Characteristics of Quinoa Protein Isolate Treated by Pulsed Electric Field.

The aim of this study was to investigate the impact of a pulsed electric field (PEF) on the structural and functional properties of quinoa protein isolate (QPI). The findings revealed a significant alteration in the secondary structure of QPI following PEF treatment, converting the random coil into the ß-sheet, resulting in an improvement in structure orderliness and an enhancement of thermal stability. The PEF treatment led to a reduction in particle size, induced structural unfolding, and increased the surface hydrophobicity, resulting in a statistically significant enhancement in the solubility, foaming, and emulsifying properties of QPI (p < 0.05). Specifically, PEF treatment at 7.5 kV/cm for 30 pulses was identified as the optimal condition for modifying QPI. This study provides a basis for the precision and range of application of pulsed electric field treatment and offers the possibility of improving the physical and chemical properties of quinoa protein.

Effect of Starch on the Solubility of Quinoa Protein Isolates during Heat Treatment.

There is increasing interest in developing quinoa products due to their unique nutritional value. Starch and protein are the primary components in quinoa, and the interaction between them affects the quality of quinoa products. This study extracted the starch and protein from quinoa and simulated the thermal processing of quinoa to investigate the effects of starch on the solubility and structure of quinoa protein isolates during heat treatment. The structure of quinoa protein isolates was characterized by fluorescence spectroscopy, Fourier transform infrared spectroscopy, laser particle size analysis, and scanning electron microscopy. The results showed that starch decreased protein solubility, and the maximum solubility was obtained after heating for 5 min. After starch addition during heat treatment, the surface charge distribution of protein changed, the degree of protein aggregation increased, the particle size of proteins increased, the thermal stability increased, and the ß-sheet ratio of the proteins increased, suggesting that the protein structure is more ordered, which is the structural foundation of protein solubility decreasing. The research about the interaction between starch and protein and the effects on the solubility of protein could provide a reference for quinoa products processing.

The Effects of Tea Polyphenol on Chicken Protein Digestion and the Mechanism under Thermal Processing.

Meat product is the main food and major source of daily protein intake. Polyphenols are always introduced into many meat products during processing. Some complex interactions may occur between polyphenol and meat protein during the processing, especially thermal processing, which may affect the digestion of protein. In this experiment, chicken protein and tea polyphenol were interacted in simulated systems to explore the effects of the interaction between meat protein and polyphenols on the digestion of meat protein. The mechanism of tea polyphenol inhibiting chicken protein digestion was studied by analyzing the changes of chicken protein in intrinsic fluorescence, surface plasmon resonance (SPR), reactive sulfhydryl group, and solubility in different solvents. The results showed that the chicken protein digestion had a negative correlation with tea polyphenol concentration and interaction temperature, and the meat protein has a higher affinity to EGCG than protease. The mechanism of tea polyphenol inhibiting chicken protein digestion was related to the changing spatial structure of chicken protein and the decreasing activity of proteases. In the simulation system, at low-concentration tea polyphenol, the inhibition of the tea polyphenol on the digestibility of chicken protein might be mainly caused by the changes in chicken protein structure, while at high concentration, the changes in protein structure and the inhibition of proteases activity played a role together. This experiment revealed the effect and the mechanism of polyphenols on the digestion performance of meat protein and provide more references for the further application of polyphenols in meat processing.

Penta-O-galloyl-ß-d-glucose inhibits the formation of advanced glycation end-products (AGEs): A mechanistic investigation.

Penta-O-galloyl-ß-d-glucose (PGG) was prepared from tannic acid methanolysis products based on HSCCC, and its protective effects and mechanism on the glucose-induced glycation were investigated for the first time. PGG was confirmed to exhibit strong anti-AGEs effects in bovine serum albumin (BSA)-glucose (Glu) and BSA-methylglyoxal (MGO) glycation systems. It was showed that PGG could inhibit the AGEs formation by blocking glycated intermediates (fructosamine and α-dicarbonyl compounds), eliminating radicals, and chelating metal-ions. In-depth mechanism analysis proved that PGG could prevent BSA from glycation by hindering the accumulation of amyloid fibrils, stabilizing the BSA secondary structures, and binding the partial glycation sites. Furthermore, PGG exhibited a prominent trapping capacities on the reactive intermediate MGO by generating PGG-mono-MGO adduct. This research indicated that PGG could be an effective agent to block Glu/MGO-triggered glycation and offered new insights into PGG as a functional ingredient in food materials for preventing diabetic syndrome.

The Expression and Function of lincRNA-154324 and the Adjoining Protein-Coding Gene vmp1 in the Caudal Fin Regeneration of Zebrafish.

Caudal fin regeneration is regulated by a variety of mechanisms, but the role of long non-coding RNA (lncRNA) has rarely been studied. The present study aimed to describe the landscape of lncRNAs during caudal fin regeneration using whole transcriptome sequencing, and then to conduct a functional study on the target lncRNAs using real-time fluorescent quantitative PCR (RT-qPCR), in situ hybridization, and the CRISPR/Cas9 method for lncRNA gene knockout. The results of the transcriptome sequencing showed that a total of 381 lncRNAs were differentially expressed, among which ENSDART00000154324 (lincRNA-154324) was found to be highly related to caudal fin regeneration, and thus it was chosen as the target lncRNA for the subsequent functional study. The results regarding the temporal and spatial expression of lincRNA-154324 and the gene knockout results from CRISPR/Cas9 indicated that lincRNA-154324 is involved in the caudal fin regeneration of zebrafish. Importantly, we serendipitously discovered that the cis correlation coefficient between lincRNA-154324 and its neighboring gene vacuole membrane protein 1 (vmp1) is extremely high, and they are essential for the process of caudal fin regeneration. Moreover, studies have found that vmp1 plays an important role in protein secretion, organelle formation, multicellular development, and autophagy. Collectively, our result may provide a framework for the identification and analysis of lncRNAs involved in the regeneration of the zebrafish caudal fin.

Neurotoxicity of Chronic Co-Exposure of Lead and Ionic Liquid in Common Carp: Synergistic or Antagonistic?

Previous studies have indicated that the harmful heavy metal lead (Pb) contamination in aquatic systems has caused intelligence development disorders and nervous system function abnormalities in juveniles due to the increased permeability of the blood-brain barrier. Ionic liquids (ILs) are considered "green" organic solvents that can replace traditional organic solvents. Studies have found the presence of ILs in soil and water due to chemical applications or unintentional leakage. Therefore, what would happen if Pb interacted with ILs in a body of water? Could ILs enable Pb to more easily cross the blood-brain barrier? Therefore, we examined the combined exposure of Pb and ILs in common carp at low concentration (18.3 mg L-1 of Pb(CH3COO)2•3 H2O and 11 mg L-1 of the IL 1-methyl-3-octylimidazolium chloride, 5% of their LC50) for 28 days in the present study. The result of a neurobehavioral assay showed that chronic exposure of lead at lower concentrations significantly altered fish movement and neurobehaviors, indicating that lead exposure caused neurotoxicity in the carp. Increases in the neurotransmitter dopamine levels and injuries in the fish brain accounted for neurobehavioral abnormalities induced by lead exposure. Moreover, we also found that lead could easily cross the blood-brain barrier and caused significant bioaccumulation in the brain. Particularly, our study indicated that the ionic liquid could not synergistically promote blood-brain barrier permeability and hence failed to increase the absorption of lead in the fish brain, suggesting that the combined exposure of lead and ILs was not a synergistic effect but antagonism to the neurotoxicity. The results of this study suggested that ILs could recede the Pb induced neurotoxicity in fish.

The galloyl moiety enhances inhibitory activity of polyphenols against adipogenic differentiation in 3T3-L1 preadipocytes.

Previous studies have proved that the characteristic galloyl moiety in polyphenols is crucial for their biological activities. However, whether the presence of the galloyl moiety in the structure of polyphenols has a great contribution to their inhibition of adipogenic differentiation is not clear. Therefore, in this study, seven polyphenols with different galloylation degrees were chosen for exploring the contribution of the galloyl group to the lipid-lowering property of polyphenols and its molecular mechanism. Our results showed that the existence of the galloyl moiety in the structure of polyphenols was necessary for their inhibition of adipogenic differentiation, which could help to delay cells from entering the G2/M phase as well as to hinder the MCE process in the early stage of differentiation and the downstream PPARγ and C/EBPα related MAPK signaling pathway, probably via binding to IR and disturbing the α-helix in its conformation. Our finding highlighted that the existence of galloyl groups in polyphenols was crucial for their anti-adipogenic activity, and provided new insights into the mechanism by which galloylated polyphenols suppress adipocyte differentiation.

Glutathione-Capped CdTe Quantum Dots Based Sensors for Detection of H2O2 and Enrofloxacin in Foods Samples.

Additives and antibiotic abuse during food production and processing are among the key factors affecting food safety. The efficient and rapid detection of hazardous substances in food is of crucial relevance to ensure food safety. In this study, a water-soluble quantum dot with glutathione as a ligand was synthesized as a fluorescent probe by hydrothermal method to achieve the detection and analysis of H2O2. The detection limits were 0.61 µM in water and 68 µM in milk. Meanwhile, it was used as a fluorescent donor probe and manganese dioxide nanosheets were used as a fluorescent acceptor probe in combination with an immunoassay platform to achieve the rapid detection and analysis of enrofloxacin (ENR) in a variety of foods with detection limits of 0.05-0.25 ng/mL in foods. The proposed systems provided new ideas for the construction of fluorescence sensors with high sensitivity.

Development of non-enzymatic and photothermal immuno-sensing assay for detecting the enrofloxacin in animal derived food by utilizing black phosphorus-platinum two-dimensional nanomaterials.

The two-dimensional black phosphorus nanosheets (BPNSs) provide strong support for the construction of nanozymes with high catalytic performance due to the sheet structure and high electronic activity. A peroxidase-like BP-Pt nanocomposites was successfully synthesized using the instability of BPNS, a non-enzymatic immunosensing assay (NISA) was established with BP-Pt as immunosensing probe. Take the antibiotic enrofloxacin (ENR) as the target, NISA realized the highly sensitive ENR detection with detection limit (IC15) of 0.005 µg/L. In addition, based on the good photothermal performance of oxTMB at 808 nm, a photothermal immunosensing assay (PT-NISA) was established, and ENR detection results was similar to NISA were obtained. In the analysis of the samples, the same detection results as the commercially available enzyme-linked immunoassay kit were obtained. These NISA and PT-NISA provide a more rapid and promising strategy for detecting food contaminants, and was expected to be used to detect other highly sensitive biological macromolecules.

Effects of Starch on the Digestibility of Gluten under Different Thermal Processing Conditions.

Gluten and starch are the primary ingredients of wheat. The complex reaction between gluten and starch will occur during thermal food processing, which will affect digestibility. The effects of proteins on the digestibility of starch have been reported, but the effects of starch on the digestibility of proteins have not been well-researched. In this paper, the effects of starch on gluten digestion during the heating process were studied by the gluten-starch simulated system, and it was found that starch can enhance gluten digestion. When the complex of 1:1 gluten-starch is heated at 100 °C, the digestibility of gluten is higher and more low-molecular-weight peptides are produced. Results from the digestibility and digestion peptide mapping of the gluten-starch complex at different conditions showed that the addition of starch during processing enhanced the digestion performance of gluten. Meanwhile, the secondary structure, intrinsic fluorescence, and microscopic structure of the gluten-starch complex were investigated to understand the mechanism of the enhancement. The digestion performance is related to the secondary structure variation during the thermal processing caused by the hydration increase and disulfide bond reduction. The gluten-starch complex spatial structure is looser than gluten after heating, which could expose more protease cleavage sites. These results suggest that starch can protect gluten from aggregation in water and destroy the spatial structure of gluten with the assistance of heating, exposing more cleavage sites and enhancing gluten digestion.

A high-sensitivity thermal analysis immunochromatographic sensor based on au nanoparticle-enhanced two-dimensional black phosphorus photothermal-sensing materials.

For the first time, a quantitative photothermal-sensing immunochromatographic sensor (PT-ICS) is described using Au nanoparticle-enhanced two-dimensional black phosphorus (BP-Au) as signal component for the photothermal-sensing antibody probe. BP-Au has good photothermal properties at 808 nm, and the photothermal conversion efficiency of the BP-Au nanosheet increased by 12.9% over the black phosphorus nanosheet alone. In addition, the antibody was more easily coupled to this nanosheet due to the good physical adsorption capacity of Au nanoparticles. We used this PT-ICS to detect veterinary antibiotics enrofloxacin (ENR), the photothermal-sensing antibody probe was competitive captured by ENR target and antigen coating on test (T) lines of the sensor. This process was exothermic under an 808 nm laser, and the thermal energy decreased as the ENR in the sample increased. This thermal energy was recorded by an infrared thermal imager or an infrared thermometer, and the concentration of the ENR residues in animal-derived foods was obtained by analyzing the temperature changes in T-lines. Under optimal conditions, the PT-ICS exhibited sensitive and specific detection of ENR from 0.03 µg/L to 10 µg/L with detection limits of 0.023 µg/L. The results agreed well with a commercial enzyme-linked-immunosorbent assay kit. This PT-ICS provided a promising strategy for the detection of ENR residues in animal-derived foods and expected to be used for the detection of other highly sensitive biomacromolecules.

Fluorometric lateral flow immunochromatographic zearalenone assay by exploiting a quencher system composed of carbon dots and silver nanoparticles.

It is found that the fluorescence of carbon dots (CD) with an emission peak at 459 nm is strongly quenched by silver nanoparticles (AgNPs) with their absorption peak at 430 nm. The finding was applied in a fluorescence quenchometric lateral flow immunochromatographic assay for detection of zearalenone (ZEN) with CDs conjugated to ovalbumin (OVA) as donor signal probe and AgNP-Ab as acceptor signal probe. The assay has an LOD of 0.1 µg·L-1 for ZEN. This is 10 times better than the respective "turn-off" AgNP-based LFIA. In case of cereal samples and their products, the LODs range from 1 to 2.5 µg·kg-1. Only minor cross reactivity is found for fusarium toxins, and no cross-sensitivity for aflatoxin B1, T-2 mycotoxin, ochratoxin A, deoxynivalenol, and fumonisin B1. The assay represents a simple, sensitive, and rapid tool for determination of ZEN in cereal samples and their products. Graphical abstract Schematic presentation of fluorescence quenching lateral flow immunochromatographic assay (FLFIA) based on carbon dots (CD) and silver nanoparticle (AgNP) fluorescence resonance energy transfer (FRET) system for the rapid high sensitive detection of zearalenone (ZEN) in cereal samples.

Three kinds of lateral flow immunochromatographic assays based on the use of nanoparticle labels for fluorometric determination of zearalenone.

Colloidal gold, quantum dots and polystyrene microspheres were used as labels in three kinds of lateral flow immunochromatographic assays (ICAs) for the detection of zearalenone (ZEN) in cereal samples. The assays allow ZEN to be quantified within 20 min. The LODs are 10 µg·L-1 of ZEN for the colloidal gold-based ICA, and 1 µg·L-1 for both the quantum dot and polystyrene microsphere based ICAs. The respective data are 60 µg·kg-1, 6 µg·kg-1 and 6 µg·kg-1, respectively, for spiked samples and cereals. Only minor cross-sensitivity occurred between ZEN and fusarium toxins, and no cross-sensitivity if found for aflatoxin B1, T-2 mycotoxin, ochratoxin A, deoxynivalenol, and fumonisin B1. LODs of the three assays are lower than the maximum limits of ZEN set by most standardization agencies. Graphical abstract Schematic presentation of three lateral flow immunochromatographic assays (ICAs) based on the use of (a) colloidal gold (CG), (b) fluorescent quantum dots (QD), and

An electrodeposited molecularly imprinted quartz crystal microbalance sensor sensitized with AuNPs and rGO material for highly selective and sensitive detection of amantadine.

In the present work, a new amantadine (AM) imprinted quartz crystal microbalance (QCM) sensor sensitized by Au nanoparticles (AuNPs) and reduced graphene oxide (rGO) material was fabricated by electrodeposition in the presence of o-aminothiophenol (o-AT) by cyclic voltammetry scanning. AuNPs and graphene, with the advantages of great chemical stability, electrical conductivity, and large surface area, show exceptionally high sensitivity. The results of different modifications of the QCM sensor fabrication process were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy. Under the optimal experimental conditions, the frequency shift of the MIP-QCM sensor showed a linear relationship with the concentration of the AM template in the range of 1.0 × 10-5 to 1.0 × 10-3 mmol L-1 with a limit of detection (LOD) of 5.40 × 10-6 mmol L-1. The imprinting factor for AM reached 7.1, the selectivity coefficient for the analogues rimantadine (RT), adamantine (AMT) and 1-chloroadamantane (CMT) were 7.3, 5.6, and 6.1, respectively. Here, a highly sensitive, selective and stable QCM sensor prepared via the imprinting approach is reported for the first time for detection of AM from animal-derived food samples.