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An ultrasensitive biosensing platform for DNA and ochratoxin A (OTA) detection is constructed based on the luminescence quenching ability of fullerenol quantum dots (FOQDs) for the first time. As the surface of FOQDs is largely covered by hydroxyl groups, stable colloidal suspension of FOQDS in aqueous solution can be obtained, which is very advantageous for application in biosensing compared to nano-C60. FOQDs can effectively quench the fluorescence of dyes with different emission wavelengths that are tagged to bioprobes to an extent of more than 87% in aqueous buffer solution through a PET mechanism. Moreover, the nonspecific quenching of the fluorescent dyes (not bound to bioprobes) caused by FOQDs is negligible, so the background signal is extremely low which is beneficial for improving the detection sensitivity. Based on the π–π stacking interaction between FOQDs and bioprobes, such as single-stranded (ss) DNA and aptamers, a nucleic acid assay with a detection of limit of 15 pM and a highly sensitive OTA assay with a detection limit of 5 pg mL−1 in grape juice samples are developed through the simple “mix and measure” protocol based on luminescence quenching-and-recovery. This is the first demonstration of constructing biosensors utilizing the luminescence quenching ability of FOQDs through a PET mechanism, and the pronounced assay performance implies the promising potential of FOQDs in biosensing.

Volatile flavor components are critical to edible oils and influence consumption choice. Meanwhile, volatile organic compounds (VOCs) in edible oils are also potential biomarkers to detect adulterated products. However, VOCs are usually complex, unstable, and easily influenced by oil processing and even analysis conditions. Here, we report headspace solid-phase microextraction for comprehensive two-dimensional gas chromatography mass spectrometric analysis of VOCs in edible oils as being optimized and validated using central composite design (CCD). The results indicated that the optimal extraction conditions are as follows: SPE column of divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS), equilibration time of 10.3 min, and extraction time of 19.6 min at 120 °C. This method could analyze edible oils to identify characteristic flavor components. As a result, 25 VOC tags were identified and used to characterize soybean oils. Chemometric methods were used to discriminate the authentic sesame oils from those adulterated with soybean oil. The results indicated that this method is an effective approach to measure VOCs in edible oils; such measurements can report counterfeit products.

Aspergillus flavus can easily infect major agricultural products and produce aflatoxin. In this study, we investigated the effect of the biocontrol bacterium Enterobacter cloacae 3J1EC on the growth of A. flavus strain 3.4408. The biocontrol bacterium played a key role in preventing infection by A. flavus. E. cloacae 3J1EC was found to inhibit the growth of A. flavus 3.4408 mycelial pellets and reduce the production of aflatoxin by 96.9%. We found differential expression between the control and the treatment groups in the transcriptome of A. flavus 3.4408. Gene ontology (GO) analysis indicated that E. cloacae 3J1EC induced the down-regulated expression of cellular component and molecular function, while its effects on the up-regulated expression indicated the relationship of biological process and molecular function. Thus, these results suggest that E. cloacae 3J1EC decreased aflatoxin production via down-regulated gene expression in terms of aflatoxin biosynthesis. In summary, E. cloacae 3J1EC can be employed as an alternative for the biological control of A. flavus 3.4408.

The synergistic effects of chain length, functional group position, and equivalence ratio on the combustion and emission characteristics of lower alcohols were investigated in a constant volume ves...

This study was conducted to determine the nutritional composition [acid detergent fibre (ADF), neutral detergent fibre (NDF), ether extract (EE) and crude protein (CP)], digestible energy (DE) and metabolizable energy (ME) of rapeseed meals (RSM) differing in glucosinolates (GLS) contents fed to growing pigs. One hundred and thirty-eight crossbred barrows with initial body weight (BW) of 39.0 ± 1.9 kg were allotted to 1 of 23 diets. Results showed that the content of GLS in RSM ranged from 1.72 to 62.94 mol/g DM with a coefficient of variation (CV) of 89%. The concentration of ADF ranged from 22.78 to 35.71% with a mean of 28.79% [DM (CV = 16.22%)]. The concentration of ether extract (EE) ranged from 1.42% to 14.55% with a mean of 7.78% [DM (CV = 45.16%)]. DE and ME values of the 22 RSM ranged from 10.10 to 15.42 MJ/kg DM and 9.09 to 14.94 MJ/kg DM (P

The simultaneous quantification of trace and micro metabolites is a bottleneck in food and biological analysis. Phenolic compounds are the most widely distributed and have various physiological functions. In this study, the strategy for the simultaneous liquid chromatography tandem-mass spectrometry (LC-MS/MS) quantification of 13 trace and micro phenolic compounds was proposed by taking product ions and isotopic ions as quantitative ions. The method validation results showed that the limits of detection (LODs) were from 0.01 to 9.84 μg/kg, and the limits of quantification (LOQs) were from 0.03 to 32.8 μg/kg. The intra-day precision and inter-day precision were below 8.4% and 14.4%, respectively. The recoveries ranged from 81.9% to 117.2%, and the matrix effects ranged from −11.5% to 13.7%, which indicated that the method has high sensitivity and suitable stability. The developed analytical method was applied to determine trace and micro constituents in rapeseed samples. The analysis results indicated that the contents of sinapine have significantly different between high and low total phenolic content rapeseeds. This method provides a reference strategy for the simultaneous quantitative analysis of other micro- and trace antioxidants.

Simultaneous determination of 19 phenolic compounds in oilseeds was performed using liquid chromatography tandem mass spectrometry (LC-MS/MS) combined with magnetic solid phase extraction (M-SPE). Magnetic graphene (Fe3O4-r-GO) was synthesized via a one-step hydrothermal method. The optimum extraction conditions were 4 mg Fe3O4/r-GO, 2 mL of 5% methanol-water as the dispersing solvent, and 6 mL of 0.1% formic acid-methanol as the elution solvent. The limits of detection and quantification were 0.02–90.00 μg/kg and 0.06–300.00 μg/kg respectively, and the recoveries of polyphenols in the oilseeds ranged from 70.5% to 116.6%; both the inter-day and intra-day precisions were less than 10.8%. This method is efficient, sensitive, and stable, therefore it can simultaneously determine these 19 phenolic compounds in oilseeds.

Using ethyl paraben as the template molecule and n-tetrabutyl titanate as the titanium source, the molecularly imprinted titanium dioxide (MIP-TiO2) photocatalyst was prepared by the sol-gel method. The effects of different pH values, imprinting molecular weights and other factors on the degradation of ethyl paraben were studied, and the materials were analyzed by TEM, XRD, FT-IR and other characterization methods. The results show that the catalyst has a mixed crystal structure in which anatase and rutile ore coexist, and the rutile ore content of MIP-TiO2 is calculated to be 78.5%. Catalytic degradation of ethyl paraben by reacting for 40 min under ultraviolet light, the removal rate of ethyl paraben by pure TiO2 is 80.74%, and the removal rate of ethyl paraben by MIP-TiO2 can reach 96.27%. MIP-TiO2 is 15.53% higher than TiO2. MIP-TiO2 has imprinting holes, which can target the target pollutants and effectively improve the selectivity of the photocatalyst MIP-TiO2. The selectivity factor of MIP-TiO2 is 1.69 times that of TiO2.

Sesame oil is a traditional and delicious edible oil in China and Southeast Asia with a high price. However, sesame oil essence was often illegally added to cheaper edible oils to counterfeit sesame oil. In this study, a rapid and accurate headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) method was proposed to detect the counterfeit sesame oil where the other cheap oils were adulterated with essence. Combined with chemometric methods including principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA) and random forest (RF), authentic and counterfeit sesame oils adulterated with sesame essence (0.5%, w/w) were easily separated into two groups. More importantly, 2-methylbutanoic acid, 2-furfurylthiol, methylpyrazine, methional, and 2,5-dimethylpyrazine were found to be markers of sesame essence, which were used to directly identify the sesame essence. The determination of volatile compounds based on HS-GC-IMS was proven to be an effective method for adulteration detection of essence in sesame oil.

Rapeseed (Brassica napus L.) is rich in phenols, vitamins, carotenoids, and mineral elements, such as selenium. Additionally, it contains the active ingredients sulforaphane and indole-3-carbinol, which have been demonstrated to have pharmacological effects. In this study, sulforaphane and indole-3-carbinol were extracted and quantified from rapeseeds using quick, easy, cheap, effective, rugged and safe (QuEChERS) method coupled with ultra high performance liquid chromarography tandem mass spectrometry (UHPLC-MS/MS). The major parameters for extraction and purification efficiency were optimized, including the hydrolysis reaction, extraction condition and type and amount of purification adsorbents. The limit of detection (LOD) and the limit of quantification (LOQ) for sulforaphane were 0.05 &mu, g/kg and 0.15 &mu, g/kg, and for indole-3-carbinol were 5 &mu, g/kg and 15 &mu, g/kg, respectively. The developed method was used to successfully analyze fifty rapeseed samples. The QuEChERS coupled with UHPLC-MS/MS simultaneously detect sulforaphane and indole-3-carbinol in vegetable matrix and evaluate the quality and nutrition of rapeseed samples.

Aflatoxins, highly toxic and carcinogenic to humans, are synthesized via multiple intermediates by a complex pathway in several Aspergilli, including Aspergillus flavus. Few analytical methods are available for monitoring the changes in metabolite profiles of the aflatoxin biosynthesis pathway under different growth and environmental conditions. In the present study, we developed by a D-optimal mixture design a solvent system, methanol/dichloromethane/ethyl acetate/formic acid (0.36/0.31/0.32/0.01), that was suitable for extracting the pathway metabolites. The matrix effect from dilution of cell extracts was negligible. To facilitate the identification of these metabolites, we constructed a fragmentation ion library. We further employed liquid chromatography coupled with high-resolution mass spectroscopy (UHPLC-HRMS) for simultaneous quantification of the metabolites. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.002-0.016 and 0.008-0.05 μg/kg, respectively. The spiked recovery rates ranged from 81.3 to 100.3% with intraday and interday precision less than 7.6%. Using the method developed to investigate the time-course aflatoxin biosynthesis, we found that precursors, including several possible toxins (with a carcinogenic group similar to aflatoxin B1), occurred together with aflatoxin, and that production increased rapidly at the early growth stage, peaked on day four, and then decreased substantially. The maximum production of aflatoxin B1 and aflatoxin B2 occurred 1 day later. Moreover, the dominant branch pathway was the one for aflatoxin B1 formation. We revealed that the antiaflatoxigenicity mechanism of Leclercia adecarboxylata WT16 was associated with a factor upstream of the aflatoxin biosynthesis pathway. The design strategies can be applied to characterize or detect other secondary metabolites to provide a snapshot of the dynamic changes during their biosynthesis.

Delamination of layer semiconductor materials into two-dimensional sheets can bring superior properties such as surface area, intrinsic carrier mobility and band structure. In this study, inerratic nanosized graphitic carbon nitride (g-C3N4) sheets with the lateral size of approximately 100 ± 50 nm are conveniently fabricated by ultrasonic exfoliation of bulk g-C3N4 that derived from thermolysis of dicyandiamide after recrystallization. The nanosized g-C3N4 sheets exhibit excellently higher photocatalytic performance toward aflatoxin B1 (AFB1) degradation under visible light than that of bulk g-C3N4. And the enhanced photocatalytic mechanisms are mainly due to the better photogenerated charges separation and larger surface area of nanosized g-C3N4 sheets, which are systematically confirmed by physicochemical and photoelectric characterization. Through identification of products structure, it is found that the initial photodegradation intermediate (C17H14O7) or main products (C14H16O4 and C12H10O4) of AFB1 after 2 h irradiation over bulk g-C3N4 and nanosized g-C3N4 sheets are different, which may be attributed to the photoactivities and number of active groups from both catalysts during photoreaction. Therefore, this work may provide referential information for preparation of inerratic nanosized sheets and understand the related photodegradation mechanism of aflatoxin B1.

A method based on comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOF/MS) was developed to analyze steroidal compounds in vegetable oils, which could provide better separation and higher sensitivity than conventional one dimensional gas chromatography, and allowed determination of 31 sterols and triterpene alcohols in one injection. Furthermore, the approach also permitted separation and detection of small amounts of other compounds (may be steroidal compounds whose molecular structures have not been confirmed), which were obscured in the lower-resolution single-column technique. With the help of the GC × GC system, a more elaborate and complete information regarding the distributions and concentrations of free phytosterols and triterpene alcohols in safflower seed oil, soybean oil, rapeseed oil, sunflower seed oil and peanut oil were obtained. The proposed method could potentially open a new opportunity for the more in-depth knowledge of the steroidal compounds of vegetable oils.

Background With a continuous increase in population and economic development, the demand for high quality seed oils keeps increasing in China. In the last decades, many minor edible oils become increasing and popular. Scope and approach In this review, the chemical composition and nutritional properties of minor edible oils, including flaxseed oil, corn oil, rice bran oil, camellia oil, safflower oil, almond oil, grape seed oil, walnut oil, perilla seed oil, pumpkin seed oil, evening primrose oil, Eucommia ulmoides Oliver seed oil, penoy seed oil, sea buckthorn seed oil, Acer truncatum Bunge seed oil, Torreya grandis seed oil and tomato seed oil, were summarized. The characteristic chemical compositions of these 17 kinds of minor edible oils were analyzed from fatty acid composition, phytosterols, tocopherols, total phenolic content, squalene and β-carotene contents. Key findings and conclusions Different types of vegetable oils have their own specific advantages and biological activities, and appropriate vegetable oils can be selected to meet individual needs accordingly. For example, Acer truncatum Bunge seed oil contains 5.52% nervonic acid (C24:1) that can promote the repair and regeneration of nerve cells and tissues damaged, while corn oil and rice bran oil have higher contents of campesterol and total phytosterol and might be therefore better choices for patients with high cholesterol and cardiovascular diseases. This review could benefit comprehensive understanding nutritional values of minor vegetable oils and future researches on nutrition and product development.

Peanut is an important resource of edible oil and digestible protein in daily life, which is rich in the nutriments and antioxidants such as vitamins, minerals and polyphenols. However, peanut is susceptible to the contamination of Aspergillus flavus (A. flavus), which can produce highly carcinogenic toxins that brings serious threats to human health and food safety. Exploring green and effective methods to control A. flavus is meaningful. Herein, a green and economical way to control A. flavus on peanuts was demonstrated. It was found that the growth of A. flavus hyphae and germination of its spores could be inhibited in the presence of α-Fe2O3 nanorods under sunlight irradiation according to the agar diffusion method, flat colony counting method and fluorescence-based live/dead test. The diameter of inhibition zone was 22.3 ± 0.2 mm and the inhibition rate of spores germination was about 60 ± 5%, when the concentration of α-Fe2O3 was 10 mg/mL for 7 h sunlight irradiation. Most important, α-Fe2O3 showed the photocatalytic inhibition of A. flavus on peanuts under sunlight irradiation with the inhibition rate of about 90 ± 5%, and the production of aflatoxin B1 and aflatoxin B2 were reduced by 90 ± 2% and 70 ± 3%, respectively. By comparing the fat contents, protein contents, acid value, peroxide value and antioxidative compositions of peanuts, it was found that there was no obvious effect on the quality of peanuts after inhibition treatment. The findings provide a green, safe and economical strategy to control A. flavus on peanuts, which may be as a promising way to be used in food and agro-food preservation.

Aspergillus flavus can cause crop loss and produce mycotoxin that bring serious threats to human health. The large usage of chemical pesticides or fungicides might cause environmental problems and fungal resistance. Therefore, developing the novel, low possibility of resistance and pro-environment way to control and reduce this fungi is meaningful. Herein, an efficient, environmental-friendly and photocatalytic method to disinfect Aspergillus flavus was demonstrated on magnetic and Z-schematic composites. The composites were composed of rhombic NiFe2O4 nanosheets and g-C3N4 nanosized sheets, and 0.2 g-C3N4/NiFe2O4 (mass ratio) showed the excellent activity with above 90% disinfection rate under 90 min visible light irradiation. The efficient disinfection activities were ascribed to the favorable charges separation, well photoelectric properties and suitable band structure. It was found that the •O2− and •OH were the main active radical species in photocatalytic disinfection. The attack of these species could cause the destruction of fungal cell structure and the leakage of intracellular contents as proved by the fluorescence staining of spores, biological scanning electron microscope and the detection of extracellular protein and DNA. Moreover, the composites also showed high photocatalytic disinfection activity of Aspergillus flavus on peanuts, which can reduce aflatoxin B1 from 315.21 µg kg−1 to 18.50 µg kg−1. This efficient method might be considered as a potential way to control the contamination of Aspergillus flavus, and as a reference to the mitigation of other pathogenic fungi in future.

Sesame is a nutritional agricultural product with medicinal properties. Accurate determination of micronutrients is important for the improvement of sesame quality and nutrition assessments. Our previous study showed that 10 antioxidants&mdash, d-homoproline, vitamin B2, coniferyl aldehyde, hesperidin, phloretin, N-acetyl-l-leucine, l-hyoscyamine, ferulic acid, 5-methoxypsoralen, and 8-methoxypsoralen&mdash, in sesame were potential characteristic nutrients in sesame. Herein, simultaneous detection of 10 different types of antioxidants was developed by using ultrasound-assisted extraction coupled with liquid chromatography-tandem mass spectrometry (UAE-LC-MS/MS) with the help of response surface methodology. The significant variables and levels were screened and optimized by combining the single factor experiment, Plackett&ndash, Burman test, and Box&ndash, Behnken design. The optimal conditions for extraction of target antioxidants in sesame were methanol solution of 75.0%, liquid-to-material ratio of 20:1 (mL/g), extraction temperature of 50 &deg, C, extraction power of 410.0 W, extraction time of 65 min. The total yield of targets was 21.74 &mu, g/g under the optimized conditions. The mobile phase used was 0.1% formic acid in acetonitrile and 0.1% formic acid in water, and the column was a Thermo Syncronis C18 reverse phase column (100 mm &times, 2.1 mm, 3 &mu, m). All targets required only one injection and could be quickly separated and assayed within 7 min. The limits of detection and limits of quantification for these 10 nutritional compounds ranged from 0.01 to 0.11 &micro, g/kg and from 0.04 to 0.34 &micro, g/kg, respectively. The validation results indicated that the method had reasonable linearity (R2 &ge, 0.9990), good recoveries (71.1%&ndash, 118.3%), satisfactory intra-day precision (&le, 9.6%) and inter-day precision (&le, 12.9%), and negligible matrix effects (&le, 13.8%). This simultaneous quantification method was accurate, fast, and robust for the assessment of sesame nutrition.

Rapeseed is an important oilseed with proper fatty acid composition and abundant bioactive components. Canada and China are the two major rapeseed-producing countries all over the world. Meanwhile, Canada and Mongolia are major importers of rapeseed due to the great demand for rapeseed in China. To investigate the metabolites in rapeseeds from three countries, ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS)-based metabolomics was employed to analyze rapeseeds from China, Canada, and Mongolia. As results, 67, 53, and 68 metabolites showed significant differences between Chinese and Canadian, Chinese and Mongolian, and Canadian and Mongolian rapeseeds, respectively. Differential metabolites were mainly distributed in the metabolic pathways including phenylpropanoid biosynthesis, flavone and flavonol biosynthesis, and ubiquinone and other terpenoid-quinone biosynthesis. Among the differential metabolites, contents of sinapate and sinapine were higher in Chinese rapeseeds, while the contents of brassicasterol, stigmasterol, and campestanol were higher in Canadian rapeseeds. These findings might provide insight into the metabolic characteristics of rapeseeds from three countries to guide processing and consumption of the products of rapeseed.

High complexity of identification for non-target triacylglycerols (TAGs) is a major challenge in lipidomics analysis. To identify non-target TAGs, a powerful tool named accurate MS n spectrometry generating so-called ion trees is used. In this paper, we presented a technique for efficient structural elucidation of TAGs on MS n spectral trees produced by LTQ Orbitrap MS n , which was implemented as an open source software package, or TIT. The TIT software was used to support automatic annotation of non-target TAGs on MS n ion trees from a self-built fragment ion database. This database includes 19108 simulate TAG molecules from a random combination of fatty acids and corresponding 500582 self-built multistage fragment ions (MS ≤ 3). Our software can identify TAGs using a “stage-by-stage elimination” strategy. By utilizing the MS 1 accurate mass and referenced RKMD, the TIT software can discriminate unique elemental composition candidates. The regiospecific isomers of fatty acyl chains will be distinguished using MS 2 and MS 3 fragment spectra. We applied the algorithm to the selection of 45 TAG standards and demonstrated that the molecular ions could be 100% correctly assigned. Therefore, the TIT software could be applied to TAG identification in complex biological samples such as mouse plasma extracts.

A novel magnetic carboxylated multi-walled carbon nanotubes (c-MWCNT-MNPs) was proposed for magnetic solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry to determine phenolic compounds in sesame oil. In this study, c-MWCNT-MNPs were acquired by simply dispersing Fe3O4 magnetic nanoparticles into carboxylated multi-walled carbon nanotubes. The major parameters affecting extraction efficiency were optimized, including the type and volume of desorption solvents, extraction and desorption time, washing solution, and sorbent amount. The limit of quantifications and limit of detections were from 0.03μg/kg to 43.00μg/kg and from 0.01μg/kg to 13.60μg/kg, respectively. The recoveries of phenolic compounds in vegetable oils were in the range of 83.8-125.9% with inter-day and intra-day precisions of less than 13.2%. It was confirmed that this method was simple, rapid and reliable with an excellent potential for routine analysis of phenolic compounds in oil samples.

To monitor capsaicinoids in serum on-site, three new monoclonal antibodies (mAbs) were firstly proposed using a conjugate of 4-[(4-hydroxy-3-methoxybenzyl) amino]-4-oxobutanoic acid as the immunogen. Among them, the YQQD8 mAb showed the highest sensitivity and cross-reactivity to major capsaicinoids, such as capsaicin, dihydrocapsaicin and N-vanillylnonanamide. A competitive indirect enzyme-linked immunosorbent assay (icELISA) and a time-resolved fluorescent immunochromatographic assay (TRFICA) were established based on this mAb. The linear range was 1.1-27.0ngmL(-1) for icELISA and 1.9-62.5ngmL(-1) for TRFICA and the limit of detection (LOD) of TRFICA was 1.5ngmL(-1). To decrease the interference of sample components and increase accuracy, serum samples were diluted four times before assays. As a result, the linear range of serum samples was 4.6-107.9ngmL(-1) for icELISA and 7.6-250.0ngmL(-1) for TRFICA. Both icELISA and TRFICA showed good recoveries (91.0-112.8% for icELISA and 87.6-111.5% for TRFICA) and concordant results in spiked experiments. Overall, this is the first report of immunoassay based on the mAbs for quantitative determination of major capsaicinoids, and the results demonstrate that both methods can meet the demands of rapid on-site assay for capsaicinoids in serum samples.

Two nanoprobes based on gold nanoparticles (AuNPs) and magnetic nanoparticles (MNPs) were synthesized, respectively. A double- nanoprobe based immunoassay with sensitivity, rapidity, and reproducibility was developed for the determination of phenanthrene (Phe) and related low-mass polycyclic aromatic hydrocarbons (PAHs) in water samples. The AuNPs probe was used as signal amplification probe, which can improve the sensitivity of the immunoassay. The MNPs probe was used as immobilization of Phe, which can lead to speed up reaction of antigen-antibody by the suspension property and dispersed nature. The linear range and the limit of detection (LOD) were 0.14–6.55 ng/mL and 0.08 ng/mL, respectively. Compared with the traditional ELISA, the sensitivity of the double-probe based immunoassay was improved about 30 times and the time for determination was shorten 104 min. The recoveries of Phe and related low-mas PAHs from tap water, contaminated water and river water were 90.5–109.8%, 91.2–108.0% and 93.0–107.8%, respectively. The correlation coefficient of the results between the developed immunoassay and GC–MS/MS was 0.9977. The developed double- nanoprobe based immunoassay was sensitive, rapid and good reproducibility for the determination of Phe and related low-mas PAHs in environmental water.

Phenolic acids have been reported to have many biological activities, but daily intake information is scarce. In this study, the phenolic acid contents of 116 commonly consumed food in five regions of China (Beijing, Hangzhou, Wuhan, Chongqing and Guangzhou) were analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS) and dietary intakes estimated. Tea had the highest total phenolic acids (TPA) content in all regions investigated. Phenolic acids were in esterified and bound forms, and hydroxycinnamic acids accounted for more than half of TPA content, except in tea and legumes. Average TPA intake was 193.50 mg/ day at the national level but ranged from 157.09 to 263.01 mg/ day among the regions. Rice, tea, and fruits were the main contributors to dietary intakes of TPA. Also, TPA intake in the period 2009–2013 increased 31.65 mg/ day compared with 2002, largely due to increased intakes of fruits, vegetables, and legumes.

Vitamin K1 is one of the important hydrophobic vitamins in fat-containing foods. Traditionally, lipase is employed in the determination of vitamin K1 to remove the lipids, which makes the detection complex, time-consuming, and insensitive. In this study, the determination of vitamin K1 in fat-containing foods was developed based on ultrasound-assisted extraction (UAE), solid-phase extraction (SPE) combined with liquid chromatography&ndash, tandem mass spectrometry (LC-MS/MS). The optimal conditions for extraction of vitamin K1 were material&ndash, liquid ratio of 1:70 (g/mL), extraction temperature of 50 &deg, C, extraction power of 700 W, extraction time of 50 min, material-wash fluid ratio of 1:60 (g/mL), and 8 mL of hexane/anhydrous ether (97:3, v/v) as the elution solvent. Then, vitamin K1 was analyzed on a ZORBAX SB-C18 column (50 mm &times, 2.1 mm, 1.8 &mu, m) by gradient elution with water (0.01% formic acid) and methanol (0.01 formic acid + 2.5 mmol/L ammonium formate) as the mobile phase. The limit of detection (LOD) and limit of quantification (LOQ) were 0.05 and 0.16 &mu, g/kg, respectively. Calibration curve was linear over the range of 10&ndash, 500 ng/mL (R2 &gt, 0.9988). The recoveries at three spiked levels were between 80.9% and 119.1%. The validation and application indicated that the proposed method was simple and sensitive in determination of vitamin K1 in fat-containing foods.

A method was developed to simultaneously determine eight bioactive compounds in edible oil based on ultrasound-assisted saponification, liquid-liquid extraction and liquid chromatography coupled with tandem mass spectrometry. Central composite design was employed to optimize ultrasonic temperature and time of saponification. Sample treatment was conducted by ultrasound-assisted saponification at temperature of 75 °C for 40 min. Limits of detection and limits of quantification ranged from 2.0 to 3.2 and from 6.1 to 10.0 ng/mL, respectively. Linear correlations were obtained (R2 > 0.99) and the recoveries at three spiked levels were between 81.7% and 112.0%. This method was employed to determine eight compounds in camellia oils and olive oils. As results, the contents of stigmasterol, δ-tocopherol, γ-tocopherol, β-carotene and lutein in camellia oils were significantly higher than those in olive oils (p

Phytosterols are well-known for their cholesterol-lowering effects, and the structures and forms of phytosterols affect their bioactivity. We aimed to illustrate the phytosterol profiles in common foods and estimate their natural intake in five geographical regions and among different age groups in China. In total, 12 phytosterols in free and esterified forms of 119 foods from five regions across China were examined using gas chromatography-mass spectrometry. Then, the dietary intake of phytosterols was calculated combined with the dietary foods intake data of Chinese people. The total phytosterol content was highest in vegetable oils (150.4-1230.9 mg/100 g), followed by legumes (129.6-275.6 mg/100 g), nuts (18.9-255.2 mg/100 g), and cereals (11.9-93.8 mg/100 g). Vegetables and fruits contained lower contents of total phytosterols. Phytosterols were mainly esterified in most common foods except in nuts. The predominant phytosterols were β-sitosterol, campesterol, and stigmasterol, all of which belonged to plant sterols and 4-desmethylsterols. Total phytosterol intake varied across different regions, ranging between 257.7 and 473.7 mg/standard-person (sp)/day, with the highest intake in Beijing, followed by Hangzhou, Wuhan, Chongqing, and Guangzhou. However, phytosterol proportion was similar across regions, with β-sitosterol accounting for 46.5-50.3% of the natural intake. Phytosterol intake was mainly constituted by plant sterols and 4-desmethylsterols in esterified form (61.9-74.6%). At the age of 2-70 years, phytosterol intake ranged from 154.3 mg/day to 348.0 mg/day in the national scale.

Adulteration of edible oils has attracted attention from more researchers and consumers in recent years. Complex multispecies adulteration is a commonly used strategy to mask the traditional adulteration detection methods. Most of the researchers were only concerned about single targeted adulterants, however, it was difficult to identify complex multispecies adulteration or untargeted adulterants. To detect adulteration of edible oil, identification of characteristic markers of adulterants was proposed to be an effective method, which could provide a solution for multispecies adulteration detection. In this study, a simple method of multispecies adulteration detection for camellia oil (adulterated with soybean oil, peanut oil, rapeseed oil) was developed by quantifying chemical markers including four isoflavones, trans-resveratrol and sinapic acid, which used liquid chromatography tandem mass spectrometry (LC-MS/MS) combined with solid phase extraction (SPE). In commercial camellia oil, only two of them were detected of daidzin with the average content of 0.06 ng/g while other markers were absent. The developed method was highly sensitive as the limits of detection (LODs) ranged from 0.02 ng/mL to 0.16 ng/mL and the mean recoveries ranged from 79.7% to 113.5%, indicating that this method was reliable to detect potential characteristic markers in edible oils. Six target compounds for pure camellia oils, soybean oils, peanut oils and rapeseed oils had been analyzed to get the results. The validation results indicated that this simple and rapid method was successfully employed to determine multispecies adulteration of camellia oil adulterated with soybean, peanut and rapeseed oils.

The radical scavenging capabilities of the extracts from eleven edible vegetable oils were investigated by using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), 2,2′‐azino‐bis‐3‐ ethylbenzothiazoline‐6‐sulfonic acid (ABTS), and ferric reducing ability of plasma (FRAP) assays. The results indicated that rapeseed oil and sesame oil showed higher radical scavenging abilities than other vegetable oils. When the radical scavenging capabilities of the extracts from virgin camellia oils and commercially available refined camellia oils were evaluated by FRAP assay, the results showed that the antioxidant capabilities of the former were higher than the latter. Therefore, it is recommended that moderate refining processes should be taken to minimize the loss of antioxidant components and people consume virgin oils or less processed edible vegetable oils for higher antioxidant activities.

Flaxseed oil is popular edible oil and an important additive in functional foods and feeds. Recently, economically motivated adulteration as a type of oil fraud becomes emerging risk. In this study, the fatty acid profiles of flaxseed oil were analyzed by gas chromatography-mass spectrometry operating in selected ion monitoring mode and then used to detect adulterated flaxseed oil with the help of multivariate statistical methods including principle component analysis (PCA), and recursive support vector machine (R-SVM). The detection results indicate that the discriminant model built with 28 fatty acids can identify adulterated flaxseed oil samples (10%) with high accuracy of 95.6%. Therefore, fatty acid profiles based adulteration detection for flaxseed oil is an important strategy for preventing customers far from adulterated flaxseed oil.

To ensure authenticity of vegetable oils, isoflavones (genistein, genistin, daidzein and daidzin) and resveratrols (cis-resveratrol and trans-resveratrol) were selected as the putative markers for adulteration of soybean and peanut oils. Firstly, mixed mode solid-phase extraction coupled with liquid chromatography tandem mass spectrometry (mixed-mode SPE LC-MS/MS) method was developed to analyze isoflavones and resveratrols in vegetable oils. The concentration of marker compounds in vegetable oils were 0.08-1.47mgkg(-1) for daidzein, ND-78.9μgkg(-1) for daidzin, 0.40-5.89mgkg(-1) for genistein, 1.2-114.9μgkg(-1) for genistin, 3.1-85.0μgkg(-1) for trans-resveratrol and 1.9-51.0μgkg(-1) for cis-resveratrol, which are compatible with the raw materials for oil press. Additionally, the applicability of this method has been successfully tested in thirteen vegetable oils from the market. Mixed-mode SPE LC-MS/MS method can simultaneously detect isoflavones and resveratrols in vegetable oils and assess adulteration and quality of soybean and peanut oils.

The adulteration of olive oils based on advanced sensors has attracted high interest owing to its health benefits in the prevention and treatment of certain pathologies. Concerning its health and commercial aspects, lower grade oil blending and other illegal additives in virgin olive oil can negatively affect the nutritive value of olive oil. This review focuses on the advances in the sensing and identification of adulteration of olive oil. Optical sensing, chromatography (usually coupled with mass spectrometry), and nuclear magnetic resonance are discussed in detail. Other methods including a DNA-based method, dielectric spectroscopy, differential scanning calorimetry, thermogravimetric analysis and electronic nose among others, are overviewed as well.

An efficient gas chromatography-mass spectrometry method was developed and validated for determination of sterol oxidation products (SOPs) in edible oils. The sample preparation involved cold saponification, liquid–liquid extraction, solid-phase extraction on a silica gel cartridge, and trimethylsilylation by N-methyl-N-(trimethylsilyl) heptafluorobutyramide with 5% 1-methyl imidazole. The trimethylsilyl ether derivatives of SOPs were separated by gas chromatography with a 30 m DB-5MS capillary column and quantified by a mass spectrometer in selective ion monitoring mode. 5α-Cholestane and 19-hydroxycholesterol were used as dual internal standards. The calibration curves for each compound showed correlation coefficients (R2) better than 0.98. The detection limits were below 12.9 ng mL−1 (except for epoxides). The intra- and inter-day determination precisions for diversiform SOPs were

Developing a method of identifying oil authenticity is becoming critical for protecting customers' rights as adulteration of edible oils is a particular concern in food quality. Since adulterants in edible oils are usually unknown, the authenticity identification is a one-class classification problem in chemometrics. In this study, a one-class classification model was built to identify the authenticity of peanut oils by fatty acid profiles. Based on previous studies, 28 fatty acids were identified and quantified for peanut oils. The authenticity identification model was built by one-class partial least squares (OCPLS) classifier for peanut oils. Subsequently, the established model was validated by independent test sets. The results indicated that the OCPLS classifier could effectively detect adulterated oils and was therefore employed for authenticity assessment. Moreover, counterfeit oils adulterated with different levels of other edible oils were simulated by the Monte Carlo method and employed to test the lowest adulteration level of this one-class classifier. As a result, the model could identify peanut oils and sensitively detect adulteration of edible oils with other vegetable oils at adulteration level of more than 4%.

Edible oil adulteration is the biggest source of food fraud all over the world. Since characteristic aroma is an important quality criterion for edible oils, we analyzed volatile organic compounds (VOCs) in four edible vegetable oils (soybean, peanut, rapeseed, and sunflower seed oils) by headspace comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (Headspace-GC×GC-TOFMS) in this study. After qualitative and quantitative analysis of VOCs, we used unsupervised (PCA) and supervised (Random forests) multivariate statistical methods to build a classification model for the four edible oils. The results indicated that the four edible oils had their own characteristic VOCs, which could be used as markers to completely classify these four edible oils into four groups.

The detection of adulteration of high priced oils is a particular concern in food quality and safety. Therefore, it is necessary to develop authenticity detection method for protecting the health of customers. In this study, fatty acid profiles of five edible oils were established by gas chromatography coupled with mass spectrometry (GC/MS) in selected ion monitoring mode. Using mass spectral characteristics of selected ions and equivalent chain length (ECL), 28 fatty acids were identified and employed to classify five kinds of edible oils by using unsupervised (principal component analysis and hierarchical clustering analysis), supervised (random forests) multivariate statistical methods. The results indicated that fatty acid profiles of these edible oils could classify five kinds of edible vegetable oils into five groups and are therefore employed to authenticity assessment. Moreover, adulterated oils were simulated by Monte Carlo method to establish simultaneous adulteration detection model for five kinds of edible oils by random forests. As a result, this model could identify five kinds of edible oils and sensitively detect adulteration of edible oil with other vegetable oils about the level of 10%.

Fatty acids are potential biomarkers of some diseases and also key markers and quality parameters of different dietary fats and related products. Thus, untargeted fatty acid profiles are important in the study of dietary fat quality and fat-related diseases, as well as in other fields such as bioenergy. In addition, accurate identification of unknown components is a technological breakthrough for the selected ion monitoring (SIM) mode for untargeted profiles. In this study, we developed untargeted fatty acid profiles based on SIM. We also investigated mass spectral characteristics and equivalent chain lengths (ECL) to eliminate the influence of non-FAMEs for identifying fatty acids in samples. As an application example, fatty acid profiles were used to classify three edible vegetable oils. The results indicated that SIM-based untargeted fatty acid profiles could yield accurate qualitative and quantitative results for more fatty acids and benefit related studies of metabolite profiles.

To prevent the potential adulteration of flaxseed oil with high amounts of nutritional components, a simple and rapid adulteration detection method was proposed based on ion mobility spectrometry (IMS). After dilution in n-hexane, the edible oil sample was analyzed by IMS for 20 s. Subsequently, the multivariate statistical methods, including principal component analysis (PCA) and recursive support vector machine (R-SVM), were employed to establish a discriminant model for authentic and adulterated flaxseed oils. The cross validation results indicated that the R-SVM model could identify adulterated flaxseed oil samples (≥5%) with a high accuracy of 93.1%. Therefore, IMS could be used as an important tool to protect customers from adulterated flaxseed oil.

A simple, directly applicable and label-free immunoassay was proposed based on a specific immune binding reaction induced fluorescence quenching of an analyte. Aflatoxin B1 (AFB1) was taken as the model analyte, whose intrinsic fluorescence was quenched by the specific anti-AFB1 monoclonal antibody. This immunoreaction-induced fluorescence quenching was utilized to quantitatively determine AFB1.

In this study, magnetic graphene nanocomposite Fe3O4/rGO was synthesized by facile one-pot solvothermal method. The nanocomposite was successfully used as magnetic solid phase extraction (MSPE) adsorbents for the determination of aflatoxins in edible vegetable oils through the &pi, &ndash, &pi, stacking interactions. MSPE parameters including the amount of adsorbents, extraction and desorption time, washing conditions, and the type and volume of desorption solvent were optimized. Under optimal conditions, good linear relationships were achieved. Limits of detection of this method were as low as 0.02 &micro, g/kg and 0.01 &micro, g/kg for aflatoxin B1 and B2, respectively. Finally, the magnetic graphene nanocomposite was successfully applied to aflatoxin analysis in vegetable oils. The results indicated that the recoveries of the B-group aflatoxins ranged from 80.4% to 106.0%, whereas the relative standard deviations (RSDs) were less than 8.1%. Owing to the simplicity, rapidity and efficiency, Fe3O4/rGO magnetic solid phase extraction coupled with high-performance liquid chromatography fluorescence with post-column photochemical derivatization (Fe3O4/rGO MSPE-HPLC-PCD-FLD) is a promising analytical method for routine and accurate determination of aflatoxins in lipid matrices.

Phytosterols are important micronutrients in human diets. Evidence has shown that phytosterols play an essential role in the reduction of cholesterol in blood and therefore decrease cardiovascular morbidity. In this study, the content and composition of phytosterols in different kinds of vegetable oils were analyzed, and the total phytosterol intake and contribution of foods to intake were estimated based on consumption data. The results showed that the phytosterol contents of rice bran oil, corn oil, and rapeseed oil were higher than those of other vegetable oils and the intake of phytosterol in the Chinese diet was about 392.3 mg/day. The main sources of phytosterols were edible vegetable oils (46.3%), followed by cereals (38.9%), vegetables (9.2%), nuts (2.0%), fruits (1.5%), beans and bean products (1.4%), and tubers (0.8%). Among all vegetable oils, rapeseed oil was the main individual contributor to phytosterol intake (22.9%), especially for the southern residents of China.

The use of the fasting plasma glucose and 2-h plasma glucose tolerance tests leads to under-diagnosis of type 2 diabetes mellitus. To explore the contribution of metabolites for diagnosis for type 2 diabetes, plasma targeted metabolites (including free amino acids, lipids, and two hepatic aminotransferases) of 95 subjects were determined by high performance liquid chromatography and routine clinical methods. Receiver operating characteristic curve analysis was employed to evaluate potential diagnosis models. Based on the processing of orthogonal partial least squares-discriminant analysis, five amino acids (lysine, aspartate acid, threonine, methionine, and alanine) and two lipids (low density lipoprotein-cholesterol and high density lipoprotein-cholesterol) were discovered as potential biomarkers of type 2 diabetes. The area under the receiver operating characteristic curve built by the combination of these biomarkers and fasting plasma glucose was 0.994, which is significantly higher than that of the la...

The residues of chlorophyll induce oxidative rancidity and deterioration through photo‐oxidation. However, the effect of chlorophyll on the quality of rapeseed oil is still unknown. In this study, chlorophyll is added into rapeseed oil to reach the desired treatment levels of 2, 5, and 10 mg kg⁻¹, while no chlorophyll is added in the control sample. Dynamic changes of the peroxide value of rapeseed oils with different chlorophyll contents exposed to light and stored in the dark at different times (0, 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 days) are investigated. The results show that the peroxide value of rapeseed oil exposed to light increased significantly, especially for the oil with a high content of chlorophyll. In contrast, the peroxide value of rapeseed oil stored in the dark is nearly unchanged no matter whether extra chlorophyll is added. This study shows that chlorophyll in rapeseed oil can trigger oil oxidation, and therefore it is necessary to take measures to reduce the chlorophyll content in rapeseed oil or store rapeseed oil in the dark as soon as possible. Practical Applications: This study shows that chlorophyll in rapeseed oil can trigger oil oxidation, and therefore it is necessary to take measures to reduce the chlorophyll content in rapeseed oil. In this study, dynamic changes of peroxide values of rapeseed oils with different chlorophyll contents exposed to light and stored in the dark at different times are investigated. The results show that the peroxide value of rapeseed oil exposed to light increases significantly, especially for the rapeseed oil with a high content of chlorophyll. In conclusion, chlorophyll in rapeseed oil can trigger oil oxidation.Therefore, it is necessary to take measures to reduce the chlorophyll content in rapeseed oil or store rapeseed oil in the dark as soon as possible.

Diabetes is a common metabolic syndrome which presents a serious threat to human health. Traditional Chinese medicine (TCM) has been widely paid attention to its advantages and characteristics in the diagnosis and the treatment of diabetes. A strategy of classifying five TCM syndromes in diabetes (Qi-deficiency, Yin-deficiency, Qi- and Yin-deficiency, Damp heat and Blood stasis) was employed based on plasma fatty acid metabolic profiles, lipid metabolism indicators and chemometrics methods. Using orthogonal signal correction-partial least squares (OSC-PLS) method, the five syndromes were obviously distinguished from those of the health control, which confirmed there existed metabolite differences in different traditional Chinese medicine syndromes. Furthermore, a new method, uncorrelated linear discriminant analysis (ULDA), was applied in the discrimination of health control, TCM deficiency syndromes (Qi-deficiency, Yin-deficiency, Qi- and Yin-deficiency) and TCM empirical syndromes (Damp heat, Blood stasis), which demonstrated better clustering results, the correct rate reached 95.7%. The four potential biomarkers, C20: 2, C20: 5, triglycerides (TG) and high density lipoprotein (HDL), performed large contributions to the classification which can provide important information assisting TCM clinical diagnosis.

A rapid and efficient baohuoside I preparation method was established. A uniform design coupled with subset selection was employed to determine pH, reaction time, and temperature parameters, as well as dextranase hydrolysis efficiency. Hydrolysis parameters were optimized using response surface and subset selection. Our results showed that pH plays an important role in the hydrolysis reaction within a relatively narrow range (pH 4-7). Temperature was the secondary factor, which was positively correlated with conversion rate. A 3-h reaction time was sufficient. Finally, a relatively good hydrolysis parameters were found, and their effectiveness was verified. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.

In this review, we summarize seven strategies for structure elucidation of small molecules based on several aspects: discovery of spectral characteristics; construction of a special database; and elimination of retention-index variation and mass spectral differences. We also discuss trends and future perspectives of the structure elucidation of small molecules using data from gas chromatography coupled to mass spectrometry.

Bioassay-directed phytochemical study of the Jerusalem artichoke ( Helianthus tuberosus L.) leaves led to the isolation of a new sesquiterpene lactone of 3-Hydroxy-8β-tigloyloxy-1,10-dehydroariglovin ( 1 ), ten known sesquiterpene lactones ( 2 – 11 ) and two known flavones ( 12 – 13 ). Their chemical structures were elucidated on the basis of NMR (1D and 2D) and mass spectroscopic analysis. The cytotoxic activities of those compounds were subsequently tested against the MCF-7, A549 and HeLa cancer cells lines. The results indicated that sesquiterpene lactones 1 – 11 exhibited consistent cytotoxicity against all three cancer cell lines, while flavones 12 and 13 showed selective inhibitory activity against HeLa cell lines. Among them, compound 3 exhibited significant growth inhibitory activity against all three cell lines. The IC 50 values of compound 3 against MCF-7, A549 and HeLa were 1.97 ± 0.04, 7.79 ± 0.44, 9.87 ± 0.20 μg/ml, respectively. In addition, some structure–activity relationships of these sesquiterpene lactones for cytotoxicity were explored and summarized in this study.

A strategy of high sensitive assay method of urine fatty acid profiles was established based on ultra-performance liquid chromatography-quadrupole time of flight-mass spectrometry (UPLC/Q-TOF) and applied in metabolomics research of diabetes mellitus. In this way, 19 fatty acids including two pair of hard-resolved isomers were separated well in only 13 minutes, and Q-TOF mass spectrometry reduced the matrix interference of urine samples by high resolution and accurate molecular weights. Under the optimal conditions, fatty acid profiles of 93 cases of urine samples were analyzed. Fatty acid profiles of type 2 diabetes mellitus showed large differences from health controls based on multivariate data analysis; C16:0, C18:0, C18:2, C20:5, and C22:6 were screened as potential clinical biomarkers. This work is complementary to the clinical diagnosis of diabetes mellitus; additionally, noninvasive testing of urine samples made it more convenient for examination while reducing the patient's pain and improving the...

Metabolite profiles and biomarker discovery benefit clinical diagnosis of type 2 diabetes mellitus (T2DM) and reflection of metabolite variations in pathophysiology. Fatty acids play an important role in the occurrence and development of diabetes mellitus. The fasting plasma glucose (FPG) values of T2DM patients are partially adjusted to normal range (FPG