Recent Advances in the Determination of Biogenic Amines in Food Samples by (U)HPLC

Targeted inhibition of biogenic amine-producing strains by spice extracts and control of biogenic amine accumulation in reduced-salt dry sausages

This study aimed to screen spice extracts that can target the inhibition of biogenic amine (BA)-producing bacteria and reduce the BA accumulation in reduced-salt dry sausages. A total of 59 bacterial strains were isolated from reduced-salt dry sausages; among them, three isolates, namely, Staphylococcus epidermidis S1, S. saprophyticus S2, and S. edaphicus S3, had the strongest ability to produce BA. Eight spice extracts, i.e. Angelica dahurica, cinnamon, ginger, clove, fennel, Amomum, nutmeg, and orange peel, were extracted. The inhibition zone diameter and minimum inhibitory concentration indicated that A. dahurica, Amomum, and clove elicited the strongest inhibitory effect on BA-producing strains. Growth kinetics showed the strongest inhibitory effect of clove extracts, followed by Amomum and A. dahurica. In the medium system, clove extract was the most effective in controlling the total BA content by inhibiting of BA-producing strains S. epidermidis S1, S. saprophyticus S2, and S. edaphicus S3; their contents were reduced by 23.74%, 31.05% and 21.37%, respectively. In the dry sausage system, the control of BA accumulation by clove was quite prominent, and the total BA content was reduced from 373.70 mg/kg to 259.05 mg/kg on day 12.

Concentration-tuned diverse response to selective biogenic amines using a reusable fluorophore: monitoring protein-rich food spoilage

Maintaining the freshness of food is essential for a healthy and quality life. Nevertheless, it remains a global challenge. Hence, an easy detection and monitoring protocol would be highly desirable. A cyanoacrylic acid (CAA)-based fluorophore is manifested as a reusable platform that responds diversely against different concentrations of selective aliphatic biogenic amines (BAs) in both solution and vapor phases. Slow spoilage of the protein-rich food is progressively monitored through emission shifts visible to the naked eye. This fluorophore provides easy and naked-eye detection of the BA vapor through a change in emission, i.e., red → orange → orange-yellow → cyan → green and quantum yield enhancement, which occur in stepwise increments of vapor concentrations. The probe design includes π-conjugated functionalized fluorescent molecules linked to multiple twisting sites, resulting in both solid and solution-state emission. The attached carboxylic acid responds quickly with selective BAs, mainly putrescine (PUT), cadaverine (CAD), and spermidine (SPM), where the concentration-based emission variation has appeared to be distinct and prominent against PUT [sensitivity (μM): 2 (solution); 3.3 (vapour)]. The selectivity towards diamine can be clarified by the formation of carboxylic acid salts and the consequent proton exchanges between free and protonated amines. In addition, -CN···H interaction is likely to develop within this ammonium carboxylate system, providing extra stability. Such ammonium carboxylate salt formation and gradual change in the molecular arrangement, resulting in symmetry development, are validated by FT-IR and wide-angle X-ray diffraction studies. Besides, this fact is supported by DFT studies that validate intramolecular H-atom exchange between free amine and ammonium salt units. A fluorophore-coated coverslip, filter paper, or silica gel-coated Al-plate is fruitfully utilized to detect the freshness of fish and chicken, which reveals the potential of this probe to prevent food waste and control food safety.

Bacterial cellulose/gelatin-based pH-responsive functional film for food freshness monitoring

Food safety is related to public health and environmental safety. Therefore, it is necessary to develop accurate and effective detection methods to assess food quality and safety. In this study, a pH-responsive functional film (BC/GA/FITC/PCA) was generated for the real-time and visual monitoring of shrimp freshness. Bacterial cellulose /Gelatin (BC/GA) was used as a film-forming matrix, and fluorescein isothiocyanate (FITC) and red cabbage (PCA) were used as the response signals. The addition of FITC and PCA increased the shading capacity (< 30 %) and antioxidant properties (22.8 %) of the films. WCA (82.73 ± 0.95°), WVP (1.48 × 10-11 g·cm/cm2·s·Pa) and OTR (2.42 × 10-15 cm3·cm/cm2·s·Pa) indicated that the film possessed water resistance and oxygen barrier properties. When exposed to daylight, the film underwent a color transition from purple to green as the ammonia concentration increased. In addition, the blue-green fluorescence of the films gradually increased and the detection limit was low (170 ppb). In particular, the change in film color caused by shrimp spoilage corresponded to the TVBN value. This study work provides a new strategy for controlling and monitoring food safety and has a wide range of applications in the fields of food-active packaging and smart packaging.

Authentication of Cocoa Products Based on Profiling and Fingerprinting Approaches: Assessment of Geographical, Varietal, Agricultural and Processing Features

Cocoa and its derivative products, especially chocolate, are highly appreciated by consumers for their exceptional organoleptic qualities, thus being often considered delicacies. They are also regarded as superfoods due to their nutritional and health properties. Cocoa is susceptible to adulteration to obtain illicit economic benefits, so strategies capable of authenticating its attributes are needed. Features such as cocoa variety, origin, fair trade, and organic production are increasingly important in our society, so they need to be guaranteed. Most of the methods dealing with food authentication rely on profiling and fingerprinting approaches. The compositional profiles of natural components -such as polyphenols, biogenic amines, amino acids, volatile organic compounds, and fatty acids- are the source of information to address these issues. As for fingerprinting, analytical techniques, such as chromatography, infrared, Raman, and mass spectrometry, generate rich fingerprints containing dozens of features to be used for discrimination purposes. In the two cases, the data generated are complex, so chemometric methods are usually applied to extract the underlying information. In this review, we present the state of the art of cocoa and chocolate authentication, highlighting the pros and cons of the different approaches. Besides, the relevance of the proposed methods in quality control and the novel trends for sample analysis are also discussed.

Multiplex Detection of Biogenic Amines for Meat Freshness Monitoring Using Nanoplasmonic Colorimetric Sensor Array

Biogenic amines (BAs) were presented as significant markers for the evaluation of the spoilage of meat and meat products. In this work, a colorimetric sensor array was developed for the discrimination and detection of spermine (SP), spermidine (SD), histamine (HS), and tryptamine (TP) as important BAs in food assessment. For this aim, two important spherical plasmonic nanoparticles, namely gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs), were utilized as the sensing elements of the probes. The cross-reactive interaction of the target biogenic amines and the plasmonic nanoparticles caused the aggregation-induced UV-Vis spectra changes, which were accompanied by visual color variation in the solution. The collected responses were analyzed by principal component analysis-linear discrimination analysis (PCA-LDA) to classify the four BAs. This colorimetric sensor array can also discriminate between the individual BAs and their mixture accurately. Partial least squares regression (PLS-R) was also utilized for quantitative analysis of the BAs. The wide linear concentration ranges of 0.1-10.0 µM for the four BAs and desirable figures of merits (FOMs) showed the potential of the developed sensor for quantitative detection of the BAs. Finally, the practical ability of the developed probe was studied by the determination of the BAs in the meat samples, which successfully proved the potential of the colorimetric sensor array in a food sample.

Characterization and Mechanism of Tea Polyphenols Inhibiting Biogenic Amine Accumulation in Marinated Spanish Mackerel

Putrescine is a low-molecular-weight organic compound that is widely found in pickled foods. Although the intake of biogenic amines is beneficial to humans, an excessive intake can cause discomfort. In this study, the ornithine decarboxylase gene (ODC) was involved in putrescine biosynthesis. After cloning, expression and functional verification, it was induced and expressed in E. coli BL21 (DE3). The relative molecular mass of the recombinant soluble ODC protein was 14.87 kDa. The function of ornithine decarboxylase was analyzed by determining the amino acid and putrescine content. The results show that the ODC protein could catalyze the decarboxylation of ornithine to putrescine. Then, the three-dimensional structure of the enzyme was used as a receptor for the virtual screening of inhibitors. The binding energy of tea polyphenol ligands to the receptor was the highest at -7.2 kcal mol^-1. Therefore, tea polyphenols were added to marinated fish to monitor the changes in putrescine content and were found to significantly inhibit putrescine production (p < 0.05). This study lays the foundation for further research on the enzymatic properties of ODC and provides insight into an effective inhibitor for controlling the putrescine content in pickled fish.

Cyanostilbene-based fluorescent paper array for monitoring fish and meat freshness via amino content detection

The detection of biogenic amines released from degraded meats is an effective method for evaluating meat freshness. However, existing traditional methods like titration are deemed tedious, while the use of sophisticated analytical instruments is not amenable to field testing. Herein, a cyanostilbene-based fluorescent array was rapidly fabricated using macroarray synthesis on a cellulose paper surface to detect amines liberated from spoiled beef, fish, and chicken. The fluorescence changes of immobilized molecules from the interaction with gaseous amines were used to monitor changes in freshness levels. Thanks to the high-throughput nature of macroarray synthesis, a set of highly responsive molecules such as pyridinium and dicyanovinyl moieties were quickly revealed. Importantly, this method offers flexibility in sensing applications including (1) sensing by individual sensor molecules, where the fluorescence response correlated well with established titration methods, and (2) collective sensing whereby chemometric analysis was used to provide a cutoff of freshness with 73-100% accuracy depending on meat types. Overall, this study paves the way for a robust and cost-effective tool for monitoring meat freshness.

The Development of an Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry Method for Biogenic Amines in Fish Samples

Biogenic amines (BAs) are a group of substances that are formed from amino acids by decarboxylation or amination and transamination of aldehydes and ketones. They may have either an aliphatic, aromatic, or heterocyclic structure. Their quantity determines their effects and optimum amounts are essential for physiological functions, but excess BAs causes various toxic effects throughout the human body. In our study, to rapidly determine 14 BAs (histamine, tyramine, dopamine, tryptamine, serotonin, putrescine, spermine, spermidine, octopamine, benzylamine, 1-Phenylethanamine, cadaverine, 2-Phenethylamine, and agmatine) in real fish samples, an ultra-performance liquid chromatography-tandem mass spectrometry method was established. The fish sample was extracted by acetonitrile with 0.1% formic acid and stable biogenic amine derivatives could be obtained by benzoyl chloride derivatization with a shorter reaction time. The method showed good linearity with a linear range of 3-4 orders of magnitude and regression coefficients ranging from 0.9961 to 0.9999. The calculated LODs ranged from 0.1 to 20 nM and the LOQs ranged from 0.3 to 60 nM. Satisfactory recovery was obtained from 84.6% to 119.3%. The proposed method was employed to determine the concentration levels of biogenic amine derivatives in different fish. The results indicated that this method was suitable for the analysis of biogenic amines.

Bioactive Amines in Wines. The Assessment of Quality Descriptors by Flow Injection Analysis with Tandem Mass Spectrometry

Biogenic amines (BAs) occur in a wide variety of foodstuffs, mainly from the decomposition of proteins by the action of microorganisms. They are involved in several cellular functions but may become toxic when ingested in high amounts through the diet. In the case of oenological products, BAs are already present in low concentrations in must, and their levels rise dramatically during the fermentation processes. This paper proposes a rapid method for the determination of BAs in wines and related samples based on precolumn derivatization with dansyl chloride and further detection by flow injection analysis with tandem mass spectrometry. Some remarkable analytes such as putrescine, ethanolamine, histamine, and tyramine have been quantified in the samples. Concentrations obtained have shown interesting patterns, pointing out the role of BAs as quality descriptors. Furthermore, it has been found that the BA content also depends on the vinification practices, with malolactic fermentation being a significant step in the formation of BAs. From the point of view of health, concentrations found in the samples are, in general, below 10 mg L^-1, so the consumption of these products does not represent any special concern. In conclusion, the proposed method results in a suitable approach for a fast screening of this family of bioactive compounds in wines to evaluate quality and health issues.

Simultaneous Determination of Amino Acids and Biogenic Amines by Liquid Chromatography Coupled to Mass Spectrometry for Assessing Wine Quality

Biogenic amines (BAs) and free amino acids (AAs) are low-molecular nitrogenous compounds occurring in a wide range of foodstuffs, found in increased amount in different fermented foods, seafood, and wines. This study deals with the development of an analytical method based on liquid chromatography with tandem mass spectrometry with precolumn derivatization with dansyl chloride for the determination of BAs and AAs in musts, wines, and sparkling wines. The resulting compositional profiles have been exploited as potential descriptors of quality and other oenological issues using chemometric methods including principal component analysis (PCA) and partial analysis of least squares-discriminants (PLS-DA). Proline is the most abundant compound, and other remarkable species are lysine, ethanolamine, tyramine, histamine, and putrescine. Fermented samples (wines and sparkling wines) are much richer in both BAs and free AAs than the initial musts. Significant differences have also been noticed in the quality, as the best products display, in general, lower levels. The dissimilarities in the content of the analytes between the two grape varieties studied (pinot noir and xarel·lo) and those dealing with quality aspects have made it possible to establish a tree to classify the samples based on these two features with excellent classification rates.

Pressure-assisted electrokinetic injection for the stacking of biogenic amines gives enhancement factor up to 1000 in CE with UV detection

Pressure-assisted electrokinetic injection (PAEKI) was applied for stacking of positively charged biogenic amines (BAs) to improve the sensitivity of capillary electrophoresis (CE). It is well known that the essential step for PAEKI is finding a stationary state of the running buffer such that the movement of the running buffer due to electroosmotic flow (EOF) is counterbalanced by external pressure in the opposite direction of the EOF under a given electric field. In order to find the balance point systematically and integrally, we studied the velocity of the whole BGE in the capillary by the impetus of opposite direction pressure (-0.1 to -0.6 psi), and the velocity of EOF with different voltages. According to the two sets of linear data, the EOF of CE coupled with PAEKI could be counterbalanced at the opposite direction pressure (-0.1 psi) and voltage (7.8 kV). In this study, the injection time was extended up to 0.35 min for all BAs and 0.70 min for the direct ultraviolet (UV) detection of BAs. Compared with hydrodynamic injection (HDI), the enrichment factors for sample injection times of 0.35 min and 0.70 min were 480-fold and 970-fold, respectively. The limits of detection (LODs) (S/N = 3) of indirect and direct UV detection were respectively 8.7-24.3 nmol L^-1 and 0.4-4.5 nmol L^-1, which reaches the sensitivity of high-performance liquid chromatography-mass spectrophotometry (HPLC-MS). With appropriate sample dilution, PAEKI can be used in the analysis of BAs in chicken.

Ratiometric Monitoring of Biogenic Amines by a Simple Ammonia-Response Aiegen

Herein, we developed a paper-based smart sensing chip for the real-time, visual, and non-destructive monitoring of food freshness using a ratiometric aggregation-induced emission (AIE) luminogen (i.e., H⁺MQ, protonated 4-(triphenylamine)styryl)quinoxalin-2(1H)-one) as pH sensitive indicators. Upon exposure to amine vapors, the deprotonation of H⁺MQ occurs and triggers its color change from blue to yellow, with the fluorescence redshift from blue to amaranth. Consequently, we successfully achieved the sensitive detection of ammonia vapors by recording the bimodal color and fluorescence changes. Given the high sensitivity of H⁺MQ to ammonia vapor, a paper-based smart sensor chip was prepared by depositing H⁺MQ on the commercial qualitative filter paper through a physical deposition strategy. After being placed inside the sealed containers, the developed H⁺MQ-loaded paper chip was applied to the real-time monitoring of biogenic amine contents according to its color difference and ratio fluorescence change. The detection results were further compared with those obtained by the high-performance liquid chromatography method, which verified the feasibility of the designed paper chip for the food spoilage degree evaluation. Briefly, this work indicates that the designed H⁺MQ-loaded paper chip could be a promising approach for improving food freshness monitoring.

Data Fusion Approaches for the Characterization of Musts and Wines Based on Biogenic Amine and Elemental Composition

Samples from various winemaking stages of the production of sparkling wines using different grape varieties were characterized based on the profile of biogenic amines (BAs) and the elemental composition. Liquid chromatography with fluorescence detection (HPLC-FLD) combined with precolumn derivatization with dansyl chloride was used to quantify BAs, while inductively coupled plasma (ICP) techniques were applied to determine a wide range of elements. Musts, base wines, and sparkling wines were analyzed accordingly, and the resulting data were subjected to further chemometric studies to try to extract information on oenological practices, product quality, and varieties. Although good descriptive models were obtained when considering each type of data separately, the performance of data fusion approaches was assessed as well. In this regard, low-level and mid-level approaches were evaluated, and from the results, it was concluded that more comprehensive models can be obtained when joining data of different natures.

A novel fluorescent probe of alkyne compounds for putrescine detection based on click reaction

Putrescine is a toxic biogenic amine produced in the process of food spoilage, and a high concentration of biogenic amines in foods will cause health problems such as abnormal blood pressure, headaches and tachycardia asthma/worsening asthma.

Formation, Analytical Methods, Change Tendency, and Control Strategies of Biogenic Amines in Canned Aquatic Products: A Systematic Review

ABSTRACT

Biogenic amines (BAs) are organic compounds with low molecular weight and can be used as indicators of the quality and safety of canned aquatic products during processing and storage. However, excess of these amines can cause foodborne poisoning. Therefore, the determination, analysis, and prevention of BAs are of great importance. This article focuses on the sources, formation, and pretreatment methods, as well as analytical techniques, change tendency, and control techniques of BAs, with the aim of promoting more appropriate analysis of canned aquatic products to provide a reference for the food industries.

HIGHLIGHTS

Oenological Processes and Product Qualities in the Elaboration of Sparkling Wines Determine the Biogenic Amine Content

The biogenic amine (BA) content in wines is dependent on the fermentation processes and other oenological practices, as well as on grape quality. These compounds can participate in different cellular functions in humans; however, the intake of high amounts can provoke some toxicological effects. For that reason, controlling the evolution of biogenic amines in wine production processes is of extreme importance. This work aims to assess the occurrence of biogenic amines in sparkling wines and related samples, including musts, base wines, stabilized wines, and three-month and seven-month aged sparkling wines obtained from Pinot Noir and Xarel lo grape varieties. The determination of BA content relies on liquid chromatography with fluorescence detection (HPLC–FLD) with precolumn derivatization of analytes with dansyl chloride. The analysis has shown that putrescine is the most abundant amine in these types of samples. Ethanolamine, tyramine, spermine, and histamine concentrations are also remarkable. Principal component analysis has been applied to try to extract featured information concerning overall patterns dealing with wine production steps and qualities. Interesting conclusions have been drawn on BA formation depending on different factors. BA concentrations are quite low in must but rise, especially after the first alcoholic fermentation. Moreover, BA levels are much lower in the range of products elaborated with grapes of the best qualities while they significantly increase when using grapes of lower qualities. The results obtained pointed out the analytical potential of using BAs to control the quality of wine and its production processes, thus providing valuable information for both wineries and consumers.

Selected Instrumental Techniques Applied in Food and Feed: Quality, Safety and Adulteration Analysis

This review presents an overall glance at selected instrumental analytical techniques and methods used in food analysis, focusing on their primary food science research applications. The methods described represent approaches that have already been developed or are currently being implemented in our laboratories. Some techniques are widespread and well known and hence we will focus only in very specific examples, whilst the relatively less common techniques applied in food science are covered in a wider fashion. We made a particular emphasis on the works published on this topic in the last five years. When appropriate, we referred the reader to specialized reports highlighting each technique's principle and focused on said technologies' applications in the food analysis field. Each example forwarded will consider the advantages and limitations of the application. Certain study cases will typify that several of the techniques mentioned are used simultaneously to resolve an issue, support novel data, or gather further information from the food sample.

Applications of surface functionalized Fe3O4 NPs-based detection methods in food safety

Food safety has always been an issue of great concern to people. The development of rapid, sensitive and specific detection technology of food pollutants is one of the hot issues in food science field. The rapid development of functionalized Fe₃O₄ nanoparticles (NPs) provides unprecedented opportunities and technical support for the innovation of food safety detection. The surface functionalized Fe₃O₄ NPs, which combine superparamagnetic with nanoscale feature, have become an excellent tool for food quality and safety detection. This review highlights the mechanism, principles, and applications of surface functionalized Fe₃O₄ NPs-based detection technique in the agrifood industry. Then the relevant characteristics, functional roles and general mechanisms of nanomaterial-based detection of various endogenous components and exogenous pollutants in foods are discussed in detail. Ultimately, this review is expected to promote the optimization of functionalized Fe₃O₄ NPs and provide direction for the diversity of signal recognition and the sustainability of detection methods.

Development of a Rapid and Eco-Friendly UHPLC Analytical Method for the Detection of Histamine in Fish Products

We developed, validated, and confirmed with proficiency tests a fast ultra-high-performance liquid chromatography with diode array detector (UHPLC-DAD) method to determine histamine in fish and fishery products. The proposed method consists of two successive solid–liquid extractions: one with a dilute solution of perchloric acid (6%) and the second only with water. The instrumental analysis with UHPLC provides a very fast run time (only 6 min) with a retention time of approximately 4 min, a limit of quantification (LOQ) of 7.2 mg kg⁻¹, a limit of detection (LOD) of 2.2 mg kg⁻¹, a recovery around 100%, a relative standard deviation (RSD%) between 0.5 and 1.4, and an r² of calibration curve equal to 0.9995. The method detected optimal values of the validation parameters and required a limited number of reagents in comparison to other methods reported in the literature. Furthermore, the method could detect histamine in a very short time compared with other methods. This method, in addition to being validated, precise, specific, and accurate, avoids wasting time, money, and resources, and limits the use of organic solvents.

Molecular characterization of non-biogenic amines producing Lactobacillus plantarum GP11 isolated from traditional pickles using HRESI-MS analysis

Fungal spoilage and toxic biogenic amine production is a major risk in fermented products. Therefore, the selection of nontoxic biogenic amines producing probiotic bacteria plays a vital role in the fermentation process. In the present study, a total of 18 bacterial isolates were isolated from eight different homemade pickle samples and 15 lactic acid bacteria (LAB) were identified based on biochemical tests. Out of which only seven isolates (GP1, GP2, GP3, GP4, GP5, GP9, and GP11) exhibited antifungal activity against pickle contaminant Aspergillus sp and Penicillium sp. Among the potential LAB isolates, GP11 showed the highest antifungal activity against Aspergillus sp and Penicillium sp with a zone of inhibition 28.33 ± 0.57and 19.66 ± 0.57 mm respectively. The potent LAB isolates were tested for amino acid decarboxylase activity, in which GP2, GP3, GP4, and GP5 exhibited to produce tyramine, cadaverine, and phenylethylamine while GP1 and GP5 have produced tyramine and phenylethylamine respectively. However, highly potent antifungal active isolate GP11 did not produce biogenic amine. Further, GP1, GP9, and GP11 were subjected to confirmation of biogenic amines production using HRESI-MS. HRESI-MS analysis of the GP1 and GP9 sample confirmed the presence of phenylethylamine and tyramine respectively. Interestingly, GP11 isolate did not show any biogenic amines production and GP11 was further subjected to 16S rRNA typing and identified as Lactobacillus plantarum. On in situ pickle sensory evaluation, GP11 lactopickle was graded as very good quality when compared to traditional one. Therefore L. plantarum GP11 could be developed as an ideal starter culture for the fermented production of a pickle.

Mass Spectrometry for Analysis of Changes during Food Storage and Processing

Many physicochemical changes occur during food storage and processing, such as rancidity, hydrolysis, oxidation, and aging, which may alter the taste, flavor, and texture of food products and pose risks to public health. Analysis of these changes has become of great interest to many researchers. Mass spectrometry is a promising technique for the study of food and nutrition domains as a result of its excellent ability in molecular profiling, food authentication, and marker detection. In this review, we summarized recent advances in mass spectrometry techniques and their applications in food storage and processing. Furthermore, current technical challenges associated with these methodologies were discussed.

Development of the High Sensitivity and Selectivity Method for the Determination of Histamine in Fish and Fish Sauce from Vietnam by UPLC-MS/MS

A selective, sensitive, and rapid method by using ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the determination of histamine in fish and fish sauce was developed. The optimal conditions of liquid chromatographic separation and mass spectroscopy of histamine have also been investigated. The linear ranges of the method were 20.0 ÷ 1000 ng/mL, and the corresponding correlation coefficient was 0.9993. Mean recoveries of the analyte at three spike levels (low, medium, and high) were within the range of 98.5% ÷ 102.5% (n = 7). The limit of detection (LOD) and limit of quantification (LOQ) values were 3.83 and 11.50 ng/mL for the fish sauce sample and 4.71 and 14.12 ng/mL for the fish sample, respectively. The influence of the matrix effect on the accuracy, repeatability, and recovery of the method was negligible. The recommended method was applied to determine the content of this substance in 21 fish sauce samples and 4 kinds of fish samples, which were collected from Ho Chi Minh City, Vietnam, in 2019.

Determination of Curcuminoids by Liquid Chromatography with Diode Array Detection: Application to the Characterization of Turmeric and Curry Samples

Background:

A simple, rapid and efficient method for the determination of curcumin and other polyphenols in turmeric and curry samples was here developed. The method relied on sample extraction with methanol and extract analysis by liquid chromatography with diode array detection (HPLC-DAD).

Methods:

The separation of components was carried out in reversed-phase mode using an elution gradient based on 0.1% (v/v) formic acid aqueous solution and acetonitrile as the components of the mobile phase. Chromatograms were recorded at 420 nm for specific monitoring of curcumin and related compounds.

Results:

Extraction and separation conditions were optimized by experimental design and multicriteria response functions. Figures of merit were established under the selected experimental conditions. In general, repeatability of peak areas were better than 0.4%, detection limits were below 0.006 mg L-1 and quantitative recoveries expressed as a percentage were about 100 ± 2. The method was applied to quantify curcuminoids in commercial samples. It was found that apart from curcumin, demethoxycurcumin and bisdemethoxycurcumin, other related molecules also occurred in the samples. In this regard, a tentative elucidation of possible unknown curcuminoids was attempted by liquid chromatography coupled to mass spectrometry.

Conclusion:

Differences in the compositional profiles among samples were encountered to be relevant, so that the resulting HPLC-DAD data was exploited for chemometric characterization of turmeric and curry samples. Samples were successfully discriminated according to matrix types, species varieties and origins.

Analysis of Seven Biogenic Amines and Two Amino Acids in Wines Using Micellar Electrokinetic Chromatography

A low-cost, simple, and fast method utilizing micellar electrokinetic chromatography for the simultaneous determination of seven biogenic amines and two amino acids was developed. A background electrolyte containing 5 mM phosphate buffer (pH 3.7) and 20 mM sodium dodecyl sulfate was used. The optimal separation of nine investigated analytes was achieved in 11 min, with limits of detection (S/N = 3) ranging from 0.11 to 0.61 µM. The linear ranges for all analytes were observed between 0.55 and 10.0 μM (R2 > 0.990). The developed approach was extended to the analysis of analytes in commercial wine and beer samples. The recoveries of the proposed method ranged from 98.8% to 115.6%.

Current Trends in Detection of Histamine in Food and Beverages

Histamine is a heterocyclic amine formed by decarboxylation of the amino acid l-histidine. It is involved in the local regulation of physiological processes but also can occur exogenously in the food supply. Histamine is toxic at high intakes; therefore, determination of the histamine level in food is an important aspect of food safety. This article will review the current understanding of physiological functions of endogenous and ingested histamine with a particular focus placed on existing and emerging technologies for histamine quantification in food. Methods reported in this article are sequentially arranged and provide a brief overview of analytical methods reported, including those based on nanotechnologies.

Study on the Binding Interaction of the α,α',δ,δ'-Tetramethylcucurbit[6]uril With Biogenic Amines in Solution and the Solid State

1H NMR spectroscopy and MALDI-TOF mass spectrometry were utilized to examine the binding interaction of α,α',δ,δ'-tetramethylcucurbit[6]uril (TMeQ[6]) and six biogenic amines (spermine, spermidine, 2-phenethylamine, tyramine, histamine, and tryptamine). Their 1H NMR spectra both at pD = 7 and pD = 3 revealed that four biogenic amines (spermine, spermidine, 2-phenethylamine, and histamine) can fit in the TMeQ[6] cavity, respectively, and other biogenic amines were located outside of the TMeQ[6] portal. In addition, a solid-state evaluation with single-crystal X-ray diffraction analysis showed the binding interaction of spermine, spermidine, 2-phenethylamine, and tyramine with TMeQ[6].

Competitive fluorescent pseudo-immunoassay exploiting molecularly imprinted polymers for the detection of biogenic amines in fish matrix

We developed a competitive fluorescent molecularly imprinted polymer (MIP) assay to detect biogenic amines in fish samples. MIPs synthesized by precipitation polymerization using histamine as template were used in a batch binding assay analogous to competitive fluoroimmunoassays. Introducing a complex sample matrix, such as fish extract, into the assay changes the environment and the binding conditions, therefore the importance of the sample preparation is extensively discussed. Several extraction and purification methods for fish were comprehensively studied, and an optimal clean-up procedure for fish samples using liquid-liquid extraction was developed. The feasibility of the competitive MIP assay was shown in the purified fish extract over a broad histamine range (1 - 430µM). The MIP had the highest affinity towards histamine, but recognized also the structurally similar biogenic amines tyramine and tryptamine, as well as spermine and spermidine, providing simultaneous analysis and assessment of the total amount of biogenic amines.