Determination of Aflatoxin B1 in Grains by Aptamer Affinity Column Enrichment and Purification Coupled with High Performance Liquid Chromatography Detection.

Aflatoxin B1 (AFB1) is a highly teratogenic and carcinogenic secondary metabolite produced by Aspergillus. It is commonly detected in agricultural products such as cereals, peanuts, corn, and feed. Grains have a complex composition. These complex components severely interfere with the effective extraction and separation of AFB1, and also cause problems such as matrix interference and instrument damage, thus posing a great challenge in the accurate analysis of AFB1. In this study, an aptamer affinity column for AFB1 analysis (AFB1-AAC) was prepared for the enrichment and purification of AFB1 from grain samples. AFB1-AAC with an AFB1-specific aptamer as the recognition element exhibited high affinity and specificity for AFB1. Grain samples were enriched and purified by AFB1-AAC, and subsequently analyzed by high performance liquid chromatography with post-column photochemical derivatization-fluorescence detection (HPLC-PCD-FLD). The average recoveries of AFB1 ranged from 88.7% to 99.1%, with relative standard deviations (RSDs) of 1.4-5.6% (n = 3) at the spiked levels of 5.0-20.0 µg kg-1. The limit of detection (LOD) for AFB1 (0.02 µg kg-1) was much below the maximum residue limits (MRLs) for AFB1. This novel method can be applied to the determination of AFB1 residues in peanut, corn, and rice.

Nano­selenium functionalized chitosan gel beads for Hg(II) removal from apple juice.

The presence of potentially toxic elements and compounds poses threats to the quality and safety of fruit juices. Among these, Hg(II) is considered as one of the most poisonous heavy metals to human health. Traditional chitosan-based and selenide-based adsorbents face challenges such as poor adsorption capacity and inconvenient separation in juice applications. In this study, we prepared nano­selenium functionalized chitosan gel beads (nanoSe@CBs) and illustrated the synergistic promotions between chitosan and nanoSe in removing Hg(II) from apple juice. The preparation conditions, adsorption behaviors, and adsorption mechanism of nanoSe@CBs were systematically investigated. The results revealed that the adsorption process was primarily controlled by chemical adsorption. At the 0.1 % dosage, the adsorbent exhibited high uptake, and the maximum adsorption capacity from the Langmuir isotherm model could reach 376.5 mg/g at room temperature. The adsorbent maintained high adsorption efficiency (> 90 %) across a wide range of Hg(II) concentrations (0.01 to 10 mg/L) and was unaffected by organic acids present in apple juice. Additionally, nanoSe@CBs showed negligible effects on the quality of apple juice. Overall, nanoSe@CBs open up possibilities to be used as a safe, low-cost and highly-efficient adsorbent for the removal of Hg(II) from juices and other liquid foods.

Effects of allicin on growth performance, antioxidant profile, and microbiota compared to monensin of growing goats.

Allicin is a sulfur-containing compound extracted from raw garlic (Allium sativum L.). We compared the effect of allicin addition on growth performance, serum biochemical parameters, and rumen microbiota of goats compared to monensin. Twenty-four Anhui white goats were assigned randomly to one of three dietary treatments: 1) a basal diet (CON); 2) the basal diet with allicin addition at 750 mg per head per day (AC); 3) the basal diet with monensin addition at 30 mg per kg of diet (MS). Animals were fed for 8 weeks. Results showed the average daily gain, and feed efficiency was increased with allicin and monensin addition. Serum levels of IgG, total superoxide dismutase, and glutathione peroxidase were higher in the AC group than those in the CON and MS groups. The microbiota analysis revealed that monensin addition mainly affected genera related to carbohydrate and protein metabolism, and allicin mainly affected genera related to energy metabolism and intestinal health. In conclusion, allicin could improve growth performance and have advantages over monensin in improving the antioxidant capacity and immune function of goats. Allicin may be a potential alternative to monensin.

A perylene diimide electrochemical probe with persulfate as a signal enhancer for dopamine sensing.

Dopamine (DA) is an important biomarker related to parkinsonism, schizophrenia and renal disease. Traditional electrochemical sensors for DA were based on the direct electrochemical oxidation of DA. In this paper, we report a new sensing strategy using N,N'-di(trimethylaminoethyl)perylene diimide (TMPDI) as an electrochemical probe and K2S2O8 as a signal enhancer for DA detection between 0 and -0.7 V with the DPV technique. MoS2 nanoflowers prepared by the hydrothermal method were used as a nanocarrier to load TMPDI. The reduction current of TMPDI was found to show a stepwise and significant increase at -0.24 V with the increase of concentration of K2S2O8 due to the continuous cycle of TMPDI molecules' electrochemical reduction and chemical oxidation. The presence of DA caused a large decrease of the reduction current of TMPDI due to the synergistic interaction of the competitive consumption of DA for K2S2O8 and the blocking effect of polyDA adhering to the electrode surface. The decreased current exhibited a linear response for DA from 10 pM to 100 µM with a detection limit of 4.1 pM and the proposed sensor showed high selectivity and excellent feasibility in human urine/serum sample detection.

Enhancing the Electrical Conductivity and Strength of PET by Single-Wall Carbon Nanotube Film Coating.

Single-wall carbon nanotubes (SWCNTs) with excellent physicochemical properties are considered a promising candidate for the electrical and mechanical reinforcements of polymers. However, the poor dispersion of SWCNTs in plastics seriously limits their application and their achieved performance enhancement. Here, we coat a freestanding, highly conductive SWCNT film onto the surface of a polyethylene terephthalate (PET) film by a hot-pressing method. Due to the uniform SWCNT network structure and strong interfacial interaction, the SWCNT/PET hybrid film showed notably enhanced electrical and mechanical properties even though with a very low SWCNT weight fraction of 0.066%. The surface square resistance of the SWCNT/PET film decreased to 120-140 Ω/□ from 1016 Ω. In addition, Young's modulus and tensile strength of the SWCNT/PET film reached 4.6 GPa and 148 MPa, which are 31.3 and 24.4%, respectively, higher than the pure PET film. The SWCNT/PET film shows excellent mechanical durability and thermal stability, demonstrating its potential use as an antistatic material.

Effect of gluconic acid rinsing on cadmium decontamination from rice protein.

Cadmium (Cd) accumulation in rice protein has long been considered a significant threat to human health. In the present study, a costless and effective method based on gluconic acid (GA) rinsing of rice protein was developed to reduce Cd contamination in rice protein. Moreover, the effect of GA on the structural and functional properties of rice protein was evaluated. With liquid-solid ratio of 30 mL/g and oscillation time of 120 min, 96.0% and 93.6% of Cd were eliminated from rice protein-H and rice protein-L, respectively. In addition, the results of scanning electron microscopy, Fourier transform infrared, and sodium dodecyl sulfate polyacrylamide gel electrophoresis analyses showed that GA treatment did not significantly change the structural properties of rice protein. However, GA treatment increased foaming properties, water holding capacity, and oil holding capacity of the rice protein, without affecting its further applicability. Thus, the proposed GA rinsing method can be considered a green and efficient strategy to solve the issue brought by Cd residual contamination in rice protein. PRACTICAL APPLICATION: Given the advantages of green and efficient agriculture, gluconic acid (GA) has emerged as a powerful strategy for removing the Cd from rice protein. The method developed herein showed great potentials for applications in the manufacture of rice-based products.

Characterization of the physiochemical properties, microstructure, and molecular interactions of a novel rice-pea protein gel.

The application of rice and pea proteins in food production is limited due to their undesirable processing performance. The objective of this research was to develop a novel rice-pea protein gel using alkali-heat treatment. This gel had a higher solubility, stronger gel strength, better water retention capacity, and denser bilayer network. This is due to the alkali-heat induced modifications for the secondary structures of proteins (i.e., a decrease in the α-helix, and an increase in the ß-sheets) and the interactions between protein molecules. The network structure of gel was more compact by adding 2% and 4% alkali-heat rice protein (AH-RP). This resulted in a stable double-layer network structure of gel. Adding 4% AH-RP significantly improved the hardness and elasticity of gel. This gel will have a good potential use for being the ingredient to produce the functional foods and meat analogs.

Facile synthesis of chitosan-tartaric acid biosorbents for removal of Cu(II) and Cd(II) from water and tea beverages.

Consumption of water and tea beverages leads to the intake of heavy metals by humans. Development of technology for decontamination greatly reduces the risks of the heavy metal exposure. In this study, environment-friendly chitosan-tartaric acid biosorbents (CTBs) were synthesized by a facile one-step cross-linking strategy to mitigate the Cu(II) and Cd(II) contamination in water and tea beverages. The cross linkage of tartaric acid and chitosan endowed CTBs with excellent properties in aspects of surface roughness, mechanical strength, and acid resistance. Adsorption performance and mechanism of CTBs were studied, and the Langmuir isotherm model and pseudo-second-order kinetic model were adhered during adsorption. Up to 90 % removal efficiencies of Cu(II) and Cd(II) from water and tea beverages by CTBs were achieved. Moreover, the adsorption showed only a slight reduction in the quality of tea beverages. This study offers a new insight for reduction of heavy metals-pollution in beverages.

New insights into the persistent effect of transient cinnamaldehyde vapor treatment on the growth and aflatoxin synthesis of Aspergillus flavus.

The antimicrobial effects of continuous treatment with essential oils (EOs) in both liquid and gaseous phases have been intensively studied. Due to their rapid volatility, the effects of EOs on microorganisms after transient treatment are also worth exploring. In this work, the persistent effects of cinnamaldehyde (CA) vapor on Aspergillus flavus were detected by a series of biochemical analyses. Transcriptome analysis was also conducted to study the gene expression changes between recovered and normal A. flavus. When CA vapor was removed, biochemical analyses showed that the oxidative stress induced by the antimicrobial atmosphere was alleviated, and almost all the damaged functions were restored apart from mitochondrial function. Remarkably, the suppressed aflatoxin production intensified, which was confirmed by the up-regulation of most genes in the aflatoxin synthetic gene cluster, the velvet-related gene FluG and the aflatoxin precursor acetyl-CoA. Transcriptomic analysis also demonstrated significant changes in secondary metabolism, energy metabolism, oxidative stress, and amino acid metabolism in the recovery group. Taken together, these findings provide new insights into the mechanisms underlying the response of A. flavus to CA vapor treatment and will guide the rational application of EOs.

The effects of wheat cultivar, flour particle size and bran content on the rheology and microstructure of dough and the texture of whole wheat breads and noodles.

The rheological properties and microstructure of doughs, and the texture properties of whole wheat breads and noodles were investigated. The gluten strength of doughs were discriminated due to wheat cultivar. Reduced flour particle size led to the doughs with a stronger gluten strength (i.e., smaller C2), lower degree of starch retrogradation (i.e., smaller C5), and longer relaxation time (i.e., larger n values). Firmer crumb of breads were prepared by flours with smaller particle size. With increased bran content, the gluten strength of dough weakened (i.e., increased C2), the development and relaxation time of dough and the degree of starch retrogradation decreased (i.e., decreased C1 time, n values and C5), the dough structure became more porous, and the product texture appeared to be firmer. As such, outcomes from this research will provide a practical guidance for the bakery industry to improve the consumer acceptability of whole wheat products.

Relationship between the expression level of miRNA-4485 and the severity of depressive symptoms in major depressive disorder patients

Background and objectives: Despite the growing pieces of evidence on the relationship between the altered expression level of miRNAs and major depressive disorder (MDD), few studies have focused on the relationship between the altered expression of miRNAs and the severity of depressive symptoms. This study aimed to investigate the relationship between the expression level of miRNA-4485 and the severity of depressive symptoms in major depressive disorder (MDD) patients.MethodsEighty MDD patients without antidepressants and 45 healthy controls were placed and tested for the expression level of miRNA-4485 using quantitative RT‒PCR. At the same time, the Hamilton Depression Scale (HAMD) was used to assess depression symptoms for MDD patients. Twenty-nine out of 80 MDD patients were selected for miRNA expression level testing and symptomatology assessments before and after three weeks of treatment.ResultsThe expression level of miRNA-4485 in the MDD group was significantly overexpressed compared to that in healthy controls (P < 0.05), and the expression level of miRNA-4485 in the higher HAMD group was also much higher than that in the lower HAMD group and healthy controls (P < 0.05). The expression level of miRNA-4485 in MDD patients was negatively correlated with HAMD total score, anxiety/somatization, and bodyweight factor score (P < 0.05), accounting for 9.4%, 12.4% and 5.7%, respectively. MiRNA-4485 significantly predicted MDD and the severity of depressive symptoms (P < 0.05). Compared with that before treatment, the expression level of miRNA-4485 was significantly downregulated after treatment, while the patient's depressive symptoms were improved (p < 0.05). The improvement in depressive symptoms was positively correlated with the downregulation of miRNA-4485, which could significantly predict the effects of antidepressant treatment on MDD (P < 0.05). (AU)

Juglans mandshurica Maximowicz as a traditional medicine: review of its phytochemistry and pharmacological activity in East Asia.

OBJECTIVES: The conducted search reveals that Juglans mandshurica Maximowicz, called Manchuria walnuts, had many local uses that can be categorized into cancer, dermatosis and acesodyne. KEY FINDINGS: Various metabolites including diarylheptanoids, naphthoquinones, and flavonoids (also their glycosides) were reported as bioactive metabolites. The isolated metabolites and extracts from J. mandshurica showed different biological activity including cytotoxicity, anti-inflammation, antimelanotic, anticomplement, anti-HIV, antimicrobial and anti-obesity activity. SUMMARY: It is indicated that this review will add value to more scientific research on J. mandshurica and enhance the increased interest in the sustainable commercialization of J. mandshurica. It also leads to the validation of unverified ethnobotanical claims. Future studies on J. mandshurica would be focused to establish the links between the pharmacological activity, bioactive metabolites, and traditional uses.

Beer-derived nitrogen, phosphorus co-doped carbon quantum dots: Highly selective on-off-on fluorescent probes for the detection of ascorbic acid in fruits.

A rapid, facile and ultrasensitive fluorescence sensing system based on beer-derived nitrogen, phosphorus co-doped carbon quantum dots (N, P-CQDs) for the detection of ascorbic acid (AA) in fruits was proposed. N, P-CQDs were successfully synthesized by one-step hydrothermal method, which afforded a high quantum yield (21.7 %), and showed the fluorescence with a maximum emission wavelength of 450 nm at an excitation wavelength of 370 nm. Further, N, P-CQDs were employed as an efficient sensor for ultrasensitive Fe3+-detection at concentrations ranging from 1-20 µM and 100-300 µM, respectively. N, P-CQDs@Fe3+ showed a high sensitivity and selectivity for AA detection. A linear response range for AA was obtained from 1 to 200 µM with limit of detection of 0.84 µM was obtained for AA. The result of MTT test showed that N, P-CQDs exhibit low toxicity, providing fast, accurate and less toxic route for testing AA in the food analysis fields.

Metabonomic identification of serum biomarkers related to heat stress tolerance of sheep.

Heat stress is considered as a limiting factor for sheep production; it is necessary to screen for sheep breeds with heat tolerance. This study was to compare the serum metabolomes of Hu sheep and Dorper sheep and identify potential biomarkers related to heat stress. The results revealed that the respiratory rate, heart rate, and rectal temperature of Dorper sheep were significantly higher than those of Hu sheep. Compared to Dorper sheep, the serum activities of total antioxidant capacity and glutathione peroxidase in Hu sheep were significantly higher, while the concentration of malondialdehyde was lower. Metabolomics analysis identified 107 differential serum metabolites. The pathways enriched from the altered serum metabolites between the two breeds were mainly involved in protein metabolism, carbohydrate metabolism, and lipid metabolism. The levels of antioxidant- and energy-related metabolites were higher in the serum of Hu sheep than that of Dorper sheep; however, the levels of lipid catabolism- and inflammation-related were higher in the serum of Dorper sheep. The results indicate that Hu sheep had better heat stress resistance capability than Dorper sheep. Moreover, high levels of metabolites in the serum of Hu sheep are potential biomarkers for heat stress tolerance, including l-methionine, s-adenosylmethionine, and nicotinuric acid.

Altering functional properties of rice protein hydrolysates by covalent conjugation with chlorogenic acid.

Proteins and phenolic compounds are common components in foods that readily interact with each other to yield complexes, leading to changes in the functional properties. In this study, we investigated the effect of covalent conjugation of rice protein hydrolysates (RPH) with chlorogenic acid (CA) on the structural and functional properties of RPH. Three RPH-CA conjugates were prepared by the alkaline, enzyme, and free radical methods, respectively. Covalent conjugation decreased the content of free amino, thiol, and tyrosine groups, and increased in the amount of CA bounds from 15.23 to 21.11 nmol/mg. Moreover, the circular dichroism analysis revealed that covalent conjugation resulted in an increase of random coils. The emulsifying activity and antioxidant capacity of RPH were also improved by the covalent conjugation with CA. This work provides a better understanding of the formation of hydrolysates-chlorogenic acid conjugates, contributing to improving the functional properties of foods.

Encapsulation of selenium-containing peptides in xanthan gum-lysozyme nanoparticles as a powerful gastrointestinal delivery system.

In this study, nanoparticles (NPs) prepared with xanthan gum and lysozyme were established as a powerful delivery system for two Se-containing peptides: TSeMMM (STP) and SeMDPGQQ (SHP). NPs-STP and NPs-SHP had relatively small particle sizes (145 nm and 148 nm) and negative zeta potentials (-47 mV and -49 mV). The encapsulation efficiency of NPs-STP and NPs-SHP was determined to be 34.35% and 41.35%, respectively. The stability and antioxidant activity of Se-containing peptides were greatly enhanced due to encapsulation. NPs-STP and NPs-SHP exhibited controlled release of Se-containing peptides under in vitro gastrointestinal conditions. NPs-STP and NPs-SHP showed low toxicity and entered Caco-2 cells through clathrin-mediated endocytosis, contributing to a significant increase in the apparent permeability coefficient of STP (2.19 × 10-6 cm/s) and SHP (2.21 × 10-6 cm/s). Thus, NPs-STP and NPs-SHP are considered promising delivery systems for Se-containing peptides and have good potential applications in the food and pharmaceutical industries.

Effect of ultrasonic treatment on the stability and release of selenium-containing peptide TSeMMM-encapsulated nanoparticles in vitro and in vivo.

Rice selenium-containing peptide TSeMMM (T) with immunomodulatory functions was isolated from selenium-enriched rice protein hydrolysates. However, its biological activity is difficult to be protected in complex digestive environments. In this study, T was encapsulated within zein and gum arabian (GA) through ultrasound treatment to improve its bioactivity and bioavailability. The zein@T/GA nanoparticles were formed using ultrasonic treatment at 360 W for 5 min with a 59.9% T-encapsulation efficiency. In vitro digestion showed that the cumulative release rate of zein@T/GA nanoparticles reached a maximum of 80.69% after 6 h. In addition, short-term animal studies revealed that the nanoparticles had an effect on the levels of tissue glutathione and improved peptides' oral bioavailability. Conclusively, these findings suggest that the ultrasonicated polysaccharide/protein system is suitable for encapsulating active small molecular peptides. Furthermore, it provides a novel foundation for studying the bioavailability of active substances in functional foods.

The effects of hydrocolloids on the thermomechanical, viscoelastic and microstructural properties of whole wheat flour dough.

To use hydrocolloids for improving the breadmaking performance of whole wheat flour dough, relationships between hydrocolloid addition and dough thermomechanical, viscoelastic and microstructural properties were investigated. The responses of dough thermomechanical and viscoelastic properties to hydrocolloid addition depended on the hydrocolloid type. A power-law gel model fitted well to the linear and non-linear viscoelastic parameters, i.e., G'(ω), G''(ω) and J(t), of doughs. The model parameters gel strength (S) and exponent (n) were well indicative of hydrocolloid-induced changes in dough strength and relaxation behavior. The torque-scale mixolab parameters C2, C3 and C5, showed a good linear relationship with hydrocolloid addition. These parameters were also well correlated with S and n. Hydrocolloids played a crucial role in the modification for dough microstructure by forming a more continuous gluten network and better connection between starch granules and protein matrix.

Effect of the starch structure fermented by Lactobacillus plantarum LB-1 and yeast on rheological and thermomechanical characteristics of dough.

This study focused on exploring the structural variations of starch co-fermented by Lactobacillus plantarum LB-1 and yeast (Saccharomyces cerevisiae), and the relationship between fermented starch structure and dough characteristics. Co-fermentation resulted in the increased short chain content and crystallinity (32.07%) of starch with lower molecular weight. A higher content of fingerprint A-chains of amylopectin and fingerprint B-chains of α, ß-limited dextrin in the co-fermented starch endowed dough with excellent anti-retrogradation ability. Moreover, the co-fermented starch with higher swelling power (9.44 g/g) and solubility (20.40%) had a rough and irregular structure and many gaps in the appearance, which were conducive to binding water, thus promoting high dough elasticity and strength. These results extended the knowledge of starch structure-property relationship under the microbial activities, which may be beneficial to promote better flour products.

The facile synthesis of nitrogen and sulfur co-doped carbon dots for developing a powerful "on-off-on" fluorescence probe to detect glutathione in vegetables.

To determine the glutathione (GSH) content in vegetables, an "on-off-on" fluorescence probe was developed by a synthesis of nitrogen and sulfur co-doped carbon dots (N,S-CDs) using the microwave pyrolysis considering citric acid and L-cysteine as precursors. The fluorescence of N,S-CDs was quenched by adding Cu2+ at a concentration of 20-200 µmol/L due to the inner filter effect. The quenched fluorescence of N,S-CDs@Cu2+ system was recovered by adding the GSH at a concentration of 10-150 µmol/L due to the sulfhydryl-metal compound mechanism. By observing the GSH concentrations measured by our N,S-CDs@Cu2+ system vs. a traditional fluorescent chelating method, the two measurements provided the GSH data with a good consistence by showing the RSD range of 1.86%-2.27%. This indicates the validation and novelty of our N,S-CDs@Cu2+ system as being a powerful fluorescent probe for effectively and efficiently determining the GSH in vegetables.