.21%. Potential adsorption mechanisms were analyzed using kinetic, isothermal, and thermodynamic models, and electrostatic attraction and hydrogen bonding were found to play a dominant role in the adsorption process. In addition, not only can Fe3O4@SiO2@MIL-53(Al) be reused up to five times to maintain high removal rates, but it can also be used in food systems. Therefore, Fe3O4@SiO2@MIL-53(Al) not only has the advantages of ease of use and stability, but also can efficiently and quickly magnetize and remove many common MPs in more complex matrices such as food.

The impact of modified polystyrene on lysozyme fibrillation studied by surface-enhanced Raman spectroscopy (SERS).

Nanoplastics could modulate the fibrillation of amyloid proteins. However, many chemical functional groups are adsorbed to change the interfacial chemistry of nanoplastics in the real world. Herein, this study aimed to investigate the effects of polystyrene (PS), carboxyl modified PS (PS-COOH), and amino modified PS (PS-NH2) on the fibrillation of hen egg-white lysozyme (HEWL). Due to the differences in the interfacial chemistry, concentration was considered an essential factor. PS-NH2 (10 µg/mL) could promote the fibrillation of HEWL similar to PS (50 µg/mL) and PS-COOH (50 µg/mL). Moreover, promoting the primary nucleation step of amyloid fibril formation was the primary reason. The differences in spatial conformation of HEWL were characterized by Fourier transform-infrared spectroscopy and surface enhanced Raman spectroscopy (SERS). Strikingly, a particular signal of SERS of HEWL incubated with PS-NH2 at 1610 cm-1 was found due to the interaction between amino group of PS-NH2 and tryptophan (or tyrosine) of HEWL. Therefore, a new perspective was provided to understand the regulation of interfacial chemistry of nanoplastics on the fibrillation of amyloid proteins. Additionally, this study suggested that SERS could be a powerful method to investigate the interactions between proteins and nanoparticles.

Lysozyme amyloid fibril: Regulation, application, hazard analysis, and future perspectives.

Self-assembly of misfolded proteins into ordered fibrillar aggregates known as amyloid results in various human diseases. However, more and more proteins, whether in human body or in food, have been found to be able to form amyloid fibrils with in-depth researches. As a model protein for amyloid research, lysozyme has always been the focus of research in various fields. Firstly, the formation mechanisms of amyloid fibrils are discussed concisely. Researches on the regulation of lysozyme amyloid fibrils are helpful to find suitable therapeutic drugs and unfriendly substances. And this review article summarizes a number of exogenous substances including small molecules, nanoparticles, macromolecules, and polymers. Small molecules are mainly connected to lysozyme through hydrophobic interaction, electrostatic interaction, π-π interaction, van der Waals force and hydrogen bond. Nanoparticles inhibit the formation of amyloid fibers by stabilizing lysozyme and fixing ß-sheet. Besides, the applications of lysozyme amyloid fibrils in food-related fields are considered furtherly due to outstanding physical and mechanical properties. Nevertheless, the potential health threats are still worthy of our attention. Finally, we also give suggestions and opinions on the future research direction of lysozyme amyloid fibrils.

Submicron-size polystyrene modulates amyloid fibril formation: From the perspective of protein corona.

At present, nanoplastics have been detected in food and the environment, but they have serious impacts on the human body. As one of the typical representatives of nanoplastics, polystyrene (PS) is generally used as an experimental object. Few studies found that PS could modulate the formation of amyloid fibrils, leading to the occurrence of diseases. However, its submicron-scale effects remain elusive. Thus, this study aimed to explore the interaction between PS of particle size 100-500 nm and hen egg-white lysozyme (HEWL). The results showed that PS of size 400 nm markedly promoted the primary nucleation step of amyloid fibril formation, and fibrils had more small fragments compared with PS of size 100 nm in the control and sample groups. PS of larger particle size changed the spatial structure of HEWL significantly. This study analyzed the experimental results from the perspective of protein corona and thermodynamics. The study confirmed that PS was able to form protein corona with HEWL in the initial stage, which was mainly driven by hydrophobic interactions. More importantly, the interface and junction of the protein corona were the main sites for the formation of amyloid fibrils. This study highlighted the role of submicron particle size and discussed the toxic effects of nanoparticles.

Microplastics contamination in eggs: Detection, occurrence and status.

Nowadays, the widespread distribution of microplastics (MPs) in various foods has received much attention. In this study, eggs were purchased as samples from local supermarkets to detect and analyze the presence of MPs. The digestion method was optimized for eggs to better isolate MPs, which proved MPs indeed exist in eggs, and the average content was 11.67 ± 3.98 particles/egg. The shape and size range of most MPs were spherical and 50-100 µm. The infrared results showed that the main type of MPs in eggs was polyethylene. The number of MPs in egg yolk was higher than that in egg white, and there was no significant change after cooking. In addition, the daily human intake of MPs was estimated. Therefore, the results of this study provided a background for the current status and pollution of MPs in eggs, and proposed the necessary control and preventive measures to avoid this situation.

Current status of microplastics and nanoplastics removal methods: Summary, comparison and prospect.

In modern society, plastics also play an indispensable role in people's lives due to their various excellent properties. However, when these plastic products are discarded after being used, after being subjected to external influences, they will continue to be worn, damaged and degraded into micro- and nano-scale plastics, which are microplastics and nanoplastics (M/NPs). Although people's attention has been paid to M/NPs at present, the focus is still mainly on the detection and hazard of M/NPs, and how to remove M/NPs is relatively less popular. This review was written in order to draw the attention of more researchers to remove M/NPs. This review first briefly introduces the research background of M/NPs, and also shows the main analytical methods currently used for qualitative and quantitative M/NPs. Then, most of the current literature on the removal of M/NPs was collected, and they were classified, summarized, and introduced according to the classification of physical, physicochemical, and biological methods. The advantages and disadvantages of various methods are summarized, and they are also compared, which can help more researchers choose the appropriate method for research. In addition, the application scenarios of these methods are briefly introduced. Finally, some future research directions are proposed for the current research status of M/NPs removal. It is hoped that this will further promote the development on the method of removing M/NPs.

Microplastics and Nanoplastics: Emerging Contaminants in Food.

As current concerns about food safety issues around the world are still relatively serious, more and more food safety issues have become the focus of people's attention. What's more serious is that environmental pollution and changes in human lifestyles have also led to the emergence of contaminants in food, microplastics (MPs) and nanoplastics (NPs) being typical representatives. MPs and NPs (M/NPs) in food are gradually becoming recognized by regulatory authorities and the public. Most published reviews on M/NPs have been focused on the environmental ecosystems. In those papers, it is only sporadically mentioned that M/NPs can also appear in food. As far as we know, there has not been a systematic review of the pollution and existing status of M/NPs in food. This Review focuses on the harmfulness of M/NPs, the ways in which M/NPs contaminate food, the residual amount of M/NPs in food, and the current analysis and detection methods for M/NPs in food. Current analysis and detection methods have problems such as being time-consuming, involving cumbersome operation, and giving poor accuracy. In the future, it will be necessary to increase the research on methods for efficient and sensitive separation and detection of M/NPs in food. Finally, it is hoped that this Review will arouse more people's awareness of and attention to the seriousness of M/NPs in food.