Kefir, a traditional probiotic beverage with significant cultural, social, and health relevance, has garnered increasing scientific interest for its functional properties. Here, we synthesized findings from 14 studies investigating the bacterial and fungal diversity in artisanal cow’s milk kefir through metagenomic analysis. Following the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), a comprehensive search was conducted in databases including Portal BVS, Scopus, Scielo, and Web of Science. From an initial pool of 522 articles, 14 were selected based on stringent inclusion and exclusion criteria, focusing on English-written studies. Key terms such as “kefir milk”, “artisanal kefir”, “milk”, “metagenomics”, and “cow” were identified through Boolean searches over the last five years. This review addresses the growing need for research on the microbial diversity of artisanal cow’s milk kefir from various global regions. The results indicate a remarkable diversity in microbial communities, primarily dominated by bacteria from the phylum Firmicutes (notably Lactobacillus) and yeasts from the genera Saccharomyces and Kluyveromyces. These microbial compositions are shaped by factors such as milk type, production methods, and grain handling practices, reflecting regional adaptations and influencing kefir’s sensory, probiotic, and functional properties. We argue that a full understanding of these microbial dynamics is critical for standardizing production processes and enhancing quality control measures, ultimately ensuring artisanal kefir’s consistency and health benefits.

Artisanal cheese, produced with raw milk by a predominantly manual approach, has a historical and cultural tradition related to the region of origin. Given its economic and cultural importance, the main objective of this study was to investigate and characterize the diversity of lactic acid bacteria (LAB) of artisanal cheeses produced and traded by family agro-industries in a region of southern Brazil. The LAB composition of artisanal cheese samples, belonging to different municipalities of the Region of Vale do Taquari, were characterized by the next-generation sequencing (NGS) method, amplifying the V3/V4 region of the 16S rRNA gene. A total of 35 LAB species, distributed in seven genera, were identified, and rarefaction analysis suggested that the total diversity assessed by 16S rRNA analysis was high in the analyzed samples. The average Ph ranged from 4.6 to 6.6, and a correlation with the genus Lactococcus (r = 0.62) was the most expressive. The LAB genera identified in the cheese samples were Bavariicococcus, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Marinillactibacillus, and Pediococcus. Lactococcus lactis was the most predominant species, present in all samples. Although some species have been identified in the three altitudes studied, the abundance varied according to geographic environments. Enterococcus italicus is more present at high altitudes, unlike Lactococcus plantarum and Lactococcus raffinolactis at low altitudes. Lactococcus lactis was present in the three geographic environments evaluated, but the highest abundance was observed at high altitudes. The identification of LAB present in fermented cheeses is essential to understand the organoleptic quality during the maturation process as well as to establish the shelf life, including the safety and the overall quality of the cheese. This specific microbiota contributes to the flavor and unique characteristics of the regional dairy products, and on the other hand can be a source of specific starter cultures that guarantee the product’s identity.

Artisanal kefir is produced by fermenting milk with kefir grains, resulting in a lightly carbonated drink with health-promoting bioactive compounds. However, sensory variability and fermentation conditions challenge its standardization, limiting commercialization in Brazil due to regulatory requirements. This study evaluated the physicochemical properties, volatile compounds, and microbiological stability of artisanal kefir produced in southern Brazil during 30 days of storage. Metabarcoding analysis, carried out by sequencing the V3/V4 regions of the 16S rRNA gene (bacteria) and the ITS region (fungi), revealed an increase in bacterial diversity, with a predominance of Enterococcus and Acetobacter, while fungal diversity decreased, with a predominance of Kazachstania. The physicochemical parameters remained stable. The concentration of volatile compounds, analyzed using a gas chromatograph coupled to a mass spectrometer, decreased, except for an increase in 2-heptanol. The aromatic profile was enriched with alcohols and ketones, possibly influenced by Enterococcus and Acetobacter. These findings show that kefir maintained microbiological stability and adequate sensory characteristics throughout the period analyzed. The study provides subsidies for the standardization of artisanal kefir and compliance with Brazilian quality standards, as well as guiding future research into durability, quality, and consumer perception.

Purpose: This study aimed to evaluate the antimicrobial activity of the aqueous extract from jaboticaba skin against important foodborne bacteria and fungi and its stability.Design/methodology/approach: Jaboticaba skin aqueous extract (at ratio of 10 g L-1) was tested againstListeria monocytogenes,Staphylococcus aureus,Bacillus cereusandEscherichia coli. Stability of the anti-staphylococcal activity, total phenolics, monomeric anthocyanins, tannins, phenolic acid content were measured and statistically correlated.Findings: The residue extract inhibited L.monocytogenes, S.aureus, B.cereus and E.coli growth but was not effective against fungi and was stable to the thermal treatments, remaining with its inhibitory activity against S.aureus. When stored for 14 days at 25 °C with an incidence of light, there was a reduction in the antibacterial activity and in the phenolic compounds. The change in pH slightly changed polyphenolic content profile, and the exposure to papain and bromelain did not affect the antimicrobial activity. Results showed strong correlation between anti-staphylococcal activity, the presence of polyphenols and anthocyanins, meanwhile moderate correlation with phenolic acids content in the extract.Originality/value: Biopreservatives are a great trend in food microbiology. The present work shows deeper information about the utilization of jaboticaba skin as antimicrobial agent and its stability, which is not found in the current literature.

One of the biggest challenges in the food industry is the incorporation of probiotics into food products while maintaining their properties, both in the processing phases and in the gastrointestinal tract. The production of this type of functional food, which has been used to prevent and/or help in the treatment of some diseases, needs improvements at the technological and economic levels. This review provides a comprehensive view of the main techniques used to encapsulate probiotic yeasts and analyzes the main variables involved in the industrial process. A systematic review and meta-analysis were carried out, considering the most current technical recommendations for this type of study, as well as the standardized criteria for the eligibility of articles. From a total of 1269 initial articles, only 14 complete articles, published in high-impact journals over the years 2013 to 2019 and focused on in vitro assays with probiotic yeasts, were considered in the analysis performed. In general, microencapsulation was efficient in maintaining yeast survival after gastrointestinal tests, viability studies, and thermal resistance in distilled water and food. Many variables can affect microencapsulation, but they are not always described or properly elucidated, leading to the conclusion that better delineated research is needed. Examples of these challenges include selecting appropriate encapsulating materials, optimizing encapsulation techniques, and ensuring the stability and viability of probiotics during processing and storage. Due to these challenges, the industrial application of probiotic microencapsulation is not yet well established; however, it holds promising potential.

The distinct microbiological and physicochemical characteristics of sheep milk enable the production of cheeses with unique organoleptic properties. The scenario of sheep cheeses in Brazil is still uncertain, lacking data and regulations. This study aims to characterize the diversity of bacterial groups with potential pathogenic and/or harmful properties to milk technology and correlate the presence of these bacteria with the physicochemical properties of sheep cheese. Additionally, it investigates the presence of virulence genes, resistance genes, and toxins in reference genomes. The main steps were (a) sample preparation and fractionation; (b) physicochemical analysis; (c) analysis of the free fatty acids profile by GC-FID; (d) analysis of the volatile compounds profile by GC-MS; (e) molecular analysis—Next Generation Sequencing of the 16S rRNA gene (V3-V4 region); and (f) in silico analysis—Genomics. A total of 1,061,392 sequences were identified, corresponding to 45 genera and 57 species. Of the total abundance, 95.7% were considered beneficial, while 3.9% were classified as bacteria with pathogenic potential (BPP) and/or bacteria harmful to milk technology (BHMT). Five phyla were identified: Firmicutes, Proteobacteria, Actinobacteriota, Bacteroidota, and Fusobacteriota. The genera Acinetobacter, Pseudomonas, and Staphylococcus stood out in the BPP and BHMT groups, showing higher abundance. Alpha diversity of the cheese samples showed that the cheese origin significantly influences the richness, evenness, and abundance of bacterial species. Some physicochemical parameters, fatty acids, and volatile organic compounds showed a negative correlation with Staphylococcus. Reference genomes of two species exhibited a higher number of resistance and virulence genes. This reinforces the need to monitor bacteria considered of lesser relevance to prevent the transmission, through food, of potentially resistant and virulent pathogens.