Changes of shrimp myofibrillar proteins hydrolyzed by Virgibacillus proteases: Structural characterization, mechanism visualization, and flavor compound formation.

To explore the mechanism of Virgibacillus proteases on hydrolysis of shrimp myofibrillar protein (SMP) and formation of volatile compounds, the fermented broth of Virgibacillus halodenitrificans was purified and the protease was identified as peptidase S8. The enzyme had optimum activity at pH 7.0-8.

The Microbial Diversity and Flavor Metabolism Regulation of During Different Natural Fermentation Time Periods.

brine is a special flavored food produced by the natural fermentation of lees. To clarify fermentation time on its quality, this study integrated flavoromics analysis, macro-genomics, and polypeptide omics to analyze the volatile flavor components, microbial species, and flavor peptide distributions of four groups of samples (XZ-1Y, XZ-2Y, XZ-3Y, and XZ-4Y) fermented for 1-4 years. The results showed that the samples fermented for 1 year had the highest contents of umami amino acids and umami peptides, and the samples fermented for 4 years had the highest contents of organic acids and fruity components.

Investigation of Efficient Pullulan Synthesis Utilizing Huangjiu Lees as a Substrate.

Pullulan is a high-value biopolymer synthesized by through the fermentation of starch and sugars. It finds extensive applications in food, packaging, biomedicine, and other sectors. However, the high production costs significantly limit the development and application of pullulan.

Metagenomics-based insights into the microbial community dynamics and flavor development potentiality of artificial and natural pit mud.

Strong-flavor Baijiu (SFB) production has relied on pit mud (PM) as a starter culture. The maturation time of natural PM (NPM) is about 30 years, so artificial PM (APM) with a shorter maturation time has attracted widespread attention. This study reveals the microbial and functional dissimilarities of APM and NPM, and helps to elucidate the different metabolic roles of microbes during substrate degradation and flavor formation.

Transcriptome Analysis Reveals the Variations in Enzyme Production of A22 under Different Temperatures.

is a key microorganism in the fermentation of traditional fermented foods, capable of producing saccharifying and liquefying enzymes at elevated temperatures. However, the specific mechanisms and regulatory pathways governing 's response to ambient temperatures are not yet fully understood. In this study, the morphological differences in screened from traditional handmade wheat Qu at different temperatures were initially explored.

Heterogenetic mechanism in multidimensional pit mud with different fermentation years: From microbial structure dynamic succession to metabolism phenotypes.

Pit mud (PM) is fermenting agents in the strong-flavor baijiu (SFB) production. In this paper, the discrepancies in fermentation parameters, microbial community succession patterns and metabolic phenotypes were compared in multidimensional PMs. The results showed that pyruvic acid, succinic acid, S-Acetyldihydrolipoamide-E, glycerol and glyceric acid were the key metabolites responsible for the metabolic differences between the 2-, 30-,100- and 300-year multidimensional PMs, while the butanoic acid, heptyl, heptanoic acid, heptanoic acid ethyl ester, hexanoic acid and octanoic acid were the key differential flavor compounds in the 2-, 30-,100- and 300-year multidimensional PMs.

Optimization of vanillin biosynthesis in Escherichia coli K12 MG1655 through metabolic engineering.

Vanillin is an important flavouring agent applied in food, spices, pharmaceutical industries and other fields. Microbial biosynthesis of vanillin is considered a sustainable and economically feasible alternative to traditional chemical synthesis. In this study, Escherichia coli K12 MG1655 was used for the de novo synthesis of VAN by screening highly active carboxylic acid reductases and catechol O-methyltransferases, optimising the protocatechuic acid pathway, and regulating competitive metabolic pathways.

Multicopper Oxidase from : Mechanism of Degradation of Tyramine and Phenylethylamine in Fermented Food.

Elevated levels of biogenic amines (BAs) in fermented food can have negative effects on both the flavor and health. Mining enzymes that degrade BAs is an effective strategy for controlling their content. The study screened a strain of 1614 from fermented food system that can degrade BAs.

Microbial-derived salt-tolerant proteases and their applications in high-salt traditional soybean fermented foods: a review.

Different microorganisms can produce different proteases, which can adapt to different industrial requirements such as pH, temperature, and pressure. Salt-tolerant proteases (STPs) from microorganisms exhibit higher salt tolerance, wider adaptability, and more efficient catalytic ability under extreme conditions compared to conventional proteases. These unique enzymes hold great promise for applications in various industries including food, medicine, environmental protection, agriculture, detergents, dyes, and others.

DSNetax: a deep learning species annotation method based on a deep-shallow parallel framework.

Microbial community analysis is an important field to study the composition and function of microbial communities. Microbial species annotation is crucial to revealing microorganisms' complex ecological functions in environmental, ecological and host interactions. Currently, widely used methods can suffer from issues such as inaccurate species-level annotations and time and memory constraints, and as sequencing technology advances and sequencing costs decline, microbial species annotation methods with higher quality classification effectiveness become critical.

Case study on the influence of serving temperature on the aroma release and perception of Huangjiu, a fermented alcoholic beverage.

Serving temperature plays a crucial role in influencing the sensory experience of consumers. In this context, this study investigated the influence of serving temperature on the aroma release and perception of a typical fermented alcoholic beverage named Huangjiu. A quantitative sensory description analysis was conducted, determining serving temperature significantly influenced the 17 sensory attributes in both semi-dry and semi-sweet Huangjiu.

Enzymatic properties and inhibition tolerance analysis of key enzymes in β-phenylethanol anabolic pathway of HJ.

is known for its unique aroma, primarily attributed to its high concentration of β-phenylethanol (ranging from 40 to 130 mg/L). Phenylalanine aminotransferase Aro9p and phenylpyruvate decarboxylase Aro10p are key enzymes in the β-phenylethanol synthetic pathway of HJ. This study examined the enzymatic properties of these two enzymes derived from HJ and S288C.

Effect of oxygen supplement on post-mortem metabolic profile of shrimp during cold storage.

Shrimp, renowned for its exceptional nutritional value, holds a pivotal position within the realm of aquatic products. The supplementation of extra oxygen to shrimp throughout the entire supply chain has found application within the commercial seafood market. In this study, a dual-platform metabolic analysis, coupled with multivariate data analysis, was employed to discern the impact of supplementary oxygen.

Environmental factors drive microbial community succession in biofortified wheat Qu and its improvement on the quality of Chinese huangjiu.

Wheat Qu plays the role of saccharification fermentation, providing microorganisms and flavor in the fermentation of huangjiu, and the use of functional microorganisms to fortify wheat Qu is becoming increasingly popular. Yet, the mechanisms promoting microbial successions of wheat Qu remain unclear. In this study, we first correlated microbial community succession with physicochemical factors (moisture, temperature, acidity, glucoamylase and amylase) in inoculated raw wheat Qu (IRWQ) with Saccharopolyspora rosea.

Structural elucidation of a highly branched α-D-glucan from Huangjiu and its hepatoprotective activity via gut microbiome regulation and intestinal barrier repairment.

Polysaccharides in Huangjiu, a traditional fermented food, are expected to be potentially effective ingredients in protecting against alcoholic liver disease (ALD). Elucidating their precise structural and functional characteristics is essential for in-depth understanding of structure-activity relationships of hepatoprotective polysaccharides. Herein, a major polysaccharide component HJPS1-2 was purified from Huangjiu with an average molecular weight of 3.

Preservative effect of gelatin/chitosan-based films incorporated with lemon essential oil on grass carp (Ctenopharyngodon idellus) fillets during storage.

The present study investigated the effect of fish gelatin/chitosan-based (FG/CS-based) films incorporated with lemon essential oil (LEO) on grass carp fillets in terms of moisture status, total volatile basic nitrogen (TVB-N), and microbial community succession during chilled (4 °C) and iced (0 °C) storage. Low-field nuclear magnetic resonance (LF-NMR) revealed that the active films remarkably inhibited moisture transformation from being the immobilized to free water in grass carp fillets, accompanied with the reduced T relaxation time. Besides, magnetic resonance imaging (MRI) detected a higher density of proton in the treated fish samples, indicating that the active films could improve the water-holding capacity of fish samples.

Sensory-Guided Isolation, Identification, and Active Site Calculation of Novel Umami Peptides from Ethanol Precipitation Fractions of Fermented Grain Wine (Huangjiu).

Huangjiu is rich in low-molecular-weight peptides and has an umami taste. In order for its umami peptides to be discovered, huangjiu was subjected to ultrafiltration, ethanol precipitation, and macroporous resin purification processes. The target fractions were gathered according to sensory evaluation.

Metabolomics investigation of global responses of Cronobacter sakazakii against common sanitizing in infant formula processing environments.

Cronobacter sakazakii, an opportunistic bacterium, has raised a serious outbreak in powdered infant formula recent years. In this work, four sanitizing strategies used during infant formula processing, including chlorine, quaternary ammonium chloride (QAC), 60 °C heating, and malic acid (MA), were utilized against C. sakazakii among planktonic, air-dried (A), and air-dried & washed (AW) state, followed by an exploration of the metabolic responses induced by these treatments via a dual-platform metabolomics analysis with the ultra-high performance liquid chromatography-mass spectrometry and nuclear magnetic resonance.

Exploring major variable factors influencing flavor and microbial characteristics of upper jiupei.

The flavor quality of jiupei gradually decreased with the increase of cellar height. In this study, high-throughput sequencing, metabolomics and HS-SPME-GC-MS techniques were used to explore the mechanism of flavor quality decline in upper jiupei in mud sealed cellars. The results showed the total content of flavor compounds increased from 1947.

Identification of common buckwheat ( Moench) adulterated in Tartary buckwheat ( (L.) Gaertn) flour based on near-infrared spectroscopy and chemometrics.

Near-infrared spectroscopy (NIRS) presents great potential in the identification of food adulteration due to its advantages of nondestructive, simple, and easy to operate. In this paper, a method based on NIRS and chemometrics was proposed to predict the content of common buckwheat ( Moench) flour in Tartary buckwheat ( (L.) Gaertn) flour.

Metabolome shifts triggered by chlorine sanitisation induce Escherichia coli on fresh produce into the viable but nonculturable state.

Facing the increasing occurrence of "big six" Escherichia coli outbreaks linked to fresh produce, chlorine-based sanitisers are widely used for fresh produce decontamination in recent years. However, latest finding that chlorine may induce E. coli cells into a viable not nonculturable (VBNC) state is bringing a new challenge to the fresh produce industry.

Microbial succession and its effect on the formation of umami peptides during sufu fermentation.

Sufu, a traditional Chinese fermented food, is famous for its unique flavor, especially umami. However, the formation mechanism of its umami peptides is still unclear. Here, we investigated the dynamic change of both umami peptides and microbial communities during sufu production.

Screening of marine sediment-derived microorganisms and their bioactive metabolites: a review.

Marine sediments are one of the largest habitats on Earth, and their unique ecology, such as high salinity, high pressure, and hypoxia, may activate certain silent genes in marine microbes, resulting in microbes, enzymes, active products, and specific metabolic pathways that can adapt to these specific ecological environments. Marine sediment-derived microorganisms and their bioactive metabolites are of great significance and have potential commercial development prospects for food, pharmaceutical, chemical industries, agriculture, environmental protection and human nutrition and health. In recent years, although there have been numerous scientific reports surrounding marine sediment-derived microorganisms and their bioactive metabolites, a comprehensive review of their research progress is lacking.