Koumiss is notable for its nutritional functions, and microorganisms in koumiss determine its versatility. In this study, the bacterial and fungal community structures in traditional koumiss from Inner Mongolia, China, were investigated. Our results demonstrated that 6 bacterial phyla represented by 126 genera and 49 species and 3 fungal phyla represented by 59 genera and 57 species were detected in 11 samples of artisanal koumiss. Among them, Lactobacillus was the predominant genus of bacterium, and Kluyveromyces and Saccharomyces dominated at the fungal genus level. In addition, there were no differences in the bacterial and fungal richness and diversity of koumiss from 3 neighboring administrative divisions in Inner Mongolia, and the bacterial and fungal community structures (the varieties and relative abundance of bacterial and fungal genera and species) were clearly distinct in individual samples. This study provides a comprehensive understanding of the bacterial and fungal population profiles and the predominant genus and species, which would be beneficial for screening, isolation, and culture of potential probiotics to simulate traditional fermentation of koumiss for industrial and standardized production in the future.

Koumiss is a popular dairy product in many lands, traditionally prepared from mare milk with spontaneous fermentation. Mare milk and its fermented derivates are more expensive than cow milk and its fermented derivates, and the possibility exists for producers and dealers to adulterate equine products with bovine items. In this work, we described the development of a triplex real-time PCR based on species-specific TaqMan probes for identification of bovine and equine DNA in milks and dairy products. In addition, a novel designed endogenous control was simultaneously amplified to eliminate possible false negatives. With this methodology, bovine and equine DNA were specifically identified by employing developed primers and probes. The limits of detection of this method were 0.001 ng for cow milk, yogurt, and mare milk, and 0.005 ng for sour soup and koumiss, respectively. In addition, the triplex real-time PCR assay for authentication of animal-derived products was effectively validated using binary DNA and milk mixtures, exhibiting well in terms of specificity, sensitivity, and reproducibility. In short, the triplex PCR assay was verified to be a time-saving and money-saving technique for the identification of bovine and equine DNA in milks and dairy products.

Mare milk originated from female horses, known as mares, to feed their foals during lactation. The health‐promoting characteristics of traditionally fermented mare milk (Chigee) are well known for the function of clinic treatment in the traditional Mongolian medicine. This study was conducted to investigate the production technology of Chigee and to evaluate the nutritional and microbiological characteristics of mare milk and Chigee based on 188 samples. The nutritional analysis of mare milk and Chigee indicated that lactose significantly decreased from 6.95 ± 0.45% to 2.82 ± 1.65% and acidity and alcoholic content significantly increased to 136.72 ± 57.88°T and 1.22 ± 0.7%, respectively, after spontaneous fermentation of mare milk. The microbiological analysis of Chigee showed that the total lactic acid bacteria (LAB) count varied from 5.32 to 8.56 log cfu/ml and total yeast count varied from 2.41 to 6.98 log cfu/ml. Moreover, the acidity of Chigee rose with the increase in LAB count within limits, and high acidity (≥178°T) inhibited the growth of coliforms. These findings provide an understanding of traditional production technology, nutrition, and microbiology that is fundamental for establishing the food standard of Chigee in China and will contribute to standardize the fermentation process for the industrial production of Chigee in the future.

No abstract

Camel milk has significant economic value and is an important food in the region of Alxa Left Banner of Inner Mongolia. Fifteen fresh camel milk samples were collected from domesticated camels in a pasture of Alxa Left Banner. The physicochemical properties and bacterial diversity of camel milk samples were analyzed. The average values of fat, total protein, nonfat milk solids, acidity, and density were 4.40%, 3.87%, 9.50%, 16.95°T, and 1.02 g/cm 3 , respectively. The bacterial microbiota of the collected fresh camel milk was investigated using PacBio single-molecule real-time (Pacific Biosciences, Menlo Park, CA) sequencing. The camel milk microbiota was highly diverse and comprised 8,513 operational taxonomic units belonging to 32 phyla, 377 genera, and 652 species. The major phyla included Proteobacteria, Firmicutes, Deinococcus-Thermus, Bacteroidetes, and Actinobacteria. A small number of lactic acid bacteria sequences were detected, representing the species Streptococcus thermophilus, Lactobacillus helveticus, Lactococcus lactis, and Leuconostoc mesenteroides. A total of 72 strains of lactic acid bacteria were isolated and identified from 15 samples, including Lactobacillus paracasei, Enterococcus italicus, Enterococcus durans, Lactococcus lactis ssp. lactis, Weissella confusa, and Enterococcus faecium. These results confirm that fresh camel milk has a high bacterial diversity and is a valuable natural resource for isolation of novel lactic acid bacteria.

Authentication of dairy and meat products is important to ensure fair competition, consumer benefit, and food safety. The large difference in price between camel and cow milk may be an incentive to adulterate camel dairy products with cow-derived foodstuffs. However, no studies so far have used triplex real-time PCR with an endogenous control to identify camel and cow origins in dairy and meat products. In this study, we developed a triplex real-time PCR assay based on amplification of mitochondrial 12S ribosomal DNA for the authentication of camel-derived dairy and meat products. This method was applied to identify camel and cow DNA in milk, yogurt, cheese, milk powder, milk beverage, meat products, and mixtures with milk and meat. Concentrations as low as 1 to 5% and 0.1% camel milk and meat, respectively, were detected in the mixtures, and 1 to 5% and 0.1% cow milk and meat, respectively, were identified via this approach. The limits of detection were 0.005 to 0.0025 ng, 0.05 to 0.001 ng, 0.001 to 0.0005 ng, and 0.00025 to 0.0001 ng of DNA in camel milk, camel yogurt, commercial camel milk beverage, and camel meat, and from 0.0025 to 0.001 ng, 0.5 to 0.001 ng, 1 to 0.05 ng, 0.01 ng, 0.001 ng, 0.0005 to 0.00025 ng, 0.0005 to 0.00025 ng, and 0.005 ng of DNA from cow milk, yogurt, cheese, acidic whey, milk powder, beef, beef jerky, and beef sausage, respectively. Different dairy and meat samples of camel and cow origins had a range of authentication limits and limits of detection. The designed triplex real-time PCR assay was shown to be a specific, sensitive, and efficient technique for the identification of camel and cow DNA in foodstuffs.

Natural fermentation of milk is a prerequisite in the production of traditional dairy products and is considered a bioresource of fermentative microorganisms and probiotics. To understand the microbial dynamics during distinct fermentative phases, the roles of different microbes, and the relationship between bacteria and fungi, microbial community dynamics was investigated by culture‐dependent and culture‐independent approaches. Natural, static fermentation of milk induces the formation of the underlying curds and the superficial sour cream (Zuohe in the Mongolian language). From an overall perspective, viable LAB increased remarkably. Yeast showed an initial increase in their abundance (from 0 hr to 24 hr), which was followed by a decrease, and mold was detected at the later stages of fermentation (after 68 hr). The observed trends in microbiota variation suggest an antagonistic interaction between bacteria (LAB) and fungi (yeast and mold). The beneficial bacterial and fungal genus and species (e.g., Lactococcus, Streptococcus, Leuconostoc, Dipodascus, Lactococcus lacti, Dipodascus australiensis) are gradually increased in concentration, and the potentially detrimental microbial genus and species (e.g., Acinetobacter, Pseudomonas, Fusarium, Aspergillus, Mortierella, Acinetobacter johnsonii, Fusarium solani) decrease during the decline of bacterial and fungi diversity from natural fermentation. The study of microbial community dynamics could make a great contribution to understand the mechanism of natural fermentation of milk and the formation of curds and Zuohe, and to discover the potentially fermentative microbes for industrial starter cultures.

Mongolian butter and Tude are traditional high‐fat dairy products produced in Xilin Gol, China, which have unique chemical and microbiological characteristics. Mongolian Tude is made from Mongolian butter, dreg, and flour. In this study, the traditional manufacturing process of Mongolian butter and Tude was investigated for the first time. Mongolian butter was characterized by high‐fat content (99.38 ± 0.63%) and high acidity (77.09 ± 52.91°T), whereas Mongolian Tude was considered a high‐fat (21.45 ± 1.23%) and high‐protein (8.28 ± 0.65%) dairy product obtained by butter, dreg, and flour. Mongolian butter and Tude were proven to be safe for human consumption in terms of benzopyrene content. In addition, Listeria monocytogenes, Staphylococcus aureus, Salmonella, coliforms, and aflatoxin M1 were not detected in the samples. Bacteria and molds were not isolated from Mongolian butter; in contrast, the total count of bacteria and molds in Mongolian Tude was within the range of 4.5 × 102 to 9.5 × 104 and 0 to 2.2 × 105, respectively. Moreover, Lactococcus (41.55%), Lactobacillus (11.05%), Zygosaccharomyces (40.20%), and Pichia (12.90%) were the predominant bacterial and fungal genera, and Lactobacillus helveticus (15.6%), Lactococcus raffinolactis (9.6%), Streptococcus salivarius (8.5%), Pantoea vagans (6.1%), Bacillus subtilis (4.2%), Kocuria rhizophila (3.5%), Acinetobacter johnsonii (3.5%), Zygosaccharomyces rouxii (46.2%), Pichia fermentans (14.7%), and Dipodascus geotrichum (11.7%) were the predominant species in the microbiota of Mongolian Tude. Thus, it can be stated that the microbiota of food products produced by different small families varied significantly. Collectively, the findings presented herein are the first report of chemical and microbiological characterization of products of geographical origin and highlight the need for standardization of manufacturing procedures of Mongolian butter and Tude in the future.