Tyramine Content Research Articles

A hand-drawn graphite electrode for affordable analysis: Application to the enzymatic determination of tyramine in fish

The development of simpler and greener, but also reliable and efficient analytical sensors that meet the increasing global demands is a current challenge. In this work, a user-friendly and low-cost electrochemical cell was developed by combining two metallic wires (from a standard connector header) and a working electrode fabricated by pencil hand-drawing, which is one of the simplest, cheapest, and greenest ways of creating miniaturized electrodes. Graphite pencils with different degrees of hardness were tested and, using a 6B pencil, an electroanalytical platform with high precision (RSD < 5 %) was achieved. This platform was used as transducer for constructing an enzymatic biosensor for the determination of tyramine, using tyrosinase as the biological recognition element. After the optimization of several parameters, the biosensor showed a linear range between 5 and 150 mg·L−1, a limit of detection of 0.4 mg·L−1, and high selectivity for tyramine with no interference from other biogenic amines. This biosensor was successfully applied to the analysis of different fish species achieving recovery values between 87 % and 100 %. Its usefulness for monitoring tyramine concentration during the spoilage of a sardine sample was also demonstrated. Therefore, this cheap and miniaturized biosensor represents an interesting alternative for tyramine determination. Moreover, the good electrochemical features of the developed electrochemical cell demonstrated its potential for the development of future electrochemical sensors.

Synthesis of nitrogen-doped carbon quantum dots (N-CQDs) using microwaveassisted hydrothermal method for tyramine determination

In this study, we develop a rapid, efficient, low-cost and environmentally friendly method to synthesize nitrogen-doped carbon quantum dots (N-CQDs). With simple input materials as citric acid and urea, N-CQDs were sucessfully synthesized in only 5 minutes using a domestic microwave oven. Characterisation results using TEM, UV&amp;ndash;VIS, IR and fluorescence methods have demonstrated the successful doping of N into CQDs. The obtained N-CQDs material has a particle size of less than 10 nm, and the fluorescence quantum efficiency (36.6%), which is significantly higher than that of undoped CQDs (17.2%). The N-CQDs material also exhibits an on-off fluorescence effect in the presence of Au nanoparticles (AuNPs) and in the presence of tyramine, a biological amine commonly found in food products such as cheese, fish sauce, soy sauce, kimchi, etc. The fluorescence recovery of N-CQDs/AuNPs is linearly proportional to the tyramine concentration in the range from 0.02 ppm to 1 ppm, showing the possibility of using this material to detect and quantify tyramine in food samples.

Contrasting alterations in brain chemistry in a crustacean intermediate host of two acanthocephalan parasites

The dynamic properties of neural systems throughout life can be hijacked by so-called manipulative parasites. This study investigated changes in the brain chemistry of the amphipod Gammarus fossarum in response to infection with two trophically-transmitted helminth parasites known to induce distinct behavioral alterations: the bird acanthocephalan Polymorphus minutus and the fish acanthocephalan Pomphorhynchus tereticollis. We quantified brain antioxidant capacity as a common marker of homeostasis and neuroprotection, and brain total protein, on 72 pools of six brains. We analyzed the concentration of serotonin (5HT), dopamine (DA) and tyramine in 52 pools of six brains, by using ultrafast high performance liquid chromatography with electrochemical detection (UHPLC-ECD). Brain total protein concentration scaled hypo-allometrically to dry body weight, and was increased in infected gammarids compared to uninfected ones. The brain of gammarids infected with P. minutus had significantly lower total antioxidant capacity relative to total proteins. Infection with P. tereticollis impacted DA level compared to uninfected ones, and in opposite direction between spring and summer. Brain 5HT level was higher in summer compared to spring independently of infection status, and was decreased by infection after correcting for brain total protein concentration estimated from dry whole-body weight. The potential implication of 5HT/DA balance in parasite manipulation, as a major modulator of the reward-punishment axis, is discussed. Taken together, these findings highlight the need to consider both brain homeostatic and/or structural changes (antioxidant and total protein content) together with neurotransmission balance and flexibility, in studies investigating the impact of parasites on brain and behavior.

Tyramine-Mediated Hyperactivity Modulates the Dietary Habits in Helicoverpa armigera.

Helicoverpa armigera exhibits extensive variability in feeding habits and food selection. Neuronal regulation of H. armigera feeding behavior is primarily influenced by biogenic amines such as Tyramine (TA) and Octopamine (OA). The molecular responses of H. armigera to dietary challenges in the presence of TA or OA have yet to be studied. This investigation dissects the impact of OA and TA on H. armigera feeding choices and behaviors under non-host nutritional stress. It has been observed that feeding behavior remains unaltered during the exogenous administration of OA and TA through an artificial diet (AD). Ingestion of higher OA or TA concentrations leads to increased mortality. OA and TA treatment in combination with host and non-host diets results in the induction of feeding and higher locomotion toward food, particularly in the case of TA treatment. Increased expression of markers, prominin-like, and tachykinin-related peptide receptor-like transcripts further assessed increased locomotion activity. Insects subjected to a non-host diet with TA treatment exhibited increased feeding and overexpression of the feeding indicator, the Neuropeptide F receptor, and the feeding regulator, Sulfakinin, compared with other conditions. Expression of sensation and biogenic amine synthesis genesis elevated in insects fed a non-host diet in combination with OA or TA. Metabolomics analysis revealed a decreased concentration of the feeding behavior elicitor, dopamine, in insects fed a non-host diet containing TA. This work highlights the complex interplay between biogenic amine functions during dietary stress and suggests the role of tyramine in feeding promotion under stressed conditions.

Metagenomic and culturomic analyses of bacterial species contributing to tyramine formation in Cheonggukjang

This study investigated bacterial compositions and their contributions to biogenic amine (BA) formation in Cheonggukjang using metagenomic and culturomic analyses. Metagenomic analysis revealed Bacillus spp. as dominant (96.19%), of which B. piscis (74.79%) and B. hisashii (19.39%) were predominant. Based on the relative abundance of BA-associated genes, B. piscis showed the highest correlations with tyrosine (R2 = 0.76) and lysine decarboxylation (R2 = 0.50), and B. hisashii with histidine decarboxylation (R2 = 0.42). Meanwhile, culturomic analysis revealed that, among mesophilic bacteria, Bacillus spp. were dominant (98.78%). As lactic acid bacteria (LAB), only Enterococcus spp. were detected. Of halotolerant LAB, Enterococcus spp. were dominant (90.72%). Based on in vitro BA productivity of all bacterial strains, Enterococcus spp. contributed primarily to tyramine formation. Thus, it was observed that the bacterial compositions and their contributions to BA formation determined using the two analyses differed considerably. To verify such observations, Cheonggukjang fermentation experiments were conducted using Bacillus and Enterococcus strains. The tyramine content was higher in the Bacillus-fermented samples (over 120.00 ± 14.18 mg/kg) than in the Enterococcus-fermented sample (34.24 ± 3.37 mg/kg). However, the spermidine and spermine content was higher in the Enterococcus-fermented sample (108.04 ± 6.69 and 22.93 ± 6.28 mg/kg, respectively). Therefore, these two bacterial species may contribute together to BA formation in Cheonggukjang but in slightly different manners.

DETERMINATION OF BIOGENIC AMINES IN CULTIVATED AND PROCESSED MUSHROOMS INTENDED FOR THE SLOVAK MARKET

Cultivated and processed white button mushrooms are widely used in the menu of the Slovak consumers. However, these food items can potentially contain biogenic amines, attributed to the presence of precursor compounds and their susceptibility to microbial spoilage. Biogenic amines significantly influence food quality and can pose health risks to consumers. This study is focused on determination of spermidine, putrescine, tyramine, cadaverine, histamine, spermine, and 2-phenylethylamine in processed mushroom products available in the Slovak market. The findings revealed considerable variability in biogenic amine content across individual products, influenced by the producer. Spermidine, putrescine and spermine emerged as the predominant biogenic amines with concentration ranges 2349.8 -7412.8, 37.2 - 607.5 and 74.2 - 267.6 mg/kg DW, respectively. Tyramine and histamine were detected in 22.2% of processed mushroom samples with one product exceeding concentration 200 mg/kg DW. Cadaverine was identified in 44.4% samples. The presence of histamine has to be concerned regarding potential health risks for consumers. Comparison of the mushroom products showed significant differences between the groups of products with whole mushrooms vs. sliced mushrooms in brine in case of the content of spermine (p&lt;0.001), water content (p&lt;0.01), putrescine, histamine and tyramine (p&lt;0.05 for all these BAs). No significant differences were found between the groups for the cadaverine, spermidine and total content of biogenic amines. In house rapid validation was performed in term of determination of limits of detection and limits of quantification and intraday precision of retention time for individual biogenic amines in this study. Limits of detection ranged from 0.013 to 0.029 µg/mL and limits for quantification were in the range from 0.039 to 0.087 µg/mL. The RSD for the retention time in standard solutions did not exceed 0.12%.

The Influence of Different Levels of Sodium Chloride, Sodium Nitrite, and Glucose on Biogenic Amines and Microbial Communities in Fermented Goat Meat Sausage.

The influence of different levels of sodium chloride, sodium nitrite, and glucose on the quality characteristics of spontaneously fermented goat meat sausage was investigated. The amounts of total biogenic amines in all the sausages ranged from 324.70 to 388.77 mg/kg; among them, spermine was the most abundant, with amounts ranging from 230.96 to 275.78 mg/kg. Increasing sodium chloride from 15 to 35 g/kg, the content of cadaverine, putrescine, tyramine, phenylethylamine, tryptamine, and total amines decreased, and Enterobacteriaceae counts decreased at the same time. Increasing sodium nitrite from 150 to 250 mg/kg, the content of cadaverine, histamine, and total amines decreased, while Enterobacteriaceae counts decreased simultaneously. Increasing glucose from 10 to 40 g/kg, the content of cadaverine, spermidine, and total amines decreased. Enterococcus was the most abundant genus across all the samples, and the relative abundance of Enterococcus was reduced obviously by increasing sodium nitrite and glucose levels. The top 10 differential bacterial taxa for each additive group were respectively obtained, and microbial biomarkers for each level of additive within its group were acquired, respectively. Through Pearson correlation, Lactobacillus was positively correlated with phenylethylamine, tryptamine, tyramine, and cadaverine, Bacteroides and Sediminibacterium were positively correlated with phenylethylamine and putrescine, respectively, suggesting they have the potential to produce biogenic amines. The results provided references for controlling the accumulation of biogenic amines in fermented goat meat sausage via the addition of auxiliary additives during the processing.

Effects of Caragana korshinskii tannin on fermentation, methane emission, community of methanogens, and metabolome of rumen in sheep.

The purpose of this research was to investigate the impact of dietary supplementation of Caragana korshinskii tannin (CKT) on rumen fermentation, methane emission, methanogen community and metabolome in rumen of sheep. A total of 15 crossbred sheep of the Dumont breed with similar body conditions, were divided into three groups (n = 5), which were fed with CKT addition at 0, 2 and 4%/kg DM. The study spanned a total of 74 days, with a 14-day period dedicated to adaptation and a subsequent 60-day period for conducting treatments. The results indicated that the levels of ammonia nitrogen (NH3-N) and acetate were reduced (p < 0.05) in rumen sheep fed with 2 and 4% CKT; The crude protein (CP) digestibility of sheep in 2 and 4% CKT groups was decreased(p < 0.05); while the neutral detergent fiber (NDF) digestibility was increased (p < 0.05) in 4% CKT group. Furthermore, the supplementation of CKT resulted in a decrease (p < 0.05) in daily CH4 emissions from sheep by reducing the richness and diversity of ruminal methanogens community, meanwhile decreasing (p < 0.05) concentrations of tyramine that contribute to methane synthesis and increasing (p < 0.05) concentrations of N-methy-L-glutamic acid that do not contribute to CH4 synthesis. However, CH4 production of DMI, OMI, NDFI and metabolic weight did not differ significantly across the various treatments. To sum up, the addition of 4% CKT appeared to be a viable approach for reducing CH4 emissions from sheep without no negative effects. These findings suggest that CKT hold promise in mitigating methane emissions of ruminant. Further investigation is required to evaluate it effectiveness in practical feeding strategies for livestock.

Effects of probiotics on biogenic amines content in fermented milk during fermentation and storage

This study aimed to investigate the formation of biogenic amines (BAs) during fermentation and storage in fermented milk. The traditional culture was used as a control, and three different probiotics were added to the above culture as different experimental groups. Results revealed that the degree of protein hydrolysis in fermented milk increased during fermentation but decreased during storage, reaching a maximum value (14.8–17.3%) at the end of fermentation. The trends of total amino acid content and total BAs content were similar to those of the degree of hydrolysis. The total amino acid content reached a maximum value (2.83–3.22 mg/mL) after 24 h of post-ripening. Fermented milk had the highest tyramine content, but it was always below 10 mg/L. The total BAs content in fermented milk during fermentation and storage ranged from 9.04 to 15.2 mg/L and 6.37 to 14.0 mg/L, respectively. These levels consistently remained below the threshold considered harmful to humans. The pH reduction rate, the total bacterial cell number, the degree of hydrolysis, and the total amino acid content in fermented milk all affected the formation and content of BAs. This study provides a foundation for assessing the potential public health impact of BAs in fermented milk.

Lentils pasta by-product in a complete extruded diet for dogs and its effect on extrusion, digestibility, and carbohydrate metabolism.

Recently, increasing effort has been directed toward environmental sustainability in pet food. The aim of this study was to evaluate the extrusion parameters, nutrient digestibility, fecal characteristics, palatability and insulinemic and glycaemic curves of a complete diet for dogs in which the main carbohydrate source was a red lentil pasta by-product (LP). Five experimental diets were formulated: a basal diet (CO) based on rice and a poultry by-product meal; three experimental diets where LP substituted rice at 33, 66, or 100% (LP33, LP66, and LP100, respectively); and a diet formulated on 70% of the basal diet (CO) plus 30% LP (LPS) to evaluate the digestibility of LP ingredient. The extruder pressure, hardness and bulk density of the kibble increased in a linear manner with increasing LP percentage (P < 0.05), without affecting starch gelatinization. According to polynomial contrast analysis, rice replacement with LP at 33 and 66% caused no reduction in apparent total tract digestibility coefficient (ATTDC), with similar or higher values compared with the CO diet. Nitrogen balance did not change (P > 0.05), but we observed a linear increase in feces production and moisture content as the LP inclusion rate rose and a linear decrease in feces pH (P < 0.05). Nevertheless, the fecal score was unaffected. Fecal acetate, propionate, total short-chain fatty acids (SCFA), branched-chain fatty acids, and lactate all increased linearly as the LP inclusion rate increased (P < 0.05), without altering ammonia concentration in feces. Feces concentrations of cadaverine, tyramine, histamine, and spermidine also increased in a linear manner with increasing LP inclusion (P < 0.05). The fermentation of LP dietary fiber by the gut microbiota increased the concentration of desirable fermentation by-products, including SCFA and spermidine. The post-prandial glucose and insulin responses were lower in the dogs fed the LP100 diet compared with CO, suggesting the possible use of this ingredient in diets designed to generate a low glycaemic response. Finally, the palatability study results showed a preference for the LP100 ration in both the "first choice" and the "consumption rate" evaluation (P < 0.05). This trial reveals how a by-product discarded from the human-grade food chain retains both its nutritional and organoleptic properties.

Tyramine Adsorption Using the Modification of Takari Natural Sand-Based Silica with Bovine Serum Albumin (BSA)

In this article, we use a batch method to convey tyramine adsorption by modifying Takari natural sand-based silica with BSA and tyramine adsorption. The research stages include the optimization of adsorbent mass, pH, temperature, determination of the isotherm model, and thermodynamic parameters of tyramine adsorption. The tyramine concentration was determined using UV-Vis. The characterizations carried out were functional groups using FT-IR and surface morphology using SEM. The results of FT-IR characterization demonstrated the success of BSA modification, as observed in the C-H, N-H, and C-N groups, which are the typical functional groups of BSA. The SEM image of SiO2@BSA before tyramine adsorption revealed unevenly sized particles, uneven distribution, and agglomeration, leading to larger particles. The morphology of SiO2@BSA-tyramine appeared to be more uniform, exhibiting a smoother shape with a slightly uneven surface. The optimum pH was 5 (qe=11.74 mg/g), and the optimum temperature was 303 K (qe= 2.47 mg/g). The isotherm study showed that the adsorption adhered to the Redlich-Peterson isotherm model with an R2 value of 0.987 (qe=5.157 mg/g and n =3.759). The thermodynamic study demonstrated ∆Ho = 49.08 kJ/mol, ∆Go =-17.84; -20.05 and -22.26 kJ/mol, and ∆So =0.22 kJ/mol.K. These results indicated that the tyramine adsorption process on SiO2@BSA adsorbent occurred endothermically and spontaneously at the temperature of 303 K, and the adsorption was of a physical-chemical adsorption type.

Proanthocyanidins from Chinese Bayberry (Myrica rubra Sieb. et Zucc.) Leaves Effectively Inhibit the Formation of Biogenic Amines in the Brewing Soy Sauce

Biogenic amines are a group of metabolites generated in the process of soy sauce brewing, which can result in severe negative impacts on human health at high concentrations. In this study, we innovatively proposed natural extracts (0.1 wt%), of proanthocyanidins, from Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves to alternate commercial additives (0.1 wt%), i.e., sodium benzoate and potassium sorbate, for lowering the harmful biogenic amine formation during the fermentation of soy sauce. HPLC results showed that natural extracts from Chinese bayberry leaves could effectively decrease the content of cadaverine, putrescine, histamine, tyramine, phenylethylamine, and agmatine (p &lt; 0.05). In contrast to the inhibitory influence exhibited by commercial sodium benzoate and potassium sorbate, extracts from bayberry leaves can maintain spermidine, spermine, and tryptamine at certain concentrations. Furthermore, both sodium benzoate and potassium sorbate significantly reduced the production of ammonium salt and characteristic components (p &lt; 0.05), like soluble saltless solids, total nitrogen, and amino acid nitrogen, during the 40-day fermentation of soy sauce, whereas proanthocyanidins extracted from Chinese bayberry leaves slightly inhibited the content of ammonium salt. Thus, we can conclude that, while inhibiting the biogenic amine and ammonium salt production, extracts from Chinese bayberry leaves facilitate or maintain the production of characteristic indicators compared to commercial sodium benzoate and potassium sorbate. Taken together, natural extracts from Chinese bayberry leaves can be considered a natural additive to significantly improve the quality of traditional brewing soy sauce.

Anonna crassiflora suppresses colonic carcinogenesis through its antioxidant effects, bioactive amines, and phenol content in rats

Marolo (Annona crassiflora) is an underutilized Brazilian Cerrado fruit with few reports in the literature about its bioactive compounds and functional properties. In this context, the chemoprevention against the carcinogen 1,2-dimethylhydrazine (DMH)-induced pre-neoplastic lesions in Wistar rat colon was investigated and correlated with marolo’s antioxidant activity and the contents of phenolic compounds and bioactive amines. Total phenolic compounds (TPC) and total flavonoids compounds (TFC) were determined in the marolo pulp extract by spectrophotometric and Ultra-Performance Liquid Chromatography and diode array detection (UPLC-DAD) analysis. Free bioactive amines were determined by High Performance Liquid Chromatography and fluorescence detection (HPLC-FLD) after post column derivatization with o-phthalaldehyde. In addition, the in vitro antioxidant activity was determined by DPPH, and ABTS. Wistar rats were treated orally with marolo pulp at 0.7, 1.4 and 2.8 g/kg body weight (bw)/day added to a standard ration. Four subcutaneous injections of DMH (40 mg/kg bw) were used to induce a pre-neoplastic lesion that was assessed by the aberrant crypt foci (ACF) assay. The marolo pulp (fresh weigh) showed high content of total phenolic compounds (9.16 mg GAE/g), with predominance of chlorogenic acid (1.86 µg/g) and epicatechin (0.99 µg/g), and total flavonoids (7.26 mg CE/g), ∼85 % of the TPC. The marolo pulp had significant contents of tyramine (31.97 mg/kg), putrescine (20.65 mg/kg), and spermidine (6.32 mg/kg). The marolo pulp inhibited (p < 0.05) pre-neoplastic lesions induced by DMH administration at the all concentrations tested. These findings indicate that marolo pulp has a colon carcinogenesis chemopreventive effect, which could be due to, at least in parts, its antioxidant action associated with its phenolics and flavonoids content as well of spermidine.

Distinct and Dynamic Changes in the Temporal Profiles of Neurotransmitters in Drosophila melanogaster Brain following Volatilized Cocaine or Methamphetamine Administrations.

Due to similarities in genetics, cellular response, and behavior, Drosophila is used as a model organism in addiction research. A well-described behavioral response examined in flies is the induced increase in locomotor activity after a single dose of volatilized cocaine (vCOC) and volatilized methamphetamine (vMETH), the sensitivity, and the escalation of the locomotor response after the repeated dose, the locomotor sensitization. However, knowledge about how vCOC and vMETH affect different neurotransmitter systems over time is scarce. We used LC-MS/MS to systematically examine changes in the concentration of neurotransmitters, metabolites and non-metabolized COC and METH in the whole head homogenates of male flies one to seven hours after single and double vCOC or vMETH administrations. vMETH leads to complex changes in the levels of examined substances over time, while vCOC strongly and briefly increases concentrations of dopamine, tyramine and octopamine followed by a delayed degradation into N-acetyl dopamine and N-acetyl tyramine. The first exposure to psychostimulants leads to significant and dynamic changes in the concentrations relative to the second administration when they are more stable over several hours. Further investigations are needed to understand neurochemical and molecular changes post-psychostimulant administration.

Quantification of biogenic amines and adaptation of an index as a quality indicator of rendered pig meals

The objective of this study was to quantify biogenic amines and to adapt equations for the calculation of the biogenic amine index (BAI) in rendered pig carcass meals (RPCM). Samples of RPCM from three different origins were evaluated: Group 1—experimentally produced meal; Group 2—meal produced in a plant dedicated to rendering pigs dead on the farm due to non-infectious causes; and Group 3—meal produced in commercial rendering plants. Group 1 meals were produced from sow carcasses that were stored either under environmental temperature (ET = 25 °C) or refrigeration temperature (RT = −6 °C), and their biogenic amine contents were analyzed at 0, 24, 48, and 72 h of storage. The levels of the biogenic amines phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, and spermine of all meals were determined by high-performance liquid chromatography, and their BAIs were calculated. Group 1 meals stored at ET presented higher phenylethylamine, putrescine, cadaverine, and tyramine contents compared with those stored at RT after 24 h storage, whereas spermidine and spermine contents decreased after 24 h of storage at ET. The adapted BAI can be used as a quality indicator of RPCM.

Towards new fluorometric methodologies based on the in-situ generation of gold nanoclusters

In this manuscript a method for the fluorometric determination of tyramine is described. It is based on the direct reaction between Au(III) and tyramine in a phosphate buffer which produces fluorescent gold nanoclusters (AuNC) (λexc = 320 nm, λem = 410 nm) with a diameter of 1.50 ± 0.06 nm. The Au(III) and buffer solutions are mixed and after 140 s, tyramine solution is added; which produces a fast and stable fluorescence signal. The formation of AuNC is demonstrated by STEM and, more importantly, this reaction could be followed by Atomic Fluorescence Microscopy (AFM). The method allows the determination of tyramine in the range from 6.0x10−7 M (limit of quantification) up to 1.2x10−4 M; with a relative standard deviation (RSD) ranges from 1.8% to 4.4% depending on the tyramine concentration. The mechanism of AuNC formation involves the Au(III) reduction via the phenol group and the complexation with the amine group. Putrescine and cadaverine do not produce interference, meanwhile histamine causes a proportional decrease in the signal which can be overcome by the standard addition method. The method was applied to the determination of tyramine in a tuna and cheese samples and the results obtained are in statistical agreement with these obtained using a validated or standard method.

Metagenomic Insights into the Regulatory Effects of Microbial Community on the Formation of Biogenic Amines and Volatile Flavor Components during the Brewing of Hongqu Rice Wine.

As one of the typical representatives of Chinese rice wine (Huangjiu), Hongqu rice wine is produced with glutinous rice as the main raw material and Hongqu as the fermentation starter. The complex microbial flora in the brewing process may have a great influence on the formation of the flavor quality and drinking safety of Hongqu rice wine. Previous studies have shown that high biogenic amine (BA) content in rice wine has potential physiological toxicity and has become a bottleneck problem restricting the development of the rice wine industry. This study aimed to evaluate the regulatory effects of the microbial community on the formation of BAs and volatile flavor components during the brewing of Hongqu rice wine. The results demonstrated that histamine, putrescine, cadaverine, tyramine, tryptamine, spermine, and spermidine were the main BAs in Hongqu rice wine. The contents of putrescine, cadaverine, histamine, tyramine, and spermidine in Hongqu rice wine of HBAs (with higher BAs content) were significantly higher than those in LBAs (with lower BAs content). GC-MS testing results showed that there were significant differences in the composition of volatile organic compounds (VOCs) between HBAs and LBAs. Among them, VOCs such as 2-methoxy-4-vinylphenol, ethyl caprate, phenethyl acetate, ethyl lactate, ethyl myristate, ethyl palmitate, ethyl n-octadecanoate, ethyl oleate, and ethyl linoleate were identified as the characteristic volatile components with significant differences between HBAs and LBAs. Microbiome analysis based on metagenomic sequencing revealed that unclassified_g_Pantoea, Klebsiella pneumoniae, Panobacter disperse, unclassified_f_Enterobacteriaceae, Leuconostoc mesenteroides, and Saccharomyces cerevisiae were the dominant microbial species in the HBA brewing process, while Weissella confuse, Pediococcus acidilactici, Saccharomyces cerevisiae, and Aspergillus niger were the dominant microbial species in the LBA brewing process. Furthermore, correlation heatmap analysis demonstrated that BAs were positively related to Lactobacillus curvatus, Lactococcus lactis, and Leuconostoc mesenteroides. Bioinformatical analysis based on the KEGG database revealed that the microbial genes encoding enzymes involved in BAs' synthesis were more abundant in HBAs, and the abundances of microbial genes encoding enzymes related to BAs' degradation and the metabolism of characteristic volatile components were higher in LBAs. Overall, this work provides important scientific data for enhancing the flavor quality of Hongqu rice wine and lays a solid foundation for the healthy development of the Hongqu rice wine industry.

Effects of Diets Based on Hydrolyzed Chicken Liver and Different Protein Concentrations on the Formation and Deamination of Biogenic Amines and Total Antioxidant Capacity of Dogs.

Biogenic amines are synthesized through the bacterial decarboxylation of amino acids, commonly found in high levels in animal by-product meals due to spoilage. Furthermore, biogenic amines and other metabolites can be produced by the fermentation of proteins in the hindgut according to the protein source and concentration of crude protein (CP) in the diet. Thus, this study aimed to evaluate two protein sources (poultry by-product meal (PBPM) and hydrolyzed chicken liver powder (HCLP)) and three CP concentrations (24, 32, and 40%) and their effects on the consumption and fecal excretion of biogenic amines, plasma monoamine oxidase (MAO) and diamine oxidase (DAO) activities, and total antioxidant capacity (TAC) of healthy adult dogs after 30 days of feeding the experimental diets. Twelve dogs were randomly distributed into six treatments (n = 6/treatment): PBPM24 (PBPM with 24% CP); PBPM32 (PBPM with 32% CP); PBPM40 (PBPM with 40% CP); HCLP24 (HCLP with 24% CP); HCLP32 (HCLP with 32% CP); HCLP40 (HCLP with 40% CP). The PBPM and PBPM-based diets had higher concentrations of putrescine, cadaverine, tyramine, histamine, agmatine, and total biogenic amines. In contrast, HCLP and HCLP-based diets contained higher concentrations of spermidine, phenylethylamine, and spermine. The PBPM and PBPM-diets had higher biogenic amine index (BAI) indicating lower quality due to the high content of putrescine, cadaverine and tyramine. Dogs fed diets with PBPM and higher protein concentrations consumed more putrescine, cadaverine, tyramine, agmatine, and total amines (p < 0.0001), while dogs fed with HCLP consumed more spermidine, phenylethylamine, and spermine (p < 0.0001). Fecal excretion of phenylethylamine was greater in dogs fed HCLP32 and HCLP40 diets (p = 0.045). Dogs fed with HCLP tended to excrete more spermidine and tryptamine via feces, while higher protein concentrations tended to increase fecal excretion of cadaverine (p < 0.10). Plasma MAO activity was higher in dogs fed HCLP24 and PBPM32 diets (p = 0.024). The plasma activities of DAO and TAC were not different between diets (p > 0.05). Although we did not evaluate the intestinal activities of MAO and DAO, our results suggest that healthy adult dogs have an efficient deamination process on the gut epithelium.

Monitoring and risk assessment of biogenic amines in Korean commercial fermented seasonings

Fermented seasonings are widely used in Korean cuisine; however, some contain high levels of biogenic amines (BAs). In this study, in order to estimate the potential BA risk from fermented seasoning, the BA contents in 50 commercial brands (n = 292) of five seasonings (soy sauce, Gochujang, Doenjang, Ssamjang, and Cheonggukjang) and their changes due to different cooking methods were evaluated by high-performance liquid chromatography. The risk assessment for consumer exposure was evaluated by computing the estimated daily intake (EDI), histamine (HIS) intake, and tyramine (TYR) intake. Maximum contents of HIS detected in Cheonggukjang, soy sauce, Doenjang, and Ssamjang were 318.46, 148.15, 123.65, and 114.07 mg/kg, respectively. However, even in the worst-case scenario, the EDI value and HIS intake results demonstrated that the seasonings had a limited impact on the risk of HIS poisoning due to their low consumption. Cheonggukjang exhibited the highest TYR content (312.89 mg/kg), and the TYR exposure results implied that those taking classical antidepressant monoamine oxidase inhibitors should pay attention to Cheonggukjang. After stir-frying, the total BA retentions in soy sauce and Gochujang were only 51.45% and 57.08%, respectively, which may be caused by high temperature. Based on the results of this study, the five seasonings contained various BAs, which can be influenced by the cooking process, and all five seasonings are safe for the general population in terms of the risk of BAs.

Ratiometric SERS aptasensing for simultaneous quantitative detection of histamine and tyramine in fishes

Herein, a SiO2@Ag NPs core/shell nanoparticles were synthesized to fabricate a surface-enhanced Raman spectroscopy (SERS) sensor for the simultaneous determination of histamine (HIS) and tyramine (TYR) based on specific aptamer recognition and ratiometric strategy. SiO2@Ag NPs with 4-thiosaminophenol (4-ATP) and Nile blue A (NBA) molecules were used as an internal standard (IS) and labeled with aptamers corresponding to HIS and TYR, respectively. Raman reporter molecules ROX and Cy5 labeled complementary DNA (cDNA) were then hybridized with aptamers to form rigid double-stranded DNA. After the HIS and TYR were captured by their aptamers, resulting in the dissociation of cDNA and separated from the SERS substrate. Therefore, the SERS signal intensity at 1503 cm−1 of ROX and 1358 cm−1 of Cy5 tagged on the terminal of cDNA decreased with the concentration of HIS and TYR increasing, while the SERS signal intensity at 1079 cm−1 of 4-APT and 592 cm−1 of NBA on the substrate remain stable. Thus, the concentrations of HIS and TYR can be determined by the I1503/I1079 and I1358/I592 values, respectively. This sensing strategy achieves a lower detection limit of 0.2 ng/mL for HIS and 0.05 ng/mL for TYR, respectively, demonstrating promising applications in sensitive detection of BAs in animal-derived foodstuff.