Determination of ethyl carbamate in wine by matrix modification-assisted headspace single-drop microextraction and gas chromatography-mass spectrometry technique

Use of magnetic ionic liquid for selective extraction of proline from wine and honey samples

A simple, cheap, green and novel air-assisted magnetic ionic liquid-based liquid phase microextraction (AA-MIL-LPME) method was developed for the selective extraction, accurate and sensitive determination of proline from wine and honey samples. Two different magnetic ionic liquids (MILs) were prepared to be investigated for use in the AA-MIL-LPME method. The accuracy of the method was evaluated using the standard addition method and comparing it with the reference method. Experimental parameters such as MIL volume, pH, amount of KCl, extraction cycle, and sample volume were optimized by Plackett-Burman design. Under optimized conditions, limits of detection and quantification of the AA-MIL-LPME method was calculated as 12.1 μg L-1 and 40 μg L-1, respectively. Relative standard deviation for 100 μg L-1 of proline (N = 10) was 3.8 %., the linear range of the method was 40-800 μg L-1 with an enrichment factor of 250. The AA-MIL-LPME method was easily applied for the determination of proline from complex sample matrices such as honey and wine by using an UV-VIS spectrophotometer.

Applications of Microextraction Technology for the Analysis of Alcoholic Beverages Quality: Current Perspectives and Future Directions

Alcoholic beverages are loved by the majority of consumers because of their diverse characteristics and rich nutritional value; thus, ensuring their quality is necessary for maintaining the rapid development of the alcoholic beverage industry. Due to trace levels of various quality factors and the complexity of the beverage body matrix, pretreatment is usually required before analysis. Among the many pretreatment methods available, microextraction has attracted increasing attention because it aligns with the development direction of green chemistry. This review surveys advancements in microextraction techniques pertaining to three quality aspects in the most frequently consumed alcoholic beverages: baijiu and huangjiu (spirits) and wine and beer (fermented alcoholic drinks). Furthermore, new directions in their development are discussed.

Extraction and analytical approaches for the determination of post-food processing major carcinogens: A comprehensive review towards healthier processed food

Different food processing methods, e.g. fermentation, grilling, frying, etc., to improve food sensory attributes or shelf-stability are typically employed in different cuisines worldwide. These methods may illicit in-situ health-hazardous chemicals via thermal or enzymatic-mediated processes or chemical interactions with food preservatives. This review provides a comparative overview of the occurrence, extraction, and determination of the major food carcinogens such as nitrosamines (NAs), biogenic amines (BAs), heterocyclic aromatic amines (HAAs), polycyclic aromatic hydrocarbons (PAHs), ethyl carbamate (EC), and malondialdehyde (MDA). Their carcinogenicity levels vary from group 1 (carcinogenic to humans) e.g. benzo[a]pyrene, group 2A (probably carcinogenic to humans) e.g. N-nitrosodiethylamine, group 2B (possibly carcinogenic to humans) e.g. chrysene or group 3 (non-classifiable as carcinogenic to humans) e.g. MDA. Chromatography-based methods are the most predominant techniques used for their analysis. LC-MS is widely used for both volatile/non-volatile NAs, HAAs, BAs, and EC, whereas GC-MS is applied more for volatile NAs, PAHs and MDA.

Direct detection of ethyl carbamate in baijiu by molecularly imprinted electrochemical sensors based on perovskite and graphene oxide

Ethyl carbamate (EC), a carcinogen commonly found in Baijiu, requires an efficient detection method for quality control and monitoring. This study introduces a novel molecularly imprinted electrochemical sensor for sensitive and selective EC detection. We proposed a simple sol-gel method for the growth of perovskite-structured lanthanum manganate (LaMnO3) on graphene oxide (GO). A non-enzymatic electrochemical sensor was developed by coating a molecularly imprinted polymer synthesized via precipitation polymerization onto the surface of LaMnO3@GO. LaMnO3, with its superior three-dimensional nanocube structure, demonstrated excellent electrocatalytic activity, while the addition of GO provided a large specific surface area. The results indicate that the developed sensor exhibits exceptional recognition ability and electrochemical activity, which is attributed to the high affinity of LaMnO3@GO@MIP for EC. The sensor displays a broad linear range from 10 to 2000 μM, with a detection limit as low as 2.18 μM and long-term durability of 28 days. Notably, it demonstrates excellent selectivity, reproducibility, and stability even under different interference conditions. The sensor was successfully used to determine EC in real Baijiu samples. Overall, the sensor has broad application prospects for detecting trace contaminants in the field of food safety.

Molecularly imprinted electrochemical sensor for ethyl carbamate detection in Baijiu based on "on-off" nanozyme-catalyzing process

Ethyl carbamate (EC) is a carcinogen widely found in the fermentation process of Baijiu. Herein, we construct a molecularly imprinted polymers/MXene/cobalt (II) based zeolitic imidazolate frameworks (MIP/MXene/ZIF-67) nano-enzyme sensor for the detection of EC during Baijiu production. The ZIF-67 is synthesized in situ on the MXene nanosheets to provide a superior catalytic activity to H2O2 and amplify the electrochemical signal. The MIP is prepared by the polymerization reaction to recognize EC. Owing to the interaction between EC and EC-MIP, the interferences are effectively eliminated, greatly improving the accuracy of the expected outcome. This approach attains an ultrasensitive assay of EC ranging from 8.9 μg/L to 44.5 mg/L with detection limit of 0.405 μg/L. The accuracy of this method is confirmed by the recovery experiment with good recoveries from 95.07% to 107.41%. This method is applied in natural EC analyses, and the results are consistent with certified gas chromatograph- mass spectrometer.

A Versatile Visual Molecular Imprinting-Driven Switchable Nanozyme Activity-Based Trimodal Assay and Logic Gate Circuits of Ethyl Carbamate

Concerns regarding the hazard of the carcinogenic ethyl carbamate (EC) have driven attempts to exploit efficient, timely, straightforward, and economic assays for warning early food safety. Here, we proposed a novel molecularly imprinted polymer Co@MOF-MIP, with a high peroxidase (POD)-like activity and a bright blue fluorescence emission, to develop a versatile visual assay for colorimetric, fluorescent, and photothermal trimodal detection and logic gate outputting of EC. Briefly, the POD-like activity of Co@MOF-MIP made it to decompose H2O2 into ·OH for oxidizing colorless 3,3',5,5'-tetramethylbenzidine (TMB) into a blue oxTMB, resulting in a 660 nm irradiated photothermal effect and bursting the blue fluorescence of Co@MOF-MIP via inner filter effect, observing a decreased fluorescence signal together with an increased colorimetric and 660 nm irradiated photothermal signals. However, EC could specifically fill the imprinted cavities of Co@MOF-MIP to block the catalytic substrates TMB and H2O2 out of Co@MOF-MIP for further reacting with the inside catalytic center of Co2+, resulting in the transformation suppressing of TMB into oxTMB, yielding an EC concentration-dependent trimodal responses in fluorescence signal enhancement, colorimetric, and 660 nm irradiated photothermal signal decreases. Assisted by the portable devices such as smartphones and hand-held thermal imagers, a visual onsite portable trimodal analytical platform was proposed for EC fast and accurate detection with the low detection limits of 1.64, 1.24, and 1.78 μg/L in colorimetric, fluorescent, and photothermal modes, respectively. Interestingly, these reactive events could be programmed by the classical Boolean logic gate analysis to offer a novel promising avenue for the big data Internet of Things monitoring and warning early residual EC in a more intelligent, dynamical, fast, and accurate manner, safeguarding food safety.

Effect of ultrasonic treatment during fermentation on the quality of fortified sweet wine

The present study aimed to investigate the potential of ultrasonic treatment during fermentation for enhancing the quality of fortified wines with varying time and power settings. Chemical analysis and sensory evaluation were conducted to assess the impact of ultrasonic treatment on wine quality. Results showed that ultrasonic treatment could increase total anthocyanin and total phenol content, reduce anthocyanin degradation rate, and improve color stability. Moreover, ethyl carbamate content was lower in the ultrasonic group after aging compared to non-ultrasonic group. A combination of 200 W for 20 min resulted in higher sensory scores and more coordinated taste, while a combination of 400 W for 40 min produced higher levels of volatile compounds (21860.12 μg/L) leading to a richer and more elegant aroma. Therefore, ultrasound can be used as a potential technology to improve the quality of wine.

Reduced production of Ethyl Carbamate in wine by regulating the accumulation of arginine in Saccharomyces cerevisiae

Ethyl carbamate (EC), a multisite carcinogenic compound, is naturally produced from urea and ethanol in alcoholic beverages. In order to reduce the content of EC in wine, the accumulation of arginine in Saccharomyces cerevisiae was regulated by genetic modifying genes involved in arginine transport and synthesis pathways to reduce the production of urea. Knockout of genes encoding arginine permease (Can1p) and amino acid permease (Gap1p) on the cell membrane as well as argininosuccinate synthase (Arg1) respectively resulted in a maximum reduction of 66.88% (9.40 µg/L) in EC, while overexpressing the gene encoding amino acid transporter (Vba2) reduced EC by 52.94% (24.13 µg/L). Simultaneously overexpressing Vba2 and deleting Arg1 showed the lowest EC production with a decrease of 68% (7.72 µg/L). The yield of total higher alcohols of the mutants all decreased compared with that of the original strain. Comprehensive consideration of flavor compound contents and sensory evaluation results indicated that mutant YG21 obtained by deleting two allele coding Gap1p performed best in must fermentation of Cabernet Sauvignon with the EC content low to 9.40 μg/L and the contents of total higher alcohols and esters of 245.61 mg/L and 41.71 mg/L respectively. This study has provided an effective strategy for reducing the EC in wine.

Formation and hazard of ethyl carbamate and construction of genetically engineered Saccharomyces cerevisiae strains in Huangjiu (Chinese grain wine)

Huangjiu, a well-known conventional fermented Chinese grain wine, is widely consumed in Asia for its distinct flavor. Trace amounts of ethyl carbamate (EC) may be generated during the fermentation or storage process. The International Agency for Research on Cancer elevated EC to a Class 2A carcinogen, so it is necessary to regulate EC content in Huangjiu. The risk of intake of dietary EC is mainly assessed through the margin of exposure (MOE) recommended by the European Food Safety Authority, with a smaller MOE indicating a higher risk. Interventions are necessary to reduce EC formation. As urea, one of the main precursors of EC formation in Huangjiu, is primarily produced by Saccharomyces cerevisiae through the catabolism of arginine, the construction of dominant engineered fermentation strains is a favorable trend for the future production and application of Huangjiu. This review summarized the formation and carcinogenic mechanism of EC from the perspectives of precursor substances, metabolic pathways after ingestion, and risk assessment. The methods of constructing dominant S. cerevisiae strains in Huangjiu by genetic engineering technology were reviewed, which provided an important theoretical basis for reducing EC content and strengthening practical control of Huangjiu safety, and the future research direction was prospected.

Development of a green liquid-phase microextraction procedure using a customized device for the comprehensive determination of legacy and current pesticides in distinct types of wine samples

In this work, we reported the development of a novel, simple, and green liquid-phase microextraction (LPME) procedure based on the use of a customized device for the determination of 47 multiclass pesticides in red, white, and rosè wine samples by GC-MS. The main parameters that affect the LPME were optimized using multivariate statistical techniques such as centroid-simplex mixture design and Doehlert design. The optimal conditions were: 70 μL of toluene as extractor solvent; concentration of NaCl (2.7%, m v-1); pH 4; and an extraction time of 30 min, under vortex-assisted agitation (at 500 rpm). After validation, it was possible to obtain LOQ values as low as 7.63 ng L-1 and extraction recoveries ranging from 81.7% to 119% for most of the target pesticides. The application of exploratory analysis, specifically Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA), provided evidence indicating contamination in the different types of wine samples, primarily by systemic fungicides.

Headspace Microextraction. A Comprehensive Review on Method Application to the Analysis of Real Samples (from 2018 till Present)

This work describes current trends in the development of headspace microextraction methods. The main trends in the selection of detection techniques used in combination with microextraction and preferences in the selection of headspace liquid-phase microextraction (HS-LPME) or headspace solid-phase microextraction (HS-SPME) methods, depending on the analytes and their quantity, are also briefly presented. In the main part of the work, on the basis of current journal literature, headspace microextraction analytical methods used for the determination of various inorganic and organic analytes are classified and compared over the last five years. The work also reflects the current modifications of techniques and approaches proposed for these microextraction methods.

A tool to assess analytical sample preparation procedures: Sample preparation metric of sustainability

Sample preparation is a key step in most analytical methods, generally regarded as the least green step of the entire procedure. The existing green metrics assess the greenness of sample preparation techniques through the evaluation of the whole analytical procedure: including sampling, sample preparation, and the final detection/quantitation. Such inclusion of the entire method makes assessing the sustainability of a newly developed sample preparation technique quite challenging, as many aspects not solely linked to the sample preparation step are unavoidably considered. Thus, an alternative metric that can explicitly and exclusively evaluate the sample preparation is proposed. The metric is simple; it reports the result with a clock-like diagram, displaying the greenness outcome of main sample preparation parameters and a total score. This new metric can differentiate closely related microextraction approaches in terms of sustainability. The metric is also open-source and can be used by downloading the Excel sheet provided.

R. Rocha C, Teixeira JA, Pereira JAM. Green Extraction Techniques as Advanced Sample Preparation Approaches in Biological, Food, and Environmental Matrices: A Review

Green extraction techniques (GreETs) emerged in the last decade as greener and sustainable alternatives to classical sample preparation procedures aiming to improve the selectivity and sensitivity of analytical methods, simultaneously reducing the deleterious side effects of classical extraction techniques (CETs) for both the operator and the environment. The implementation of improved processes that overcome the main constraints of classical methods in terms of efficiency and ability to minimize or eliminate the use and generation of harmful substances will promote more efficient use of energy and resources in close association with the principles supporting the concept of green chemistry. The current review aims to update the state of the art of some cutting-edge GreETs developed and implemented in recent years focusing on the improvement of the main analytical features, practical aspects, and relevant applications in the biological, food, and environmental fields. Approaches to improve and accelerate the extraction efficiency and to lower solvent consumption, including sorbent-based techniques, such as solid-phase microextraction (SPME) and fabric-phase sorbent extraction (FPSE), and solvent-based techniques (μQuEChERS; micro quick, easy, cheap, effective, rugged, and safe), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), in addition to supercritical fluid extraction (SFE) and pressurized solvent extraction (PSE), are highlighted.