Effect of Chinese bayberry residue on quality of Chinese quinoa (Chenopodium quinoa Willd.) Rice wine.

Chinese bayberry residue (CBR) is a by-product of processing, which can be used as an auxiliary material during the processing of quinoa rice wine. In this study, the effects of CBR on the chemical profile, bioactive function, taste traits, and flavor of Chinese quinoa rice wine (CQRW) were investigated. The results showed that adding CBR increased the total phenolics, the total flavonoids, and antioxidant capacity. Malic acid content was the highest in Chinese rice wine (CRW), while the total content of components detected in HPLC-MS/MS was the highest in 10%CBR + CQRW. The CQRW exhibited the highest amino acid content, followed by 20%CBR + CQRW. E-tongue analysis results showed that 10%CBR + CQRW, 20%CBR + CQRW, and CQRW had the closest taste traits. Moreover, GC-MS analysis identified 72 aroma compounds in 10%CBR + CQRW sample, more than other samples. In summary, adding 10% CBR significantly improved the quality of CQRW.

Lot-to-lot variation in the microbiota during the brewing process of kimoto-type Japanese rice wine.

Kimoto-type Japanese rice wine (sake) has a wide variety of flavors, as the predominant microbes, including lactic acid bacteria (LAB) and nitrate-reducing bacteria, that spontaneously proliferate in the fermentation starter vary depending on the brewery. In this study, we traced the microbiota in four lots of starters manufactured in a newly established brewery and evaluated the lot-to-lot variation and characteristics of the microbiota in the brewery. The results of a 16S ribosomal RNA amplicon analysis showed that the starters brewed in the second brewing year had a more diverse microbiota than those in the first brewing year. Among the LAB predominated at the middle production stage, lactococci, including Leuconostoc spp., were detected in all the lots, while lactobacilli predominated for the first time in the second year. These results suggest that repeated brewing increased microbial diversity and altered the microbial transition pattern in the kimoto-style fermentation starters. Phylogenetic analyses for the LAB isolates from each starter identified Leuconostoc suionicum, Leuconostoc citreum, and Leuconostoc mesenteroides as predominant lactococci as well as a unique lactobacillus in place of Latilactobacillus sakei. We also found that a rice koji-derived Staphylococcus gallinarum with nitrate-reducing activity was generally predominant during the early production stage, suggesting that there was a case in which staphylococci played a role in nitrite production in the starters. These findings are expected to contribute to the understanding of the diversity of microbiota in kimoto-type sake brewing and enable control of the microbiota for consistent sake quality.

Metatranscriptomics reveals microbial community function succession and characteristic flavor formation mechanisms during black rice wine fermentation.

Black rice wine (BRW) is a traditional Chinese rice wine with unique flavors; however, the formation pathways of flavor compounds driven by microbiota remain unclear. This study employed HPLC and GC-MS to reveal that during BRW fermentation, free amino acids increased sevenfold, volatile compounds doubled, and 28 key characteristic flavor compounds were identified. Metatranscriptomic analysis indicated that during fermentation, driven by physicochemical factors and microbial interactions, Saccharomyces gradually became the dominant active microorganism (relative abundance 87.01%-97.70%). Other dominant microorganisms (relative abundance >0.1%), including Saccharomycopsis, Pediococcus, Wickerhamomyces, and Weissella, significantly decreased. Meanwhile, the microflora's signature functions underwent succession: transcription early, carbohydrate metabolism mid-stage, and autophagy late. These microbial and functional successions facilitated the accumulation of flavor compounds. Metabolic network reconstruction revealed that Saccharomyces was pivotal in substrate degradation and flavor formation, while other dominant microorganisms actively promoted these processes. This study provides insights into regulating BRW's flavor through microorganisms.

Integrative metagenomics, volatilomics and chemometrics for deciphering the microbial structure and core metabolic network during Chinese rice wine (Huangjiu) fermentation in different regions.

Huangjiu is a spontaneously fermented alcoholic beverage, that undergoes intricate microbial compositional changes. This study aimed to unravel the flavor and quality formation mechanisms based on the microbial metabolism of Huangjiu. Here, metagenome techniques, chemometrics analysis, and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) metabolomics combined with microbial metabolic network were employed to investigate the distinctions and relationship between the microbial profiles and the quality characteristics, flavor metabolites, functional metabolic patterns of Huangjiu across three regions. Significant variations (P < 0.05) were observed in metabolic rate of physicochemical parameters and biogenic amine concentration among three regions. 8 aroma compounds (phenethyl acetate, phenylethyl alcohol, isobutyl alcohol, ethyl octanoate, ethyl acetate, ethyl hexanoate, isoamyl alcohol, and diethyl succinate) out of 448 volatile compounds were identified as the regional chemical markers. 25 dominant microbial genera were observed through metagenomic analysis, and 13 species were confirmed as microbial markers in three regions. A metabolic network analysis revealed that Saccharomycetales (Saccharomyces), Lactobacillales (Lactobacillus, Weissella, and Leuconostoc), and Eurotiales (Aspergillus) were the predominant populations responsible for substrate, flavor (mainly esters and phenylethyl alcohol) metabolism, Lactobacillales and Enterobacterales were closely linked with biogenic amine. These findings provide scientific evidence for regional microbial contributions to geographical characteristics of Huangjiu, and perspectives for optimizing microbial function to promote Huangjiu quality.

Unraveling the Metabolic Behavior and Interspecific Interaction Pattern of Lactic Acid Bacteria within Chinese Rice Wine.

The synthetic community of lactic acid bacteria (LAB) is commonly utilized in the food industry for manipulating product properties. However, the intermediate interactions and ecological stability resulting from metabolic differences among various LAB types remain poorly understood. We aimed to analyze the metabolic behavior of single and combined lactic acid bacteria in China rice wine based on microbial succession. Three-stage succession patterns with obligate heterofermentative LAB dominating prefermentation and homofermentative LAB prevailing in main fermentation were observed. Facultative heterofermentative LAB exhibited significant growth. Pairwise coculture interactions revealed 63.5% positive, 34.4% negative, and 2.1% neutral interactions, forming nontransitive and transitive competition modes. Nontransitive competitive combinations demonstrated stability over ∼200 generations through amino acid (mainly aspartic acid, glutamine, and serine) cross-feeding and lactic acid detoxification, which also showed potential for controlling biogenic amines and developing LAB starter cultures. Our findings offer insights into the mechanistic underpinnings of LAB interaction networks.

Advancements in Fermented Beverage Safety: Isolation and Application of Clavispora lusitaniae Cl-p for Ethyl Carbamate Degradation and Enhanced Flavor Profile.

Ethyl carbamate (EC) is a natural by-product in the production of fermented food and alcoholic beverages and is carcinogenic and genotoxic, posing a significant food safety concern. In this study, Clavispora lusitaniae Cl-p with a strong EC degradation ability was isolated from Daqu rich in microorganisms by using EC as the sole nitrogen source. When 2.5 g/L of EC was added to the fermentation medium, the strain decomposed 47.69% of ethyl carbamate after five days of fermentation. It was unexpectedly found that the strain had the ability to produce aroma and ester, and the esterification power reached 30.78 mg/(g·100 h). When the strain was added to rice wine fermentation, compared with the control group, the EC content decreased by 41.82%, and flavor substances such as ethyl acetate and ß-phenylethanol were added. The EC degradation rate of the immobilized crude enzyme in the finished yellow rice wine reached 31.01%, and the flavor substances of yellow rice wine were not affected. The strain is expected to be used in the fermented food industry to reduce EC residue and improve the safety of fermented food.

Structure-guided engineered urethanase from Candida parapsilosis with pH and ethanol tolerance to efficiently degrade ethyl carbamate in Chinese rice wine.

Urethane hydrolase can degrade the carcinogen ethyl carbamate (EC) in fermented food, but its stability and activity limit its application. In this study, a mutant G246A and a double mutant N194V/G246A with improved cpUH activity and stability of Candida parapsilosis were obtained by site-directed mutagenesis. The catalytic efficiency (Kcat/Km) of mutant G246A and double mutant N194V/G246A are 1.95 times and 1.88 times higher than that of WT, respectively. In addition, compared with WT, the thermal stability and pH stability of mutant G246A and double mutant N194V/G246A were enhanced. The ability of mutant G246A and double mutant N194V/G246A to degrade EC in rice wine was also stronger than that of WT. The mutation increased the stability of the enzyme, as evidenced by decreased root mean square deviation (RMSD) and increased hydrogen bonds between the enzyme and substrate by molecular dynamics simulation and molecular docking analysis. The molecule modification of new cpUH promotes the industrial process of EC degradation.

Optimization of fermentation conditions and quality evaluation of Chaenomeles sinensis glutinous rice wine.

The present study was conducted to optimize fermentation conditions for preparation of Chaenomeles sinensis Glutinous Rice Wine (CRW). The dynamic changes of main substances in the liquor during fermentation process, aroma components, biologically active substances and antioxidant capacity in the CRW after 6 months of aging were tested. The results showed that under optimized conditions, the yield and alcohol content of wine was 44.97 and 20.00%, respectively. After aging, 64 aroma components were detected in the wine, mainly alcohols and esters. The alcohol content of the CRW was 14.8%. Polyphenols and flavonoids reached 0.23 g/L and 0.037 g/L respectively. Furthermore, the CRW had an excellent free radical scavenging ability. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-024-05934-0.

Application of fixed-frequency ultrasound in the cultivation of Saccharomyces cerevisiae for rice wine fermentation.

BACKGROUND: Rice wine (RW) fermentation is limited by its long fermentation time, weak taste and unpleasant flavors such as oil and odor. In this study, a novel ultrasound technology of Saccharomyces cerevisiae was used with the aim of improving fermentation efficiency and volatile flavor quality of RW. RESULTS: The results showed that fixed-frequency ultrasonic treatment (28 kHz, 45 W L-1, 20 min) of S. cerevisiae seed culture at its logarithmic metaphase significantly increased the biomass and alcohol yield by 31.58% and 26.45%, respectively, and reduced fermentation time by nearly 2 days. Flavor analysis indicated that the flavor compounds in RW, specifically the esters and alcohols, were also increased in quantity after the ultrasonic treatment of S. cerevisiae seed liquid. Isobutyl acetate, ethyl butyrate, ethyl hexanoate and phenethyl acetate contents were increased by 78.92%, 129.19%, 7.79% and 97.84%, respectively, as compared to the control. CONCLUSION: Ultrasonic treatment of S. cerevisiae reduced fermentation time and enhanced the flavor profile of RW. This study could provide a theoretical and/or technological basis for the research and development of RW. © 2024 Society of Chemical Industry.

Importance of Intracellular Energy Status on High-Hydrostatic-Pressure Inactivation of sake Yeast Saccharomyces cerevisiae.

The HHP inactivation behaviors of Niigata sake yeast Saccharomyces cerevisiae strain S9arg and its aerobic respiratory-deficient mutant strains were investigated after cultivating them in a YPD media containing 2% to 15% glucose, as well as in moromi mash, in a laboratory-scale sake brewing process. The piezotolerance of strain S9arg, shown after cultivation in a YPD medium containing 2% glucose, decreased to become piezosensitive with increasing glucose concentrations in YPD media. In contrast, the piezosensitivity of a mutant strain UV1, shown after cultivation in the YPD medium containing 2% glucose, decreased to become piezotolerant with increasing glucose concentrations in the YPD medium. The intracellular ATP concentrations were analyzed for an S. cerevisiae strain with intact aerobic respiratory ability, as well as for strain UV1. The higher concentration of ATP after cultivation suggested a higher energy status and may be closely related to higher piezotolerance for the yeast strains. The decreased piezotolerance of strain S9arg observed after a laboratory-scale sake brewing test may be due to a lower energy status resulting from a high glucose concentration in moromi mash during the early period of brewing, as well as a lower aeration efficiency during the brewing process, compared with cultivation in a YPD medium containing 2% glucose.

In-situ substitution and community dynamics modeling for enhanced safety in Chinese rice wine brewing.

This research paper focuses on the application of the "Design-Build-Test-Learn" framework to design and evaluate a synthetic microbial community aimed at studying the impact of Lactic Acid Bacteria (LAB) interactions and fitness on the formation of biogenic amines (BAs) in Chinese rice wine (CRW). The study reveals a close correlation between the assembly model of LAB and the accumulation of BAs in CRW, and multiple interactions were observed between amine-producing and non-amine-producing LAB, including commensalism, amensalism, and competition. The commensalism among amine-producing LAB was found to promote BAs accumulation through metabolic cross-feeding of amino acids. Moreover, the higher-order interaction community was designed to regulate the BAs formation effectively. For instance, the interference of Lactiplantibacillus plantarum (ACBC271) resulted in the elimination of amine-producing LAB viability, resulting in a 22% decrease (not exceeding 43.54 mg/L) in the total amount of BAs. Simulation of community dynamics models further suggests that LAB with quantitative social interactions can effectively control LAB accumulation in CRW by forecasting fluctuation in BAs generation through fitness competition and metabolic interference. Overall, this study provides valuable insights into the complex interaction networks within microbial communities in traditional fermentation ecosystems. It also proposes a novel approach for quality control of nitrogen food safety factors in fermented foods.

Comparing the differences of physicochemical properties and volatiles in semi-dry Hakka rice wine and traditional sweet rice wine via HPLC, GC-MS and E-tongue analysis.

This study aimed to explore effects of indica rice addition, rice soaking time and rice soup addition on total sugar and alcohol content of semi-dry Hakka rice wine (HRW) and compare its difference in physicochemical properties and volatiles with traditional sweet rice wine (TSRW) via HPLC, GC-MS and E-tongue. The optimal fermentation conditions of semi-dry HRW were 50 % indica rice addition, 12 h rice soaking time and 85 % rice soup addition. The total sugar (16.13 mg/mL) of semi-dry HRW was significantly lower than that of TSRW (135.79 mg/mL), especially the trehalose, glucose, sucrose and maltose. Its alcohol content was significantly higher than that of TSRW. There were significant differences in volatile components between semi-dry HRW and TSRW, especially esters, alcohols and ketones, but no significant differences in organic acids and amino acids. Results obtained could provide reference data for improving the fermentation process and quality of semi-dry HRW.

Characterization of Carbohydrates, Amino Acids, Viscosity, and Antioxidant Capacity in Rice Wines Made in Saitama, Japan, with Different Sake Rice.

We investigated the physicochemical properties of Japanese rice wines, including their functional properties and carbohydrate and amino acid content in solution and solid state. Three samples were tested. The glucose, allose, and raffinose contents in samples (A, B, C) in g/100 g were (3.47, 3.45, 7.05), (1.60, 1.63, 1.61), and (2.14, 2.75, 1.49), respectively. The total amino acid in µmol/mL was (3.1, 3.5, 4.4). Glutamic acid, alanine, and arginine varied in content across the samples. The viscosity (10 °C) and activation energy (ΔE) calculated using the Andrade equation were (2.81 ± 0.03, 2.74 ± 0.06, 2.69 ± 0.03) mPa-s and (22.3 ± 1.1, 22.0 ± 0.2, 21.3 ± 0.5) kJ/mol, respectively. Principal component analysis using FT-IR spectra confirmed the separation of the samples into principal components 2 and 3. The IC50 values from the DPPH radical scavenging test were (2364.7 ± 185.3, 3041.9 ± 355.1, 3842.7 ± 228.1) µg/mL. Thus, the three rice wines had different carbohydrate and amino acid contents, viscosities, and antioxidant capacities.

Comparative analysis of microbial communities and volatile flavor components in the brewing of Hongqu rice wines fermented with different starters.

As one of the quintessential representatives of Chinese rice wine, Hongqu rice wine is brewed with glutinous rice as the main raw material and Hongqu (Gutian Qu or Wuyi Qu) as the fermentation starter. The present study aimed to investigate the impact of Hongqu on the volatile compositions and the microbial communities in the traditional production of Gutian Hongqu rice wine (GT) and Wuyi Hongqu rice wine (WY). Through the OPLS-DA analysis, 3-methylbutan-1-ol, isobutanol, ethyl lactate, ethyl acetate, octanoic acid, diethyl succinate, phenylethyl alcohol, hexanoic acid and n-decanoic acid were identified as the characteristic volatile flavor components between GT and WY. Microbiome analysis revealed significant enrichments of Lactobacillus, Pediococcus, Aspergillus and Hyphopichia in WY brewing, whereas Monascus, Saccharomyces, Pantoea, and Burkholderia-Caballeronia-Paraburkholderia were significantly enriched in GT brewing. Additionally, correlation analysis showed that Saccharomyces, Lactobacillus, Weissella and Pediococcus were significantly positively correlated wih most characteristic volatile components. Conversely, Picha, Monascus, Franconibacter and Kosakonia showed significant negative correlations with most of the characteristic volatile components. Furthermore, bioinformatical analysis indicated that the gene abundances for enzymes including glucan 1,4-alpha-glucosidase, carboxylesterase, alcohol dehydrogenase, dihydroxy-acid dehydratase and branched-chain-amino-acid transaminase were significantly higher in WY compared to GT. This finding explains the higher content of higher alcohols and characteristic esters in WY relative to GT. Collectively, this study provides a theoretical basis for improving the flavor profile of Hongqu rice wine and establishing a solid scientific foundation for the sustainable development of Hongqu rice wine industry.

Effects of sediment and temperature on the long-term aging process of rice wine: Microbial and metabolic insights.

Rice wine is low in alcohol content (6 %), rich in nutrients, and contains live microorganisms; therefore, it is generally produced without an aging process during manufacturing. In this study, we investigated the microbial and metabolic changes that occur during the long-term aging of undiluted rice wine with different amount of sediment and aging temperatures. Rice wine samples with higher amounts of sediment had higher yeast counts and alcohol content, indicating a crucial role of sediment in providing nutrients for yeast survival during aging. Furthermore, the rice wine samples that were aged at 12 °C exhibited a notable increase in the relative abundance of Lactobacillus after 100 days of aging. Metabolic profiling revealed that the production of metabolites during rice wine aging was greatly influenced by the amount of sediment and aging temperature, with most metabolites showing a strong correlation with these factors. This study provides valuable insights into the impact of sediment and temperature on the microbial and metabolic changes that occur during the long-term aging of rice wine.

Correlation between changes in flavor compounds and microbial community ecological succession in the liquid fermentation of rice wine.

Microorganisms play an important role in regulating flavor compounds in rice wine, whereas we often don't understand how did they affect flavor compounds. Here, the relations between flavor compounds and microbial community ecological succession were investigated by monitoring flavor compounds and microbial community throughout the fermentation stage of rice wine. The composition of microbial community showed a dynamic change, but 13 dominant bacterial genera and 4 dominant fungal genera were detected throughout the fermentation stages. Saccharomyces presented a strong negative correlation with fungi genera but had positive associations with bacteria genera. Similarly, flavor compounds in rice wine were also showed the dynamic change, and 112 volatile compounds and 17 free amino acids were identified in the whole stages. The alcohol-ester ratio was decreased in the LTF stage, indicating that low temperature boosts ester formation. The potential correlation between flavor compounds and microbial community indicated that Delftia, Chryseobacterium, Rhizopus and Wickerhamomyces were the core functional microorganisms in rice wine. These findings clarified the correlation between changes in flavor compounds and in microbial community in the liquid fermentation of rice wine, and these results have some reference value for the quality improvement and technological optimization in liquid fermentation of rice wine.

Comparative study on Angelica sinensis after different processing with yellow rice wine in color, aromas, chemical components, and antioxidant activities.

This study aimed to explore the differences in raw Angelica Sinensis (RAS), wine washing AS (WAS), and wine stir-frying AS (WSAS). The results showed there were differences among the three AS in color and aroma, and 34 aroma compounds were identified. The content determination results revealed the ferulic acid and Z-ligustilide levels of RAS decreased after processing, and those in WAS were higher than in WSAS. Furthermore, 85 representative common components and 37 unique components were tentatively identified in three AS. Finally, the free radical scavenging assay results indicated the antioxidant capacity of RAS was reduced after processing, and the antioxidant capacity of WAS was better than WSAS. Collectively, the RAS undergoes significant changes in color, aromas, components, and antioxidant ability after processing, and the different processing methods also result in significant differences between WAS and WSAS.

Insights into microbial communities and metabolic profiles in the traditional production of the two representative Hongqu rice wines fermented with Gutian Qu and Wuyi Qu based on single-molecule real-time sequencing.

Hongqu rice wine, a famous traditional fermented alcoholic beverage, is brewed with traditional Hongqu (mainly including Gutian Qu and Wuyi Qu). This study aimed to compare the microbial communities and metabolic profiles in the traditional brewing of Hongqu rice wines fermented with Gutian Qu and Wuyi Qu. Compared with Hongqu rice wine fermented with Wuyi Qu (WY), Hongqu rice wine fermented with Gutian Qu (GT) exhibited higher levels of biogenic amines. The composition of volatile flavor components of Hongqu rice wine brewed by different fermentation starters (Gutian Qu and Wuyi Qu) was obviously different. Among them, ethyl acetate, isobutanol, 3-methylbutan-1-ol, ethyl decanoate, ethyl palmitate, ethyl oleate, nonanoic acid, 4-ethylguaiacol, 5-pentyldihydro-2(3H)-furanone, ethyl acetate, n-decanoic acid etc. were identified as the characteristic aroma-active compounds between GT and WY. Microbiome analysis based on high-throughput sequencing of full-length 16S rDNA/ITS-5.8S rDNA amplicons revealed that Lactococcus, Leuconostoc, Pseudomonas, Serratia, Enterobacter, Weissella, Saccharomyces, Monascus and Candida were the predominant microbial genera during the traditional production of GT, while Lactococcus, Lactobacillus, Leuconostoc, Enterobacter, Kozakia, Weissella, Klebsiella, Cronobacter, Saccharomyces, Millerozyma, Monascus, Talaromyces and Meyerozyma were the predominant microbial genera in the traditional fermentation of WY. Correlation analysis revealed that Lactobacillus showed significant positive correlations with most of the characteristic volatile flavor components and biogenic amines. Furthermore, bioinformatical analysis based on PICRUSt revealed that microbial enzymes related to biogenic amines synthesis were more abundant in GT than those in WY, and the enzymes responsible for the degradation of biogenic amines were less abundant in GT than those in WY. Collectively, this study provides important scientific data for enhancing the flavor quality of Hongqu rice wine, and lays a solid foundation for the healthy and sustainable development of Hongqu rice wine industry.

Diversifying the Flavor of Black Rice Wines through Three Different Regional Xiaoqus in China and Unraveling Their Core Functional Microorganisms.

The flavor of black rice wine (BRW) can be diversified by the Xiaoqus, from different regions; however, the functional microbiota that contributes to its flavor remains unclear. Accordingly, this study selected three regional Xiaoqus from Sichuan Dazhu (Q1), Jiangxi Yingtan (Q2), and Hubei Fangxian (Q3) as starters to investigate flavor compounds and microbial communities during BRW brewing. Results indicated that altogether 61 flavor substances were identified, 16 of which were common characteristic flavor compounds (odor activity value > 0.1). Each BRW possessed unique characteristic flavor compounds. O2PLS and Spearman's correlation analysis determined that characteristic flavor compounds of BRW were mainly produced by Saccharomyces cerevisiae, non-Saccharomyces yeasts, and lactic acid bacteria, with the common core functional strains being Wickerhamomyces and Pediococcus, and with their unique core functional strain likely causing a unique characteristic flavor. This study could promote the high-quality development of the black rice wine industry.

Effects of saccharification agents on the microbial and metabolic profiles of Korean rice wine (makgeolli).

To brew rice wine, a saccharification agent is critical to provide sugars necessary for yeast to ferment alcohol. Nuruk, a traditional Korean saccharification agent, contains saccharification enzymes and various microorganisms, including fungi and lactic acid bacteria (LAB). To investigate the effect of saccharification agents on Korean rice wine (makgeolli), we analyzed makgeolli brewed with different saccharification agents, such as koji and nuruk. In contrast to koji makgeolli, nuruk makgeolli had a distinct microbial profile with higher proportion of LAB. Comparing the microbial profiles of the saccharification agents and makgeolli revealed that the dominant microorganisms in the makgeolli were possibly derived from the saccharification agents. Several metabolites also exhibited distinct profiles depending on the saccharification agent generating the total metabolic profile difference of makgeolli samples. Collectively, the saccharification agent could provide dominant microorganisms in the makgeolli microbiota, leading to a distinct microbial and metabolic profile of makgeolli depending on its type.