Biogenic Amines in White Brined Cheeses

In the current study, a comprehensive analysis of biogenic amines in white brined cheeses was conducted. BAs may accumulate in food in high concentrations via the activities of microorganisms that produce decarboxylation enzymes. Neither tryptamine, phenylethylamine, nor spermidine was detected in the monitored cheese samples. Biogenic amines were detected in 20 samples, with tyramine and spermine being the most abundant, particularly in Feta cheeses, where tyramine concentrations exceeded 100 mg/kg in three samples. In 25% of the tested cheeses, total concentration of all the monitored biogenic amines and polyamines exceeded the level of 100 mg/kg, which may be considered of toxicological significance to sensitive persons. Decarboxylase activity was identified in 94 isolates, including significant producers such as Levilactobacillus brevis and Enterococcus durans. The correlation between high total microbial counts and lactic acid bacteria suggests that these microorganisms play a critical role in biogenic amine production. Our findings highlight the importance of monitoring specific microbial populations to mitigate biogenic amine risks in cheese production.

Probiotics in inflammatory bowel disease: microbial modulation and therapeutic prospects

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder that represents a significant public health challenge worldwide. This multifactorial condition results from complex interactions among genetic, environmental, immune, and microbial factors. Some beneficial microbes, known as probiotics, have been identified as promising therapeutic agents for inflammatory conditions, such as IBD. In this review, we explore the potential of probiotics as a therapeutic strategy for managing IBD. Probiotics have shown promise due to their ability to modulate the gut microbiota, regulate histamine levels, and enhance vitamin D metabolism, thereby promoting a tolerant immune profile and reducing inflammation. While the exact mechanisms underlying these benefits remain incompletely understood, probiotics represent a novel and emerging approach for alleviating the exacerbated inflammation characteristic of this disorder.

Metagenomics reveals the differences in flavor quality of rice wines with Hongqu and Maiqu as the fermentation starters

Chinese rice wine (CRW) is an alcoholic beverage made mainly from rice or grain through saccharification and fermentation with Jiuqu (starter). Jiuqu makes an important contribution to the formation of the flavor characteristics of rice wine. Hongqu and Maiqu are two kinds of Jiuqu commonly used in CRW brewing. This study compared the microbial community, biogenic amines (BAs), and volatile flavor components (VFCs) of two types of rice wine brewed with Hongqu and Maiqu as fermentation agents. The results showed that the amino acid content of rice wine fermented with Maiqu (MQW) was significantly lower than that of rice wine fermented with Hongqu (HQW). On the contrary, the majority of BAs in MQW were significantly higher than those in HQW, except for putrescine. Multivariate statistical analysis indicated that most of the VFCs detected were enriched in HQW, while ethyl 3-phenylpropanoate and citronellol were enriched in MQW. The results of metagenomic analysis showed that Weissiella, Enterobacter, Leuconostoc, Kosakonia, Saccharomyces, Aspergilus and Monascus were identified as the predominant microbial genera in HQW brewing process, while Saccharopolyspora, Lactococcus, Enterobacter, Leuconostoc, Kosakonia, Pediococcus, Pantoea, Saccharomyces, Aspergillus, Lichtheimia and Nakaseomyces were the predominant microbial genera in MQW brewing. In addition, some VFCs and BAs were strongly correlated with dominant microbial genera in HQW and MQW brewing. Bioinformatics analysis showed that the abundance of genes involved in BAs synthesis in MQW brewing was much higher than that in HQW brewing, while the abundances of genes related to metabolic pathway of characteristic VFCs in HQW brewing were obviously higher than those in MQW, which explained the differences in flavor quality between HQW and MQW from the perspective of microbial genes. Collectively, these findings provide scientific evidence for elucidating the contribution of different microbial genera to the formation of flavor quality of CRW, and is helpful for screening beneficial microbes to enhance flavor quality and drinking comfort of CRW.

Provolone del Monaco PDO cheese: Lactic microflora, biogenic amines and volatilome characterization

One commercial production run of Provolone del Monaco - a long-ripened pasta filata cheese - was followed up to the end of ripening for a total of 20 samples. 371 LAB isolates were subject to genetic characterization followed by 16S rRNA gene sequencing. The dominant species were Lacticaseibacillus casei/paracasei (19.4 %), Streptococcus macedonicus (19.1 %) and Enterococcus faecalis (13.2 %). Strains were screened for features of technological interest or safety relevance. Tyramine-producing cultures were quite common, above all within enterococci. By MALDI TOF Mass Spectrometry, one Lactococcus lactis and one Enterococcus faecium strain proved to be bacteriocin producers. Four further cheese wheels from the same production run at 623 days of ripening were evaluated for volatile organic compounds, biogenic amines, and bacterial community by metagenomic sequencing. Three individual wheel samples shared a rather similar microbiome with Lactobacillus delbrueckii and Streptococcus thermophilus as the most represented species, while the fourth wheel appeared wholly different being dominated by Lentilactobacillus buchneri and St. infantarius. Additionally, this sample had the greatest content of biogenic amines and a different VOCs composition. Given the variance seen among cheese wheels processed and ripened under the same conditions, the search for adjunct cultures in the production of this cheese seems to be of utmost importance.

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.

Focus on Histamine Production During Cheese Manufacture and Processing: A Review

Histamine (HIS) intoxication is a poisoning caused by histamine in food. Cheese is one of the most common dairy products associated with histamine levels which vary depending on the processing methods. The final content of histamine in cheese is influenced by intrinsic and extrinsic factors, their interactions, and contamination stemming from food processing. The application of control measures may be useful to inhibit/reduce production during cheese manufacture and processing but have a limited effect. To reduce histamine intoxication outbreaks from cheese consumption the introduction of quality control programs and appropriate risk mitigation options should be applied along the dairy chain from an overall perspective of food safety based on individual susceptibility and consumer sensitivity. As key food safety, this topic should be considered in future regulations in dairy products because the lack of a clear law on HIS limits in cheese may result in a significant potential deviation from the EU food safety strategy.