UHPLC analysis of biogenic amines in different cheese varieties

Effect of Ripening Temperature on Microbial Safety and Biogenic Amine Levels in Rennet Cheeses Produced from Raw Cow Milk

Europe is the largest producer and consumer of cheese, with growing interest in raw milk cheeses due to their natural qualities and unique flavor. However, the absence of pasteurization increases the risk of pathogens and biogenic amines (BAs), which can cause foodborne illnesses. This study examined the effect of two ripening temperatures (5 °C and 12 °C) on microbial quality and BAs in rennet cheeses made from unpasteurized cow's milk over 63 days. Microbial counts and BAs were analyzed at nine ripening stages (0, 7, 14, 21, 28, 35, 42, 50, and 63 days). BAs, including histamine, tyramine, tryptamine, and putrescine, were quantified using high-performance liquid chromatography (HPLC) with a UV/VIS DAD detector. Microbiological tests followed ISO standards, assessing total microorganisms, lactic acid bacteria, molds, yeasts, E. coli, Enterobacteriaceae, coagulase-positive staphylococci, Salmonella spp., L. monocytogenes, and Campylobacter spp. Data were analyzed using ANOVA with Bonferroni correction (P < 0.05). Although raw milk samples did not meet hygiene standards, neither the milk nor cheese contained Salmonella spp., L. monocytogenes, or Campylobacter spp. Ripening temperature significantly affected BA levels, with cheeses ripened at 12 °C showing higher total BAs (464.08 mg/kg) than those at 5 °C (296.63 mg/kg), with tyramine being most prevalent. A positive correlation was found between raw milk use and increased tyramine levels, further elevated by higher ripening temperatures. The presence of hygiene indicator microorganisms (molds, yeasts, staphylococci, E. coli, Enterobacteriaceae) and elevated BA levels highlight the need for strict control measures to ensure cheese safety.

Can the Contents of Biogenic Amines in Olomoucké Tvarůžky Cheeses Be Risky for Consumers?

Smear-ripened cheeses are fermented dairy products characterised by an increased content of biogenic amines (BAs). The high contents of these bioactive compounds can negatively affect consumers. The study aimed to observe the contents of BAs and po-lyamines (PAs) in Olomoucké tvarůžky cheeses depending on selected factors (year, batch, ripening/storage time, shape, weight, specific surface area, acidity, and salt content). The results showed that the variability was explained primarily by the batch (83% for the sum of BAs) and by the year (63% for the sum of PAs). The storage time significantly influenced the contents of putrescine, cadaverine, spermidine, and spermine (the explained variability was only 1-3%). The total BA contents negatively correlated with weight (r = -0.6374; p < 0.001) and positively with specific surface area (r = +0.4349; p < 0.001). A negligible positive correlation coefficient was found between the total BAs and pH (r = +0.1303). A low negative correlation was also found between the total BAs and salt content (r = -0.1328). Compared to previous studies, the total average BA contents were considerably low. In conclusion, this type of cheese does not represent a serious problem for most consumers.

Direct competitive immunoassay method for sensitive detection of the histamine in foods based on a MI-Cu-GMP nanozyme marker and molecularly imprinted biomimetic antibody

BACKGROUND

Histamine may lead to low blood pressure, skin flushing and edema when it accumulates in large amounts in the body. Therefore, establishing sensitive methods for the detection of histamine in foods is extremely important to ensure food safety and human health.

RESULTS

The MI-Cu-GMP NPs (2-methylimidazole-copper-guanosine monophosphate nanozymes) with high laccase-like activity were synthesized. Using the prepared molecular imprinted membrane as biomimetic antibody and MI-Cu-GMP NPs as marker, a sensitive direct competitive biomimetic enzyme-linked immunoassay (BELISA) method for rapid detection of the histamine in foods was developed. Under optimal conditions, the limit of detection (LOD, IC15) and sensitivity (IC50) of the BELISA method for histamine was 0.05 mg L-1 and 1.22 mg L-1, respectively. The liquor samples spiked with histamine was detected by the BELISA method with satisfactory recoveries ranging from 90.00% to 116.00%. Further, the level of histamine in three samples (cooking wine, rice vinegar and soy sauce) was tested by the BELISA and high-performance liquid chromatography (HPLC), with no significant difference found between the two methods.

CONCLUSION

Given the advantages, the established BELISA method is expected to provide practical guidance for the monitoring of histamine in food and provides a foundation for the detection of other food hazards. © 2024 Society of Chemical Industry.

Identification of technological/metabolic/environmental profiles associated with cheeses accumulating the neuroactive compound tryptamine

Tryptamine is a neuromodulator of the central nervous system. It is also a biogenic amine, formed by the microbial decarboxylation of L-tryptophan. Tryptamine accumulation in cheese has been scarcely examined. No studies are available regarding the factors that could influence its accumulation. Determining the tryptamine content and identifying the factors that influence its accumulation could help in the design of functional tryptamine-enriched cheeses without potentially toxic concentrations being reached. We report the tryptamine concentration of 300 cheese samples representing 201 varieties. 16% of the samples accumulated tryptamine, at between 3.20 mg kg-1 and 3012.14 mg kg-1 (mean of 29.21 mg kg-1). 4.7% of cheeses accumulated tryptamine at higher levels than those described as potentially toxic. Moreover, three technological/metabolic/environmental profiles associated with tryptamine-containing cheese were identified, as well as the hallmark varieties reflecting each. Such knowledge could be useful for the dairy industry to control the tryptamine content of their products.

A Comprehensive Review on the Biogenic Amines in Cheeses: Their Origin, Chemical Characteristics, Hazard and Reduction Strategies

Most of the biogenic amines are naturally found in fermented foods as a consequence of amino acid decarboxylation. Their formation is ascribable to microorganisms (starters, contaminants and autochthonous) present in the food matrix. The concentration of these molecules is important for food security reasons, as they are involved in food poisoning illnesses. The most frequent amines found in foods are histamine, putrescine, cadaverine, tyramine, tryptamine, phenylethylamine, spermine and spermidine. One of the most risk-prone foods are cheeses, mostly ripened ones, which could easily accumulate amines due to their peculiar manufacturing process and ripening. Cheeses represent a pivotal food in our diet, providing for nutrients such as amino acids, calcium, vitamins and others; thus, since they are widely consumed, it is important to evaluate the presence of toxic molecules to avoid consumers' poisoning. This review aimed to gather general information on the role of biogenic amines, their formation, the health issues and the microorganisms and processes that produce/reduce them, with a focus on their content in different types of cheese (from soft to hard cheeses) and the biotic and abiotic factors that influence their formation or reduction and concentration. Finally, a multivariate analysis was performed on the biogenic amine content, derived from data available in the literature, to obtain more information about the factors influencing their presence in cheeses.

Experimental Design Application for Measuring Histamine in Tuna Fish Samples by Phenyl Isothiocyanate Derivation Method Using Ultra-Performance Liquid Chromatography

Histamine as an important biogenic amino acid was measured in tuna fish samples by ultra-performance liquid chromatography using a phenyl isothiocyanate derivative. Minitab software was used to design the experiment and investigate the effective factors during the process, which includes screening and optimization steps. A partial factorial design was used in the screening stage and a central composite design was used in the optimization. Effective parameters in histamine derivatized were examined in the screening step including triethylamine volume, phenyl isothiocyanate volume, reaction temperature, reaction time and mobile phase pH. Then, in the optimization, effective parameters were identified and finally, the calibration curve was drawn from a concentration of 0.5-10.0 μg.mL-1 for histamine derivatized and a correlation coefficient of 0.994 was obtained for histamine derivatized. The method detection limit was 0.36 μg.mL-1 and the limit of quantification (LOQ) was 1.19 μg.mL-1. The relative standard deviation of the method was obtained for concentrations of 1.0-100.0 μg.mL-1 in the range between 1.06 and 2.21%. The recovery method was obtained from 90.8 to 103.1% for measuring histamine derivatized in real fish samples.

Determination of Biogenic Amines in Wine from Chinese Markets Using Ion Chromatography-Tandem Mass Spectrometry

A method for the determination of nine biogenic amines (BAs) in wine was established using ion chromatography-tandem mass spectrometry (IC-MS/MS) without derivatization. BAs were separated by a cation exchange column (IonPac CG17, 50 mm × 4 mm, 7 µm) with a gradient aqueous formic acid elution. Good linearity was obtained for nine BAs with coefficients of determination (R²) > 0.9972 within the range of 0.01-50 mg/L. The limits of detection and quantification were within the ranges of 0.6-40 µg/L and 2.0-135 µg/L, respectively, with the exception of spermine (SPM). The recoveries were demonstrated within the range of 82.6-103.0%, with relative standard deviations (RSDs) of less than 4.2%. This simple method featuring excellent sensitivity and selectivity was suitable for the quantification of BAs in wines. The occurrence of BAs in 236 wine samples that are commercially available in China was determined. The BA levels in wines of different geographical origins varied significantly. The acute dietary exposure assessment of BAs was carried out by calculating the estimated short-term intake (ESTI) and comparing the acute reference dose (ARfD) specified by the European Food Safety Authority (EFSA). Results showed that the exposure to histamine (HIS) and tyramine (TYR) via the consumption of wines was much lower than the recommended ARfD level for healthy individuals. However, exposure could lead to symptoms in susceptible individuals. These results provided basic data regarding the occurrence and risk of BAs in wines for wine production, health guidance and consumer safety.

Effects of selected Bacillus strains on the biogenic amines, bioactive ingredients and antioxidant capacity of shuidouchi

The control of biogenic amines (BAs) is crucial to guarantee the safety of fermented soybean products. In this study, the BAs composition of eleven shuidouchi samples was analyzed, and the BAs degradation strains were selected from shuidouchi samples with a low BAs content. Then the influences of screened BAs degradation strains on BAs, total phenolics (TP), total flavonoids (TF), isoflavones and the antioxidant ability of fermented shuidouchi were evaluated. Results showed that the total BAs content of all shuidouchi samples was within the safe range, while the GZXQ, GZQY and GZMX samples had higher levels of tyramine. Meanwhile, 109 strains were isolated from the YNLJ, GZLG, GZMZ, GZDY, and YNHY sample. Bacillus tropicus A11, Bacillus siamensis D11, Bacillus subtilis T2, and B. subtilis U2 with higher BAs degradation capacity and lower BAs production ability were selected to ferment shuidouchi. These four Bacillus strains could effectively control the BAs concentration of fermented shuidouchi, especially B. tropicus A11 and B. siamensis D11. Furthermore, compared to naturally fermented shuidouchi, higher levels of antioxidant ability, TP, TF, daidzein, glyciein, and genistein were found in the shuidouchi fermented with selected strains. These findings demonstrated that these screened strains could be applied as potential candidates for the production of high quality shuidouchi.

Effect of Adding Bifidobacterium animalis BZ25 on the Flavor, Functional Components and Biogenic Amines of Natto by Bacillus subtilis GUTU09

Natto is a high-value fermented soybean produced by B. subtilis. However, B. subtilis produces a pungent amine odor. This study compared the volatile organic compounds (VOCs), free amino acids (FAAs) and biogenic amines (BAs), nattokinase (NK) of natto made by two-strain fermentation with Bifidobacterium animalis BZ25 and Bacillus subtilis GUTU09 (NMBB) and that of natto made by single-strain fermentation with Bacillus subtilis GUTU09 (NMB). Compared with NMB, volatile amine substances disappeared, ketones and aldehydes of NMBB were reduced, and alcohols increased. Besides that, the taste activity value of other bitter amino acids was lowered, and BA content was decreased from 255.88 mg/kg to 238.35 mg/kg but increased NK activity from 143.89 FU/g to 151.05 FU/g. Correlation analysis showed that the addition of BZ25 reduced the correlation between GUTU09 and BAs from 0.878 to 0.808, and pH was changed from a positive correlation to a negative one. All these results showed that the quality of natto was improved by two-strain co-fermentation, which laid a foundation for its potential industrial application.

The microbial community, biogenic amines content of soybean paste, and the degradation of biogenic amines by Lactobacillus plantarum HM24

Soybean paste was a traditional fermented product in Northeast China, mainly fermented by molds, yeast, Bacillus, and lactic acid bacteria. This study investigated the dynamic changes of the microbial community and biogenic amine content during the fermentation of the traditional soybean paste. The microbial diversity of soybean paste in different regions was analyzed by MiSeq sequencing technology. The results showed that Penicillium and Tetragenococcus were the dominant microorganisms responsible for the fermentation of soybean paste. Biogenic amine was found in the traditional soybean paste at different fermentation stages, putrescine, and tyramine were the mainly biogenic amines and their content increased with the extension of fermentation time. Serratia in the soybean paste was positively correlated with the formation of spermine, cadaverine (p < .01), and β-phenethylamine (p < .05), Leuconostoc was negatively correlated with tyramine formation (p < .05), and Enterococcus was positively correlated with the formation of histamine, tryptamine and cadaverine (p < .01). Lactobacillus fermentum HM22, Lactobacillus plantarum HM24, and Enterococcus faecalis YF10042 with strong biogenic amine degrading capacity were inoculated into the koji. After 20 days of fermentation, the degradation rates of tryptamine, β-phenylethylamine, putrescine, cadaverine, histamine, and tyramine in soybean paste inoculated with L. plantarum HM24 were 35.31%, 43.14%, 30.18%, 33.44%, 32.74%, and 39.91%, respectively, indicating that the use of L. plantarum HM24 as a starter culture in soybean paste fermentation might be a good strategy for biogenic amines reduction.

Colorimetric detection of food freshness based on amine-responsive dopamine polymerization on gold nanoparticles

Biogenic amines (BAs) are not only well-known indicators for food freshness but can cause serious harm to the body after excessive consumption, which makes the determination of its content in food of great significance. In this work, a simple and convenient method for colorimetric detection of BAs was developed based on the sensitivity of the polymerization of dopamine to the presence of BAs on the surface of gold nanoparticles (AuNPs). Taking histamine as a representative, the system exhibited a distinct color change from wine red to black among the amine concentration of 1-100 μg/mL with the detection limit of 2.8 μg/mL. The detection system also exhibited sensitivity to other common kinds of BAs, such as putrescine, cadaverine, spermine, spermidine, tyramine, and tryptamine. Moreover, the proposed method showed encouraging performance in visual detection of the freshness of real samples, which provided a new approach for food quality and freshness evaluation.

Contents of Functionally Bioactive Peptides, Free Amino Acids, and Biogenic Amines in Dutch-Type Cheese Models Produced with Different Lactobacilli

Cheese ripening involves a number of biochemical processes, mainly of a proteolytic nature, which are initially triggered principally by milk-coagulating enzymes and, afterward, by microorganisms or enzymes of microbial origin. The proteolytic reactions affect, primarily, the synthesis of macro- and medium-molecular peptides from casein. In turn, the advanced proteolysis ends in the formation of short peptides and free amino acids. Further reactions may lead to the formation of nutritionally unfavorable biogenic amines. The present study aimed to determine changes in the contents of bioactive peptides (anserine and L-carnosine), free amino acids, and biogenic amines throughout the ripening of cheese models produced with the addition of Lactobacillus genus bacteria. The contents of amino acids varied considerably in the cheese models, depending on the bacterial strain added and ripening time. After five weeks of ripening, the total content of free amino acids in the cheese models ranged from 611.02 (a cheese model with Lactobacillus casei 2639) to 1596.64 mg kg⁻¹ (a cheese model with Lb. acidophilus 2499). After the same time, the contents of the total biogenic amines in the cheese models with the addition of lactobacilli were lower than in the control cheese model (except for the model with Lb. rhamnosus 489). Anserine was detected in all cheese models (79.29–119.02 mg kg⁻¹), whereas no L-carnosine was found over a five-week ripening period in the cheese models with Lb. delbrueckii 490 and Lb. casei 2639. After a five-week ripening, the highest total content of bioactive peptides was determined in the cheese models containing Lb. acidophilus 2499 (136.11 mg kg⁻¹).

Occurrence of Yeasts in White-Brined Cheeses: Methodologies for Identification, Spoilage Potential and Good Manufacturing Practices

Yeasts are generally recognized as contaminants in the production of white-brined cheeses, such as Feta and Feta-type cheeses. The most predominant yeasts species are Debaryomyces hansenii, Geotrichum candidum, Kluyveromyces marxianus, Kluyveromyces lactis, Rhodotorula mucilaginosa, and Trichosporon spp. Although their spoilage potential varies at both species and strain levels, yeasts will, in case of excessive growth, present a microbiological hazard, effecting cheese quality. To evaluate the hazard and trace routes of contamination, the exact taxonomic classification of yeasts is required. Today, identification of dairy yeasts is mainly based on DNA sequencing, various genotyping techniques, and, to some extent, advanced phenotypic identification technologies. Even though these technologies are state of the art at the scientific level, they are only hardly implemented at the industrial level. Quality defects, caused by yeasts in white-brined cheese, are mainly linked to enzymatic activities and metabolism of fermentable carbohydrates, leading to production of metabolites (CO2, fatty acids, volatile compounds, amino acids, sulfur compounds, etc.) and resulting in off-flavors, texture softening, discoloration, and swelling of cheese packages. The proliferation of spoilage yeast depends on maturation and storage conditions at each specific dairy, product characteristics, nutrients availability, and interactions with the co-existing microorganisms. To prevent and control yeast contamination, different strategies based on the principles of HACCP and Good Manufacturing Practice (GMP) have been introduced in white-brined cheese production. These strategies include milk pasteurization, refrigeration, hygienic sanitation, air filtration, as well as aseptic and modified atmosphere packaging. Though a lot of research has been dedicated to yeasts in dairy products, the role of yeast contaminants, specifically in white-brined cheeses, is still insufficiently understood. This review aims to summarize the current knowledge on the identification of contaminant yeasts in white-brined cheeses, their occurrence and spoilage potential related to different varieties of white-brined cheeses, their interactions with other microorganisms, as well as guidelines used by dairies to prevent cheese contamination.

Green coffee derived supplements and infusions as a source of polyamines and free amino acids

This work reports on monoamines (MA), diamines (DA) and polyamines (PA) as well as free amino acids (fAA) in nutritional supplements and infusions derived from green coffee beans. Samples were investigated using a ultra-high performance liquid chromatography UV/FLR method, which was validated regarding specificity, linearity, range, precision, accuracy and limits of detection and quantification. Nutritional supplements based on green coffee beans showed large amounts of total amines ranging from 1090 to 2593 mg/kg, with exceptional high levels of spermidine up to 724 mg/kg, and a content of fAA from 4004 to 12,389 mg/kg. Infusions brewed from green coffee beans showed much lower contents of amines (14–17 mg/L) and fAA (78–100 mg/L). However, if the customary edible portion was considered, infusions from green coffee were a mainly better source for MA and PA as well for fAA, compared to nutritional supplements. Tryptamine and tyramine were predominant as MA putrescine as DA, and spermidine as PA, respectively.

Graphic abstract

Accumulation of Agmatine, Spermidine, and Spermine in Sprouts and Microgreens of Alfalfa, Fenugreek, Lentil, and Daikon Radish

Sprouts and microgreens are a rich source of various bioactive compounds. Seeds of lentil, fenugreek, alfalfa, and daikon radish seeds were germinated and the contents of the polyamines agmatine (AGM), putrescine (PUT), cadaverine (CAD), spermidine (SPD), and spermine (SPM) in ungerminated seeds, sprouts, and microgreens were determined. In general, sprouting led to the accumulation of the total polyamine content. The highest levels of AGM (5392 mg/kg) were found in alfalfa microgreens, PUT (1079 mg/kg) and CAD (3563 mg/kg) in fenugreek sprouts, SPD (579 mg/kg) in lentil microgreens, and SPM (922 mg/kg) in fenugreek microgreens. A large increase in CAD content was observed in all three legume sprouts. Conversely, the nutritionally beneficial polyamines AGM, SPD, and SPM were accumulated in microgreens, while their contents of CAD were significantly lower. In contrast, daikon radish sprouts exhibited a nutritionally better profile of polyamines than the microgreens. Freezing and thawing of legume sprouts resulted in significant degradation of CAD, PUT, and AGM by endogenous diamine oxidases. The enzymatic potential of fenugreek sprouts can be used to degrade exogenous PUT, CAD, and tyramine at pH values above 5.

Effect of high hydrostatic pressure challenge on biogenic amines, microbiota, and sensory profile in traditional poultry- and pork-based semidried fermented sausage

The processing of traditional poultry- and pork-based semidried fermented smoked sausages needs to be modernized to improve product quality and further extend its shelf life. The aim of the present study was to apply different combinations of high pressure (300 to 600 MPa) and time (154 to 1,800 s) on the sausages using an experimental design based on response surface methodology. The chemical, microbial, and sensory characteristics of sausages treated with high-pressure processing (HPP) were investigated. HPP application to semidried fermented sausages resulted in color changes, which could be dependent on the ingredients, formulation, and smoking conditions used. Nevertheless, none of the HPP treatments applied resulted in detectable changes in sensory properties, as tested in a triangle test and confirmed by the analysis of focus groups assessment. Significant differences were detected for lactic acid bacteria (LAB) counts from 344 MPa and 1,530 s onward, with a marked decrease for the combination of 600 MPa and 960 s (P < 0.05). Coagulase-negative staphylococci showed higher tolerance to the increase in pressure than LAB. HPP induced a microbial reduction on Enterobacteriaceae, molds, and yeasts, minimizing the production of the main biogenic amines. However, the polyamines (spermine and spermidine) increased since their metabolic use by microorganisms did not occur. Given the reduction of the main spoilage microbial indicators with no detectable sensory changes observed with the binomial condition of 600 MPa and 960 s, this was chosen as the optimal combination to be further applied. PRACTICAL APPLICATION: The results from sensory analysis revealed that any of the HPP treatments applied resulted in detectable changes in sensory properties, as tested in a triangle test and confirmed by the analysis of the focus groups speeches.

Monitoring the Levels of Biogenic Amines in Canned Fish Products Marketed in Ghana

An ion-pair HPLC method with postcolumn o-phthalaldehyde (OPA) derivatization and fluorescence detection was validated for quantitative determination of five biogenic amines (histamine, tyramine, cadaverine, putrescine, and agmatine) in canned fish products (mackerel, sardine, and tuna) marketed in Ghana. The validated method exhibited excellent selectivity and good linearity (R2 > 0.9990) for all the amines. The limits of detection and quantification for studied biogenic amines were in the range of 0.32–0.78 mg·kg−1 and 1.10–2.57 mg·kg−1, respectively. Also, a satisfactory recovery was obtained for all the amines (82.1–101.4%), and the relative standard deviations were lower than 9.3% under repeatability conditions for the studied amines. Subsequently, the method was applied to the analysis of biogenic amines in canned fish products to estimate the safety of Ghanaian consumers. The maximum levels of histamine, tyramine, cadaverine, putrescine, and agmatine detected in the analysed canned fish products were 64.05 mg·kg−1, 27.44 mg·kg−1, 27.23 mg·kg−1, 18.74 mg·kg−1, and 52.72 mg·kg−1, respectively. Thus, the levels of biogenic amines detected in the canned fish products were lower than the acceptable levels and, therefore, can be considered relatively safe for human consumption.

The Occurrence and Dietary Exposure Assessment of Mycotoxins, Biogenic Amines, and Heavy Metals in Mould-Ripened Blue Cheeses

The occurrence and dietary exposure assessment of 16 mycotoxins, 6 biogenic amines (BAs), and 13 metallic elements in blue-veined cheeses (n = 46) is reported. Co-occurrence of mycophenolic acid (≤599 µg·kg-1) with roquefortine C (≤5454 µg·kg-1) was observed in 63% of the tested cheeses, while BAs were frequently present at concentrations between 0.2 and 717 mg kg-1. The concentrations of heavy metals in cheeses were very low. Chronic/acute exposure assessment based on consumption data from different European populations indicated that the levels of mycotoxins and heavy metals are safe to consumers, whereas, rather high hazard indexes (HI up to 0.77) were determined for BAs according to the worst-case scenario based on high consumption and 95th percentile occurrence. A more detailed acute dietary intake study indicated that histamine and tyramine were predominant among these BAs, reaching 27 and 41% of the acute oral intake reference doses.

Evaluation of the Biogenic Amines and Microbial Contribution in Traditional Chinese Sausages

Biogenic amines (BAs) in sausages represent a health risk for consumers, and thus investigating the BAs accumulation mechanism is important to control the BAs. In this study, the BAs profiles of 16 typical Chinese sausage samples were evaluated, and 8 kinds of common BAs were detected from different samples. As a whole, the BAs contents of the majority of Chinese sausage samples were within the safe dosage range, except that the total BAs and histamine concentrations of sample HBBD were above the toxic dosage levels. Furthermore, the bacterial and fungal communities of the Chinese sausage samples were investigated by high-throughput sequencing analysis, and Staphylococcus, Bacillus, Lactococcus, Lactobacillus, Debaryomyces, and Aspergillus were identified as the predominant genera. Accordingly, 13 representative strains were selected from the dominant genera, and their BAs formation and degradation properties were evaluated. Finally, the results of fermented meats model experiment indicated that the Staphylococcus isolates including Staphylococcus pasteuri Sp, Staphylococcus epidermidis Se, Staphylococcus carnosus Sc1, Staphylococcus carnosus Sc2, and Staphylococcus simulans Ss could significantly reduce BAs, possessing the potential as the starter cultures to control the BAs in fermented meat products. The present study not only helped to explain the BAs accumulation mechanism in Chinese sausage, but also developed the candidates for potential BAs control in fermented meat products.

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.