Synergistic stabilization of a menthol Pickering emulsion by zein nanoparticles and starch nanocrystals: Preparation, structural characterization, and functional properties.

A Pickering emulsion was synergistically stabilised with zein nanoparticles (ZNPs) and starch nanocrystals (SNCs) to prepare it for menthol loading. After response surface optimisation of the emulsion preparation conditions, a Pickering emulsion prepared with a ZNPs:SNCs ratio of 1:1, a particle concentration of 2 wt% and a water:oil ratio of 1:1 provided the highest menthol encapsulation rate of the emulsions tested (83%) with good storage stability within 30 days. We examined the bilayer interface structure of the emulsion by optical microscopy, scanning electron microscopy, and confocal laser scanning microscopy. The results of simulated digestion experiments showed that the release rate of free fatty acid was 75.06 ± 1.23%, which ensured bioavailability. At the same time, the emulsions facilitated the slow release of menthol. Bacteriostatic studies revealed that the Pickering emulsion had a protective effect on menthol, with the most significant inhibitory effects on Escherichia coli and Staphylococcus aureus under the same conditions. Overall, this study proposes a novel approach for the application and development of l-menthol by combining it with Pickering emulsion.

Diazo-functionalised immunoelectrochemical sensor for the detection of ochratoxin a in foods.

Ochratoxin A (OTA) is a toxic fungal metabolite that is commonly found in cereals and animal feed. It is economically damaging and potentially hazardous to human health. Herein, we propose an electrochemical immunosensor for the rapid detection of OTA using anti-OTA antibodies and diazonium-functionalized, screen-printed electrodes. We attached 4-aminobenzoic acid to an electrode surface, activated the carboxyl groups on the surface with carbodiimide, and attached an antibody to the diazo layer. Subsequently, we used bovine serum protein as a blocker to prevent non-specific antigens from binding to the antibody. We evaluated the performance of the sensor by cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry. The sensor is highly specific and sensitive, has good linear responses in the range 20-200 ng/mL, a limit of detection of 0.5 ng/mL, and good recoveries of 90.5%-100.9% in spiked samples. It can be stored at 4 °C for approximately 2 weeks, and is highly stable, with a current response variation of no more than 4.6%.

Bisphenol A Exposure Interferes with Reproductive Hormones and Decreases Sperm Counts: A Systematic Review and Meta-Analysis of Epidemiological Studies.

Bisphenol A (BPA), an acknowledged endocrine disrupter, is easily exposed to humans via food packaging and container. However, a consensus has not been reached on the extent to which BPA exposure affects the reproductive system. We therefore conducted this systematic review and meta-analysis to elucidate the relationship between BPA exposure and male reproduction-related indicators. Up to October 2023, a comprehensive search was carried out in the PubMed, Embase, Cochrane and Web of Science, and 18 studies were ultimately included. ß coefficients from multivariate linear regression analyses were pooled using a random effects model. The results showed that the urinary BPA concentration was negatively correlated with the sperm concentration (ß coefficient = -0.03; 95% CI: -0.06 to -0.01; I2 = 0.0%, p = 0.003) and total sperm count (ß coefficient = -0.05; 95% CI: -0.08 to -0.02; I2 = 0.0%, p < 0.001). In addition, BPA concentrations were associated with increased sex hormone-binding globulin (SHBG) levels, increased estradiol (E2) levels, and reduced biologically active androgen levels. However, the relationship between an increased risk of below-reference sperm quality and BPA exposure was not robust. This systematic review revealed that BPA exposure disrupts reproductive hormones, reduces sperm counts and may ultimately adversely affect male reproduction.

Reduction of starch granule surface lipids alters the physicochemical properties of crosslinked maize starch.

Normal and waxy maize starches with and without removal of starch granule surface lipids (SGSLs) were crosslinked by POCl3 (0.01 %, 0.1 % and 1 %). Crosslinked starches showed lower swelling power and solubility, but higher pasting viscosity, pseudoplasticity, thixotropy, storage modulus and loss modulus. Crosslinking increased the double helical structure but decreased the crystallinity for waxy maize starch. The phosphorus content of crosslinked waxy maize starches after SGSLs removal increased, indicating SGSLs removal promoted crosslinking. SGSLs removal increased G' and G" for crosslinked waxy maize starches. SGSLs removal increased SP and solubility and decreased pasting and rheological parameters of starches. With increased POCl3 dosage, the effect of SGSLs removal on starch properties was gradually suppressed by crosslinking. Waxy and normal maize starches showed significantly different changes with crosslinking and SGSLs removal, and the presence of amylose seemed to impede the effect of crosslinking and SGSLs removal. The removal of SGSLs could extend the application of crosslinked starch in frozen foods, drinks, and canned foods as thickener and stabilizer, due to its better hydrophilicity and viscous liquid-like rheological properties. The study will assist carbohydrate chemists and food processors in developing new food products.

A ThT Derivative as Zn2+ Sensor Based on DNA G-quadruplex.

In this report, we developed a sensing strategy based on ThT-E (a ThT derivative) and DNA G-quadruplex for the label-free detection of Zn2+. In the absence of Zn2+, there was a fluorescence enhancement of ThT-E by interaction with human telomere sequence. On the addition of Zn2+, Zn2+ induced a more compact antiparallel G-quadruplex to release ThT-E, resulting in fluorescence quenching. The detection limit was 0.6996 µM, and the fluorescence intensity showed a good linear relationship with the concentration of Zn2+ in the range of 0-10 µM. This sensing strategy which only needs to mix two kinds of materials has the characteristics of label-feel, simple operation, short response time, economical and efficient.

Determination of 3-chloro-1,2-propanediol in biological samples by quick-easy-cheap-effective-rugged-and-safe extraction coupled with gas chromatography-mass spectrometry and its biodistribution in rats.

3-Chloro-1,2-propanediol is a common food contaminant, but reports on its determination in biological tissues are lacking. In the present study, a method was developed to detect 3-chloro-1,2-propanediol contents in rat tissues by quick-easy-cheap-effective-rugged-and-safe extraction and gas chromatography-mass spectrometry analysis. Biological samples were extracted with ethyl acetate and purified with adsorbents. The optimized adsorbent for each sample was selected from 4-5 combinations of N-propylethylenediamine, octadecylsilane, graphitized carbon black, strong anion exchange, and florisil. Extracted 3-chloro-1,2-propanediol was derivatized with heptafluorobutyric anhydride and subjected to gas chromatography-mass spectrometry. This method had good linearity (correlation coefficients >0.99) in the range of 2-2000 ng/g for blood, kidney, liver, testis, and brain samples. The limits of detection were under 0.8 ng/g; the limits of quantification were 2 ng/g; the recovery rates were 85%-102%; and the matrix effects were 1.98%-7.67%. This method also had good precision. The dynamic changes in 3-chloro-1,2-propanediol in rats gavaged with 20 mg/kg b.w. for 24 h were detected using this method. The 3-chloro-1,2-propanediol content in each tissue sharply increased to a peak, rapidly decreased within 2 h, and stabilized at 12 h. 3-Chloro-1,2-propanediol persisted in the kidney, testis, and liver 24 h after gavage.

Changes in quality components and antioxidant activity of peony seed soy sauce during low-salt solid-state fermentation.

BACKGROUND: In this study, the fermentation conditions of peony seed soy sauce (PSSS) koji were optimized by response surface method, and the quality components and antioxidant activity of PSSS were investigated at different low-salt solid-state fermentation stages. RESULTS: Results of response surface method showed that the optimal fermentation conditions were 460.6 g kg-1 water content, 48.6 h culture time, 31.5 °C culture temperature and ratio 2.1:1 (w/w) of peony seed meal:wheat bran, with the highest neutral protease activity (2193.78 U g-1 ) of PSSS koji. PSSS had the highest amino acid nitrogen (7.69 g L-1 ), salt-free soluble solids (185.26 g L-1 ), total free amino acids (49.03 g L-1 ), essential free amino acids (19.58 g L-1 ) and umami free amino acids (16.64 g L-1 ) at 20 days of fermentation. The highest total phenolics were 5.414 g gallic acid equivalent L-1 and total flavonoids 0.617 g rutin equivalent L-1 , as well as the highest DPPH radical scavenging activity (86.19%) and reducing power (0.8802, A700 ) of PSSS fermented at 30 days. Sensory evaluation showed that fermentation of 20 days and 25 days could produce a better taste and aroma of PSSS than 15 days and 30 days. CONCLUSION: PSSS had the highest quality components in the middle of fermentation (20 days) and the highest antioxidant activity in the late fermentation period (30 days). These results demonstrated that peony seed meal could be used to produce high-quality soy sauce with high antioxidant activity. © 2023 Society of Chemical Industry.

Encoding CsPbX3 perovskite quantum dots with different colors in molecularly imprinted polymers as fluorescent probes for the quantitative detection of Sudan I in food matrices.

All-inorganic cesium lead halides (CsPbX3, X  = Cl, Br, I) perovskite quantum dots (PQDs) have attracted extensive research attention due to their unique optical properties. However, their instability and sensitivity to air and moisture hinder further use in fluorescent sensing applications. In this work, the construction and application of PQDs encoded molecularly imprinted polymers (MIPs-CsPbX3) for Sudan I detection were proposed. After being encoded the PQDs, the obtained MIPs-CsPbX3 microspheres exhibited high stability for the external environment, remarkable bright fluorescence, and specific recognition for Sudan I. The fluorescent intensity of the MIPs-CsPbX3 microspheres was obviously quenched upon loading Sudan I, and good linear responses in the range of 0.5-150 µg L-1, limit of detection of 0.3 µg L-1, and good recoveries of 95.27 % to 105.96 % in spiked samples were obtained. The developed fluorescent probe provided a selective and sensitive quantified method for Sudan I detection in food matrices.

Influencing Factors of Porosity and Strength of Plant-Growing Concrete.

A standardized preparation process is proposed in this study for achieving optimal strength and vegetative properties in vegetated concrete, using Yunnan red soil as a growth substrate for plants. The porosity of vegetated concrete is a crucial factor influencing plant growth, while compressive strength is a significant mechanical property. To assess the strength and porosity of vegetated concrete, different design porosities (22%, 24%, 26%, 28%) and cement-to-aggregate ratios (4, 5, 6, 7) were utilized in the preparation of vegetated concrete samples. The shell-making and static-pressure-molding methods were optimized for specimen preparation. Analyzing the stress-strain full curve characteristics of vegetation-type concrete under different influencing factors, an in-depth investigation into its failure mechanism was conducted. It was determined that the design porosity and cement content significantly impact the concrete's performance, particularly in terms of 30-day compressive strength and effective porosity. Furthermore, an increase in the fly ash ratio led to an increase in porosity and a decrease in compressive strength, providing a certain guidance for optimizing concrete performance. Comparative analysis through vegetation experiments revealed that black rye grass exhibited favorable growth adaptability compared to other grass species.

Antioxidant Activity, Functional Properties, and Cytoprotective Effects on HepG2 Cells of Tree Peony (Paeonia suffruticosa Andr.) Seed Protein Hydrolysate as Influenced by Molecular Weights Fractionation.

In recent years, plant protein hydrolysates have gained increased attention due to their superior antioxidant activity and potential to prevent several chronic diseases associated with oxidative stress. This study aimed to investigate the antioxidant activity, functional properties, and cytoprotective effects of the tree peony seed protein hydrolysate (TPSPH) with different molecular weights (MWs). The antioxidant activities were evaluated by DPPH, hydroxyl radicals scavenging, Fe2+ chelating, and inhibition of the ß-carotene oxidation abilities. The protective effects and mechanism against oxidative stress were determined using H2O2-stressed HepG2 cells. MW > 30 kDa of TPSPH showed the highest radical scavenging (DPPH IC50 = 0.04, hydroxyl IC50 = 0.89 mg/mL) and inhibition of ß-carotene oxidation (80.07% at 2.0 mg/mL) activity. Moreover, MW > 30 kDa possessed high hydrophobicity, emulsifying capacity, and abundant antioxidant amino acids (28.22% of hydrophobic amino acids and 8.3% of aromatic amino acids). MW 5−10 kDa exhibited more effective protection against H2O2-induced HepG2 cells, by reducing reactive oxygen species (ROS), malonaldehyde (MDA), lactate dehydrogenase (LDH), and activating antioxidant enzymes (superoxide dismutase and catalase). These results indicated the potential application of TPSPH as an antioxidant in food and functional foods.

Removal of starch granule-associated surface and channel lipids alters the properties of sodium trimetaphosphate crosslinked maize starch.

Starch granule-associated surface and channel lipids (SGALs) were effectively removed from waxy maize starch (WMS) and normal maize starch (NMS), then the starches were crosslinked by different levels of sodium trimetaphosphate (STMP) (0.25 %, 0.5 %, 1 % and 2 %). The effective removal of SGALs and successful crosslinking, were evidenced by the disappearance of surface-fluorescence and channel-fluorescence of Pro-Q Diamond-stained granules, and the increased phosphorus content respectively. STMP crosslinking increased peak and final viscosity for WMS and NMS. Crosslinking at high STMP levels (0.5 %, 1 % and 2 %) transformed the starch pastes from thixotropic to anti-thixotropic. STMP crosslinking significantly decreased the tan δ values of maize starches, enhancing the elastic structure of the gel. Crosslinked maize starches without SGALs had lower breakdown than crosslinked starches at same STMP level, indicating higher tightened crosslinked starch granules after SGALs removal. Removal of SGALs increased the anti-thixotropy of crosslinked starches, facilitating the reorientation of crosslinked amylopectin/amylose molecules during shearing. Removal of SGALs increased the tan δ values from frequency sweep of WMS and NMS during STMP crosslinking, indicating the presence of surface-lipids and channel-lipids could enhance the elastic gel network structure of crosslinked maize starch.

Physicochemical, functional and antioxidant properties of mung bean protein enzymatic hydrolysates.

This study aimed to investigate physicochemical, functional and antioxidant properties of mung bean protein (MBP) enzymatic hydrolysates (MBPEHs) by alcalase, neutrase, protamex, flavourzyme and papain. Physicochemical properties were evaluated by SDS-PAGE, particle size distribution, FTIR, ultraviolet visible and fluorescence spectrophotometries. ABTS, hydroxyl scavenging, Fe2+ chelating activity were used to evaluate antioxidant activity. Enzymolysis with five proteases decreased average particle size, α-helix, ß-sheet, surface hydrophobicity of hydrolysates. Alcalase hydrolysate had the highest degree of hydrolysis (23.55%), absolute zeta potential (33.73 mV) and the lowest molecular weight (<10 kDa). Protamex and papain hydrolysates had higher foaming capacities, emulsification activity indexes, emulsion stability indexes (235.00%, 123.07 m2/g, 132.54 min; 200.10%, 105.39 m2/g, 190.67 min) than MBP (135.03%, 20.03 m2/g, 30.88 min). Alcalase hydrolysate demonstrated the lowest IC50 (mg/mL) in ABTS (0.12), hydroxyl (2.98), Fe2+ chelating (0.22). These results provide support for application of MBPEHs as foaming agent, emulsifier and antioxidant in food industry.

Influence of ultrasound treatment on the physicochemical and antioxidant properties of mung bean protein hydrolysate.

This study aimed to investigate influence of ultrasonic treatment on physicochemical and antioxidant properties of mung bean protein hydrolysate (MPH). Physicochemical properties of MPH were evaluated by Tricine-SDS-PAGE, particle size distribution, fourier transform infrared spectroscopy (FTIR) and fluorescence spectroscopy, among others. Radicals scavenging activities of ABTS, hydroxyl, superoxide anion, Fe2+ chelating ability and reducing power characterized antioxidant activities of MPH. MPH contained four bands of 25.6, 12.8, 10.6 and 4.9 kDa, in which 4.9 kDa was the most abundant. Ultrasonic treatment increased the contents of aromatic and hydrophobic amino acids in MPH. Ultrasonic treatment decreased the content of α-helix of MPH and increased ß-sheet and ß-turn compared to MPH. MPH-546 W (ultrasonic treatment 546 W, 20 min) had the lowest average particle size (290.13 nm), zeta potential (-36.37 mV) and surface hydrophobicity (367.95 A.U.). Antioxidant activities of ultrasonicated-MPH increased with the ultrasonic power, achieving the lowest IC50 (mg/mL) of 0.1087 (ABTS), 1.796 (hydroxyl), 1.003 (superoxide anion) and 0.185 (Fe2+ chelating ability) in 546 W power. These results indicated ultrasonic treatment would be a promising method to improve the antioxidant properties of MPH, which would broaden the application scope of MPH as bioactive components in the food industry.

Selective recognition of tetracycline residues in animal derived samples based on molecularly imprinted microspheres from silica-stabilised Pickering emulsion polymerisation.

Novel molecularly imprinted polymers for selective binding of tetracyclines were synthesised through oil-in-water Pickering emulsion polymerisation with SiO2 particles as stabilisers. The products were used for solid phase extraction coupled with high-performance liquid chromatography to detect trace tetracycline and oxytetracycline in animal-derived samples. The SPE materials were characterised in detail by Fourier transform infrared spectrometry, scanning electron microscopy and thermogravimetry analysis. The imprinted polymers displayed high adsorption capacity, fast binding process and high selectivity through evaluation of adsorption performance employing kinetic, static adsorption and selectivity experiments. Under optimum detection conditions, good linearity (12 to 121 µg kg-1) and limits of detection (1.8 to 1.9 µg kg-1) for tetracyclines were obtained. In addition, satisfactory recoveries of 75% to 115 % were also achieved by spiking tetracyclines into milk, chicken, fish and pork samples, giving direct evidence of real practicality of our proposed separation method.

Climate change affected the spatio-temporal occurrence of disasters in China over the past five centuries.

Climate change may contribute to the spatio-temporal occurrence of disasters. Long-term studies of either homogeneous or heterogeneous responses of historical disasters to climate change are, however, limited by the quality and quantity of the available proxy data. Here we reconstruct spatio-temporal patterns of five types of disasters in China during the period AD 1368-1911. Our analyses of these time series reveal that warmer temperatures decreased the occurrence of disasters in the monsoon-affected parts of central-east China, but it increased the frequency and intensity of disasters along the boundary of arid and humid conditions in parts of southwest and northeast China, probably driven by the interplay among monsoon, westerlies, polar vortex and variation of temperature. Moreover, we show that drought and flood events had cascading effects on the occurrences of locust outbreaks, famine and human epidemics. Our findings suggest that climate can contribute to the spatio-temporal occurrence of disasters, and therefore may contribute to an improvement of China's regional to national risk management of future climate and environmental change.

Development of hydrophilic magnetic molecularly imprinted polymers for the dispersive solid-phase extraction of sulfonamides from animal-derived samples before HPLC detection.

Highly hydrophilic magnetic molecularly imprinted polymers were prepared through a surface imprinting technique for dispersive solid-phase extraction coupled with high-performance liquid chromatography to detect trace levels of ten sulfonamides in animal-derived samples. The obtained imprinted polymers were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and adsorption experiments, which exhibited excellent specific adsorption for template sulfamethazine in aqueous solution. Moreover, the adsorption process could be completed within 25 min. Under the optimum conditions, the method exhibits good linear performance in the range of 5-to 10 mg/L, limits of detection ranging from 0.57 to 1.50 µg/L, and good recoveries of 85.09-110.93% in the spiked samples (chicken, cow milk, and goat milk). The proposed detection method not only avoids the use of organic solvents but also simplifies the pretreatment procedure via excellent magnetic properties. Furthermore, the method shows great potential for the rapid detection of drug residues.

Physicochemical properties and antioxidant activities of tree peony (Paeonia suffruticosa Andr.) seed protein hydrolysates obtained with different proteases.

The physicochemical and antioxidant properties of tree peony seed protein (TPSP) hydrolysates by Alcalase, Neutrase, Papain, Protamex, and Flavourzyme were investigated in this study. The physicochemical properties were characterized by SDS-PAGE, particle size distribution, fourier transform infrared and fluorescence spectroscopy etc. The antioxidant activities were determined by DPPH radical, ABTS radical, Fe2+ chelating, and reducing power. The results showed five proteases produced hydrolysates with a significantly reduced average particle size, α-helices, and surface hydrophobicity compared to TPSP. Alcalase and Neutrase hydrolysis enhanced the nutritional value of the hydrolysates. Alcalase hydrolysates possessed the highest degree of hydrolysis (27.97%) and lowest molecular weight (<13 kDa) with average particle size (231.33 nm). Alcalase hydrolysate displayed the highest radical scavenging (DPPH IC50 = 0.18 mg/mL, ABTS IC50 = 1.57 mg/mL), Fe2+ chelating activity (IC50 = 0.99 mg/mL), and reducing power (0.594). These results provide the fundamentals for TPSP hydrolysates as antioxidants to be employed in food industry or pharmaceutical industry.

The cell structure damage and embden-meyerhof-parnas pathway inhibition of Listeria monocytogenes induced by glycinin basic peptide.

Glycinin basic peptide (GBP) is a natural antibacterial peptide. This study aimed to explore the antibacterial characteristics of GBP against Listeria monocytogenes (L. monocytogenes) by measuring the membrane potential, membrane permeability, cell damage, morphological changes, respiration metabolism inhibition and DNA content. GBP increased the surface zeta potential and decreased the trans-membrane potential of L. monocytogenes in a dose-dependent manner. Compared with the control, the electrical conductivities of GBP-treated bacterial suspensions were significantly increased. The percentages of bacteria with damaged membrane increased from 6.40% to 70.90% with GBP from 0 to 0.8 mg/mL. Obvious rupture and deform of bacterial cells with GBP were observed by transmission electron microscope (TEM), showing the destructive effect of GBP on L. monocytogenes. GBP also inhibited the embden-meyerhof-parnas pathway of the bacterial respiration metabolism and reduced the activities of its key regulator enzymes. Besides, the content of DNA in GBP-treated L. monocytogenes was lower than that in control.

Extraction of tetracycline in food samples using biochar microspheres prepared by a Pickering emulsion method.

We report for the first time the use of biochar as a stabilizer for oil-in-water (o/w) Pickering emulsion. The emulsion is subsequently used to prepare tetracycline-imprinted biochar composite microspheres (MIPMs) with tailored sizes and good uniformity. The adsorption properties of tetracycline to the MIPMs were investigated using different adsorption experiments including adsorption kinetic experiment, equilibrium binding experiment, selectivity evaluation and competitive adsorption tests. The MIPMs were used as adsorbent for solid phase extraction (SPE) for the extraction of tetracycline present in drinking water, fish, and chicken samples. Under optimal conditions, the results showed good recovery yield ranging from ~73% to ~95% with a relative standard deviation (RSD) ranging from ~0.3% to ~8.4%, respectively.

Preparation of polydopamine-coated, graphene oxide/Fe3 O4 - imprinted nanoparticles for selective removal of sulfonylurea herbicides in cereals.

BACKGROUND: Sulfonylureas are potentially toxic broad-spectrum herbicides. They pose a persistent threat to food safety and the environment. It is therefore important to develop a rapid and efficient pretreatment and detection method to prevent their harmful effects on human health. RESULTS: In the present work, a novel and highly selective absorbent for chlorosulfuron (CS) detection was prepared by the simple self-polymerization of dopamine on the surface of magnetic graphene oxide using a CS template. The resultant imprinted nanoparticles (MGO@PDA-MIPs) were characterized by transmission electron microscopy, X-ray diffraction, vibrating-sample magnetometry, thermogravimetric analysis, and nitrogen adsorption-desorption. The adsorption experiments demonstrated that the MGO@PDA-MIPs have excellent selectivity with regard to CS, with a high imprinting factor of 3.41 compared with a non-imprinted polymer. The nanoparticles rapidly achieve adsorption equilibrium and efficient desorption because there are numerous binding sites on the thin polydopamine imprinting layer. Under optimized conditions, the MGO@PDA-MIPs can be used to detect sulfonylurea residues in cereal samples by magnetic solid phase extraction coupled with high performance liquid chromatography (HPLC). The nanoparticles have a satisfactory recovery rate (80.65-101.01%) with a relative standard deviation (RSD) of less than 7.15%, and a limit of detection with regard to CS of 1.61 µg kg-1 (S/N = 3). They can also be re-used at least seven times. CONCLUSION: The MGO@PDA-MIPs have outstanding recognition performance, and can be prepared by a facile, single-step, and environmentally friendly process. They therefore have excellent potential for the recognition and separation of trace sulfonylurea herbicides in complex matrices. © 2020 Society of Chemical Industry.