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 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.

The pulp surrounding the seeds of some fruits is rich in mucilage, carbohydrates, etc. Some seeds are rich in proteins and polyphenols. Fruit seeds, like cacao (Theobroma cacao) and cupuassu (Theobroma grandiflorum), are subjected to fermentation to develop flavor. During fermentation, ethanol is produced [2-6]. All of these compounds are considered as interfering substances that hinder the DNA extraction [4-8]. Protocols commonly used in the DNA extraction in samples of plant origin were used, but without success. Thus, a protocol for DNA samples under different conditions that can be used for similar samples was developed and applied with success. The protocol initially described for RNA samples by Zeng et al. [9] and with changes proposed by Provost et al. [5] was adapted for extracting DNA samples from those described. However, several modifications have been proposed:•Samples were initially washed with petroleum ether for fat phase removal.•RNAse was added to the extraction buffer, while spermidin was removed.•Additional steps of extraction with 5 M NaCl, saturated NaCl and CTAB (10%) were included and precipitation was carried out with isopropanol, followed by washing with ethanol.

This study investigated the impact of ripening temperature on the microbial diversity of Serrano artisanal cheese (SAC), a raw milk specialty from southern Brazil. Despite its cultural and economic significance, the effects of ripening conditions on SAC microbiota remain underexplored, particularly in unpasteurized dairy products. Cheese maturation was conducted at 5°C, 12.5°C, and 20°C for 60 days, with microbial assessments every 15 days using metabarcoding (16S rDNA and ITS sequencing). The results revealed temperature-dependent shifts in bacterial and fungal communities. Maturation at 5°C favored the proliferation of pathogens associated with raw milk contamination, while higher temperatures reduced pathogenic bacteria and promoted lactic acid bacteria (LAB) (Enterococcus, Lactococcus, Lactobacillus, Leuconostoc, and Streptococcus), which contribute to pathogen inhibition and sensory quality preservation. Physicochemical analyses demonstrated correlations between temperature, humidity, pH, fat, NaCl, and microbial composition. A review of ripening criteria is recommended, including a reduction in the minimum legally required maturation period (from 60 to 30 days) under controlled temperature conditions, as demonstrated in this study, alongside the implementation of technical regulations and knowledge dissemination to ensure product quality and safety.