The mechanism of microbial structure and flavor characteristics in Qing-Jiang-flavor Jiupei regulated by different fermentation seasons.

The physicochemical characteristics of Jiupei are crucial in regulating the metabolism of microbial communities and the flavor profile of Baijiu during the fermentation process. This study systematically monitored the physicochemical characteristics of Qing-Jiang-flavor Baijiu Jiupei (QJFJ) and analyzed its microbial community structure and flavor compounds. Results indicated that dominant bacteria were significantly enriched in Summer- and Autumn-Jiupei (Spring: Summer: Autumn: Winter = 1.00: 1.40: 1.29: 1.21), while dominant fungi were significantly enriched in Spring- and Autumn-Jiupei (Spring: Summer: Autumn: Winter = 1.45: 1.00: 1.35: 1.31). Sequentially, reducing sugars (day 0), temperature (day 5 - day 10), moisture (day 15), and acidity (day 20 - day 25) in Jiupei affected the succession pattern of the microbial community, regulating the abundance of Saccharomyces, Staphylococcus, Cyberlindnera, and Lactobacillus, individually. Alcohol and acid compounds are considered seasonal differential compounds in QJFJ. This study will provide a theoretical basis for Baijiu production across different seasons.

Identification of the chemical composition of distiller's grain polyphenols and their effects on the fecal microbial community structure.

Distiller grains are the main by-products of Baijiu production and are usually discarded, ignoring their abundant functional phytochemicals. The free and bound polyphenols from distiller grains were extracted and their potential effect on modulating fecal microbiota was investigated using in vitro fecal fermentation. The results showed that 34 polyphenols were quantified from distiller grains. The antioxidant activity was positively correlated with quercetin, myricetin, epicatechin, and naringenin. The abundance of Bifidobacterium, Ruminobacterium, Lactobacillus, Akkermansia, and butyrate-producing bacteria was enhanced by distiller's grain polyphenols by approximately 10.66-, 6.39-, 7.83-, 2.59-, and 7.74-fold, respectively. Moreover, the production of short-chain fatty acids (SCFAs), especially acetic, butyric, and propionic acid, was promoted (increased 1.99-, 1.71-, and 1.34-fold, respectively). Correlated analysis revealed quercetin, daidzein, and kaempferol as the key polyphenols by analyzing the effects on gut microbiota and SCFAs. This study could provide a reference for converting distiller grains into high-nutrient functional food ingredients and feeds.

Comparative characterization and contribution of key aroma compounds in the typical base liquor of Jiang-flavor Baijiu from different distributions in the Chinese Chishui River basin.

The characteristic of typical base liquor is crucial in controlling ultimate quality of Jiang-flavor Baijiu. This study investigates the flavor compounds of three typical base liquors (Jiangxiang, Chuntian, and Jiaodixiang) by LLE/LLME/HS-SPME, gas chromatography-mass spectrometry (GC-MS), gas chromatography-flame ionization detection (GC-FID), sensory analysis, and odor activity value (OAV). Of the 201 main volatile compounds identified, 37 significant compounds distinguished the three typical base liquors. Acid (441.72 ±â€¯0.17 mg/L), alcohol (5388.88 ±â€¯0.55 mg/L), and ester compounds (8181.64 ±â€¯0.15 mg/L) were respectively marked in Jiangxiang, Chuntian, and Jiaodixiang typical base liquors. Orthogonal partial least squares discriminant analysis (OPLS-DA), correlation analysis, and aroma recombination showed that butyric acid (OAV: 102.23), butyl 2-methylbutyrate (OAV: 6045.59), and ethyl caproate (OAV: 418.37) were significantly correlated with sweet, fruity, pit mud, jiang, and ethanol aromas. It identifies the primary constituents that affect flavor variations in the three typical base liquors and provides guidance for investigations on the flavor formation of Jiang-flavor Baijiu.

Effect of free and bound polyphenols from Rosa roxburghii Tratt distiller's grains on moderating fecal microbiota.

Rosa roxburghii Tratt distiller's grains (R. roxburghii DGs), the main by-product of wine processing, showed functional value and potential for high-value usage which benefited from their rich polyphenols. In this study, the free and bound polyphenols from R. roxburghii DGs were extracted and their potential effect on modulating fecal microbiota was investigated using in vitro fecal fermentation. The free polyphenols (26.32-26.45 mg GAE/g) showed higher antioxidant activity compared to the bound polyphenols (8.76-9.01 mg GAE/g). The free and bound polyphenols significantly improved the fecal microbiota community structure and enhanced short chain fatty acids concentrations after the stimulated colonic fermentation for 24 h. Furthermore, the effect of R. roxburghii DGs polyphenols on modulating fecal microbiota was primarily attributed to quercetin, catechin, kaempferol, cyanidin and baicalin. This research suggests that R. roxburghii DGs are a promising source of natural antioxidants and prebiotic foods.

Metagenomic analyses reveal microbial communities and functional differences between Daqu from seven provinces.

Microbial communities perform the brewing function in Daqu. Macrogenomics and PICRUST II analyses revealed the differences in microbes and metabolic functions among Daqu from the seven Baijiu-producing provinces. Jiang-flavored Daqu (Guizhou, Shandong, and Hubei provinces) generally forms an aroma-producing functional microbiota with Kroppenstedtia, Bacillus, Thermoascus, Virgibacillus, and Thermomyces as the core, which promotes the metabolism of various amino acids and aroma compounds. Light-flavored Daqu (Shanxi Province) enriched the Saccharomycopsis, Saccharomyces, and lactic acid bacteria (LAB) microbiota through low-temperature fermentation. These microbes can synthesize alcohol and lactic acid but inhibit amino acid metabolism within the Light-flavored Daqu. Bifidobacterium and Saccharomycopsis were dominant in the Tao-flavored Daqu (Henan province). This unique microbial structure is beneficial for pyruvate fermentation to lactate. Research also found that Strong-flavored Daqu from Jiangsu and Sichuan provinces differed significantly. The microbial communities and metabolic pathways within Jiangsu Daqu were similar to those within Jiang-flavored Daqu, but Sichuan Daqu was dominated by Thermoascus, LAB, and Thermoactinomyces. In addition, Spearman correlation analysis indicated that Kroppenstedtia, Bacillus, and Thermomyces were not only positively related to flavor metabolism but also negatively correlated with Saccharomycopsis. This research will help establish a systematic understanding of the microbial community and functional characteristics in Daqu.

Thermal stability of levopimaric acid and its oxidation products.

Biofuels are renewable alternatives to fossil fuels. Levopimaric acid‒base biofuels have attracted increasing attention. However, their stability remains a critical issue in practice. Thus, there is a strong impetus to evaluate the thermal stability of levopimaric acid. Through thermogravimetry (TG) and a custom-designed mini closed pressure vessel test (MCPVT) operating under isothermal and stepped temperature conditions, we investigated thermal oxidation characteristics of levopimaric acid under oxygen atmosphere. Thin-layer chromatography (TLC) and iodimetry were used to measure the hydrogen peroxides generated by levopimaric acid oxidation. A high pressure differential scanning calorimeter (HPDSC) was used to assess hydroperoxide thermal decomposition characteristics. Gas chromatography-mass spectrometry (GC-MS) was used to characterize the oxidation products. The thermal decomposition kinetics of levopimaric acid were thus elucidated, and a high peroxide value was detected in the levopimaric acid. The decomposition heat (QDSC) and exothermic onset temperature (Tonset) of hydroperoxides were 338.75 J g-1 and 375.37 K, respectively. Finally, levopimaric acid underwent a second-stage oxidation process at its melt point (423.15 K), resulting in complex oxidation products. Thermal oxidation of levopimaric acid could yield potential thermal hazards, indicating that antioxidants must be added during levopimaric acid application to protect against such hazardous effects.

Millimeter-wave generation based on a monolithic dual-wavelength DFB laser with four phase-shifted sampled gratings and equivalent chirp technology.

A dual-wavelength DFB laser array based on four phase-shifted grating and equivalent chirp technology is first proposed, fabricated, and experimentally demonstrated. The dual-wavelength emitting is achieved by symmetrically introducing two π phase shifts into a chirped four phase-shifted sampled grating cavity. Meanwhile, the beating signal of the dual-wavelength output is stabilized by applying an electro-absorption modulator integrated at the rear of the cavity. Under different grating chirp rates, a series of RF signals from 66.8 GHz to 73.6 GHz with a linewidth of less than 210 kHz is obtained.

Stepped-height ridge waveguide MQW polarization mode converter monolithically integrated with sidewall grating DFB laser.

We report, to the best of our knowledge, the first demonstration of a 1555-nm stepped-height ridge waveguide polarization mode converter monolithically integrated with a sidewall grating distributed-feedback (DFB) laser using the identical epitaxial layer scheme. The device shows stable single longitudinal mode (SLM) operation with the output light converted from TE to TM polarization with an efficiency of >94% over a wide range of DFB injection currents (IDFB) from 140 mA to 190 mA. The highest TM mode purity of 98.2% was obtained at IDFB = 180 mA. A particular advantage of this device is that only a single step of metalorganic vapor-phase epitaxy and two steps of III-V material dry etching are required for the whole integrated device fabrication, significantly reducing complexity and cost.

Study on the drunkenness of Chinese Baijiu with representative flavor based on behavioral characteristics.

The essential role of drunkenness on the healthy development of Chinese Baijiu was studied in this research. This study revealed the effects of Baijiu on the behaviors of mice and evaluated the degree of drunkenness of soy sauce-, strong-, light-, and light and soy sauce-flavored Baijiu. The parameters obtained from the open field test were transformed into the behavioral drunkenness index by mathematical statistical analysis and the drunkenness-associated key compounds of Baijiu were analyzed. The results showed that strong- and light-flavored Baijiu presented higher levels of drunkenness and sobriety than soy sauce-flavored Baijiu. Interestingly, light and soy sauce-flavored Baijiu showed low drunkenness but a high sobriety degree. Specifically, the degree of drunkenness was positively correlated with fusel alcohol and aldehydes but negatively correlated with esters and acids. This study will enrich references for Baijiu behavior studies and lay a foundation for the research and development of healthy Baijiu.

Exploring the impacts of traditional crafts on microbial community succession in Jiang-flavored Daqu.

The usage of traditional crafts during the fermentation process has a great influence on the quality of Jiang-flavored Daqu. This study focused on exploring the impacts of traditional crafts on Daqu microecology through high-throughput sequencing and statistical analyses. These results show that traditional crafts modulated microbial community succession through the regulation of temperature, moisture, and acidity. High temperatures (66 ± 1 °C) were conducive to the growth of microbes that produced flavor compounds, such as Bacillus and Thermoactinomyces. Low moisture content (correlated with 22 genera) and high acidity (8 genera) were mainly responsible for the decreased microbial diversity. Two flipping processes showed significant effects on the internal microecology and microbial metabolism. The first flip of Daqu may assist in regulating the microbial community structure and promoting the enrichment of flavor-functional microorganisms. The second flipping was reasonable for the enrichment of esterifying functional microorganisms, thus enhancing the esterifying power of Daqu with reduced acidity. Furthermore, analysis of the metabolic pathways at different stages of the process showed that the levels of flavor precursors and secondary metabolites within Jiang-flavored Daqu significantly increased during fermentation.

DFB laser array based on four phase-shifted sampled Bragg gratings with precise wavelength control.

A four-laser array based on sampled Bragg grating distributed feedback (DFB) lasers in which each sampled period contains four phase-shift sections is proposed, fabricated, and experimentally demonstrated. The wavelength spacing between adjacent lasers is accurately controlled to 0.8 nm ± 0.026 nm and the lasers have single mode suppression ratios larger than 50 dB. Using an integrated semiconductor optical amplifier, the output power can reach 33 mW and the optical linewidth of the DFB lasers can be as narrow as 64 kHz. This laser array uses a ridge waveguide with sidewall gratings and needs only one metalorganic vapor-phase epitaxy (MOVPE) step and one III-V material etching process, simplifying the whole device fabrication process, and meeting the requirements of dense wavelength division multiplexing systems.

Analysis of bacterial diversity and functional differences of Jiang-flavored Daqu produced in different seasons.

High-temperature Daqu is an important saccharifying fermenting starter for brewing Jiang-flavored Baijiu. This paper analyzed the diversity characteristics of bacterial communities of Jiang-flavored Daqu (JFDQ) with seasonal changes through Illumina HiSeq sequencing and multivariate statistical methods. Results showed that 21 phyla, 529 genera, and 47 core bacterial genera were identified from the 48 composite samples. Among them, eight functional genera were only found in the summer-produced Daqu (Propionigenium, etc.). Pantoea, Bacillus, Lentibacillus, and Oceanobacillus, respectively, served as the representative functional bacterial genera of the four seasons. Functional prediction analysis showed that Amino acid metabolism Carbohydrate metabolism, Lipid metabolism, Metabolism of cofactors and vitamins, and Nucleotide metabolism (relative abundance > 1%) were the most critical microbial functions in JFDQ, and these key enzymes involved in acetoin biosynthesis, and acetyl-CoA biosynthesis were more abundant in the summer than in the winter. The functional microorganisms community in this paper would provide valuable suggestions about the seasonal production of JFDQ, guiding the Baijiu brewing processes.

Encapsulation of tartary buckwheat flavonoids and application to yoghurt.

Aims: The present work investigates the effect of tartary buckwheat flavonoid (TBF) capsules on the physical and chemical properties of yoghurt using polymeric whey protein (PWP) as a wall material.Methods: PWP was prepared by thermal polymerisation. TBF was encapsulated using PWP as the wall material via the pore-coagulation bath method. The physicochemical properties of the TBF capsules, such as the entrapment yield, moisture, average particle size, particle size distribution, surface morphology, molecular interactions, and thermal stability were investigated, in addition to the release of TBF in simulated gastric and intestinal juices. Yoghurt formulation was carried out using encapsulated TBF (3%, w/w), blank PWP beads (2.7%, w/w), and unencapsulated TBF (0.3%, w/w). A control yoghurt sample was prepared without these ingredients. The effects of encapsulated TBF on the chemical composition, acidity, texture, synaeresis, sensory properties, number of Streptococcus thermophilus and Lactobacillus, and other physical and chemical properties of the yoghurt were investigated.Results: TBF capsules were found to be sphere-shaped with porous surfaces, an average particle size of 1728.67 µm, an encapsulation yield of 92.85 ± 1.98% (w/w), and a glass transition temperature of 152.06 °C. When the TBF capsules were exposed to simulated gastric fluid for 4 h, the TBF release rate was 15.75% (w/w), while in simulated intestinal fluid, the TBF release rate reached 65.99% (w/w) after 1 h. After 5-6 h in simulated intestinal fluid, the TBF release rate reached 100% (w/w). The protein content of the yoghurt with encapsulated TBF was 3.57 ± 0.26% (w/w, p < 0.01), and the numbers of Lactobacillus and Streptococcus thermophilus were 2.45 ± 0.98 × 108 (p < 0.01) and 5.43 ± 2.24 × 107 CFU/mL (p < 0.05), respectively, with strong water retention being detected (p < 0.01). Samples containing the encapsulated TBF exhibited a significantly higher acceptability than the unencapsulated TBF (p < 0.01).Conclusions: Encapsulation using PWP effectively delivers TBF to the small intestine through the stomach. It also masks the bitter taste, enhances the colour of TBF-containing yoghurt, and improves the physical and chemical properties of the yoghurt.

Frequency comb with 100 GHz spacing generated by an asymmetric MQW passively mode-locked laser.

A L-band two-section AlGaInAs/InP asymmetric multiple quantum well (QW) passively mode-locked laser has been used to generate a frequency comb with a 100 GHz spacing at a central wavelength of 1610 nm. The comb contains 10 optical lines within a -3dB bandwidth of 8.05 nm and 34 optical lines within a -20dB bandwidth of 30 nm. The mode-locked pulse duration was 440 fs. To the best of our knowledge, this is the shortest pulse duration from any directly electrically pumped QW semiconductor mode-locked laser.

The development of alcohol policy in contemporary China.

Over recent years, an increase in alcohol-related problems has been noted in China. Taking effective measures against the problem requires clear reviewing and understanding of the evolution of the Chinese alcohol policy. This study is aimed to evaluate the alcohol policy with special focus on reviewing the alcohol production and consumption situation in China and assessing the changes in Chinese alcohol policy along with other related fields. This article finishes with a set of recommended policy changes that could help solve the recent alcohol-related problems and analyze the major impediments.

Two-dimensional periodic structure induced by single-beam femtosecond laser pulses irradiating titanium.

A novel two-dimensional (2-D) periodic structure on the ablated hole wall is formed by using the method of single-beam femtosecond laser pulses irradiating a titanium target. This 2-D structure on the ablated surface, after consecutive irradiation of 10000 pulses, presents different spatial periods which characters a 1500 nm period along the hole wall in the vertical direction and a 400 nm period in the azimuthal direction of the hole. The reported experimental results can be well interpreted by a prophetic theoretical model of Bonch-Bruevich (A. M. Bonch-Bruevich et al., Opt. Eng. 31, 718 (1992)).

[Effect of primary percutaneous coronary intervention on plasma B-type natriuretic peptide in patients with acute myocardial infarction].

OBJECTIVE: To observe the effect of primary percutaneous coronary intervention (PCI) on plasma B-type natriuretc peptide (BNP) in patients with acute myocardial infarction (AMI). METHODS: Thirty-eight patients with AMI were divided into two groups for PCI (n=26) and conventional treatment (n=12). The plasma BNP levels were measured by fluorescence immunoassay (FIA) in these patients immediately, 24 h, 7 d, and 30 days after admission, and the infarct-related coronary arteries (IRA) were treated only with emergency interventional therapy in PCI group. RESULTS: BNP of the patients in the PCI and conventional treatment group B increased immediately and 24 h after admission, but there was no significant difference between the two groups (243.74+/-75.68 vs 228.65+/-82.32 and 283.42+/-88.66 vs 275.48+/-89.67, P>0.05). BNP in PCI group decreased but that in conventional treatment group increased 7 days after admission, showing significant difference between them (203.63+/-59.42 vs 388.74+/-108.52, P<0.05 ). BNP remained significantly lower in the PCI group than in the other group 30 days after admission (96.31+/-43.22 vs 237.66+/-75.48, P<0.01). Emergency PCI for different IRA resulted in the significant difference in BNP between the patients, and intervention of the left anterior descending artery (LAD) resulted in more obvious BNP reduction in comparison with that due to interventional of the right coronary artery (RCA) and left circumflex coronary artery (LCX). The changes in left ventricular ejection fraction (LVEF) and left ventricular end-diastolic dimension (LVEDD) were correlated to the changes of BNP. The mean BNP in the 3 fatal cases was nearly 10-fold higher than the normal level. CONCLUSIONS: BNP of AMI patients decreases on days 7 and 30 after reperfusion therapy with primary PCI, and the reduction can be more obvious 30 days after admission.