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Rice wine is primarily crafted from grains through saccharification and liquification with the help of Qu. Qu plays an important role in the formation of the flavor quality of rice wine. Hongqu and Xiaoqu represent two prevalent varieties of Qu that are typically utilized in the brewing process of rice wine and play a crucial role in its production. In this study, GC, GC-MS, HPLC, and metagenomic sequencing techniques were used to contrast the microbial flora, biogenic amines, and aroma characteristics developed during the fermentation of rice wines, with Hongqu and Xiaoqu being used as initiating agents for the brewing process. The results show that the content of higher alcohols (including n-propanol, isobutanol, 3-methyl-1-butanol, and phenethyl alcohol) in rice wine brewed with Xiaoqu (XQW) was significantly higher than that in rice wine brewed with Hongqu (HQW). Contrarily, the concentration of biogenic amines in HQW surpassed that of XQW by a notable margin, but tyramine was significantly enriched in XQW and not detected in HQW. In addition, a multivariate statistical analysis revealed distinct disparities in the constitution of volatile components between HQW and XQW. Hexanoic acid, ethyl acetate, isoamyl acetate, ethyl caproate, ethyl decanoate, 2-methoxy-4-vinylphenol, etc., were identified as the characteristic aroma-active compounds in HQW and XQW. A microbiome analysis based on metagenomic sequencing showed that HQW and XQW had different dominant microorganisms in the brewing process. Burkholderia, Klebsiella, Leuconostoc, Monascus, and Aspergillus were identified as the primary microbial genera in the HQW fermentation period, while Pediococcus, Enterobacter, Rhizopus, Ascoidea, and Wickerhamomyces were the main microbial genera in the XQW brewing process. A bioinformatics analysis revealed that the concentrations of microbial genes involved in biogenic amines and esters biosynthesis were significantly higher in HQW than those in XQW, while the content of genes relevant to glycolysis, higher alcohol biosynthesis, and fatty acid metabolism was significantly higher in XQW than in HQW, which are the possible reasons for the difference in flavor quality between the two kinds of rice wine from the perspective of microbial functional genes. [ABSTRACT FROM AUTHOR]

Hongqu rice wine was brewed with glutinous rice as raw material and Hongqu as starter. Monascus and Sac-charomyces cerevisiae were the core microorganisms in the brewing system. In this paper, using glutinous rice as the fermentation substrate, Monascus purpureus, Monascus ruber and Monascus kaoliang were combined with S. cerevisiae to study the effects of different combinations and fermentation modes (simultaneous fermentation and sequential fermentation) on the production of volatile components. A total of 89 volatile flavor compounds were identified from fermented rice wine based on headspace solid phase microextraction-gas chromatography mass spectrometry (HS-SPME-GC-MS). Heat map analysis showed that the combined fermentation of Monascus and S. cerevisiae produced more aroma substances than the pure fermentation of Monascus, and the sequential fermentation produced more aroma substances than the simultaneous fermentation, especially the sequential fermentation of M. purpureus, M. ruber and S. cerevisiae. According to the principal component analysis of volatile flavor components of different Monascus and S. cerevisiae combined fermentation, M. purpureus and M. ruber and S. cerevisiae will produce more volatile flavor components under the sequential fermentation mode, and their flavor compositions were close to each other. Through the analysis of the content difference of volatile flavor components, isobutanol, 1-heptanol, (3Z)-3-nonene-1-ol, 2-tetradecanol, (Z)-5-octene-1-ol, decanal, ethyl caproate, ethyl decanoate, 9 -decenoate, ethyl phenylacetate, ethyl acetate, 1,2 -dimethoxy -4 -vinyl benzene, acridine were the characteristic volatile flavor substances in the combined fermentation products of Monascus and S. cerevisiae. The results of this study could provide a theoretical basis for the improvement of flavor quality and quality control in the industrial production of Hongqu rice wine. [ABSTRACT FROM AUTHOR]

The stable regulation of cerebral blood flow plays an important role in the normal operation of brain function. The disturbance of cerebral blood flow automatic regulation will lead to brain injury and lead to cerebrovascular disease. Therefore, it is of practical clinical significance to study the fine modeling of intracranial blood vessels. First of all, based on the anatomic structure of the intracranial blood vessels, the above sagittal sinus vein, sigmoid sinus, superior petrosal sinus, transverse sinus and cerebral arterial circle were mainly modeled, the three-dimensional model of cerebral blood flow is constructed. Secondly, the three-dimensional model is given conductivity characteristics. Through the expansion and contraction of cerebral blood vessels to simulate the self-regulation of cerebral blood flow, the simulation method of cerebral blood flow impedance is studied. When the blood flow changes, the brain impedance is calculated. The simulation data shows that the change trend of the electric potential and the whole brain impedance of the outer layer of the brain is consistent with the theoretical analysis. The experimental results show that the impedance curves and changes calculated by the brain model in this study are consistent with the measured impedance results, which shows that the modeling method in this paper is precise and effective, and provides a theoretical basis for further study of cerebral blood flow problems.