Simultaneous Determination of Acrylamide, 5-Hydroxymethylfurfural, and Heterocyclic Aromatic Amines in Thermally Processed Foods by Ultrahigh-Performance Liquid Chromatography Coupled with a Q Exactive HF-X Mass Spectrometer

The magnetic layered double hydroxide/zeolitic imidazolate framework-8 nanocomposite coupled with HPLC-MS/MS for the detection of heterocyclic aromatic amines in thermally processed meat

In this research, a novel magnetic nanocomposite (Fe3O4@Zn/Al-LABSA-LDH/ZIF-8) was synthesized using Fe3O4 as the magnetic core, layered double hydroxide (LDH) with linear alkylbenzene sulfonic acid (LABSA) intercalation and zeolitic imidazolate framework-8 (ZIF-8) as the shell. Benefiting from the intercalation of LABSA into LDH combined with ZIF-8, the multiple interactions, including π-π stacking, hydrogen bonding, and electrostatic interactions, conferred high selectivity and good extraction capability to the material towards heterocyclic aromatic amines (HAAs). Fe3O4@Zn/Al-LABSA-LDH@ZIF-8 was used as an adsorbent for magnetic solid-phase extraction (MSPE) to enrich HAAs in thermally processed meat samples, followed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) detection. The method exhibited a low detection limit (0.021-0.221 ng/g), good linearity (R2 ≥ 0.9999), high precision (RSD < 7.2 %), and satisfactory sample recovery (89.7 % -107.5 %). This research provides a promising approach for developing novel adsorbents in sample preparation and improving analytical performance.

The formation and conversion of characteristic aroma profiles and key harmful substances in different high-temperature processing of hairtail (Trichiurus Haumela)

The balance regulation between characteristic aroma and hazards in high-temperature processed fish is a hot spot. This study was aimed to explore the interactive relationship between the nutritional value, microstructures, aroma, and harmful substances of hairtail under different frying methods including traditional frying (TF), air frying (AF), and vacuum frying (VF) via chemical pattern recognition. The results indicated that VF-prepared hairtail could form a crunchy mouthfeel and retain the highest content of protein (645.53 mg/g) and the lowest content of fat (242.03 mg/g). Vacuum frying reduced lipid oxidation in hairtail, resulting in the POV reaching 0.02 mg/g, significantly lower than that of TF (0.05 mg/g) and AF (0.21 mg/g), and TBARS reached 0.83 mg/g, significantly lower than that of AF (1.96 mg/g) (P < 0.05), respectively. Notable variations were observedin the aroma profileof hairtail preparedfrom different frying methods. Vacuum frying of hairtail resulted in higher levels of pyrazines and alcohols, whereas traditional frying and air frying were associated with the formation of aldehydes and ketones, respectively. Air frying was not a healthy way to cook hairtail which produced the highest concentration of harmful substances (up to 190.63 ng/g), significantly higher than VF (5.72 ng/g) and TF (52.78 ng/g) (P < 0.05), especially norharman (122.57 ng/g), significantly higher than VF (4.50 ng/g) and TF (32.63 ng/g) (P < 0.05). Norharman and acrylamide were the key harmful substances in hairtail treated with traditional frying. The vacuum frying method was an excellent alternative for deep-fried hairtail as a snack food with fewer harmful substances and a fine aroma, providing a theoretic guidance for preparing healthy hairtail food with high nutrition and superior sensory attraction.

Development and comparison of parallel reaction monitoring and data-independent acquisition methods for quantitative analysis of hydrophilic compounds in white tea

In the present work, parallel reaction monitoring (PRM) and data-independent acquisition (DIA) methods were developed for the accurate quantitation of amino acids, alkaloids nucleosides and nucleotides in tea. The quality peaks were significantly enhanced by optimizing the LC elution procedure, HCD voltage, MS resolution, and scanning event. Both methods were validated with good liner linearity (0.004-200 μg/mL), LODs (0.001-0.309 μg/mL for PRM and 0.001-0.564 μg/mL for DIA). Applied to white tea sample, the contents of these hydrophilic compounds were range from 34,655.39 to 70,586.14 mg/kg, and caffeine (32,529.02 mg/kg) and theanine (5483.46 mg/kg) were determined as the most abundant ones. Based on the quantitation data set, the white tea samples from Puer, Lincang and Xishuangbanna were clearly discriminated using multivariate data analysis. The results of the present works show that PRM and DIA have great potential in quantitative analysis of multiple hydrophilic compounds in food samples.

Preconcentration of Heterocyclic Aromatic Amines in Edible Fried Insects Using Surfactant-Assisted Hydrophobic Deep Eutectic Solvent for Homogeneous Liquid-Liquid Microextraction prior to HPLC

Thermal processing techniques are often accompanied by the production of many harmful compounds such as heterocyclic aromatic amines (HAAs). To protect human health, an efficient and environmentally friendly method, namely, homogeneous liquid-liquid microextraction (HLLME), was investigated. This method is based on a surfactant-assisted hydrophobic deep eutectic solvent for the determination of HAAs in edible fried insect samples prior to their analysis by high-performance liquid chromatography coupled with UV detection. A hydrophobic deep eutectic solvent (as extraction solvent) was synthesized using decanoic acid as a hydrogen bond donor and tetrabutylammonium bromide (TBABr) as a hydrogen bond acceptor and then characterized by Fourier transform infrared (FTIR) spectroscopy. The surfactant was used as the emulsifier and induces mass transfer, resulting in an increasing extraction efficiency of the proposed method. Various factors affecting the extraction performance were investigated and optimized. A matrix-match calibration method was used to analyze HAAs in high heat-treated edible fried insect samples. Under optimized conditions, the proposed method showed good linearity (R2 ≥ 0.99) with satisfactory limits of detection and satisfactory reproducibility with relative standard deviation of less than 10.0%. Furthermore, the procedure greenness was assessed using the Analytical Eco-Scale. This paper represents the first application of HLLME based on a surfactant-assisted hydrophobic deep eutectic solvent to analyze HAAs in edible fried insect samples.

Research progress on generation, detection and inhibition of multiple hazards - acrylamide, 5-hydroxymethylfurfural, advanced glycation end products, methylimidazole - in baked goods

While baking produces attractive flavors for foods, it also generates various endogenous by-products, including acrylamide (AA), 5-hydroxymethylfurfural (5-HMF), advanced glycation end products (AGEs) and methylimidazole (MI). This review briefly presents the recent studies on the above hazards, and research progress on the formation and control of the above substances in detail. There have been more detailed studies on a single category of hazards. However, few studies and reports have considered the integrated prevention and control of multiple hazards, which is related to the difficulty of analyzing the reaction mechanisms of multiple hazards at multiple scales and under multiple phases in complex food matrices. In this regard, the sample pretreatment methods are a crucial step in achieving simultaneous detection. The coordinated implementation of various methods, including reducing precursor levels, modifying baking conditions and equipment, and incorporating exogenous additives, is necessary to achieve a synchronized reduction in multiple hazardous substances.

Development of a two-step pretreatment and UPLC-MS/MS-based method for simultaneous determination of acrylamide, 5-hydroxymethylfurfural, advanced glycation end products and heterocyclic amines in thermally processed foods

A two-step pretreatment and UPLC-MS/MS-based method was established to extract and determine 17 thermal processing hazards (TPHs) simultaneously. The first step was to extract acrylamide (AA), 5-hydroxymethylfurfural (HMF) and free heterocyclic amines (HAs). The bound HAs and advanced glycation end products (AGEs) were released by acid hydrolysis in the second step. A fairly good separation was achieved within 7 min. Almost all TPHs showed high correlation coefficients (R2 >0.999) in their respective linear ranges. The accuracy ranged from 98.13 to 100.96%. LODs and LOQs were in the range of 0.01-0.89 µg/L and 0.02-2.96 µg/L, respectively. The method was successfully applied to four representative food products, including high-starch, high-protein, high-fat and high-sugar foods, showing acceptable recoveries, intra-day and inter-day precisions. Moreover, PCA was performed to visualize the association between TPHs and food matrices. The developed method provided technical support for the formation and control researches of TPHs.

Simultaneous detection of heterocyclic aromatic amines and acrylamide in thermally processed foods by magnetic solid-phase extraction combined with HPLC-MS/MS based on cysteine-functionalized covalent organic frameworks

Acrylamide (AA) and heterocyclic aromatic amines (HAAs), as classic hazards produced during food thermal processing, have been widely concerned, but because of their polarity difference, it is very difficult to detect these contaminants simultaneously. Herein, novel cysteine (Cys)-functionalized magnetic covalent organic frameworks (Fe₃O₄@COF@Cys) were synthesized via a thiol-ene click strategy and then used as adsorbents for magnetic solid-phase extraction (MSPE). Benefiting from the hydrophobic properties of COFs and the modification of hydrophilic Cys, AA and HAAs could be enriched simultaneously. Then, a rapid and reliable method based on MSPE coupled with HPLC-MS/MS was developed for the simultaneous detection of AA and 5 HAAs in thermally processed foods. The proposed method showed good linearity (R² ≥ 0.9987) with satisfactory limits of detection (0.012-0.210 μg kg^-1) and recoveries (90.4-102.8%). Actual sample analysis showed that the levels of AA and HAAs in French fries were affected by frying time and temperature, water activity of samples, content and type of reaction precursors, and reuse of oils.

Heterocyclic aromatic amines induce Neuro-2a cells cytotoxicity through oxidative stress-mediated mitochondria-dependent apoptotic signals

Heterocyclic aromatic amines (HAAs) are a class of hazardous compounds produced in food thermal processing. These compounds raise concerns because they have mutagenic and carcinogenic properties. However, the neurotoxicity of these compounds has received limited attention. Here, the toxic effects of three HAAs, i.e. 9H-pyrido[3,4-b]indole (Norharman), 1-methyl-9H-pyrido[3,4-b]indole (Harman), and 2-amino-3-methylimidazole[4,5-f]quinoline (IQ) were investigated in Neuro-2a cells model. The results showed that the survival rate of cells decreased in a dose-dependent manner and apoptosis occurred after exposure to the three HAAs for 24 h and 48 h. Their neurotoxicity was ranked as Harman > Norharman > IQ. Further, treatment of Harman, Norharman, or IQ at 50 and 100 μM for 48 h led to intracellular REDOX imbalance, which was manifested as increased ROS and malondialdehyde (MDA) levels, decreased GSH/GSSG ratio, and reduced SOD and CAT activities. Moreover, Norharman and Harman up-regulated the expression level of nuclear factor erythroid 2-related factor 2 (Nrf2), as well as the mRNA levels of Heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoredutase1 (NQO1), while IQ had no significant effect on the levels of Nrf2, HO-1, and NQO1. Additionally, Harman, Norharman, or IQ exposure significantly reduced mitochondrial membrane potential and intracellular ATP levels and up-regulated the levels of apoptosis-related genes and proteins. Collectively, our finding suggested that HAAs were neurotoxic, with mechanisms related to induction of oxidative stress and mitochondrial dysfunction.

A fluorescence biosensor based on double-stranded DNA and a cationic conjugated polymer coupled with exonuclease III for acrylamide detection

As a toxic substance on human health produced in food thermal treatment, simple analytical approaches are highly desired for the detection of acrylamide (ACR) in foods. With the aid of exonuclease III (Exo III), a simple fluorescence sensor was proposed based on carboxyfluorescein-labeled double-stranded DNA (FAM-dsDNA) and a cationic conjugated polymer (PFP). Fluorescence resonance energy transfer (FRET) efficiency between FAM and PFP was changed with and without ACR. When ACR was present, ACR and single-stranded DNA (P1, ssDNA) formed an adduct, allowing free FAM-labeled complementarity strand DNA (P2, FAM-csDNA) to appear in the solution and avoiding the digestion of P2 by Exo III. After the addition of PFP, the interaction of PFP and FAM induced strong FRET. Under optimized conditions, ACR was detected with a limit of detection (LOD) of 0.16 μM. According to this biosensor, a LOD of 1.3 μM in water extract samples was observed with a good recovery rate (95-110 %).

The role of 5-hydroxymethylfurfural in food and recent advances in analytical methods

The thermal processing, storage, and transportation of foodstuffs (e.g., fruit juices, coffee, honey, and vinegar) generate 5-hydroxymethylfurfural (HMF). The food industry uses this compound as a quality marker, thus increasing the demand for fast and reliable analytical methods for its determination. This review focuses on the formation of HMF in food, its desirable and toxic effects, and recent advances in analytical methods for its determination in foodstuffs. The advantages and limitations of these analytical approaches are discussed relative to the main analytical features.

Comparative Pharmacokinetics of Seven Major Compounds in Normal and Atherosclerosis Mice after Oral Administration of Simiao Yong'an Decoction

Simiao Yong'an decoction (SMYAD), a classic traditional Chinese medicine formula, has been used to treat atherosclerosis (AS) in clinical in China, but its therapeutic mechanism and pharmacodynamic material basis are not clear. In this study, the AS model was caused by a high-fat diet and perivascular carotid collar placement (PCCP), and SMYAD was orally administered to the model and normal mice. A rapid, sensitive, selective, and reliable method using ultrahigh-performance liquid chromatography (UHPLC) system combined with a Q Exactive HF-X mass spectrometer (UHPLC-Q Exactive HF-X MS) was established and validated for the simultaneous determination of seven compounds, including harpagide, chlorogenic acid, swertiamarin, sweroside, angoroside C, liquiritin, and isoliquiritigenin in the plasma of normal and AS mice. The specificity, linearity, precision, accuracy, recovery, and stability of the method were all within the acceptable criteria. The results showed that some pharmacokinetic behaviors of harpagide, chlorogenic acid, and isoliquiritigenin were significantly different among the two groups of mice. The specific parameter changes were harpagide (AUC_0–t and AUC_0–∞ were 11075.09 ± 2132.38 and 16221.95 ± 5622.42 ng·mL⁻¹·h, respectively; CLz/F was 2.45 ± 0.87 L/h/mg), chlorogenic acid (t_1/2 was 21.59 ± 9.16 h; AUC_0–∞ was 2637.51 ± 322.54 ng·mL⁻¹·h; CLz/F was 13.49 ± 1.81 L/h/mg) and isoliquiritigenin (AUC_0–t and AUC_0–∞ were 502.25 ± 165.65 and 653.68 ± 251.34 ng·mL⁻¹·h, respectively; CLz/F was 62.16 ± 23.35 L/h/mg) were altered under the pathological status of AS. These differences might be partly ascribed to the changes in gastrointestinal microbiota, nonspecific drug transporters, and cytochrome P450 activity under the AS state, providing research ideas and experimental basis for pharmacological effects and pharmacodynamic material basis.