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A magnetic beads (MBs)–assisted fluorescence aptasensing approach based on dual DNA tweezers and magnetic separation was established for the detection of ochratoxin A (OTA) and fumonisin B1 (FB1). A dual DNA tweezers structure with four ends linked with fluorophores (FAM, ROX) and quenchers (BHQ1, BHQ2) was designed, and produced the high initial fluorescence signals because of the long spatial distance between FAM and BHQ1, ROX, and BHQ2. Bio-aptamer/anti-aptamer of OTA and bio-aptamer/anti-aptamer of FB1 were respectively annealed to form dsDNA, and immobilized to MBs coated with streptavidin (SA). With the existence of OTA and FB1, OTA and FB1 preferentially bound with their respective bio-aptamers, which made anti-aptamers dissociate from dsDNA coupled on MBs. After magnetic separation, the dissociated anti-aptamers reacted with dual DNA tweezers, respectively, which made DNA tweezers close and the fluorescence was quenched. The linear ranges of approach for OTA and FB1 detection were 0.05–20 ng/mL and 0.1–40 ng/mL, respectively. The limit of detection for OTA and FB1 was 0.029 ng/mL and 0.061 ng/mL. The prepared MBs-assisted fluorescence aptasensing approach was applied to detect OTA and FB1 in spiked red wine and corn samples, which showed good recoveries between 92 and 106%. [ABSTRACT FROM AUTHOR]

In order to stabilize the whole wheat flour and extend its shelf life, microwave was employed to heat the wheat bran to inactivate the lipase in this paper. The effects of microwave heating of wheat bran on the lipase activities, gluten properties, dough properties and storage stability of the stabilized whole wheat flour, and the quality of steamed bread made of stabilized whole wheat flour were investigated. Furthermore, molecular docking was applied to interpret the mechanism. The results showed that microwave can reduce lipase activity, maintain the quality of whole wheat flour dough and steamed bread, and retard rancidity. The molecular docking results displayed that the conformation of the amino acids chains near the lipase catalytic center changed, which made the substrate difficult to enter the catalytic center and prevented the hydrolysis of the fat substrate. [ABSTRACT FROM AUTHOR]

In this work, a kind of homogeneous electrochemical aptasensor based on DNA assembly was designed to detect zearalenone (ZEN). The three DNA strands of ZEN aptamer (Apt), complementary strand DNA1, and complementary strand DNA2 are first mixed to form DNA duplex structure, which cannot be cleaved by RecJf Exonuclease (RecJf Exo) and hinders the electron transfer after addition to the electrode surface. With the existence of ZEN, the combination of ZEN and Apt destroys the duplex structure, and RecJf Exo can catalyze the cleavage of Apt to form short DNA strands, which accelerates the electron transfer after addition to the electrode surface. According to the current difference with or without ZEN, the detection purpose is achieved. The linear relationship between I and LgCZEN was found in the range of 5.0 × 10−6 ng/ml to 50 ng/ml, and the detection limit is as low as 0.51 fg/ml. The prepared sensor showed high selectivity, favorable repeatability, and reproducibility and was effectively used for testing the spiked corn flour and beer samples. [ABSTRACT FROM AUTHOR]

Vitamin D plays an important role in insulin secretion. As the enzyme that initiates degradation of the active metabolite of vitamin D (1,25-(OH)2 vitamin D), 24-hydroxylase encoded by CYP24A1 may be associated with insulin secretion. In this study, we aimed at investigating the association between copy number of CYP24A1 and the concentration of insulin. Included in the study were 1528 rural people from Henan Province of China. The copy number of CYP24A1 and the concentrations of serum 25(OH) vitamin D3 and insulin were determined. Association between copy number of CYP24A1 and vitamin D deficiency was investigated with logistic regression model. Correlation between copy number of CYP24A1 and serum insulin was observed by Spearman correlation. The results suggested that copy number variation of CYP24A1 was associated with vitamin D deficiency. Higher copy number of CYP24A1 was a risk factor for vitamin D deficiency (adjusted odds ratio: 1.199; 95% confidence interval: 1.028–1.397; P = 0.021). Furthermore, copy number of CYP24A1 was positive correlated with the concentration of serum insulin (r = 0.115; P < 0.001), regardless of vitamin D status, age, and body mass index (BMI). Increased copy number of CYP24A1 is associated with not only vitamin D deficiency but also increased serum insulin. Vitamin D supplement may be beneficial to individuals with high copy number of CYP24A1. Novelty Increased copy number of CYP24A1 was a risk factor of vitamin D deficiency. Increased copy number of CYP24A1 was associated with increased serum concentration of insulin independent of age, BMI, and vitamin D status. [ABSTRACT FROM AUTHOR]

AbstractMicroRNA (miRNA) has emerged as a promising biomarker for disease diagnosis and a potential therapeutic targets for drug development. The detection of miRNA can serve as a noninvasive tool in diseases diagnosis and predicting diseases prognosis. CRISPR/Cas12a system has great potential in nucleic acid detection due to its high sensitivity and specificity, which has been developed to be a versatile tool for nucleic acid-based detection of targets in various fields. However, conversion from RNA to DNA with or without amplification operation is necessary for miRNA detection based on CRISPR/Cas12a system, because dsDNA containing PAM sequence or ssDNA is traditionally considered as the activator of Cas12a. Until recently, direct detection of miRNA by CRISPR/Cas12a system has been reported. In this review, we provide an overview of the evolution of biosensors based on CRISPR/Cas12a for miRNA detection from indirect to direct, which would be beneficial to the development of CRISPR/Cas12a-based sensors with better performance for direct detection of miRNA. [ABSTRACT FROM AUTHOR]

Nitrogen controlled atmosphere (N-CA) was widely used to keep grains from pest infestation. However, there was few studies on the grain quality changes during re-aeration after N-CA storage, i.e. N 2 -re-aeration storage (NRAS). In this paper, quality changes of two varieties of rice (Oryza sativa L.) during NRAS was investigated. Moreover, a non-targeted metabolomics approach was employed to reveal the mechanisms of rice quality changes after NRAS. Compared with rice in conventional storage (CS), fatty acid values (FAVs) and malondialdehyde (MDA) contents of rice showed slower increase rates in NRAS before re-aeration (0–60 days), while displayed faster increase rates after reaeration (60–150 days). And NRAS had no obvious effect on pasting and texture properties of rice. Additionally, metabolisms that are sensitive to changes in storage atmosphere are screened out, such as glycine, 4-aminobutyric acid, gluconic acid, sorbitol, γ-linolenic acid and stearidonic acid. This work provided a new insight into the mechanisms of rice quality changes after NRAS and helped reserve corporation develop storage policy for rice storage. • The quality changes of rice during NRAS were studied for the first time. • FAVs and MDA contents of rice showed faster increase rates than CS after re-aeration. • Re-aeration had no obvious effect on pasting and texture properties of rice. • AntiOxidant-related metabolites significantly down-regulated after re-aeration. • The resistance of the rice to oxidative stress was weakened after re-aeration. [ABSTRACT FROM AUTHOR]

Highlights: [•] Different extraction methods affected the antioxidant activity differently. [•] Power was the key parameter in ultrasonic and microwave extraction. [•] Powers of 300W and 600W were two critical points in microwave extraction. [•] Sevag reagent combined with H2O2 was best for protein and pigment removal. [ABSTRACT FROM AUTHOR]

Abstract: In order to study the different effects of ginsenosides with similar structures, research on interactions between ginsenoside Rg1, Re and lysozyme was carried out by electrospray ionization mass spectrometry (ESI-MS) and molecular docking. The 1:1 and 2:1 noncovalent complexes of ginsenosides and lysozyme were observed in the mass spectra and the dissociation constants for them were directly calculated based on peak intensities of lysozyme and its noncovalent complexes with ginsenosides. The results showed that the 1:1 complex of ginsenoside Rg1 and lysozyme was more stable than that of ginsenoside Re and lysozyme. As the acidity increased, the stabilities of the 1:1 complexes of Rg1, Re and lysozyme both decreased. Interestingly, as the acidity increased, the stability of the 2:1 complex of Rg1 and lysozyme increased while that of Re decreased. From the result of molecular docking, ginsenosides interacted with the active sites of lysozyme. And the stability of the complexes could be affected by the conformation changes of lysozyme as acidity increased. [ABSTRACT FROM AUTHOR]

Abstract: In order to evaluate the essence of the interactions of ginsenosides and proteins which are composed by α-amino acids, electrospray ionization mass spectrometry was employed to study the noncovalent interactions between ginsenosides (Rb2, Rb3, Re, Rg1 and Rh1) and 18 kinds of α-amino acids (Asp, Glu, Asn, Phe, Gln, Thr, Ser, Met, Trp, Val, Gly, Ile, Ala, Leu, Pro, His, Lys and Arg). The 1:1 and 2:1 noncovalent complexes of ginsenosides and amino acids were observed in the mass spectra. The dissociation constants for the noncovalent complexes were directly calculated based on peak intensities of ginsenosides and the noncovalent complexes in the mass spectra. Based on the dissociation constants, it can be concluded that the acidic and the basic amino acids, Asp, Glu, Lys and Arg, bound to ginsenosides more strongly than other amino acids. The experimental results were verified by theoretical calculations of parameters of noncovalent interaction between ginsenoside Re and Arg which served as a representative example. Two kinds of binding forms, “head–tail” (“H–T”) and “head–head” (“H–H”), were proposed to explain the interaction between ginsenosides and amino acids. And the interaction in “H–T” form was stronger than that in “H–H” form. [Copyright &y& Elsevier]

Abstract: The contents of 12 ginsenosides (Rg1, Re, F11, Rf, Rg2, Rh1, Rb1, Rc, Rb2, Rb3, Rd, Rh2) in different parts and ages of Panax quinquefolius L. (American ginseng) were quantified by high pressure microwave-assisted extraction (HPMAE) high-performance liquid chromatography coupled with evaporative light scattering detection (HPLC-ELSD). The analytical method was established and analytical performances were evaluated. The chemical marker of American ginseng F11 was detected, and Rf which is the chemical marker of Asian ginseng was not found. Rare ginsenoside Rh1, Rg2 and Rh2 were also studied in this experiment. The total contents of these 12 ginsenosides in the different parts of 5-year-old American ginseng follow this order: leaf>root-hair>rhizome>root>stem. Therefore, compared with the other parts of American ginseng, the leaf is a better available source of ginsenosides. The contents of ginsenosides in root and leaf also change with age. [Copyright &y& Elsevier]

Background: Physical activity and vitamin D receptor (VDR) have been associated with type 2 diabetes mellitus (T2DM). However, the associations of VDR methylation with T2DM and physical activity remained unknown. We aimed to investigate whether VDR methylation was a link between physical activity and T2DM. Methods: A 1:1 matching case‐control study was designed based on the Henan Rural Cohort Study, including 272 pairs of T2DM patients and nonpatients. Physical activity level was assessed using the International Physical Activity Questionnaire. The high‐resolution melt method was applied to determine the methylation level of the promoter region of VDR. The association between physical activity and T2DM was analyzed with a conditional logistic regression model. The effect modification of VDR methylation levels on the association between physical activity and T2DM was conducted. A multivariate correlation analysis model was applied to investigate correlations of VDR methylation with insulin sensitivity. Results: Physical activity level was associated with T2DM risk (crude model: odds ratio [OR] 0.611; 95% CI, 0.416‐0.897; adjusted model: OR 0.619; 95% CI, 0.418‐0.917). In effect modification analysis, the effects of physical activity on T2DM were stronger for low VDR methylation levels than for high (P =.025). Moreover, VDR methylation levels were associated with insulin (r = −0.089, P =.039) as well as homeostatic model assessment of insulin resistance (r = −0.098, P =.022). Conclusions: The methylation status of the VDR promoter is associated with the secretion and sensitivity of insulin. VDR methylation attenuates the association between physical activity and T2DM, indicating that proactively physical activity may reduce the risk of T2DM, especially in people with low VDR methylation level. [ABSTRACT FROM AUTHOR]

Summary: Peanuts produce millions of tons of high‐protein peanut meal (after oil extraction) annually that can be used for food. Peanut protein, as a plant‐based protein, is a great alternative to animal protein to address protein deficiencies and rising health problems in the world. It has a high nutritional value, while the globular structure results in poor functional properties, limiting its application. Better functional properties can be obtained through processing and modification. This paper elaborates the nutritional and functional properties of peanut protein and highlights the application of peanut protein in food industry in recent years. Applications for peanut protein include meat and milk substitutes, edible films, nanoparticles, and some new technologies such as electrostatic spinning and three‐dimensional (3D) printing in recent years. This paper could improve people's understanding of the molecular structure of peanut protein and the physicochemical properties associated with the structure changes during processing. It could also contribute to better utilisation of peanut protein, providing more varieties of peanut protein products for the food industry. [ABSTRACT FROM AUTHOR]

In this study, glycosylated gluten was modified to form a glycosylated gluten covalent complex. The covalent complex then forms nanoparticles through self-assembly under heating to stabilize the Pickering emulsion. The emulsion was loaded with β-carotene to investigate its protective effects on carotene. The research findings showed the thermal and storage stability of Pickering emulsion was the best when the concentration of glycosylated gluten nanoparticles was 4 % and oil-water volume was 40 %. Under these conditions, the smallest and most uniform distribution of emulsion droplets was observed using scanning electron microscopy (SEM) and particle size analysis. Confocal laser scanning microscopy (CLSM) confirmed that the glycosylated gluten nanoparticles formed a three-dimensional network through their interactions at the oil-water interface, inhibited droplet aggregation, and increased the stability of the emulsion. Through simulated digestion in vitro, confirmed β-carotene can be well protected by the prepared Pickering emulsion. • The hydrophilicity of gluten protein was improved by glycosylation. • Glycosylated gluten is heated to form nanoparticles to stabilize Pickering emulsion. • CLSM confirmed that the nanoparticles increased the stability of the emulsion. • In vitro digestion model found that the β-carotene can be protected by the emulsion. [ABSTRACT FROM AUTHOR]

Abstract: The inclusion complex of β-cyclodextrin (β-CD) and osthole was studied by the electrospray ionization mass spectrometry (ESI-MS) and fluorescence spectrometry. From the mass spectrum, the 1:1 stoichiometric inclusion complex of β-CD and osthole was observed. The tandem mass spectrum was performed. The fluorescence intensity of osthole increased in the present of β-CD. According to the 1:1 β-CD–osthole mode, the dissociation constant (K D) was obtained by ESI-MS and fluorescence spectrometry. The K D of β-CD–osthole inclusion complex is 6.96×10−3 molL−1 obtained by mass spectrometry and that is 8.14×10−3 molL−1 obtained by fluorescence spectrometry, which is consistent with each other. [Copyright &y& Elsevier]

Abstract: The noncovalent complexes of cytochrome c and ginsenoside were studied by electrospray ionization mass spectrometry (ESI-MS). Ginsenoside Rb2 and Re were bound to cytochrome c to form several complexes with different stoichiometric relation. The 1:1 and 1:2 complexes of cytochrome c to ginsenoside were considered and the dissociation constants were obtained according to the intensities of cytochrome c and complexes when the concentrations of cytochrome c and ginsenoside have been known. Competition experiment was performed to validate the result. The K D values obtained with different reactive systems were consistent with each other. [Copyright &y& Elsevier]

Abstract Deoxynivalenol (DON), Fumonisin B 1 (FB 1) and Aflatoxin B 1 (AFB 1) have strong toxicity to humans and exist widely in grain and food. It is necessary to screen these mycotoxins to guarantee food safety. In order to develop a rapid, simple, low-cost and simultaneous-detection method, composites of antibody-nano-Au-particles, DON-BSA, FB 1 -BSA, and AFB 1 -BSA were prepared to establish a lateral flow assay based on competitive inhibition. The results suggested that the visual detection limits for DON, FB 1 and AFB 1 were 10, 30, and 10 ng mL−1, respectively. On the other hand, it had no reactivity to T-2 toxin, zearalenone, ochratoxin A and nivalenol, which demonstrates good specificity. Besides, the strip had good repeatability and stability. Therefore, DON, FB 1 and AFB 1 would be screened simultaneously by lateral flow assay for food safety. Highlights • A lateral flow assay for simultaneous detection of DON, FB 1 and AFB 1. • The visual detection limit was down to 10 ng mL−1. • The assay showed high stability and specificity. [ABSTRACT FROM AUTHOR]

Abstract: Ultrasonic nebulization extraction (UNE) coupled with on-line gas chromatography (GC) was proposed for the determination of trans-anethole in fruits of Illicium verum Hook. f. and Foeniculum vulgare Mill. The extraction was performed in a common self-made extraction system. In the UNE the analyte was transferred and enriched from the solid sample to gas phase. The sample gas containing analyte obtained by UNE was introduced into the sampling loop with the purging gas (N2). And then the sample gas in the sampling loop was introduced into the GC column. Several experimental parameters of on-line UNE-GC, including sampling time, flow rate of purging gas, standstill time and temperature of tubing, were optimized. The calibration curve ranging from 0.05 to 1.5mgg−1 for determining the trans-anethole was obtained. The recoveries for determining trans-anethole are between 99.2% and 111.2% and RSDs are less than 8.3% when the UNE was applied. The analytes can rapidly be extracted and transferred from the solid sample to gas phase. The analytes in the gas phase are easier to be introduced into GC system than those in the solid and liquid phase. Compared with off-line systems, the proposed on-line system is more suitable to detect volatile compounds. [Copyright &y& Elsevier]

Abstract: High pressure microwave assisted extraction (HPMAE) was applied to extract the ginsenosides from Panax ginseng root. The influences of extraction solvent, extraction pressure and extraction time were individually investigated. HPMAE has been compared with other extraction methods, including Soxhlet extraction, ultrasound-assisted extraction and heat reflux extraction. The determination of ginsenosides was performed by HPLC–ESI-MS. The results indicated that the HPMAE not only took a shorter time but also afforded higher extraction yields of ginsenosides, especially ginsenoside Rb1, Rc, Rb2 and Rd. Furthermore, the neutral ginsenosides and malonyl ginsenosides in Panax ginseng root extracts by HPMAE were investigated. The malonyl ginsenoside m-Rb1, m-Rc, m-Rb2 and m-Rd degraded in HPMAE at 400kPa (109–112°C) in 70%(v/v) ethanol–water and at 600kPa (112–115°C) in methanol, and transformed into corresponding neutral ginsenoside Rb1, Rc, Rb2 and Rd. Using water as extraction solution, the neutral ginsenosides degraded under HPMAE at 400kPa (135–140°C), and transformed into less polarity rare ginsenosides. [Copyright &y& Elsevier]

Abstract: The HPLC coupled with electrospray ionization mass spectrometry (ESI-MS) was applied for the determination of tributyltin chloride (TBT), triphenyltin chloride (TPhT), triethyltin chloride (TET) in textile and plastic samples. The separation was performed in the isocratic mode on ion exchange SCX column with a mobile phase containing methanol–ammonium acetate (50mmoll−1)–acetic acid (90/9.98/0.02, v/v/v). Sensitive detection of three organotin compounds by ESI-MS was performed on the basis of multiple reaction monitoring (MRM) mode. Limits of detection were 0.4, 20, 4ngml−1 for TBT, TPhT, and TET, respectively. Microwave-assisted extraction (MAE) of organotin compounds was finished in 60% (v/v) methanol aqueous solution. Under the experimental conditions used, recoveries of three organotin compounds obtained for spiked textile and plastic samples are in the range of 55–95% and the R.S.D.s are 3–9%. [Copyright &y& Elsevier]

Abstract: An apparatus for extraction of flavonoids from Herba Epimedii has been constructed which utilizes a microwave technique for heating in a dynamic mode. A TM010 microwave resonance cavity was applied to concentrate the microwave energy; the power needed to achieve efficient extraction was significantly reduced. The method has been compared with other extraction methods, such as pressurized microwave-assisted extraction (PMAE), ultrasonic extraction (UE), heat reflux extraction (RE) and Soxhlet extraction (SOX). The four flavonoids in extract were identified by HPLC–MS. The influence of extraction parameters on the extraction yield of flavonoids has been evaluated by comparison with the peak areas of HPLC-DAD spectra in the different extraction methods. The results showed that the extraction yield of flavonoids in Herba Epimedii obtained by dynamic microwave-assisted extraction (DMAE) was higher than that obtained by UE, RE and SOX, and the extraction time is dramatically reduced. The extraction yield obtained by DMAE is similar to that obtained by PMAE. But the flavonoids in Herba Epimedii would not decompose easily when increasing the extraction time in DMAE. This is the benefit of dynamic extraction system which can transfer the analytes extracted from the sample matrix with flowed fresh solvent to the out of extraction vessel. [Copyright &y& Elsevier]

Abstract: A novel technique based on dynamic microwave-assisted extraction (DMAE) coupled on-line with high-performance liquid chromatography (HPLC) through a flow injection interface has been developed for determination of andrographolide and dehydroandrographolide in Andrographis paniculata Nees. A TM010 microwave resonance cavity built in the laboratory was applied to concentrating the microwave energy. An extraction vessel was placed in microwave irradiation zone. The extraction was performed in a recirculating system. When a number of extraction cycles were completed, the fractional extract (20μL) was driven to the analytical column by 65% aqueous methanol and was measured by diode array detector (DAD) at 225nm. The optimized extraction conditions are follows: extraction solvent 60% aqueous methanol; microwave forward power 80W; extraction time 6min; extraction solvent flow-rate 1.0mLmin−1. The detection and quantification limits obtained are 0.5 and 1.7μgmL−1 for andrographolide and 0.6 and 1.9μgmL−1 for dehydroandrographolide, respectively. The within-day and between-day precision (RSD) are 2.1% and 3.7% for andrographolide and 1.7% and 4.1% for dehydroandrographolide, respectively. Mean recoveries for andrographolide and dehydroandrographolide are 97.7% and 98.7%, respectively. Compared with ultrasonic extraction used in the Chinese pharmacopoeia, the proposed method was demonstrated to obtain higher extraction yield in a shorter time. In addition, only small quantities of solvent (5mL) and sample (10mg) were required. [Copyright &y& Elsevier]

Abstract: A rapid dynamic microwave-assisted extraction and on-line detection by spectrophotometry is proposed for the determination of safflower yellow in Flos Carthami. A high pressure and a peristaltic pump were used to deliver the solvent. A TM010 microwave resonance cavity was applied to concentrate the microwave energy and the forward power about 60W was enough for the extraction. Other extraction conditions also were examined and optimized. In this work, the extraction process can be monitored by measuring the absorption of safflower yellow in the extract, which would be convenient for rapid optimization of the extraction process. The detection and quantification limits are 8 and 27μgmL−1, respectively. The within-day and between-day precision (R.S.D.) are 1.6–3.2% and 2.8–4.2%, respectively. Compared with off-line detection, the proposed method may provide more rapid measurement and is more convenient for obtaining continuous measurements. [Copyright &y& Elsevier]