Modified QuEChERS purification and Fe3O4 nanoparticle decoloration for robust analysis of 14 heterocyclic aromatic amines and acrylamide in coffee products using UHPLC-MS/MS

Functional Application of Sulfur-Containing Spice Compounds

Sulfur-containing spice compounds possess diverse biological functions and play an important role in food, chemicals, pharmaceuticals, and agriculture. The development of functional spices has become increasingly popular, especially for medicinal functions for dietary health. Thus, this review focuses on the properties and functions of sulfur-containing spice compounds, including antioxidant, anti-inflammatory, antiobesity, anticancer, antibacterial, and insecticidal functions, among others. Developments over the last five years concerning the properties of sulfur-containing spice compounds are summarized and discussed.

Investigating the migration of pyrethroid residues between mung bean sprouts and growth media

To study the migration of pyrethroids (cypermethrin, deltamethrin, fenvalerate, and permethrin) from growth media (soil or water) to mung bean sprouts, pyrethroid residues were quantified using polystyrene-magnetic nanoparticles and HPLC-PDA. Pyrethroids reductions in growth media followed a double-exponential decline model (RMSE of 0.0068-0.1845), while the higher accumulation in the vegetable were observed in roots (0.50-6.75 mg/kg) than in sprouts (0.12-2.01 mg/kg). The accumulation was influenced by pyrethroid species, type of growth media, and plant parts. This study contributed a novel prediction method to assess the migration of pesticides from the growth media to the vegetable with the satisfactory sensitivity of the proposed detection method. The recoveries, detection limits (LOD), and quantification limits (LOQ) were 82.9-112.1%, 0.0627-0.1974 µg/L and 0.1892-0.6279 µg/L, respectively, for four pyrethroids. The research provided solid basis for future study of crops that can be used for bioconcentration of chemical hazards in environments.

Comparative evaluation of acrylamide and polycyclic aromatic hydrocarbons contents in Robusta coffee beans roasted by hot air and superheated steam

Although hot air (HA) is a conventional roasting medium for coffee beans, HA roasting is known to result in possible formation of toxic compounds, including acrolein, acrylamide and polycyclic aromatic hydrocarbons (PAHs). Superheated steam (SHS) roasting is therefore proposed as an alternative means to alleviate the formation of these toxic compounds in roasted coffee beans. Robusta coffee beans were roasted either with HA or SHS in a fluidized bed roaster at 210-250 °C until the bean color reached the targeted roast levels. The contents of acrolein, acrylamide and 16 PAHs in the roasted beans were determined; only acrylamide and 5 PAHs were nevertheless found. SHS roasting interestingly resulted in lower acrylamide contents in dark-roasted beans; similar trend was noted in the beans medium-roasted at 250 °C. The contents of three-ring PAHs, namely fluorene, phenanthrene and anthracene, in dark-roasted beans were significantly lower upon SHS roasting at 250 °C.

High throughput analysis of 21 perfluorinated compounds in drinking water, tap water, river water and plant effluent from southern China by supramolecular solvents-based microextraction coupled with HPLC-Orbitrap HRMS

The present work reported a high-throughput strategy for the analysis of 21 perfluorinated compounds (PFCs) in drinking water, tap water, river water and plant effluent from southern China by supramolecular solvent (SUPARS) vortex-mixed microextraction combined with high performance liquid chromatography-Orbitrap high resolution mass spectrometry (HPLC-Orbitrap HRMS). The SUPRAS without heating assistance is less solvent-consumption, meeting the requirements for green environmental protection and sustainable development. Parameters in the microextraction such as volume of dodecanol and tetrahydrofuran (THF), vortexing extraction and centrifugation time, salt concentration were investigated. The optimal extraction conditions were 250 μL of undecanol, 1.0 mL of THF and 20.0% (w/v, 4 g) NaCl. Under the optimum conditions, method limit of detection and method limit of quantitation in the ranges of 0.01-0.08 μg/L and 0.03-0.25 μg/L, good recoveries (72.5-117.8%) and intra-day precision (1.1-11.2%, n = 6), high enrichment factors (48-78) were obtained. The developed method was successfully applied for analysis of PFCs in 13 drinking water, tap water, river water and plant effluent samples collected from southern China. Perfluorobutane sulfonic acid was detected in one river water with concentration of 0.48 μg/L and 1H,1H,2H,2H-Perfluorooctane sulfonic acid was detected in one river water and two plant effluent samples with concentrations in the range of 0.14-0.67 μg/L.

A novel magnetic solid-phase extraction method for detection of 14 heterocyclic aromatic amines by UPLC-MS/MS in meat products

The current study developed a cheap and effective method for the simultaneous extraction of 14 heterocyclic aromatic amines (HAAs) in food matrix. Core-shell Fe₃O₄@PDA nanoparticles were constructed and acted as the magnetic solid-phase extraction adsorbent to separate and purify HAAs from meat products for the first time. Then, UPLC-MS/MS technique was employed to identify and quantify the HAAs easily. Fe₃O₄@PDA nanoparticles were synthesized and characterized successfully. Totally 14 HAAs were completely separated in 19.99 min with good regression coefficients. LODs and LOQs were in the range of 0.013-0.247 ng/g and 0.056-0.803 ng/g, respectively. The intra-day precisions and inter-day precisions were below 9%. Except for IQ[4,5-b], Phe-p-1, PhIP, other 11 types of HAAs (DMIP, 1,5,6-TMIP, IQ, IQx, MeIQ, MeIQx, 7,8-DiMeIQx, AαC, MeAαC, Harman, Norharman) could acquire relatively high recoveries (71.06%-108.49%). The proposed method was successfully devoted to the evaluation of HAAs levels in 8 commercial meat products to verify the adaptability.

Fluorine and nitrogen functionalized magnetic graphene as a novel adsorbent for extraction of perfluoroalkyl and polyfluoroalkyl substances from water and functional beverages followed by HPLC-Orbitrap HRMS determination

Most of the reported magnetic adsorbents are difficult to absorb multi-class of per- and polyfluoroalkyl substances (PFASs), especially the short-chain PFASs. In this work, a novel fluorine and nitrogen functionalized magnetic graphene (G-NH-FBC/Fe₂O₃) was first synthesized and characterized by scanning electron microscope (SEM), Fourier Transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The as-prepared G-NH-FBC/Fe₂O₃ was utilized as adsorbents for the magnetic solid-phase extraction (MSPE) of 19 PFASs from water and functional beverages and showed excellent adsorption capacity probably due to the hydrophobic interaction. Under the optimal pretreatment and instrumental conditions, a selective and sensitive high performance liquid chromatography Orbitrap high resolution mass spectrometry (HPLC-Orbitrap HRMS) method was developed for the determination of PFASs. Results indicated that the proposed method had favorable linearity (R² ≥ 0.994) within a wide range of concentrations. Limit of detection (LOD) and limit of quantification (LOQ) for the developed method ranged from 3 ng/L to 15 ng/L and 10 ng/L to 49 ng/L, respectively. Finally, the method was successfully applied to determine PFASs in drinking water, river water, tap water, factory drainage and functional beverages with recoveries ranging from 71.9% to 117.6% and relative standard deviation of <10%. The prepared G-NH-FBC/Fe₂O₃ was easy to recycle and could be reused for five times without significant decrease in extraction recoveries of PFASs. These results demonstrated that this novel magnetic G-NH-FBC/Fe₂O₃ could efficiently enrich PFASs and the proposed method is reliable and robust for the determination of PFASs in water and beverage samples.

Preventive potential and mechanism of dietary polyphenols on the formation of heterocyclic aromatic amines

Thermal processing is the most important and popular domestic cooking method. More than 30 heterocyclic aromatic amines have been identified in cooked meat using various methods. This review highlights preventive potential and mechanism of dietary polyphenols on the formation of heterocyclic amines. Tea, coffee, fruits, vegetable, and spice extracts rich in polyphenols exerted significant inhibition against the formation of heterocyclic aromatic amines. Some polyphenols, such as naringenin and epigallocatechin 3‐O‐gallate, can actively participate into food chemistry reaction to trap Strecker aldehyde and lower the formation of heterocyclic aromatic amines. In addition, some polyphenols can lower the mutagenicity of heterocyclic aromatic amines. More specifically, polyphenols possessing two hydroxyl groups at the meta position of aromatic ring are the most efficient one, but the presence of carboxylic or alkyl groups as substituents in the aromatic ring slightly reduced the inhibitory effect.

Thin-layer chromatography combined with surface-enhanced Raman scattering for rapid detection of benzidine and 4-aminobiphenyl in migration from food contact materials based on gold nanoparticle doped metal-organic framework

In this work, a rapid and sensitive thin-layer chromatography combined with surface-enhanced Raman spectroscopy method was established for rapid detection of benzidine and 4-aminobiphenyl in migration from food contact materials based on Au nanoparticle doped metal-organic framework. Benzidine and 4-aminobiphenyl were firstly separated by thin-layer chromatography to solve the limitation of their overlapping Raman peaks. Then the target molecules were monitored by adding AuNPs/MIL-101(Cr) on the sample spots. Under the optimum conditions, the concentration of benzidine and 4-aminobiphenyl can be quantitatively measured in the range of 2.0-20.0 and1.0-15.0 μg/L, respectively with good linear relationship, and the limits of detection were 0.21 and 0.23 μg/L, respectively. Furthermore, the developed method was applied to analyze benzidine and 4-aminobiphenyl in migration of different food contact materials. The recoveries of benzidine and 4-aminobiphenyl for migration of food contact materials, including paper cups, polypropylene food containers, and polyethylene glycol terephthalate bottles, were 80.6-116.0 and 80.7-118% with relative standard deviations of 1.1-9.1 and 3.1-9.9%, respectively. Surface-enhanced Raman scattering detection was performed conveniently in the on-plate mode without additional elution process. The method shows great potential in rapid monitoring of hazardous substances with overlapping characteristic Raman peaks in food contact materials.

Enzymatic hydrolysis pretreatment for enhancing the protein solubility and physicochemical quality of Cordyceps militaris chicken soup

Chicken soup is one of the most popular Chinese-style soups due to its high nutritional value and special flavor. However, the nutrients, mainly soluble protein, in the soup are relatively low. The aim of the present work was to enhance the protein solubility and other physicochemical properties of Cordyceps militaris chicken soup by enzymatic hydrolysis pretreatment. Results indicated that the soluble protein dissolution rate and flavor nucleotides (I+G) of Cordyceps militaris chicken soup had 1.6-fold and 0.5-fold increase, respectively, after enzymatic hydrolysis pretreatment. Not only the contents of total amino acids (TAA) and essential amino acids (EAA) in Cordyceps militaris chicken soup significantly increased, the organoleptic quality was also markedly improved after the enzymatic hydrolysis pretreatment. The present work provides a potential approach, which is enzymatic hydrolysis pretreatment of chicken meat, to enhance the protein solubility and physicochemical quality of Cordyceps militaris chicken soup.

Analysis of heterocyclic aromatic amine profiles in Chinese traditional bacon and sausage based on ultrahigh-performance liquid chromatography-quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap-HRMS)

Ultrahigh-performance liquid chromatography coupled to quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap-HRMS) was used for the screening and determination of 14 heterocyclic aromatic amines (HAAs) in Chinese traditional bacon and sausage. HAAs were extracted from samples using sodium hydroxide solution with acetonitrile, and purified by solid-phase extraction. UHPLC-Q-Orbitrap-HRMS acquired full MS data for quantification, and UHPLC-Q-Orbitrap-Full MS/dd-MS2 (i.e., data-dependent scan mode) obtained product ion spectra for identification. Quantification was achieved using matrix-matched standard calibration curves along with the use of isotope labeled standards as internal standards. Linearity was observed in the range of 0.2-500 μg/L for 14 HAAs, with determination coefficients (R²) greater than 0.997. Limits of detection and limits of quantification were in the ranges of 0.1-0.8 μg/kg and 0.3-2.5 μg/kg, respectively. UHPLC-Q-Orbitrap-HRMS demonstrated acceptable performance for quantification and confirmation of HAAs, while UHPLC-Q-Orbitrap-Full MS/dd-MS2 along with library matching showed great potential for screening and confirmation of unknown HAAs in meat products.

Electrorheological Characteristics of Poly(diphenylamine)/magnetite Composite-Based Suspension

Electro-responsive poly(diphenylamine)(PDPA)/Fe3O4 composite particles were prepared by the synthesis of PDPA particles using a chemical oxidative polymerization technique followed by loading nano-sized Fe3O4 particles onto PDPA via a chemical co-precipitation process. The morphological image of the PDPA/Fe3O4 particles was characterized by scanning electron microscope and transmission electron microscope. The crystalline structure was scrutinized by X-ray diffraction. The rheological characteristics of the suspension composed of PDPA/Fe3O4 particles suspended in silicone oil were investigated by a rotation rheometer, demonstrating standard electrorheological (ER) characteristics with a dramatic increase in shear stress and dynamic moduli under the application of an electrical field strength. The shear stress curves under an electrical field could be described using the Bingham model and the yield stress showed a power-law relationship with the electric field strength with an exponent of 1.5, following the conduction model. Furthermore, the frequency-dependent dielectric behaviors of the PDPA/Fe3O4 ER suspension was tested using an inductance (L)-capacitance (C)-resistance (R) (LCR) meter. The dielectric properties were well described using the Cole-Cole equation and were consistent with the results of the ER experiments.