To investigate the characteristic aromatic compounds, present in the traditional fermented koumiss of the Kazakh ethnic group in different regions of Xinjiang, GC-IMS, and GC-MS were used to analyze the volatile compounds in koumiss from four regions. A total of 87 volatile substances were detected, and esters, acids, and alcohols were found to be the main aroma compounds in koumiss. While the types of aroma compounds in koumiss were similar across different regions, the differences in their concentrations were significant and displayed clear regional characteristics. The fingerprint spectrum of GC-IMS, combined with PLS-DA analysis, indicates that eight distinctive volatile compounds, including ethyl butyrate, can be utilized to distinguish between different origins. Additionally, we analyzed the OVA value and sensory quantification of koumiss in different regions. We found that aroma components such as ethyl caprylate and ethyl caprate, which exhibit buttery and milky characteristics, were prominent in the YL and TC regions. In contrast, aroma components such as phenylethanol, which feature a floral fragrance, were more prominent in the ALTe region. The aroma profiles of koumiss from the four regions were defined. These studies provide theoretical guidance for the industrial production of Kazakh koumiss products.

In order to explore the aromatic differences between Xinjiang cow milk powder and specialty milk powder (donkey, camel, and horse milk powder), Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) analysis was employed to investigate the volatile compounds in these four types of milk powders. A total of 61 volatile substances were detected, with ketones, aldehydes, and alcohols being the primary flavor components in the milk powders. While the aromatic components of the different milk powders showed similarities in terms of types, there were significant differences in their concentrations, exhibiting distinct characteristics for each type. The Partial Least Squares Discriminant Analysis (PLS-DA) showed that there were 15, 14, and 23 volatile compounds that could be used for discrimination of cow milk powder against specialty milk powders, respectively. And it was validated by Receiver Operating Characteristic (ROC) analysis, and finally, 8, 6, and 19 volatile compounds were identified as valid differential marker substances. To facilitate visual discrimination between the different milk powders, we established GC-IMS fingerprint spectra based on the final discriminant markers. These studies provide theoretical guidance for the application of volatile compounds to discriminate adulteration of milk powder marketed in Xinjiang.

The quality and flavor development of fermented koumiss are intricately connected to metabolic processes in microbial communities. This study utilized a combination of macrogenome sequencing technology and gas chromatography–mass spectrometry to explore variations in bacterial and fungal communities, flavor compounds, and environmental factors and mine their associated functional genes in traditional Kazakh fermented koumiss from Altay, Tacheng, and Ili Kazakh Autonomous Prefecture in Xinjiang. A total of 87 volatile flavor compounds were successfully identified. Flavor compounds exhibited a close correlation with Lactobacillus, which was identified as a potential core functional microbial group in koumiss fermentation on the basis of its abundance and hypothesized flavor contributions. The analysis of environmental factors revealed the significant influence of geographical location on the distribution of microbial communities. The microbial flavor network highlighted the significance of Lactobacillus and Kluyveromyces as pivotal microbial groups with crucial contributions to the formation of flavor‐active substances. Kluyveromyces and Acetobacter followed these genera in importance. Moreover, the types and concentrations of acids, esters, and alcohols had a substantial effect on the formation of koumiss flavor. Furthermore, metagenomic data were annotated and analyzed by using Kyoto Encyclopedia of Genes and Genomes and evolutionary genealogy of genes: Nonsupervised Orthologous Groups databases. Microorganisms in koumiss possessed prominent functions in carbohydrate and amino acid degradation pathways. Annotation with the Carbohydrate‐Active enZYmes Database revealed that glycoside hydrolases constituted the highest proportion. The enzymatic features corresponding to genes in bacteria with high abundance were also characterized. The findings of this research offer valuable insights for screening and applying aroma‐producing microorganisms in fermented koumiss. They facilitate the targeted isolation of functional microbes, which are ideally suited for koumiss fermentation processes.

What we see is seemingly definite, belying the fact that the visual inputs are flooded with ambiguities. Generally, the visual system resolves the ambiguity almost instantaneously, e.g., recognize either the profile or the frontal view of a maiden from a Picasso’s painting even before noticing the alternative. By contrast, the perceived content at first glance varies dramatically from one person to another, resulting in idiosyncratic onset bias that challenges the conformity of vision. What drives the discrepancy between individuals in their conscious resolution of the physically ambiguous stimuli? Using a twin method that allows us to identify the determinant of individual difference, we dissociate the role of gene from environment in the process of visual disambiguation. Specifically, monozygotic twins (with identical genes) are more similar than dizygotic twins (sharing 50% genes) in the immediate perception of bistable biological motion but not generic object motion, indicating a domain-specific genetic influence on the way human brain making sense of biological entity. These results challenge the prevalent view that learning-based statistics is the major source of conscious perception, and suggest that part of the disposition of what we turn out to see from relevant yet inconclusive visual information is programmed in the genes. Meeting abstract presented at VSS 2013